67 citations · 223 across the 19 of their papers we have counts for
19 papers
The mass of TOI-1883 b: A low density super-Neptune in the ridge regime transiting an early-M dwarf
Izuru Fukuda, Norio Narita, Akihiko Fukui +36
Recent large-scale transit surveys conducted by space telescopes such as Kepler and TESS have revealed a vast number of exoplanets, uncovering the diversity of their population. On…
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…
The mass of TOI-654 b: A short-period sub-Neptune transiting a mid-M dwarf
Kai Ikuta, Norio Narita, Takuya Takarada +40
Sub-Neptunes are small planets between the size of the Earth and Neptune. The orbital and bulk properties of transiting sub-Neptunes can provide clues for their formation and evolu…
Evolution of Accretion Disk Structure of the Black Hole X-ray Binary MAXI J1820070 during the Rebrightening Phase
Tomohiro Yoshitake, Megumi Shidatsu, Yoshihiro Ueda +18
To understand the evolution of global accretion disk structure in the ``rebrightening'' phase of MAXI J1820070, we perform a comprehensive analysis of its near infrared/optical/…
Multiwavelength Observations of the Black Hole X-ray Binary MAXI J1820070 in the Rebrightening Phase
Tomohiro Yoshitake, Megumi Shidatsu, Yoshihiro Ueda +14
We report the results of quasi-simultaneous multiwavelength (near-infrared, optical, UV, and X-ray) observations of the Galactic X-ray black hole binary MAXI J1820+070 performed in…
Atmospheric retrieval of Subaru/IRD high-resolution spectrum of the archetype T-type brown dwarf Gl 229 B
Yui Kawashima, Hajime Kawahara, Yui Kasagi +14
Brown dwarfs provide a unique opportunity to study atmospheres and their physical and chemical processes with high precision, especially in temperature ranges relevant to exoplanet…
Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
M. Kuzuhara, A. Fukui, J. H. Livingston +103
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observ…
Two long-period giant planets around two giant stars: HD 112570 and HD 154391
Guang-Yao Xiao, Huan-Yu Teng, Jianzhao Zhou +24
We present the discoveries of two giant planets orbiting the red giant branch (RGB) star HD 112570 and the red clump (RC) star HD 154391, based on the radial velocity (RV) measurem…
Revisiting Planetary Systems in Okayama Planet Search Program: A new long-period planet, RV astrometry joint analysis, and multiplicity-metallicity trend around evolved stars
Huan-Yu Teng, Bun'ei Sato, Masayuki Kuzuhara +15
In this study, we revisit 32 planetary systems around evolved stars observed within the framework of the Okayama Planet Search Program and its collaborative framework of the EAPS-N…
An Earth-sized Planet around an M5 Dwarf Star at 22 pc
Teruyuki Hirano, Fei Dai, John H. Livingston +46
We report on the discovery of an Earth-sized transiting planet () in a day orbit around K2-415 (EPIC 211414619), an M5V star at 22 pc. The pla…
A Close-in Planet Orbiting Giant Star HD 167768
Huan-Yu Teng, Bun'ei Sato, Masanobu Kunitomo +12
We report the detection of a giant planet orbiting a G-type giant star HD 167768 from radial velocity measurements using HIgh Dispersion Echelle Spectrograph (HIDES) at Okayama Ast…
A Trio of Giant Planets Orbiting Evolved Star HD 184010
Huan-Yu Teng, Bun'ei Sato, Takuya Takarada +11
We report the discovery of a triple-giant-planet system around an evolved star HD 184010 (HR 7421, HIP 96016). This discovery is based on observations from Okayama Planet Search Pr…
Direct Imaging Discovery and Dynamical Mass of a Substellar Companion Orbiting an Accelerating Hyades Sun-like Star with SCExAO/CHARIS
Masayuki Kuzuhara, Thayne Currie, Takuya Takarada +33
We present the direct-imaging discovery of a substellar companion in orbit around a Sun-like star member of the Hyades open cluster. So far, no other substellar companions have bee…
A Super-Earth Orbiting Near the Inner Edge of the Habitable Zone around the M4.5-dwarf Ross 508
Hiroki Harakawa, Takuya Takarada, Yui Kasagi +46
We report the near-infrared radial-velocity (RV) discovery of a super-Earth planet on a 10.77-day orbit around the M4.5 dwarf Ross 508 (). Using precision RVs f…
Regular Radial Velocity Variations in Nine G- and K-type Giant Stars: Eight Planets and One Planet Candidate
Huan-Yu Teng, Bun'ei Sato, Takuya Takarada +9
We report the detection of radial velocity variations in nine evolved G- and K-type giant stars. The observations were conducted at Okayama Astrophysical Observatory. Planets or pl…
J-GEM optical and near-infrared follow-up of gravitational wave events during LIGO's and Virgo's third observing run
Mahito Sasada, Yousuke Utsumi, Ryosuke Itoh +68
The Laser Interferometer Gravitational-wave Observatory Scientific Collaboration and Virgo Collaboration (LVC) sent out 56 gravitational-wave (GW) notices during the third observin…
Radial-velocity search and statistical studies for short-period planets in the Pleiades open cluster
Takuya Takarada, Bun'ei Sato, Masashi Omiya +2
We report radial-velocity search for short-period planets in the Pleiades open cluster. We observed 30 Pleiades member stars at the Okayama Astrophysical Observatory (OAO) with Hig…
Planets around the evolved stars 24 Booties and Libra: A 30d-period planet and a double giant-planet system in possible 7:3 MMR
Takuya Takarada, Bun'ei Sato, Masashi Omiya +10
We report the detection of planets around two evolved giant stars from radial velocity measurements at Okayama Astrophysical observatory. 24 Boo (G3IV) has a mass of $0.99\,M_{\odo…
Precise Radial Velocity Measurements for Kepler Giants Hosting Planetary Candidates: Kepler-91 and KOI-1894
Bun'ei Sato, Teruyuki Hirano, Masashi Omiya +6
We present results of radial-velocity follow-up observations for the two Kepler evolved stars Kepler-91 (KOI-2133) and KOI-1894, which had been announced as candidates to host tran…