collaborators

10 papers

astro-ph.EP2026

Planet-Planet Scattering Explains the Mass-Eccentricity Relation of Warm Jupiters

Jiayin Dong, Eve J. Lee, Eiichiro Kokubo +2

Warm giant planets with orbital periods of tens of days exhibit a positive correlation between mass and eccentricity. We interpret this trend as the outcome of planet-planet scatte…

astro-ph.SR2026

Unraveling Year-Long Radial Velocity Variations in Red Clump Region -- I: Comprehensive analysis of a K0 Giant star, 2 Draconis

Udomlerd Srisuchinwong, Jianzhao Zhou, Huan-Yu Teng +18

Slow-rotating evolved stars frequently exhibit radial velocity (RV) variations on annual timescales, complicated by instrumental systematics and aliasing in the one-year regime. He…

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

A Scaling Law for the Orbital Architecture of Planetary Systems Formed by Gravitational Scattering and Collisions

Eiichiro Kokubo, Haruka Hoshino, Yuji Matsumoto +1

In the standard formation models of terrestrial planets in the solar system and close-in super-Earths in non-resonant orbits recently discovered by exoplanet observations, planets…

astro-ph.EP2025

Semi-analytical model for the dynamical evolution of planetary system II: Application to systems formed by a planet formation model

Tadahiro Kimura, Eiichiro Kokubo, Yuji Matsumoto +2

The standard formation model of close-in low-mass planets involves efficient inward migration followed by growth through giant impacts after the protoplanetary gas disk disperses.…

astro-ph.EP2025

A Resonant Beginning for the Solar System Terrestrial Planets

Shuo Huang, Chris Ormel, Simon Portegies Zwart +2

In the past two decades, transit surveys have revealed a class of planets with thick atmospheres -- sub-Neptunes -- that must have completed their accretion in protoplanet disks. W…