activity
20232026
most citedThe OATMEAL Survey. II. The 3D spin-orbit obliquity of an eccentric transiting brown dwarf in the Ruprecht 147 open cluster

3 citations · 6 across the 21 of their papers we have counts for

collaborators

22 papers

astro-ph.EP2026

POSEIDON III: The Aligned Orbit of the Hot Neptune Around the Hot Star WASP-195

Juan I. Espinoza-Retamal, Joshua N. Winn, Rafael Brahm +33

Stellar obliquities provide important clues as to the formation and migration histories of planetary systems, but measurements remain scarce for Neptune-mass planets, especially th…

astro-ph.EP2026

Spin-Orbit Alignment of Two Neptune-size Planets Younger than 500 Myr: TOI-560 b and TOI-5082 b

Elina Y. Zhang, Fei Dai, Andrew W. Howard +25

Stellar obliquity measurements provide a direct probe of planetary system dynamics, but remain sparse for Neptune-size planets, particularly at young ages. We present Rossiter-McLa…

astro-ph.IM2026

AstroAlertBench: Evaluating the Accuracy, Reasoning, and Honesty of Multimodal LLMs in Astronomical Classification

Claire Chen, Jiabao Sean Xiao, Shuze Daniel Liu +7

Modern astronomical observatories generate a massive volume of multimodal data, creating a critical bottleneck for expert human review. While multimodal large language models (LLMs…

astro-ph.EP2026

The KPF-SLOPE Survey - Small, Compact Multi-Planet Systems Appear Spin-Orbit Aligned

Luke B. Handley, Andrew W. Howard, Fei Dai +16

The angle between stellar spin axes and planetary orbits -- stellar obliquity -- probes the dynamics of planetary migration and evolution. The obliquities of giant planets have bee…

astro-ph.EP2026

Secular Excitation of Polar Neptune Orbits in Pure Disk-Planet Systems

Luke B. Handley, Konstantin Batygin

The stellar spin-orbit angles of Neptune-sized planets present a primordial yet puzzling view of the planetary formation epoch. The striking dichotomy of aligned and perpendicular…

astro-ph.EP2026

TOI-4495: A Pair of Aligned, Near-Resonant Sub-Neptunes that Likely Experienced Overstable Migration

Mu-Tian Wang, Fei Dai, Hui-Gen Liu +24

We report the discovery of a sub-Neptune and a Neptune-like planet (, ) orbiting the F-type star TOI-449…

astro-ph.EP2025

The Transition from Giant Planets to Brown Dwarfs beyond 1 au from the Stellar Metallicity Distribution

Steven Giacalone, Andrew W. Howard, Gregory J. Gilbert +3

Giant planets and brown dwarfs are thought to form via a combination of pathways, including bottom-up mechanisms in which gas is accreted onto a solid core and top-down mechanisms…

astro-ph.EP2025

Orbital Eccentricities Suggest a Gradual Transition from Giant Planets to Brown Dwarfs

Gregory J. Gilbert, Judah Van Zandt, Erik A. Petigura +3

To date, hundreds of sub-stellar objects with masses between have been detected orbiting main-sequence stars. The current convention uses the deuterium-burning…

astro-ph.EP2025

A Smooth Transition from Giant Planets to Brown Dwarfs from the Radial Occurrence Distribution

Judah Van Zandt, Greg Gilbert, Steven Giacalone +3

Measuring the occurrence rates of celestial objects is a valuable way to study their origins and evolution. Giant planets and brown dwarfs produce large Doppler signatures that are…

astro-ph.EP2025

The KPF SURFS-UP Survey I: Transmission Spectroscopy of WASP-76 b

Aaron Householder, Fei Dai, Aurora Kesseli +25

We introduce the KPF SURFS-UP (Spectroscopy of the Upper-atmospheres and ReFractory Species in Ultra-hot Planets) Survey, a high-resolution survey to investigate the atmospheric co…

astro-ph.EP2025

TOI-880 is an Aligned, Coplanar, Multi-planet System

Elina Y. Zhang, Huan-Yu Teng, Fei Dai +22

Although many cases of stellar spin-orbit misalignment are known, it is usually unclear whether a single planet's orbit was tilted or if the entire protoplanetary disk was misalign…

astro-ph.EP2025

A Hot Jupiter with a Retrograde Orbit around a Sun-like Star and a Toy Model of Hot Jupiters in Wide Binary Star Systems

Steven Giacalone, Andrew W. Howard, Ryan A. Rubenzahl +21

We report an observation of a transit of the hot Jupiter (HJ) KELT-23A b with the Keck Planet Finder spectrograph and a measurement of the sky-projected obliquity () of its Sun-…

astro-ph.IM2025

AstroQ: Automated Scheduling of Cadenced Astronomical Observations

Jack Lubin, Erik A. Petigura, Velibor V. Mišić +2

Astronomy relies heavily on time domain observations. To maximize the scientific yield of such observations, astronomers must carefully match the observational cadence to the pheno…

astro-ph.EP2025★ 3 cited

The OATMEAL Survey. II. The 3D spin-orbit obliquity of an eccentric transiting brown dwarf in the Ruprecht 147 open cluster

Theron W. Carmichael, Steven Giacalone, Noah Vowell +11

We present new analysis of the CWW 89 system as part of the Orbital Architectures of Transiting Massive Exoplanets And Low-mass stars (OATMEAL) survey. The CWW 89 system is a membe…

astro-ph.EP2025

Stellar Obliquity of the Ultra-Short-Period Planet System HD 93963

Huan-Yu Teng, Fei Dai, Andrew W. Howard +24

We report an observation of the Rossiter-McLaughlin (RM) effect of the transiting planet HD 93963 Ac, a mini-Neptune planet orbiting a G0-type star with an orbital period of $P_{\r…

astro-ph.EP2025

TOI-6324b: An Earth-Mass Ultra-Short-Period Planet Transiting a Nearby M Dwarf

Rena A. Lee, Fei Dai, Andrew W. Howard +71

We report the confirmation of TOI-6324 b, an Earth-sized (1.059 0.041 R) ultra-short-period (USP) planet orbiting a nearby (20 pc) M dwarf. Using the newly com…

astro-ph.EP2024

An Obliquity Measurement of the Hot Neptune TOI-1694b

Luke B. Handley, Andrew W. Howard, Ryan A. Rubenzahl +9

We present spectral observations of the multiplanet host TOI-1694 during the transit of TOI-1694b, a 26.1 hot Neptune with a 3.77-day orbit. By analyzing radial velociti…

astro-ph.EP2024

HD 119130 b is not an "ultra-dense" sub-Neptune

Joseph M. Akana Murphy, Rafael Luque, Natalie M. Batalha +13

We present a revised mass measurement for HD 119130 b (aka K2-292 b), a transiting planet ( days, ) orbiting a chro…

astro-ph.EP2024★ 1 cited

The Compositions of Rocky Planets in Close-in Orbits Tend to be Earth-Like

Casey L. Brinkman, Lauren M. Weiss, Daniel Huber +54

Hundreds of exoplanets between 1-1.8 times the size of the Earth have been discovered on close in orbits. However, these planets show such a diversity in densities that some appear…

astro-ph.EP2024

A Larger Sample Confirms Small Planets Around Hot Stars Are Misaligned

Emma M. Louden, Songhu Wang, Joshua N. Winn +7

The distribution of stellar obliquities provides critical insight into the formation and evolution pathways of exoplanets. In the past decade, it was found that hot stars hosting h…

astro-ph.IM2024★ 2 cited

Automated Scheduling of Doppler Exoplanet Observations at Keck Observatory

Luke B. Handley, Erik A. Petigura, Velibor V. Misic +2

Precise Doppler studies of extrasolar planets require fine-grained control of observational cadence, i.e. the timing of and spacing between observations. We present a novel framewo…

astro-ph.IM2023

Solving the Traveling Telescope Problem with Mixed Integer Linear Programming

Luke B. Handley, Erik A. Petigura, Velibor V. Misic

The size and complexity of modern astronomical surveys has grown to the point where, in many cases, traditional human scheduling of observations are tedious at best and impractical…