[ { "id": "authors:xd4jd-k0972", "collection": "authors", "collection_id": "xd4jd-k0972", "cite_using_url": "https://authors.library.caltech.edu/records/xd4jd-k0972", "type": "article", "title": "Chemical Abundances Shape History (CASH). I. A Link between Giant Planets' Orbital Periods and Host Stellar C/O Ratios", "author": [ { "family_name": "Zhang", "given_name": "Ruisheng", "orcid": "0000-0001-5487-9450" }, { "family_name": "Xie", "given_name": "Ji-Wei", "orcid": "0000-0002-6472-5348" }, { "family_name": "Pan", "given_name": "Mengrui", "orcid": "0000-0002-0162-163X" }, { "family_name": "Liu", "given_name": "Beibei", "orcid": "0000-0001-5830-3619" }, { "family_name": "Zhou", "given_name": "Ji-Lin", "orcid": "0000-0003-1680-2940" }, { "family_name": "Wang", "given_name": "Ji", "orcid": "0000-0002-4361-8885" }, { "family_name": "Wang", "given_name": "Haiyang S.", "orcid": "0000-0001-8618-3343" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" } ], "abstract": "

The chemical abundance of host stars plays a pivotal role in shaping the formation history of planetary systems, yet the influence of elements beyond iron remains poorly understood. Here, we investigate the relationship between the carbon-to-oxygen (C/O) ratio of host stars and the orbital periods of giant planets. By analyzing high-resolution spectroscopic data from 598 planet-hosting stars (hosting 929 planets) across the Sloan Digital Sky Survey, Keck, and HARPS surveys, we identify a correlation; stars with higher C/O ratios are more likely to host longer-period giant planets. Theoretical models of pebble-driven planet formation and migration further support this observation, demonstrating that elevated C/O ratios enhance solid material availability at outer disk regions, promoting giant planet formation at larger distances and subsequent moderate inward migration. Our findings establish stellar C/O as a critical factor in shaping the orbital architecture of giant planets, bridging disk chemistry to planetary system evolution.

", "doi": "10.3847/1538-3881/ae5952", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2026-05", "series_number": "5", "volume": "171", "issue": "5", "pages": "302" }, { "id": "authors:vv9ky-xs310", "collection": "authors", "collection_id": "vv9ky-xs310", "cite_using_url": "https://authors.library.caltech.edu/records/vv9ky-xs310", "type": "article", "title": "The ESO SupJup Survey. X. A carbon isotope contrast in the young ROXs 12 system", "author": [ { "family_name": "Grasser", "given_name": "N.", "orcid": "0009-0009-6634-1741" }, { "family_name": "Snellen", "given_name": "I. A. G.", "orcid": "0000-0003-1624-3667" }, { "family_name": "de Regt", "given_name": "S.", "orcid": "0000-0003-4760-6168" }, { "family_name": "Gonz\u00e1lez Picos", "given_name": "D.", "orcid": "0000-0001-9282-9462" }, { "family_name": "Zhang", "given_name": "Y.", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Stolker", "given_name": "T.", "orcid": "0000-0002-5823-3072" }, { "family_name": "Gandhi", "given_name": "S.", "orcid": "0000-0001-9552-3709" }, { "family_name": "Landman", "given_name": "R.", "orcid": "0000-0002-7261-8083" }, { "family_name": "Molli\u00e8re", "given_name": "P.", "orcid": "0000-0003-4096-7067" }, { "family_name": "Allard", "given_name": "N. F.", "orcid": "0000-0001-6220-6221" } ], "abstract": "

Context. Emerging research suggests that elemental and isotopic ratios of exoplanet and brown dwarf atmospheres may serve as potential tracers of their formation pathways. The ESO SupJup Survey aims to shed light on this hypothesis, with a focus on the 12CO/13CO ratio, by investigating the atmospheric composition of substellar companions and isolated brown dwarfs.

\n

Aims. In this work, we aim to characterize the atmospheres and determine the ratios of 12CO/13CO of the Rho Ophiuchus X-ray source (ROXs) 12 system (∼6 Myr), consisting of an M0 host with an L0 companion, as part of the ESO SupJup survey. This system provides a great opportunity to directly compare the atmospheric compositions of the host star and its companion.

\n

Methods. Using high-resolution CRIRES+ K band spectra of these objects, we perform atmospheric retrieval analyses to derive their atmospheric properties, including the 12CO/13CO ratio. Our retrieval framework is built on the radiative transfer code petitRADTRANS, with which we generate model spectra based on equilibrium chemistry tables computed with FastChem, coupled with the nested sampling algorithm PyMultiNest.

\n

Results. We report the presence of H2O, 12CO, 13CO, and HF in both the star and companion, with a tentative detection of H182O in ROXs 12B. The 12CO/13CO ratios of the two objects show a measurable, though not strongly significant, difference, namely 77−7+10 and 55−7+10 for ROXs 12A and B. Both are consistent with the local present interstellar medium. We measure a C/O ratio of 0.54 ± 0.01 and obtain a lower limit of H162O/H182O \u2a86 300 for ROXs 12B, while the C/O ratio of the star is not reliably constrained due to the absence of atomic oxygen lines in the K band. The companion also appears to exhibit a more isothermal temperature structure than expected from models. Furthermore, we retrieve moderate veiling in the host star of rk = 0.17−0.03+0.02.

\n

Conclusions. Systems such as ROXs 12, in which both star and planet can be chemically and isotopically characterized, are crucial for constraining potential formation mechanisms of massive, wide-orbit super-Jupiters. The differing 12CO/13CO ratios in the ROXs 12 system highlight the need for a broader sample to assess the frequency of isotopic variations and whether they may be linked to formation history.

", "doi": "10.1051/0004-6361/202659035", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2026-05", "volume": "709", "pages": "A141" }, { "id": "authors:98hkr-t5c05", "collection": "authors", "collection_id": "98hkr-t5c05", "cite_using_url": "https://authors.library.caltech.edu/records/98hkr-t5c05", "type": "article", "title": "Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions", "author": [ { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Wang \u738b", "given_name": "Jason J. \u52b2\u98de", "orcid": "0000-0003-0774-6502", "clpid": "Wang-Jason-J" }, { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Horstman", "given_name": "Katelyn", "orcid": "0000-0001-9708-8667", "clpid": "Horstman-Katelyn" }, { "family_name": "Cronin", "given_name": "Julianne", "orcid": "0000-0003-1172-5755" }, { "family_name": "Xin", "given_name": "Yinzi", "orcid": "0000-0002-6171-9081", "clpid": "Xin-Yinzi" }, { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-D" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486", "clpid": "Calvin-Benjamin" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Gregory W." }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Konopacky", "given_name": "Quinn M.", "orcid": "0000-0002-9936-6285" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042", "clpid": "Liberman-Joshua" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Morris", "given_name": "Evan", "orcid": "0000-0003-3165-0922" }, { "family_name": "Pezzato", "given_name": "Jacklyn", "clpid": "Pezzato-Jacklyn" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang \u738b", "given_name": "Ji \u5409", "orcid": "0000-0002-4361-8885" } ], "abstract": "

We present a rotational velocity (v sin i) survey of 32 stellar/substellar objects and giant planets using Keck/KPIC high-resolution spectroscopy, including 6 giant planets (2–7 MJup) and 25 substellar/stellar companions (12–88 MJup). Adding companions with spin measurements from the literature, we construct a curated spin sample for 43 benchmark stellar/substellar companions and giant planets and 54 free-floating brown dwarfs and planetary mass objects. We compare their spins, parameterized as fractional breakup velocities at 10 Myr, assuming constant angular momentum evolution. We find the first clear evidence that giant planets exhibit distinct spins versus low-mass brown dwarf companions (10–40 MJup) at 4–4.5σ significance assuming inclinations aligned with their orbits, while under randomly oriented inclinations the significance is at 1.6–2.1σ. Our findings hold when considering various assumptions about planets, and the mass ratio below 0.8% gives a clean cut for rotation between giant planets and brown dwarf companions. The higher fractional breakup velocities of planets can be interpreted as less angular momentum loss through circumplanetary disk braking during the planet formation phase. Brown dwarf companions exhibit evidence of slower rotation compared to isolated brown dwarfs, while planets and planetary mass objects show similar spins. Finally, our analysis of specific angular momentum versus age of 221 stellar/substellar objects below 0.1 M\u2299 with spin measurements in the literature indicates that the substellar objects of 5–40 MJup retain much higher angular momenta compared to stellar and substellar objects of 40–100 MJup after 10 Myr, when their initial angular momenta were set.

", "doi": "10.3847/1538-3881/ae434b", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2026-04", "series_number": "4", "volume": "171", "issue": "4", "pages": "224" }, { "id": "authors:95dpg-4mq40", "collection": "authors", "collection_id": "95dpg-4mq40", "cite_using_url": "https://authors.library.caltech.edu/records/95dpg-4mq40", "type": "article", "title": "The Compositions of the HR 8799 Planets Reflect Accretion of Both Solids and Metal-enriched Gas", "author": [ { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" }, { "family_name": "Chachan", "given_name": "Yayaati", "orcid": "0000-0003-1728-8269" }, { "family_name": "Ohno", "given_name": "Kazumasa", "orcid": "0000-0003-3290-6758" }, { "family_name": "Kesseli", "given_name": "Aurora", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-Aurora" }, { "family_name": "Murray-Clay", "given_name": "Ruth", "orcid": "0000-0001-5061-0462" }, { "family_name": "Lee", "given_name": "Eve J.", "orcid": "0000-0002-1228-9820" }, { "family_name": "Moses", "given_name": "Julianne I.", "orcid": "0000-0002-8837-0035" }, { "family_name": "Balmer", "given_name": "William O.", "orcid": "0000-0001-6396-8439" }, { "family_name": "Baburaj", "given_name": "Aneesh", "orcid": "0000-0003-3708-241X" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Johnstone", "given_name": "Doug", "orcid": "0000-0002-6773-459X" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Knutson", "given_name": "Heather A.", "orcid": "0000-0002-5375-4725", "clpid": "Knutson-H-A" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Beichman", "given_name": "Charles", "orcid": "0000-0002-5627-5471", "clpid": "Beichman-C-A" }, { "family_name": "Hodapp", "given_name": "Klaus", "orcid": "0000-0003-0786-2140" }, { "family_name": "Perrin", "given_name": "Marshall D.", "orcid": "0000-0002-3191-8151" }, { "family_name": "Konopacky", "given_name": "Quinn", "orcid": "0000-0002-9936-6285" }, { "family_name": "Meyer", "given_name": "Michael", "orcid": "0000-0003-1227-3084" }, { "family_name": "Bryden", "given_name": "Geoffrey", "orcid": "0000-0001-5966-837X", "clpid": "Bryden-Geoffrey" }, { "family_name": "Greene", "given_name": "Thomas P.", "orcid": "0000-0002-8963-8056", "clpid": "Greene-Thomas-P" }, { "family_name": "Leisenring", "given_name": "Jarron", "orcid": "0000-0002-0834-6140" }, { "family_name": "Ygouf", "given_name": "Marie", "orcid": "0000-0001-7591-2731", "clpid": "Ygouf-M" }, { "family_name": "Benneke", "given_name": "Bj\u00f6rn", "orcid": "0000-0001-5578-1498" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Wallack", "given_name": "Nicole L.", "orcid": "0000-0003-0354-0187", "clpid": "Wallack-N-L" } ], "abstract": "

With four giant planets (m ∼ 5MJup−10MJup, Teff ∼ 900–1200 K) orbiting between 15 and 70 au, HR 8799 provides an unparalleled test bed for studying giant planet formation and probing compositional trends across the protoplanetary disk. We present new JWST/NIRSpec integral field unit observations (2.85–5.3 μm, R ≈ 2700) that now include the spectrum of HR 8799 b and higher signal-to-noise ratio spectra for HR 8799 c, d, and e compared to those in J.-B. Ruffio et al. We detect CO, CH4, H2O, H2S, CO2, and, for planet b, NH3. We combine the NIRSpec spectra with 1–5 μm photometry to perform atmospheric retrievals that account for disequilibrium chemistry and clouds, and we allow C/H, O/H, N/H, and S/H to scale independently. While the four planets are similarly enriched in carbon and oxygen, with C/H and O/H between 3× and 5× stellar, we observe a tentative trend of increasing S/H—a tracer of refractory solids—from 2× to 5× stellar with increasing orbital distance. From HR 8799 b’s NH3 abundance, we estimate N/H = 21.2_(−8.8)^(+16.2) x stellar, suggesting that the outer planet accreted significant amounts of N-rich gas. Overall, the elemental abundance patterns we observe are consistent with a picture where planet b formed between the CO snowline and the more distant N2 snowline, while the inner planets accreted 3×  stellar CO-enriched disk gas within the CO snowline. The excess volatile mass from pebble drift and evaporation implies an integrated pebble flux of 750 ± 200 M⊕. The increase in the planets’ S/H with orbital distance implies more solid accretion further out, which is quantitatively compatible with expectations from both pebble and planetesimal accretion (2× minimum-mass solar nebula) paradigms.

", "doi": "10.3847/1538-4357/ae448f", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2026-03-20", "series_number": "1", "volume": "1000", "issue": "1", "pages": "27" }, { "id": "authors:5rtk6-0h758", "collection": "authors", "collection_id": "5rtk6-0h758", "cite_using_url": "https://authors.library.caltech.edu/records/5rtk6-0h758", "type": "article", "title": "The ESO SupJup Survey. IX. Isotopic evidence of a recent formation for Luhman 16AB", "author": [ { "family_name": "de Regt", "given_name": "S.", "orcid": "0000-0003-4760-6168" }, { "family_name": "Snellen", "given_name": "I. A. G.", "orcid": "0000-0003-1624-3667" }, { "family_name": "Gonz\u00e1lez Picos", "given_name": "D.", "orcid": "0000-0001-9282-9462" }, { "family_name": "Gandhi", "given_name": "S.", "orcid": "0000-0001-9552-3709" }, { "family_name": "Grasser", "given_name": "N.", "orcid": "0009-0009-6634-1741" }, { "family_name": "Kesseli", "given_name": "A. Y.", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-Aurora-Y" }, { "family_name": "Landman", "given_name": "R.", "orcid": "0000-0002-7261-8083" }, { "family_name": "Molli\u00e8re", "given_name": "P.", "orcid": "0000-0003-4096-7067" }, { "family_name": "Nasedkin", "given_name": "E.", "orcid": "0000-0002-9792-3121" }, { "family_name": "Stolker", "given_name": "T.", "orcid": "0000-0002-5823-3072" }, { "family_name": "Zhang", "given_name": "Y.", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" } ], "abstract": "

Context. The distinct formation pathways proposed for directly imaged exoplanets and isolated brown dwarfs might leave imprints in the inherited chemical composition. Elemental and isotopic tracers could help inform the suspected histories, but this requires a careful characterisation of the sub-stellar atmospheres. In particular, objects at the L-T transition exhibit signs of dynamics that can drive their atmospheres out of chemical equilibrium.

\n

Aims. In this work, we studied the nearest L-T brown dwarfs, Luhman 16A and B, to assess the chemical disequilibrium in their atmospheres. We also investigated the elemental and isotopic compositions in the context of their probable formation history within the Oceanus moving group.

\n

Methods. As part of the ESO SupJup Survey, we obtained spatially resolved CRIRES+ K-band spectra of the binary. These high-resolution observations were analysed using an atmospheric retrieval framework that couples the radiative transfer code petitRADTRANS to the MultiNest sampling algorithm.

\n

Results. We detect and retrieve the abundances of 12CO, H2O, CH4, NH3, H2S, HF, and the 13CO isotopologue. We find that both atmospheres are in chemical disequilibrium with somewhat stronger vertical mixing in Luhman 16A compared to B (Kzz,A ~ 108.7 vs Kzz,B ~ 108.2 cm2 s−1). The tested chemical models, free-equilibrium and disequilibrium chemistry, yield consistent mixing ratios and agree with earlier work at shorter wavelengths. The free-chemistry gaseous C/O ratios show evidence of oxygen trapping in silicate-oxide clouds. While the C/O ratios are consistent with the solar composition, the metallicities are modestly enhanced with [C/H] ~ 0.15. The carbon isotope ratios are measured at 12C/13CA = 74−2+2 and 2C/13CB = 74−3+3.

\n

Conclusions. The coincident constraints of metallicities and isotopes across the binary provide further evidence in favour of a common formation. The 12C/13C ratios are aligned with the present-day interstellar medium but lower than the Solar System value. This suggests a recent inheritance and corroborates the relatively young age (~500 Myr) of Luhman 16A and B as members of the Oceanus moving group.

", "doi": "10.1051/0004-6361/202558089", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2026-03", "volume": "707", "pages": "A210" }, { "id": "authors:w04d7-4kc40", "collection": "authors", "collection_id": "w04d7-4kc40", "cite_using_url": "https://authors.library.caltech.edu/records/w04d7-4kc40", "type": "article", "title": "Chemical and Isotopic Homogeneity between the L Dwarf CD-35 2722 B and Its Early M Host Star", "author": [ { "family_name": "Wang", "given_name": "Gavin", "orcid": "0000-0003-3092-4418", "clpid": "Wang-Gavin" }, { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Picos", "given_name": "Dar\u00edo Gonz\u00e1lez", "orcid": "0000-0001-9282-9462" }, { "family_name": "Zhang \u5f20", "given_name": "Zhoujian \u5468\u5065", "orcid": "0000-0002-3726-4881" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Wang \u738b", "given_name": "Jason J. \u52b2\u98de", "orcid": "0000-0003-0774-6502", "clpid": "Wang-Jason-J" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" }, { "family_name": "Horstman", "given_name": "Katelyn", "orcid": "0000-0001-9708-8667", "clpid": "Horstman-Katelyn" }, { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Xin", "given_name": "Yinzi", "orcid": "0000-0002-6171-9081", "clpid": "Xin-Yinzi" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-D" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486", "clpid": "Calvin-Benjamin" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Gregory W." }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042", "clpid": "Liberman-Joshua" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Morris", "given_name": "Evan", "orcid": "0000-0003-3165-0922" }, { "family_name": "Pezzato-Rovner", "given_name": "Jacklyn", "clpid": "Pezzato-Rovner-Jacklyn" }, { "family_name": "Phillips", "given_name": "Caprice L.", "orcid": "0000-0001-5610-5328" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang \u738b", "given_name": "Ji \u5409", "orcid": "0000-0002-4361-8885" } ], "abstract": "

CD-35 2722 B is an L dwarf companion to the nearby, ∼50–200 Myr old M1 dwarf CD-35 2722 A. We present a detailed analysis of both objects using high-resolution ( R ∼ 35,000) K -band spectroscopy from the Keck Planet Imager and Characterizer combined with archival photometry. With a mass of 30 −4 + 5 M Jup (planet-to-host mass ratio 0.05) and projected separation of 67 ± 4 au from its host, CD-35 2722 B likely formed via gravitational instability. We explore whether the chemical composition of the system tells a similar story. Accounting for systematic uncertainties, we find [ M / H ] = − 0.16 −0.02 + 0.03 ( stat ) ± 0.25 ( sys ) dex and 12C/13C = 132 −14 +20 for the host, and [ M / H ] = 0.27 -0.06+0.07 ( stat ) ±0.12 (sys) dex, 12CO/13CO = 159 −24+33 (stat) −33+40 ( sys ), and C/O = 0.55 ± 0.01 (stat) ± 0.04 (sys) for the companion. The chemical compositions for the brown dwarf and host star agree within the 1.5 σ level, supporting a scenario where CD-35 2722 B formed via gravitational instability. We do not find evidence for clouds on CD-35 2722 B despite it being a photometrically red mid-L dwarf and thus expected to be quite cloudy. We retrieve a temperature structure that is more isothermal than models and investigate its impact on our measurements, finding that constraining the temperature structure to self-consistent models does not significantly impact our retrieved chemical properties. Our observations highlight the need for data from complementary wavelength ranges to verify the presence of aerosols in likely cloudy L dwarfs.

", "doi": "10.3847/1538-4357/ae232f", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2026-02-01", "series_number": "2", "volume": "997", "issue": "2", "pages": "195" }, { "id": "authors:xppkv-cy151", "collection": "authors", "collection_id": "xppkv-cy151", "cite_using_url": "https://authors.library.caltech.edu/records/xppkv-cy151", "type": "article", "title": "Extreme Winds on the Emerging Dayside of an Ultrahot Jupiter", "author": [ { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Wardenier", "given_name": "Joost P.", "orcid": "0000-0003-3191-2486" }, { "family_name": "Householder", "given_name": "Aaron", "orcid": "0000-0002-5812-3236" }, { "family_name": "Komacek", "given_name": "Thaddeus D.", "orcid": "0000-0002-9258-5311" }, { "family_name": "Kesseli", "given_name": "Aurora Y.", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-Aurora-Y" }, { "family_name": "Dai", "given_name": "Fei", "orcid": "0000-0002-8958-0683" }, { "family_name": "Howard", "given_name": "Andrew W.", "orcid": "0000-0001-8638-0320", "clpid": "Howard-A-W" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Isaacson", "given_name": "Howard", "orcid": "0000-0002-0531-1073" }, { "family_name": "Knutson", "given_name": "Heather A.", "orcid": "0000-0002-5375-4725", "clpid": "Knutson-H-A" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Pino", "given_name": "Lorenzo", "orcid": "0000-0002-1321-8856" }, { "family_name": "Wallack", "given_name": "Nicole", "orcid": "0000-0003-0354-0187", "clpid": "Wallack-N-L" }, { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Carmichael", "given_name": "Theron W.", "orcid": "0000-0001-6416-1274" }, { "family_name": "Huber", "given_name": "Daniel", "orcid": "0000-0001-8832-4488" }, { "family_name": "Lee", "given_name": "Rena A.", "orcid": "0000-0001-7058-4134" }, { "family_name": "Saunders", "given_name": "Nicholas", "orcid": "0000-0003-2657-3889" }, { "family_name": "Weiss", "given_name": "Lauren", "orcid": "0000-0002-3725-3058" }, { "family_name": "Zhang", "given_name": "Jingwen", "orcid": "0000-0002-2696-2406" } ], "abstract": "
\n

High-resolution spectroscopy provides a unique opportunity to directly probe atmospheric dynamics by resolving Doppler shifts of planetary signals as a function of orbital phase. Using the optical spectrometer the Keck Planet Finder, we carry out a pilot study on high-resolution phase-curve spectra of the ultrahot Jupiter KELT-9 b. We spectrally and temporally resolve its dayside emission from posttransit to preeclipse (orbital phase \u03d5 = 0.1–0.45). The signal strength and width increase with orbital phase as the dayside rotates into view. The net Doppler shift varies progressively from −13.4 ± 0.6 to −0.4 ± 1.0 km s−1, the extent of which exceeds its rotation velocity of 6.4 ± 0.1 km s−1, providing unambiguous evidence of atmospheric winds. We devise a retrieval framework to fit the full time-series spectra, accounting for the variation of the line profiles due to the rotation and winds. We retrieve a supersonic day-to-night wind speed up to 11.7 ± 0.6 km s−1 on the emerging dayside, representing the most extreme atmospheric winds in hot Jupiters to date. Comparison to 3D circulation models reveals weak atmospheric drag, consistent with relatively efficient heat recirculation, as also supported by space-based phase-curve measurements. Additionally, we retrieve the dayside chemistry (including Fe i, Fe ii, Ti i, Ti ii, Ca i, Ca ii, Mg i, and Si i) and temperature structure, and we place constraints on the nightside thermal profile. Our high-resolution phase-curve spectra and the measured supersonic winds provide excellent benchmarks for extreme physics in circulation models, demonstrating the power of this technique in understanding the climates of hot Jupiters.

\n
", "doi": "10.3847/2041-8213/ae36a1", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2026-02-01", "series_number": "2", "volume": "997", "issue": "2", "pages": "L40" }, { "id": "authors:3en76-5f668", "collection": "authors", "collection_id": "3en76-5f668", "cite_using_url": "https://authors.library.caltech.edu/records/3en76-5f668", "type": "article", "title": "WIde Separation Planets In Time (WISPIT)", "author": [ { "family_name": "van Capelleveen", "given_name": "Richelle F.", "orcid": "0009-0002-6729-646X" }, { "family_name": "Kenworthy", "given_name": "Matthew A.", "orcid": "0000-0002-7064-8270" }, { "family_name": "Ginski", "given_name": "Christian", "orcid": "0000-0002-4438-1971" }, { "family_name": "Mamajek", "given_name": "Eric E.", "orcid": "0000-0003-2008-1488" }, { "family_name": "Bohn", "given_name": "Alexander J.", "orcid": "0000-0003-1401-9952" }, { "family_name": "Landman", "given_name": "Rico", "orcid": "0000-0002-7261-8083" }, { "family_name": "Stolker", "given_name": "Tomas", "orcid": "0000-0002-5823-3072" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "van der Marel", "given_name": "Nienke", "orcid": "0000-0003-2458-9756" }, { "family_name": "Snellen", "given_name": "Ignas", "orcid": "0000-0003-1624-3667" } ], "abstract": "

Context. Wide separation gas giant planets present a challenge to current planet formation theories, and the detection and characterisation of these systems enables us to constrain their formation pathways.

\n

Aims. The WIde Separation Planets In Time (WISPIT) survey aims to detect and characterise wide separation planetary-mass companions over a range of ages from <5 to 20 Myr around solar-type host stars at distances of 75-500 (median 140) parsecs.

\n

Methods. The WISPIT survey carries out two five-minute H-band exposures with the VLT/SPHERE instrument and IRDIS camera separated by at least six months to identify co-moving companions via proper motion analysis. These two H-band observations in combination with a follow-up Ks-band observation were used to determine the colour and magnitude of the co-moving companions and to derive their masses through comparison to AMES-COND and AMES-DUSTY evolutionary tracks.

\n

Results. We report the discovery of WISPIT 1b and WISPIT 1c, two gas giant exoplanets that are co-moving with the stellar binary WISPIT 1, which itself consists of a K4 star and M5.5 star in a multi-decadal orbit. The planets are at projected separations of 338 au and 840 au and have masses of 10 MJ and 4 MJ, respectively.

\n

Conclusions. We identified two common proper motion planetary companions of a (previously unknown) stellar binary with a Sunlike primary. These targets are ideal for follow-up characterisation with both ground- and space-based telescopes. Monitoring of the orbit with the GRAVITY interferometer will place constraints on their eccentricity, and spectroscopic characterisation will identify the composition and metallicity, providing information on their formation pathways.

", "doi": "10.1051/0004-6361/202556584", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2025-12", "volume": "704", "pages": "A221" }, { "id": "authors:1a51f-mqg93", "collection": "authors", "collection_id": "1a51f-mqg93", "cite_using_url": "https://authors.library.caltech.edu/records/1a51f-mqg93", "type": "article", "title": "Silicate clouds and a circumplanetary disk in the YSES-1 exoplanet system", "author": [ { "family_name": "Hoch", "given_name": "K. K. W.", "orcid": "0000-0002-9803-8255" }, { "family_name": "Rowland", "given_name": "M.", "orcid": "0000-0003-4225-6314" }, { "family_name": "Petrus", "given_name": "S." }, { "family_name": "Nasedkin", "given_name": "E." }, { "family_name": "Ingebretsen", "given_name": "C." }, { "family_name": "Kammerer", "given_name": "J.", "orcid": "0000-0003-2769-0438" }, { "family_name": "Perrin", "given_name": "M." }, { "family_name": "D'Orazi", "given_name": "V.", "orcid": "0000-0002-2662-3762" }, { "family_name": "Balmer", "given_name": "W. O.", "orcid": "0000-0001-6396-8439" }, { "family_name": "Barman", "given_name": "T." }, { "family_name": "Bonnefoy", "given_name": "M." }, { "family_name": "Chauvin", "given_name": "G." }, { "family_name": "Chen", "given_name": "C." }, { "family_name": "De Rosa", "given_name": "R. J.", "orcid": "0000-0002-4918-0247" }, { "family_name": "Girard", "given_name": "J.", "orcid": "0000-0001-8627-0404" }, { "family_name": "Gonzales", "given_name": "E." }, { "family_name": "Kenworthy", "given_name": "M.", "orcid": "0000-0002-7064-8270" }, { "family_name": "Konopacky", "given_name": "Q. M." }, { "family_name": "Macintosh", "given_name": "B." }, { "family_name": "Moran", "given_name": "S. E." }, { "family_name": "Morley", "given_name": "C. V." }, { "family_name": "Palma-Bifani", "given_name": "P.", "orcid": "0000-0002-6217-6867" }, { "family_name": "Pueyo", "given_name": "L." }, { "family_name": "Ren", "given_name": "B.", "orcid": "0000-0003-1698-9696", "clpid": "Ren-Bin" }, { "family_name": "Rickman", "given_name": "E.", "orcid": "0000-0003-4203-9715" }, { "family_name": "Ruffio", "given_name": "J.-B." }, { "family_name": "Theissen", "given_name": "C. A.", "orcid": "0000-0002-9807-5435" }, { "family_name": "Ward-Duong", "given_name": "K." }, { "family_name": "Zhang", "given_name": "Y.", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" } ], "abstract": "

Young exoplanets provide an important link between understanding planet formation and atmospheric evolution. Direct imaging spectroscopy allows us to infer the properties of young, wide-orbit, giant planets with high signal-to-noise ratio. This allows us to compare this young population with exoplanets characterized by transmission spectroscopy, which has indirectly revealed the presence of clouds, photochemistry and a diversity of atmospheric compositions. Direct detections have also been made for brown dwarfs, but direct studies of young giant planets in the mid-infrared were not possible before James Webb Space Telescope. With two exoplanets around a solar-type star, the YSES-1 system is an ideal laboratory for studying this early phase of exoplanet evolution. Here we report the direct observations of silicate clouds in the atmosphere of the exoplanet YSES-1 c through its 9–11 µm absorption feature, and the first circumplanetary disk silicate emission around its sibling planet, YSES-1 b. The clouds of YSES-1 c are composed of either amorphous iron-enriched pyroxene or a combination of amorphous MgSiO3 and Mg2SiO4, with particle sizes of ≤0.1 μm at 1 millibar pressure. We attribute the emission from the disk around YSES-1 b to be from submicron olivine dust grains, which may have formed through collisions of planet-forming bodies in the disk.

", "doi": "10.1038/s41586-025-09174-w", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2025-07-24", "series_number": "8073", "volume": "643", "issue": "8073", "pages": "938-942" }, { "id": "authors:mbrh8-vm629", "collection": "authors", "collection_id": "mbrh8-vm629", "cite_using_url": "https://authors.library.caltech.edu/records/mbrh8-vm629", "type": "article", "title": "The ESO SupJup Survey. VIII. Chemical fingerprints of young L dwarf twins", "author": [ { "family_name": "Grasser", "given_name": "N.", "orcid": "0009-0009-6634-1741" }, { "family_name": "Snellen", "given_name": "I. A. G.", "orcid": "0000-0003-1624-3667" }, { "family_name": "de Regt", "given_name": "S.", "orcid": "0000-0003-4760-6168" }, { "family_name": "Gonz\u00e1lez Picos", "given_name": "D.", "orcid": "0000-0001-9282-9462" }, { "family_name": "Zhang", "given_name": "Y.", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Stolker", "given_name": "T.", "orcid": "0000-0002-5823-3072" }, { "family_name": "Gandhi", "given_name": "S.", "orcid": "0000-0001-9552-3709" }, { "family_name": "Nasedkin", "given_name": "E.", "orcid": "0000-0002-9792-3121" }, { "family_name": "Landman", "given_name": "R.", "orcid": "0000-0002-7261-8083" }, { "family_name": "Kesseli", "given_name": "A. Y.", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-Aurora-Y" }, { "family_name": "Mulder", "given_name": "W.", "orcid": "0000-0001-5762-9385" } ], "abstract": "

Context. The potentially distinct formation pathways of exoplanets and brown dwarfs may be imprinted in their elemental and isotopic ratios. This work is part of the ESO SupJup Survey, which aims to disentangle the formation pathways of super-Jupiters and brown dwarfs through the analysis of their chemical and isotopic ratios.

\n

Aims. In this study, we aim to characterize the atmospheres of two young L4 dwarfs, 2MASS J03552337+1133437 (2M0355) and 2MASS J14252798–3650229 (2M1425), in the AB Doradus Moving Group. This involved constraining their chemical composition, 12CO/13CO ratio, pressure-temperature profile, surface gravity, and rotational velocity, among other parameters.

\n

Methods. We have obtained high-resolution CRIRES+ K-band spectra of these brown dwarfs, which we analyzed with an atmospheric retrieval pipeline. Atmospheric models were generated with the radiative transfer code petitRADTRANS, for which we employed a free and equilibrium chemistry approach, which we coupled with the PyMultiNest sampling algorithm to determine the best fit.

\n

Results. We report robust detections of 13CO (13.4 and 8.0 σ) and HF (11.6 and 15.8 σ) in 2M0355 and 2M1425, respectively. The objects have similar overall atmospheric properties, including 12CO/13CO isotope ratios of 95.5−6.4+6.8 for 2M0355 and 109.6−9.6+10.6 for 2M1425. The most notable difference is the robust evidence of CH4 (5.5 σ) but no H2S (<2.3 σ) in 2M1425, in contrast to 2M0355, for which we retrieved H2S (4.6 σ) but not CH4 (<2.2 σ). We also find tentative hints of NH3 in 2M1425 (3.0 σ). In both brown dwarfs, we find only tentative hints of H218O (1.1 and 3.0 σ), with lower limits of H216O/H218O ∼ 1000. Both objects appear to be close to chemical equilibrium, considering the main spectral contributors. We also find that 2M1425 is 50–200 K hotter than 2M0355 and has a higher surface gravity.

\n

Conclusions. Retrievals of high-resolution K-band spectra of young brown dwarfs enable a detailed insight into their atmospheres. As with similar targets, these brown dwarfs also exhibit a depletion of 13CO compared to the interstellar medium. Future studies will put them into the context of other objects observed as part of the ESO SupJup Survey.

", "doi": "10.1051/0004-6361/202554195", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2025-06", "volume": "698", "pages": "A252" }, { "id": "authors:pty0x-abg85", "collection": "authors", "collection_id": "pty0x-abg85", "cite_using_url": "https://authors.library.caltech.edu/records/pty0x-abg85", "type": "article", "title": "The ESO SupJup Survey VII. Clouds and line asymmetries in CRIRES\u207a J-band spectra of the Luhman 16 binary", "author": [ { "family_name": "de Regt", "given_name": "S.", "orcid": "0000-0003-4760-6168" }, { "family_name": "Snellen", "given_name": "I. A. G.", "orcid": "0000-0003-1624-3667" }, { "family_name": "Allard", "given_name": "N. F.", "orcid": "0000-0001-6220-6221" }, { "family_name": "Gonz\u00e1lez Picos", "given_name": "D.", "orcid": "0000-0001-9282-9462" }, { "family_name": "Gandhi", "given_name": "S.", "orcid": "0000-0001-9552-3709" }, { "family_name": "Grasser", "given_name": "N.", "orcid": "0009-0009-6634-1741" }, { "family_name": "Landman", "given_name": "R.", "orcid": "0000-0002-7261-8083" }, { "family_name": "Molli\u00e8re", "given_name": "P.", "orcid": "0000-0003-4096-7067" }, { "family_name": "Nasedkin", "given_name": "E.", "orcid": "0000-0002-9792-3121" }, { "family_name": "Stolker", "given_name": "T.", "orcid": "0000-0002-5823-3072" }, { "family_name": "Zhang", "given_name": "Y.", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" } ], "abstract": "

Context. Brown dwarfs at the L–T transition likely experience an inhomogeneous clearing of the clouds in their atmospheres. The resulting surface of thin and thick cloudy patches has been put forward to explain the observed variability, J-band brightening, and re-emergence of FeH absorption.

\n

Aims. We studied the closest binary brown dwarfs, Luhman 16A and B, in an effort to constrain their chemical and cloud compositions. As this binary consists of an L7.5 and a T0.5 component, we gain insight into the atmospheric properties at the L–T transition.

\n

Methods. As part of the ESO SupJup Survey, we observed Luhman 16AB at high spectral resolution in the J band (1.1–1.4 μm) using CRIRES+. To analyse the spectra, we employed an atmospheric retrieval framework, coupling the radiative transfer code petitRADTRANS with the MultiNest sampling algorithm.

\n

Results. For both objects, we report detections of H2O, K, Na, FeH, and, for the first time in the J band, hydrogen fluoride (HF). The K doublet at 1250 nm shows asymmetric absorption in the blue line wings, which are reproduced via pressure- and temperature-dependent shifts in the line cores. We find evidence of clouds in both spectra and place constraints on an FeH depletion in the Luhman 16A photosphere. The inferred over-abundance of FeH for Luhman 16B is in contradiction with its predicted rainout into iron clouds. A two-column model, which emulates the patchy surface expected at the L–T transition, is weakly preferred (~1.8σ) for component B but disfavoured for A (~5.5σ).

\n

Conclusions. The results suggest a uniform surface on Luhman 16A, which is in good agreement with the reduced variability observed for this L-type component. While the presented evidence is not sufficient to allow us to draw conclusions about any inhomogeneity on Luhman 16B, future observations covering a broader wavelength range could help us test the cloud-clearing hypothesis.

", "doi": "10.1051/0004-6361/202453190", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2025-04", "volume": "696", "pages": "A225" }, { "id": "authors:6165k-gtn92", "collection": "authors", "collection_id": "6165k-gtn92", "cite_using_url": "https://authors.library.caltech.edu/records/6165k-gtn92", "type": "article", "title": "HD 206893 B at High Spectral Resolution with the Keck Planet Imager and Characterizer", "author": [ { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Konopacky", "given_name": "Quinn", "orcid": "0000-0002-9936-6285" }, { "family_name": "\u00d3", "given_name": "Clarissa R. Do", "orcid": "0000-0001-5173-2947" }, { "family_name": "Barman", "given_name": "Travis", "orcid": "0000-0002-7129-3002" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821" }, { "family_name": "Wang \u738b", "given_name": "Jason \u52b2\u98de", "orcid": "0000-0003-0774-6502" }, { "family_name": "Theissen", "given_name": "Christopher A.", "orcid": "0000-0002-9807-5435" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Xuan", "given_name": "Jerry", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry" }, { "family_name": "Hortsman", "given_name": "Katelyn", "clpid": "Hortsman-Katelyn" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Wallack", "given_name": "Nicole L.", "orcid": "0000-0003-0354-0187" }, { "family_name": "Sanghi", "given_name": "Aniket", "orcid": "0000-0002-1838-4757", "clpid": "Sanghi-Aniket" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Bond", "given_name": "Charlotte Z." }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486", "clpid": "Calvin-Benjamin" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Greg" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-Daniel" }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042", "clpid": "Liberman-Joshua" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Martin", "given_name": "Emily C.", "orcid": "0000-0002-0618-5128" }, { "family_name": "Morris", "given_name": "Evan" }, { "family_name": "Pezzato-Rovner", "given_name": "Jacklyn", "clpid": "Pezzato-Rovner-Jacklyn" }, { "family_name": "Phillips", "given_name": "Caprice L.", "orcid": "0000-0001-5610-5328" }, { "family_name": "Ruane", "given_name": "Garreth", "orcid": "0000-0003-4769-1665", "clpid": "Ruane-Garreth" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew" }, { "family_name": "Venenciano", "given_name": "Taylor" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang \u738b", "given_name": "Ji \u5409", "orcid": "0000-0002-4361-8885" }, { "family_name": "Wizinowich", "given_name": "Peter" }, { "family_name": "Xin", "given_name": "Yinzi", "orcid": "0000-0002-6171-9081", "clpid": "Xin-Yinzi" } ], "abstract": "

We present an atmospheric characterization and orbital analysis of HD 206893 B, an exceptionally red, L/T-transition substellar companion in a multiplanetary system, via Keck Planet Imager and Characterizer (KPIC) high-resolution (R ∼ 35,000) K-band spectroscopy. Using PHOENIX atmospheric models in a forward-model framework that fits the spectrum of the companion and diffracted starlight simultaneously, we detect HD 206893 B at >8σ significance via cross correlation in two epochs. We find an effective temperature for the companion of 1634_(−38)^(+72) K and a logg of 4.55_(−0.22)^(+0.17). Only accounting for statistical uncertainties, we measure the carbon-oxygen ratio (C/O) of this companion to be 0.57 ± 0.02, or near-solar while assuming solar metallicity. The C/O ratio we measure fits the tentative trend of >4 MJup companions having near-solar C/O ratios while less massive companions have greater-than-solar C/O ratios. Using substellar evolution models, we find an age of 112_(−22)^(+36) Myr, a mass of 22.7_(−1.7)^(+2.5) MJup, and a radius of 1.11 ± 0.03 RJup for this companion. We also use KPIC radial velocity data to fit the orbit of HD 206893 B and analyze the orbital stability of this system. We find that the orbital stability is relatively independent of the mass of HD 206893 B, and favors an orbital configuration where B and its interior planetary companion, HD 206893 c, are coplanar. The measured C/O ratio coupled with the current architecture of the system cannot rule out the core accretion scenario, nor the disk fragmentation scenario regarding the formation pathway of HD 206893 B.

", "doi": "10.3847/1538-3881/adad70", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2025-03", "series_number": "3", "volume": "169", "issue": "3", "pages": "175" }, { "id": "authors:70xfj-d1b37", "collection": "authors", "collection_id": "70xfj-d1b37", "cite_using_url": "https://authors.library.caltech.edu/records/70xfj-d1b37", "type": "article", "title": "The ESO SupJup Survey V: Exploring atmospheric variability and orbit of the super-Jupiter AB Pictoris b with CRIRES+", "author": [ { "family_name": "Gandhi", "given_name": "Siddharth", "orcid": "0000-0001-9552-3709" }, { "family_name": "de Regt", "given_name": "Sam" }, { "family_name": "Snellen", "given_name": "Ignas", "orcid": "0000-0003-1624-3667" }, { "family_name": "Palma-Bifani", "given_name": "Paulina", "orcid": "0000-0002-6217-6867" }, { "family_name": "Abdoulwahab", "given_name": "Idriss" }, { "family_name": "Chauvin", "given_name": "Ga\u00ebl", "orcid": "0000-0003-4022-8598" }, { "family_name": "Picos", "given_name": "Dar\u00edo Gonz\u00e1lez" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Landman", "given_name": "Rico", "orcid": "0000-0002-7261-8083" }, { "family_name": "Stolker", "given_name": "Tomas", "orcid": "0000-0002-5823-3072" }, { "family_name": "Kesseli", "given_name": "Aurora", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-Aurora" }, { "family_name": "Mulder", "given_name": "Willeke" }, { "family_name": "Chomez", "given_name": "Antoine" }, { "family_name": "Lagrange", "given_name": "Anne-Marie" }, { "family_name": "Zurlo", "given_name": "Alice", "orcid": "0000-0002-5903-8316" } ], "abstract": "

A growing number of directly-imaged companions have been recently characterized, with robust constraints on carbon-to-oxygen ratios and even isotopic ratios. Many companions and isolated targets have also shown spectral variability. In this work, we observed the super-Jupiter AB Pictoris b across four consecutive nights using VLT/CRIRES+ as part of the ESO SupJup survey, exploring how the constraints on chemical composition and temperature profile change over time using spectral line shape variations between nights. We performed atmospheric retrievals of the high-resolution observations and found broadly consistent results across all four nights, but there were differences for some parameters. We clearly detect H\u2082O, ¹²CO, and ¹³CO in each night, but abundances varied by ∼2σ\u2060, which was correlated to the deep atmosphere temperature profiles. We also found differences in the ¹²C/¹³C ratios in each night by up to ∼3σ\u2060, which seemed to be correlated with the cloud deck pressure. Our combined retrieval simultaneously analysing all nights together constrained broadly the average of each night individually, with the C/O=0.59±0.01\u2060, consistent with solar composition, and ¹²C/¹³C =102±8\u2060, slightly higher than the Interstellar Medium (ISM) and Solar System values. We also find a low projected rotational velocity, suggesting that AB Pictoris b is either intrinsically a slow rotator due to its young age or that the spin axis is observed pole-on with a ∼90\u2218 misalignment with its orbit inclination. Future observations will be able to further explore the variability.

", "doi": "10.1093/mnras/staf004", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2025-02", "series_number": "1", "volume": "537", "issue": "1", "pages": "134-153" }, { "id": "authors:yqns3-vm988", "collection": "authors", "collection_id": "yqns3-vm988", "cite_using_url": "https://authors.library.caltech.edu/records/yqns3-vm988", "type": "article", "title": "PDS 70b Shows Stellar-like Carbon-to-oxygen Ratio", "author": [ { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Wang \u738b", "given_name": "Jason J. \u52b2\u98de", "orcid": "0000-0003-0774-6502" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821" }, { "family_name": "Horstman", "given_name": "Katelyn", "orcid": "0000-0001-9708-8667", "clpid": "Horstman-Katelyn" }, { "family_name": "Cronin", "given_name": "Julianne", "orcid": "0000-0003-1172-5755" }, { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Xin", "given_name": "Yinzi", "orcid": "0000-0002-6171-9081", "clpid": "Xin-Yinzi" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-Daniel" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Do \u00d3", "given_name": "Clarissa R.", "orcid": "0000-0001-5173-2947" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486", "clpid": "Calvin-Benjamin" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Gregory W." }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Morris", "given_name": "Evan", "orcid": "0000-0003-3165-0922" }, { "family_name": "Pezzato-Rovner", "given_name": "Jacklyn", "clpid": "Pezzato-Rovner-Jacklyn" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang \u738b", "given_name": "Ji \u5409", "orcid": "0000-0002-4361-8885" } ], "abstract": "

The ~5 Myr PDS 70 is the only known system with protoplanets residing in the cavity of the circumstellar disk from which they formed, ideal for studying exoplanet formation and evolution within its natal environment. Here, we report the first spin constraint and C/O measurement of PDS 70b from Keck/KPIC high-resolution spectroscopy. We detected CO (3.8σ) and H2O (3.5σ) molecules in the PDS 70b atmosphere via cross correlation, with a combined CO and H2O template detection significance of 4.2σ. Our forward-model fits, using BT-Settl model grids, provide an upper limit for the spin rate of PDS 70b (<29 km s−1). The atmospheric retrievals constrain the PDS 70b C/O ratio to 0.28_(−0.12)^(+0.20) (<0.63 under 95% confidence level) and a metallicity [C/H] of −0.2_(−0.5)^(+0.8) dex, consistent with that of its host star. The following scenarios can explain our measured C/O of PDS 70b in contrast with that of the gas-rich outer disk (for which C/O \u2273 1). First, the bulk composition of PDS 70b might be dominated by dust+ice aggregates rather than disk gas. Another possible explanation is that the disk became carbon enriched after PDS 70b was formed, as predicted in models of disk chemical evolution and as observed in both very low-mass stars and older disk systems with JWST/MIRI. Because PDS 70b continues to accrete and its chemical evolution is not yet complete, more sophisticated modeling of the planet and the disk, and higher-quality observations of PDS 70b (and possibly PDS 70c), are necessary to validate these scenarios.

", "doi": "10.3847/2041-8213/ad95e8", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2024-12-20", "series_number": "2", "volume": "977", "issue": "2", "pages": "L47" }, { "id": "authors:p1jrr-fm354", "collection": "authors", "collection_id": "p1jrr-fm354", "cite_using_url": "https://authors.library.caltech.edu/records/p1jrr-fm354", "type": "article", "title": "Atmospheric Abundances and Bulk Properties of the Binary Brown Dwarf Gliese 229Bab from JWST/MIRI Spectroscopy", "author": [ { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Perrin", "given_name": "Marshall D.", "orcid": "0000-0002-3191-8151" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Knutson", "given_name": "Heather A.", "orcid": "0000-0002-5375-4725", "clpid": "Knutson-H-A" }, { "family_name": "Mukherjee", "given_name": "Sagnick", "orcid": "0000-0003-1622-1302" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Hoch", "given_name": "Kielan K. W.", "orcid": "0000-0002-9803-8255" }, { "family_name": "Wang", "given_name": "Jason J.", "orcid": "0000-0003-0774-6502", "clpid": "Wang-Jason-J" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Wallack", "given_name": "Nicole L.", "orcid": "0000-0003-0354-0187", "clpid": "Wallack-N-L" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" } ], "abstract": "

We present JWST/Mid Infrared Instrument (MIRI) low-resolution spectroscopy (4.75–14 μm) of the first known substellar companion, Gliese 229Bab, which was recently resolved into a tight binary brown dwarf. Previous atmospheric retrieval studies modeling Gliese 229B as a single brown dwarf have reported anomalously high carbon-to-oxygen ratios (C/O) of ≈1.1 using 1–5 μm ground-based spectra. Here, we fit the MIRI spectrum of Gliese 229Bab with a two-component binary model using the Sonora Elf Owl grid and additionally account for the observed K-band flux ratio of the binary brown dwarf. Assuming the two brown dwarfs share the same abundances, we obtain C/O = 0.65 ± 0.05 and [M/H] = 0.0 0 − 0.03 + 0.04 as their abundances (2σ statistical errors), which are fully consistent with the host star abundances. We also recover the same abundances if we fit the MIRI spectrum with a single brown dwarf model, indicating that binarity does not strongly affect inferred abundances from mid-infrared data when the T eff are similar between components of the binary. In addition, we measure T eff = 90 0 − 29 + 78 K and T eff = 77 5 − 33 + 20 K for the two brown dwarfs. We find that the vertical diffusion coefficients of log K z z ≈ 4.0 are identical between the two brown dwarfs and in line with log K z z values inferred for isolated brown dwarfs of similar T eff. Our results demonstrate the power of mid-infrared spectroscopy in providing robust atmospheric abundance measurements for brown dwarf companions and, by extension, giant planets.

", "doi": "10.3847/2041-8213/ad92f9", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2024-12-20", "series_number": "2", "volume": "977", "issue": "2", "pages": "L32" }, { "id": "authors:cwq75-y7n72", "collection": "authors", "collection_id": "cwq75-y7n72", "cite_using_url": "https://authors.library.caltech.edu/records/cwq75-y7n72", "type": "article", "title": "Atmospheric Characterization of the Super-Jupiter HIP 99770 b with KPIC", "author": [ { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Wang", "given_name": "Jason J.", "orcid": "0000-0003-0774-6502", "clpid": "Wang-Jason-J" }, { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Ruffio", "given_name": "Jean-Bapiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" }, { "family_name": "Knutson", "given_name": "Heather A.", "orcid": "0000-0002-5375-4725", "clpid": "Knutson-H-A" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Chachan", "given_name": "Yayaati", "orcid": "0000-0003-1728-8269" }, { "family_name": "Horstman", "given_name": "Katelyn", "orcid": "0000-0001-9708-8667", "clpid": "Horstman-Katelyn" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Greg" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-D" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042", "clpid": "Liberman-Joshua" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Morris", "given_name": "Evan", "orcid": "0000-0003-3165-0922" }, { "family_name": "Pezzato", "given_name": "Jacklyn", "clpid": "Pezzato-Jacklyn" }, { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang", "given_name": "Ji", "orcid": "0000-0002-4361-8885" }, { "family_name": "Do \u00d3", "given_name": "Clarissa R.", "orcid": "0000-0001-5173-2947" } ], "abstract": "

Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test for planet formation and evolution theories. By spectroscopically characterizing the atmospheric compositions of these super-Jupiters, we can constrain their formation histories. Here we present studies of the recently discovered HIP 99770 b, a 16 M Jup high-contrast companion on a 17 au orbit, using the fiber-fed high-resolution spectrograph KPIC ( R ∼ 35,000) on the Keck II telescope. Our K-band observations led to detections of H2O and CO in the atmosphere of HIP 99770 b. We carried out free retrieval analyses using petitRADTRANS to measure its chemical abundances, including the metallicity and C/O ratio, projected rotation velocity ( v sin i ), and radial velocity (RV). We found that the companion's atmosphere has C/O = 0.55 − 0.04 + 0.06 and [M/H] = 0.26 − 0.23 + 0.24 (1σ confidence intervals), values consistent with those of the Sun and with a companion formation via gravitational instability or core accretion. The projected rotation velocity v sin ( i ) < 7.8 km s\u207b¹ is small relative to other directly imaged companions with similar masses and ages. This may imply a nearly pole-on orientation or effective magnetic braking by a circumplanetary disk. In addition, we added the companion-to-primary relative RV measurement to the orbital fitting and obtained updated constraints on orbital parameters. Detailed characterization of super-Jovian companions within 20 au like HIP 99770 b is critical for understanding the formation histories of this population.

", "doi": "10.3847/1538-3881/ad6609", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2024-09", "series_number": "3", "volume": "168", "issue": "3", "pages": "131" }, { "id": "authors:h5z2c-86g12", "collection": "authors", "collection_id": "h5z2c-86g12", "cite_using_url": "https://authors.library.caltech.edu/records/h5z2c-86g12", "type": "article", "title": "Are These Planets or Brown Dwarfs? Broadly Solar Compositions from High-resolution Atmospheric Retrievals of \u223c10\u201330 M_(Jup) Companions", "author": [ { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Wang", "given_name": "Jason", "orcid": "0000-0003-0774-6502", "clpid": "Wang-Jason-J" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Knutson", "given_name": "Heather", "orcid": "0000-0002-5375-4725", "clpid": "Knutson-H-A" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Mamajek", "given_name": "Eric E.", "orcid": "0000-0003-2008-1488", "clpid": "Mamajek-Eric-E" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Wallack", "given_name": "Nicole L.", "orcid": "0000-0003-0354-0187", "clpid": "Wallack-N-L" }, { "family_name": "Bryan", "given_name": "Marta L.", "orcid": "0000-0002-6076-5967" }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Molli\u00e8re", "given_name": "Paul", "orcid": "0000-0003-4096-7067" }, { "family_name": "Hejazi", "given_name": "Neda", "orcid": "0000-0001-5541-6087" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Greg" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-D" }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042", "clpid": "Liberman-Joshua" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Morris", "given_name": "Evan", "orcid": "0000-0003-3165-0922" }, { "family_name": "Pezzato", "given_name": "Jacklyn", "clpid": "Pezzato-Jacklyn" }, { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang", "given_name": "Ji", "orcid": "0000-0002-4361-8885" }, { "family_name": "Agrawal", "given_name": "Shubh", "orcid": "0000-0003-2429-5811" }, { "family_name": "Horstman", "given_name": "Katelyn", "orcid": "0000-0001-9708-8667", "clpid": "Horstman-Katelyn" } ], "abstract": "

Using Keck Planet Imager and Characterizer high-resolution (R ∼ 35,000) spectroscopy from 2.29 to 2.49 μm, we present uniform atmospheric retrievals for eight young substellar companions with masses of ∼10–30 MJup, orbital separations spanning ∼50–360 au, and Teff between ∼1500 and 2600 K. We find that all companions have solar C/O ratios and metallicities to within the 1σ–2σ level, with the measurements clustered around solar composition. Stars in the same stellar associations as our systems have near-solar abundances, so these results indicate that this population of companions is consistent with formation via direct gravitational collapse. Alternatively, core accretion outside the CO snowline would be compatible with our measurements, though the high mass ratios of most systems would require rapid core assembly and gas accretion in massive disks. On a population level, our findings can be contrasted with abundance measurements for directly imaged planets with m < 10 MJup, which show tentative atmospheric metal enrichment compared to their host stars. In addition, the atmospheric compositions of our sample of companions are distinct from those of hot Jupiters, which most likely form via core accretion. For two companions with Teff ∼ 1700–2000 K (κ And b and GSC 6214–210 b), our best-fit models prefer a nongray cloud model with >3σ significance. The cloudy models yield 2σ−3σ lower Teff for these companions, though the C/O and [C/H] still agree between cloudy and clear models at the 1σ level. Finally, we constrain 12CO/13CO for three companions with the highest signal-to-noise ratio data (GQ Lup b, HIP 79098b, and DH Tau b) and report 

", "doi": "10.3847/1538-4357/ad4796", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-07-20", "series_number": "1", "volume": "970", "issue": "1", "pages": "71" }, { "id": "authors:h03b9-38d60", "collection": "authors", "collection_id": "h03b9-38d60", "cite_using_url": "https://authors.library.caltech.edu/records/h03b9-38d60", "type": "article", "title": "Validation of Elemental and Isotopic Abundances in Late-M Spectral Types with the Benchmark HIP 55507 AB System", "author": [ { "family_name": "Xuan", "given_name": "Jerry W.", "orcid": "0000-0002-6618-1137", "clpid": "Xuan-Jerry-W" }, { "family_name": "Wang", "given_name": "Jason", "orcid": "0000-0003-0774-6502" }, { "family_name": "Finnerty", "given_name": "Luke", "orcid": "0000-0002-1392-0768" }, { "family_name": "Horstman", "given_name": "Katelyn", "orcid": "0000-0001-9708-8667", "clpid": "Horstman-Katelyn" }, { "family_name": "Grimm", "given_name": "Simon" }, { "family_name": "Peck", "given_name": "Anne E.", "orcid": "0000-0003-2461-6881" }, { "family_name": "Nielsen", "given_name": "Eric", "orcid": "0000-0001-6975-9056" }, { "family_name": "Knutson", "given_name": "Heather A.", "orcid": "0000-0002-5375-4725", "clpid": "Knutson-H-A" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Isaacson", "given_name": "Howard", "orcid": "0000-0002-0531-1073" }, { "family_name": "Howard", "given_name": "Andrew W.", "orcid": "0000-0001-8638-0320", "clpid": "Howard-A-W" }, { "family_name": "Liu", "given_name": "Michael C.", "orcid": "0000-0003-2232-7664" }, { "family_name": "Walker", "given_name": "Sam", "orcid": "0000-0001-7062-815X" }, { "family_name": "Phillips", "given_name": "Mark W." }, { "family_name": "Blake", "given_name": "Geoffrey A.", "orcid": "0000-0003-0787-1610", "clpid": "Blake-G-A" }, { "family_name": "Ruffio", "given_name": "Jean-Baptiste", "orcid": "0000-0003-2233-4821", "clpid": "Ruffio-J-B" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Inglis", "given_name": "Julie", "orcid": "0000-0001-9164-7966", "clpid": "Inglis-Julie" }, { "family_name": "Wallack", "given_name": "Nicole L.", "orcid": "0000-0003-0354-0187", "clpid": "Wallack-N-L" }, { "family_name": "Sanghi", "given_name": "Aniket", "orcid": "0000-0002-1838-4757", "clpid": "Sanghi-Aniket" }, { "family_name": "Gonzales", "given_name": "Erica J.", "orcid": "0000-0002-9329-2190" }, { "family_name": "Dai", "given_name": "Fei", "orcid": "0000-0002-8958-0683", "clpid": "Dai-Fei" }, { "family_name": "Baker", "given_name": "Ashley", "orcid": "0000-0002-6525-7013", "clpid": "Baker-Ashley" }, { "family_name": "Bartos", "given_name": "Randall", "clpid": "Bartos-Randall" }, { "family_name": "Bond", "given_name": "Charlotte Z." }, { "family_name": "Bryan", "given_name": "Marta L.", "orcid": "0000-0002-6076-5967" }, { "family_name": "Calvin", "given_name": "Benjamin", "orcid": "0000-0003-4737-5486", "clpid": "Calvin-Benjamin" }, { "family_name": "Cetre", "given_name": "Sylvain" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "orcid": "0000-0001-8953-1008" }, { "family_name": "Doppmann", "given_name": "Greg" }, { "family_name": "Echeverri", "given_name": "Daniel", "orcid": "0000-0002-1583-2040", "clpid": "Echeverri-Daniel" }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "orcid": "0000-0001-5213-6207", "clpid": "Jovanovic-N" }, { "family_name": "Liberman", "given_name": "Joshua", "orcid": "0000-0002-4934-3042", "clpid": "Liberman-Joshua" }, { "family_name": "L\u00f3pez", "given_name": "Ronald A.", "orcid": "0000-0002-2019-4995" }, { "family_name": "Martin", "given_name": "Emily C.", "orcid": "0000-0002-0618-5128" }, { "family_name": "Morris", "given_name": "Evan" }, { "family_name": "Pezzato", "given_name": "Jacklyn", "clpid": "Pezzato-Jacklyn" }, { "family_name": "Ruane", "given_name": "Garreth", "orcid": "0000-0003-4769-1665", "clpid": "Ruane-G-J" }, { "family_name": "Sappey", "given_name": "Ben", "orcid": "0000-0003-1399-3593" }, { "family_name": "Schofield", "given_name": "Tobias", "clpid": "Schofield-Tobias" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924" }, { "family_name": "Venenciano", "given_name": "Taylor", "orcid": "0000-0003-0122-8915" }, { "family_name": "Wallace", "given_name": "J. Kent", "orcid": "0000-0001-5299-6899", "clpid": "Wallace-J-Kent" }, { "family_name": "Wang", "given_name": "Ji", "orcid": "0000-0002-4361-8885" }, { "family_name": "Wizinowich", "given_name": "Peter", "orcid": "0000-0002-1646-442X" }, { "family_name": "Xin", "given_name": "Yinzi", "orcid": "0000-0002-6171-9081", "clpid": "Xin-Yinzi" }, { "family_name": "Agrawal", "given_name": "Shubh", "orcid": "0000-0003-2429-5811" }, { "family_name": "Do \u00d3", "given_name": "Clarissa R.", "orcid": "0000-0001-5173-2947" }, { "family_name": "Hsu", "given_name": "Chih-Chun", "orcid": "0000-0002-5370-7494" }, { "family_name": "Phillips", "given_name": "Caprice L.", "orcid": "0000-0001-5610-5328" } ], "abstract": "

M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which share similar Teff ∼ 2300–2800 K. We present atmospheric analyses for the M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution (R ∼ 35,000) K-band spectroscopy. First, by including KPIC relative radial velocities between the primary and secondary in the orbit fit, we improve the dynamical mass precision by 60% and find M_B = 88.0_(−3.2)^(+3.4) M_Jup, putting HIP 55507 B above the stellar–substellar boundary. We also find that HIP 55507 B orbits its K6V primary star with a = 38\u208b\u2083\u207a\u2074 au and e = 0.40 ± 0.04. From atmospheric retrievals of HIP 55507 B, we measure [C/H] = 0.24 ± 0.13, [O/H] = 0.15 ± 0.13, and C/O = 0.67 ± 0.04. Moreover, we strongly detect 13CO (7.8σ significance) and tentatively detect H218O (3.7σ significance) in the companion's atmosphere and measure 12C/13C = 98\u208b\u2082\u2082\u207a²\u2078 and H\u208216O/H\u208218O = 240\u208b\u2088\u2080\u207a¹\u2074\u2075 after accounting for systematic errors. From a simplified retrieval analysis of HIP 55507 A, we measure 12C/13C = 79\u208b\u2081\u2086\u207a²¹ and C16O/C18O = 288\u208b\u2087\u2080\u207a¹²\u2075 for the primary star. These results demonstrate that HIP 55507 A and B have consistent 12C/13C and 16O/18O to the <1σ level, as expected for a chemically homogeneous binary system. Given the similar flux ratios and separations between HIP 55507 AB and systems with young substellar companions, our results open the door to systematically measuring 13CO and H\u208218O abundances in the atmospheres of substellar or even planetary-mass companions with similar spectral types.

", "doi": "10.3847/1538-4357/ad1243", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-02-10", "series_number": "1", "volume": "962", "issue": "1", "pages": "10" }, { "id": "authors:xx6hv-0pw86", "collection": "authors", "collection_id": "xx6hv-0pw86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230530-441768000.56", "type": "article", "title": "Retrieval Survey of Metals in Six Ultrahot Jupiters: Trends in Chemistry, Rain-out, Ionization, and Atmospheric Dynamics", "author": [ { "family_name": "Gandhi", "given_name": "Siddharth", "orcid": "0000-0001-9552-3709", "clpid": "Gandhi-Siddharth" }, { "family_name": "Kesseli", "given_name": "Aurora", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-Aurora-Y" }, { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Louca", "given_name": "Amy", "orcid": "0000-0002-3191-2200", "clpid": "Louca-Amy" }, { "family_name": "Snellen", "given_name": "Ignas", "orcid": "0000-0003-1624-3667", "clpid": "Snellen-Ignas-A-G" }, { "family_name": "Brogi", "given_name": "Matteo", "orcid": "0000-0002-7704-0153", "clpid": "Brogi-Matteo" }, { "family_name": "Miguel", "given_name": "Yamila", "orcid": "0000-0002-0747-8862", "clpid": "Miguel-Yamila" }, { "family_name": "Casasayas-Barris", "given_name": "N\u00faria", "orcid": "0000-0002-2891-8222", "clpid": "Casasayas-Barris-N\u00faria" }, { "family_name": "Pelletier", "given_name": "Stefan", "orcid": "0000-0002-8573-805X", "clpid": "Pelletier-Stefan" }, { "family_name": "Landman", "given_name": "Rico", "orcid": "0000-0002-7261-8083", "clpid": "Landman-Rico" }, { "family_name": "Maguire", "given_name": "Cathal", "orcid": "0000-0002-9061-780X", "clpid": "Maguire-Cathal" }, { "family_name": "Gibson", "given_name": "Neale P.", "orcid": "0000-0002-9308-2353", "clpid": "Gibson-Neale-P" } ], "abstract": "Ground-based high-resolution spectroscopy (HRS) has detected numerous chemical species and atmospheric dynamics in exoplanets, most notably ultrahot Jupiters (UHJs). However, quantitative estimates on abundances have been challenging but are essential for accurate comparative characterization and to determine formation scenarios. In this work, we retrieve the atmospheres of six UHJs (WASP-76 b, MASCARA-4 b, MASCARA-2 b, WASP-121 b, HAT-P-70 b, and WASP-189 b) with ESPRESSO and HARPS-N/HARPS observations, exploring trends in eleven neutral species and dynamics. While Fe abundances agree well with stellar values, Mg, Ni, Cr, Mn, and V show more variation, highlighting the difficulty in using a single species as a proxy for metallicity. We find that Ca, Na, Ti, and TiO are underabundant, potentially due to ionization and/or nightside rain-out. Our retrievals also show that relative abundances between species are more robust, consistent with previous works. We perform spatially resolved and phase-resolved retrievals for WASP-76 b and WASP-121 b given their high signal-to-noise observations, and find the chemical abundances in each of the terminator regions are broadly consistent. We additionally constrain dynamics for our sample through Doppler shifts and broadening of the planetary signals during the primary eclipse, with median blueshifts between \u223c0.9 and 9.0 km s\u207b\u00b9 due to day\u2013night winds. Furthermore, we constrain spectroscopic masses for MASCARA-2 b and HAT-P-70 b consistent with their known upper limits, but we note that these may be biased due to degeneracies. This work highlights the importance of future HRS studies to further probe differences and trends between exoplanets.", "doi": "10.3847/1538-3881/accd65", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2023-06", "series_number": "6", "volume": "165", "issue": "6", "pages": "Art. No. 242" }, { "id": "authors:5dz65-vhx21", "collection": "authors", "collection_id": "5dz65-vhx21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221017-12657600.26", "type": "article", "title": "Transmission spectroscopy of the ultra-hot Jupiter MASCARA-4 b", "author": [ { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Snellen", "given_name": "Ignas A. G.", "orcid": "0000-0003-1624-3667", "clpid": "Snellen-Ignas-A-G" }, { "family_name": "Wyttenbach", "given_name": "Aur\u00e8lien", "orcid": "0000-0001-9003-7699", "clpid": "Wyttenbach-Aur\u00e8lien" }, { "family_name": "Nielsen", "given_name": "Louise D.", "orcid": "0000-0002-5254-2499", "clpid": "Nielsen-Louise-D" }, { "family_name": "Lendl", "given_name": "Monika", "orcid": "0000-0001-9699-1459", "clpid": "Lendl-Monika" }, { "family_name": "Casasayas-Barris", "given_name": "N\u00faria", "orcid": "0000-0002-2891-8222", "clpid": "Casasayas-Barris-N\u00faria" }, { "family_name": "Chaverot", "given_name": "Guillaume", "orcid": "0000-0003-4711-3099", "clpid": "Chaverot-Guillaume" }, { "family_name": "Kesseli", "given_name": "Aurora Y.", "orcid": "0000-0002-3239-5989", "clpid": "Kesseli-A-Y" }, { "family_name": "Lovis", "given_name": "Christophe", "orcid": "0000-0001-7120-5837", "clpid": "Lovis-Christophe" }, { "family_name": "Pepe", "given_name": "Francesco A.", "orcid": "0000-0002-9815-773X", "clpid": "Pepe-Francesco-A" }, { "family_name": "Psaridi", "given_name": "Angelica", "orcid": "0000-0002-4797-2419", "clpid": "Psaridi-Angelica" }, { "family_name": "Seidel", "given_name": "Julia V.", "orcid": "0000-0002-7990-9596", "clpid": "Seidel-Julia-V" }, { "family_name": "Udry", "given_name": "St\u00e9phane", "orcid": "0000-0001-7576-6236", "clpid": "Udry-St\u00e9phane" }, { "family_name": "Ulmer-Moll", "given_name": "Sol\u00e8ne", "orcid": "0000-0003-2417-7006", "clpid": "Ulmer-Moll-Sol\u00e8ne" } ], "abstract": "Context. Ultra-hot Jupiters (UHJs), rendering the hottest planetary atmospheres, offer great opportunities of detailed characterisation with high-resolution spectroscopy. MASCARA-4 b is a recently discovered close-in gas giant belonging to this category.\n\nAims. We aim to characterise MASCARA-4 b, search for chemical species in its atmosphere, and put these in the context of the growing knowledge on the atmospheric properties of UHJs.\n\nMethods. In order to refine system and planet parameters, we carried out radial velocity measurements and transit photometry with the CORALIE spectrograph and EulerCam at the Swiss 1.2 m Euler telescope. We observed two transits of MASCARA-4 b with the high-resolution spectrograph ESPRESSO at ESO's Very Large Telescope. We searched for atomic, ionic, and molecular species via individual absorption lines and cross-correlation techniques. These results are compared to literature studies on UHJs characterised to date.\n\nResults. With CORALIE and EulerCam observations, we update the mass of MASCARA-4 b (M\u209a = 1.675 \u00b1 0.241 M_(Jup)) as well as other system and planet parameters. In the transmission spectrum derived from ESPRESSO observations, we resolve excess absorption by H\u03b1, H\u03b2, NaI D1&D2, CaII H&K, and a few strong lines of MgI, FeI, and FeII. We also present the cross-correlation detection of Mg I, CaI, Cr I, Fe I, and Fe II. The absorption strength of Fe II significantly exceeds the prediction from a hydrostatic atmospheric model, as commonly observed in other UHJs. We attribute this to the presence of Fe II in the exosphere due to hydrodynamic outflows. This is further supported by the positive correlation of absorption strengths of Fe II with the H\u03b1 line, which is expected to probe the extended upper atmosphere and the mass loss process. Comparing transmission signatures of various species in the UHJ population allows us to disentangle the hydrostatic regime (as traced via the absorption by Mg I and Fe I) from the exospheres (as probed by H\u03b1 and Fe II) of the strongly irradiated atmospheres.", "doi": "10.1051/0004-6361/202244203", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2022-10", "volume": "666", "pages": "Art. No. A47" }, { "id": "authors:4hmnn-7jn87", "collection": "authors", "collection_id": "4hmnn-7jn87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210719-203550633", "type": "article", "title": "The \u00b9\u00b3CO-rich atmosphere of a young accreting super-Jupiter", "author": [ { "family_name": "Zhang", "given_name": "Yapeng", "orcid": "0000-0003-0097-4414", "clpid": "Zhang-Yapeng" }, { "family_name": "Snellen", "given_name": "Ignas A. G.", "orcid": "0000-0003-1624-3667", "clpid": "Snellen-Ignas-A-G" }, { "family_name": "Bohn", "given_name": "Alexander J.", "orcid": "0000-0003-1401-9952", "clpid": "Bohn-Alexander-J" }, { "family_name": "Molli\u00e8re", "given_name": "Paul", "orcid": "0000-0003-4096-7067", "clpid": "Molli\u00e8re-Paul" }, { "family_name": "Ginski", "given_name": "Christian", "orcid": "0000-0002-4438-1971", "clpid": "Ginski-Christian" }, { "family_name": "Hoeijmakers", "given_name": "H. Jens", "orcid": "0000-0001-8981-6759", "clpid": "Hoeijmakers-H-Jens" }, { "family_name": "Kenworthy", "given_name": "Matthew A.", "orcid": "0000-0002-7064-8270", "clpid": "Kenworthy-Matthew-A" }, { "family_name": "Mamajek", "given_name": "Eric E.", "orcid": "0000-0003-2008-1488", "clpid": "Mamajek-Eric-E" }, { "family_name": "Meshkat", "given_name": "Tiffany", "orcid": "0000-0001-6126-2467", "clpid": "Meshkat-Tiffany" }, { "family_name": "Reggiani", "given_name": "Maddalena", "orcid": "0000-0003-2911-0898", "clpid": "Reggiani-Maddalena" }, { "family_name": "Snik", "given_name": "Frans", "orcid": "0000-0003-1946-7009", "clpid": "Snik-Frans" } ], "abstract": "Isotope abundance ratios have an important role in astronomy and planetary sciences, providing insights into the origin and evolution of the Solar System, interstellar chemistry and stellar nucleosynthesis. In contrast to deuterium/hydrogen ratios, carbon isotope ratios are found to be roughly constant (around 89) in the Solar System, but do vary on galactic scales with a \u00b9\u00b2C/\u00b9\u00b3C isotopologue ratio of around 68 in the current local interstellar medium. In molecular clouds and protoplanetary disks, \u00b9\u00b2CO/\u00b9\u00b3CO ratios can be altered by ice and gas partitioning, low-temperature isotopic ion-exchange reactions and isotope-selective photodissociation. Here we report observations of \u00b9\u00b3CO in the atmosphere of the young, accreting super-Jupiter TYC 8998-760-1 b, at a statistical significance of more than six sigma. Marginalizing over the planet's atmospheric temperature structure, chemical composition and spectral calibration uncertainties suggests a \u00b9\u00b2CO/\u00b9\u00b3CO ratio of 31\u207a\u00b9\u2077\u208b\u2081\u2080(90% confidence), a substantial enrichment in \u00b9\u00b3C with respect to the terrestrial standard and the local interstellar value. As the current location of TYC 8998-760-1 b at greater than or equal to 160 astronomical units is far beyond the CO snowline, we postulate that it accreted a substantial fraction of its carbon from ices enriched in \u00b9\u00b3C through fractionation.", "doi": "10.1038/s41586-021-03616-x", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2021-07-15", "series_number": "7867", "volume": "595", "issue": "7867", "pages": "370-372" } ]