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20132026
most citedPolarized Blazar X-rays imply particle acceleration in shocks

140 citations · 630 across the 93 of their papers we have counts for

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astro-ph.EP2026

Astrometric Evidence for Outer Giant Planets in Known Exoplanet Systems

Clarissa R. Do Ó, William Thompson, Dori Blakely +19

Outer giant planets can influence the formation and dynamical evolution of their planetary systems. However, their long orbital periods make them difficult to detect using transit…

astro-ph.EP2026

Worlds Next Door. V. A Candidate Solar System Scale Super-Jupiter in the 61 Cygni Binary System

Aniket Sanghi, Billy Quarles, Andrea S. J. Lin +16

We present new constraints on a candidate third companion in the 61 Cygni binary system-one of the closest neighbors to our solar system (3.5 pc), the first stars to have a measure…

astro-ph.EP2026

Searching for Embedded Protoplanets with the Keck/NIRC2 Vortex Coronagraph: Confirmation of a Core-accretion Planet in the Narrow Gap of the Elias 2-24 Disk

Andrea Bernardi, Alice Zurlo, Lucas A. Cieza +8

We present high-contrast imaging observations of seven stars obtained with the Keck/NIRC2 vortex coronagraph between 2018 May and June in the and bands. All targets host…

astro-ph.EP2026

The Science Potential of Characterizing Gas Giant Exoplanets with HWO

Beck Dacus, Jean-Baptiste Ruffio, Quinn Konopacky +19

With the ability to directly image Earth-like exoplanets and search their atmospheres for biosignatures, the upcoming Habitable Worlds Observatory (HWO) will also collect high sign…

astro-ph.EP2026

A Sulfur-Rich Atmosphere for the Young Jupiter Analog AF Lep b Reveals Significant Solid Accretion

Jerry W. Xuan, William O. Balmer, Yayaati Chachan +25

AF Lep b is one of the closest analogs to Jupiter in terms of mass () and semi-major axis ( AU) amenable to spectroscopic characterization. We present JWST/NIR…

astro-ph.EP2026

The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems VIII: patchy forsterite and enstatite clouds in the atmosphere of VHS 1256 b, retrieval lessons learned and outlook to the future

Niall Whiteford, Jacqueline K. Faherty, Ben Burningham +123

JWST defines a new era for the data-driven approach of retrieval modelling, which has become a cornerstone tool for the statistical inference of exoplanetary and brown dwarf proper…

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.EP2026

Multi-epoch scattered-light analysis of HD 135344B: new evidence for a spiral-driving protoplanet

J. Latour, V. Christiaens, O. Absil +17

The HD 135344B (SAO 206462) disk exhibits strong signposts of planet formation. ALMA images in the sub-mm revealed a gap-crossing dust filament whose position coincides with a twis…

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.EP2026

Worlds Next Door. IV. Mapping the Late Stages of Giant Planet Evolution with a Precise Dynamical Mass and Luminosity for Ind Ab

Aniket Sanghi, William Thompson, James Mang +21

We present new JWST/NIRCam 4-5 m (F410M, F430M) and JWST/MIRI 18-25 m (F1800W, F2100W, F2550W) imaging detections of the nearby (3.6 pc) cold (275 K) gas giant exoplanet …

astro-ph.EP2026

Worlds Next Door. III. Indirect Evidence for Enhanced Atmospheric Metallicity and/or the Presence of Water Clouds in the Nearest Jupiter-analog Eri b

Aniket Sanghi, James Mang, Jorge Llop-Sayson +12

We present the most sensitive direct imaging search for the nearest ( pc) Jupiter-analog exoplanet, Eri b, with JWST/NIRCam coronagraphy between 4-5 m (F444W). We a…

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

Keck Observations in the INfrared of Taurus and Oph Exoplanets And Ultracool dwarfs (KOINTREAU) II: Two Young Bound Companions to Ophiuchus Stars

Samuel Walker, Michael C. Liu, Dimitri Mawet +4

We present the second set of discoveries from Keck Observations in the INfrared of Taurus and Oph Exoplanets And Ultracool dwarfs (KOINTREAU), an adaptive optics survey of youn…

astro-ph.EP2026★ 8 cited

Extreme winds on the emerging dayside of an ultrahot Jupiter

Yapeng Zhang, Joost P. Wardenier, Aaron Householder +16

High-resolution spectroscopy provides a unique opportunity to directly probe atmospheric dynamics by resolving Doppler shifts of planetary signal as a function of orbital phases. U…

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★ 2 cited

Keck Observations in the INfrared of Taurus and Oph Exoplanets And Ultracool dwarfs (KOINTREAU) I: A Planetary-Mass Companion and a Disk-Obscured Stellar Companion Discovered in Taurus

Samuel A. U. Walker, Michael C. Liu, Dimitri Mawet +10

We present the first discoveries from Keck Observations in the INfrared of Taurus and Oph Exoplanets And Ultracool dwarfs (KOINTREAU), an adaptive optics imaging survey of youn…

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.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…