activity
20202026
most citedEvidence for a high mutual inclination between the cold Jupiter and transiting super Earth orbiting Men

82 citations · 781 across the 59 of their papers we have counts for

collaborators

60 papers

astro-ph.EP2026

Atmospheric characterization of six ultra-hot Jupiters from -band high-resolution spectroscopy

Luke Finnerty, Michael P. Fitzgerald, Yinzi Xin +27

We present new Keck/KPIC high-resolution spectroscopic detections of three ultra-hot Jupiters (UHJs) in the band: WASP-189b (), MASCARA-1b (), and…

astro-ph.EP2026

Hydrogen airglow from an escaping ultrahot Jupiter atmosphere

Yapeng Zhang, Chenliang Huang, Aaron Householder +17

Intense high-energy irradiation of close-in gaseous exoplanets drives the rapid escape of their atmospheres, fundamentally shaping planetary demographics. While atmospheric loss is…

astro-ph.EP2026

Chemistry and Isotope Ratios of Substellar Atmospheres in the Pictoris Young Moving Group and Vicinity

Yurou Liu, Yapeng Zhang, Jerry W. Xuan +7

Measuring the chemical and isotopic compositions of gas giants and brown dwarfs provides insights into their formation pathways and birth environments. 2MASS J0249-0557 c is an L2-…

astro-ph.SR2026

Discovery of a Low-Mass Companion to the Accelerating Star HIP 53005 with Strongly Conflicting Mass Estimates

Taichi Uyama, Thayne Currie, Jerry W. Xuan +22

We present the discovery of a low-mass companion located at 0\farcs{}85 () from the early-type 1.2 Gyr-old star HIP 53005 using direct imagin…

astro-ph.EP2026★ 12 cited

The compositions of the HR 8799 planets reflect accretion of both solids and metal-enriched gas

Jerry W. Xuan, Jean-Baptiste Ruffio, Yayaati Chachan +24

With four giant planets (, $T_\rm{eff}\sim900-1200$ K) orbiting between 15-70 au, HR 8799 provides an unparalleled testbed for studying giant planet formatio…

astro-ph.SR2026★ 1 cited

A Mass Transferring Brown Dwarf Binary on a 57 Minute Orbit

Samuel Whitebook, Antonio C. Rodriguez, Kevin Burdge +9

Mass transfer in stellar binaries has been well studied in most stellar mass ranges, with the notable exception of ultracool stars and substellar brown dwarfs. We report the discov…

astro-ph.EP2026

Possible stratospheric emission in the warm Neptune GJ 436 b from high-resolution spectroscopy

Luke Finnerty, Michael P Fitzgerald, Jerry W Xuan +26

We present high spectral resolution band (2.91--3.85 m) observations of the warm Neptune GJ 436 b from Keck II/KPIC. KPIC's single-mode fiber feed reduces the band sky b…

astro-ph.EP2026

Detecting and Characterizing Companions with a Calibrated Gaia DR2, DR3, and Hipparcos Catalog (G23H)

William Thompson, Dori Blakely, Jerry W. Xuan +16

Gaia DR4 epoch astrometry will enable the detection of thousands of exoplanets through astrometric motion. Here, we present a composite catalog and modeling framework that extracts…

astro-ph.EP2026★ 12 cited

Jupiter-like uniform metal enrichment in a system of multiple giant exoplanets

Jean-Baptiste Ruffio, Jerry W. Xuan, Yayaati Chachan +15

The accretion of icy and rocky solids during the formation of a gas giant planet is poorly constrained and challenging to model. Refractory species, like sulfur, are only present i…

astro-ph.EP2026★ 4 cited

Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions

Chih-Chun Hsu, Jason J. Wang, Jerry W. Xuan +27

We present a rotational velocity (vsini) survey of 32 stellar/substellar objects and giant planets using Keck/KPIC high-resolution spectroscopy, including 6 giant planets (2-7 M$_\…

astro-ph.EP2025

Chemical and Isotopic Homogeneity Between the L Dwarf CD-35 2722 B and its Early M Host Star

Gavin Wang, Jerry Xuan, Darío Picos +29

CD-35 2722 B is an L dwarf companion to the nearby, Myr old M1 dwarf CD-35 2722 A. We present a detailed analysis of both objects using high-resolution ($R \sim 35,00…

astro-ph.SR2025

Direct Imaging Explorations for Companions from the Subaru/IRD Strategic Program II; Discovery of a Brown-dwarf Companion around a Nearby mid-M~dwarf LSPM~J1446+4633

Taichi Uyama, Masayuki Kuzuhara, Charles Beichman +35

We report the discovery of a new directly-imaged brown dwarf companion with Keck/NIRC2+pyWFS around a nearby mid-type M~dwarf LSPM~J1446+4633 (hereafter J1446). The -band contr…

astro-ph.EP2025★ 3 cited

Dynamical Architectures of S-type Transiting Planets in Binaries II: A Dichotomy in Orbital Alignment of Small Planets in Close Binary Systems

Jingwen Zhang, Daniel Huber, Michael Bottom +35

Stellar multiplicity plays a crucial role in shaping planet formation and dynamical evolution. We present a survey of 54 TESS Objects of Interest (TOIs) within 300 pc that exhibit…

astro-ph.EP2025★ 3 cited

HD 143811 AB b: A Directly Imaged Planet Orbiting a Spectroscopic Binary in Sco-Cen

Nathalie K. Jones, Jason J. Wang, Eric L. Nielsen +51

We present confirmation of HD 143811 AB b, a substellar companion to spectroscopic binary HD 143811 AB through direct imaging with the Gemini Planet Imager (GPI) and Keck NIRC2. HD…

astro-ph.EP2025

Characterization of the Host Binary of the Directly Imaged Exoplanet HD 143811 AB b

Anne E. Peck, William Roberson, Eric L. Nielsen +50

HD~143811~AB is the host star to the directly imaged planet HD~143811~AB~b, which was recently discovered using data from the Gemini Planet Imager and Keck NIRC2. A member of the S…

astro-ph.EP2025

The watery atmosphere of HD~209458~b revealed by joint - and -band high-resolution spectroscopy

Luke Finnerty, Julie Inglis, Michael P. Fitzgerald +26

We present a joint analysis of high-resolution - and -band observations of the benchmark hot Jupiter \hdb\ from the Keck Planet Imager and Characterizer (KPIC). One half nigh…

astro-ph.EP2025

Water dissociation and rotational broadening in the atmosphere of KELT-20 b from high-resolution spectroscopy

Luke Finnerty, Yinzi Xin, Jerry W. Xuan +29

We present atmospheric retrievals from Keck/KPIC phase II observations of the ultra-hot Jupiter KELT-20/MASCARA-2~b. Previous free retrievals of molecular abundances for ultra-hot…

astro-ph.SR2025

On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb

William Thompson, Dori Blakely, Jerry W. Xuan +21

The companion GL229B was recently resolved by Xuan et al. (2024) as a tight binary of two brown dwarfs (Ba and Bb) through VLTI-GRAVITY interferometry and VLT-CRIRES+ RV measuremen…

astro-ph.IM2025★ 9 cited

Technical description and performance of the phase II version of the Keck Planet Imager and Characterizer

Nemanja Jovanovic, Daniel Echeverri, Jacques-Robert Delorme +46

The Keck Planet Imager and Characterizer (KPIC) is a series of upgrades for the Keck II Adaptive Optics (AO) system and the NIRSPEC spectrograph to enable diffraction limited, high…

astro-ph.EP2025

HD 206893 B at High Spectral Resolution with the Keck Planet Imager and Characterizer (KPIC)

Ben Sappey, Quinn Konopacky, Clarissa R. Do O +38

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 Plane…

astro-ph.EP2024★ 8 cited

PDS 70b Shows Stellar-like Carbon-to-oxygen Ratio

Chih-Chun Hsu, Jason J. Wang, Geoffrey A. Blake +27

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 an…

astro-ph.EP2024

True mass and atmospheric composition of the non-transiting hot Jupiter HD 143105 b

Luke Finnerty, Yinzi Xin, Jerry W. Xuan +28

We present Keck/KPIC phase II -band observations of the non-transiting hot Jupiter HD 143105 b. Using a cross-correlation approach, we make the first detection of the planetary…

astro-ph.SR2024

Chemical Links between a Young M-type T Tauri Star and its Substellar Companion: Spectral Analysis and C/O Measurement of DH Tau A

Neda Hejazi, Jerry W. Xuan, David R. Coria +5

The chemical abundance measurements of host stars and their substellar companions provide a powerful tool to trace the formation mechanism of the planetary systems. We present a de…

astro-ph.SR2024★ 6 cited

Atmospheric abundances and bulk properties of the binary brown dwarf Gliese 229 Bab from JWST/MIRI spectroscopy

Jerry W. Xuan, Marshall D. Perrin, Dimitri Mawet +8

We present JWST/MIRI low-resolution spectroscopy (m) of the first known substellar companion, Gliese 229 Bab, which was recently resolved into a tight binary brown dwarf…