60 citations · 247 across the 25 of their papers we have counts for
26 papers
Transiting Planetary Systems with Distant Giant Companions Remain Moderately Coplanar
Guang-Yao Xiao, Huan-Yu Teng, Xiumin Huang +4
The mutual inclination between inner planets and distant giant companions provides an important probe of planetary system formation and dynamical evolution, yet direct measurements…
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…
A Search for helium in the atmospheres of three sub-Neptunes and a super-Earth around M-dwarfs
Kiyoe Kawauchi, Norio Narita, Yuichi Ito +26
Thousands of sub-Neptunes have been discovered mainly through space-based surveys such as Kepler and TESS. Their bulk compositions and internal structures are thought to reflect th…
A Search for Exoplanets around Northern Circumpolar Stars X. The origin of radial velocity variations in the evolved star HD 216595
Sang-Hee Kim, Byeong-Cheol Lee, Shenghong Gu +9
Detecting planetary companions around evolved stars, particularly asymptotic giant branch (AGB) stars, is challenging due to intrinsic stellar variability such as surface convectio…
The 3D Architecture of a pair of 6:1 Resonant Brown Dwarfs around the Naked-eye star Ophiuchi
Tianshenhong Sang, Guang-Yao Xiao, Ying-Yi Cao +8
We present a revisiting study of the brown dwarf pair orbiting the naked-eye () K-giant ~Ophiuchi, located only 44\,pc from our Solar system. By jointly analysing archiva…
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…
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…
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…
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…
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…
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…
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…
The mass determination of TOI-519 b: a close-in giant planet transiting a metal-rich mid-M dwarf
Taiki Kagetani, Norio Narita, Tadahiro Kimura +33
We report the mass determination of TOI-519 b, a transiting substellar object around a mid-M dwarf. We carried out radial velocity measurements using Subaru / InfraRed Doppler (IRD…
The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements
Guang-Yao Xiao, Yu-Juan Liu, Huan-Yu Teng +6
Being one of the most fundamental physical parameter of astronomical objects, mass plays a vital role in the study of exoplanets, including their temperature structure, chemical co…
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…
TOI-1696: a nearby M4 dwarf with a planet in the Neptunian desert
Mayuko Mori, John H. Livingston, Jerome de Leon +59
We present the discovery and validation of a temperate sub-Neptune around the nearby mid-M dwarf TIC 470381900 (TOI-1696), with a radius of and an orbita…
Validation and atmospheric exploration of the sub-Neptune TOI-2136b around a nearby M3 dwarf
K. Kawauchi, F. Murgas, E. Palle +51
The NASA space telescope is currently in the extended mission of its all-sky search for new transiting planets. Of the thousands of candidates that TESS is expected to deliv…
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…
Testing backreaction effects with observational Hubble parameter data
Shu-Lei Cao, Huan-Yu Teng, Hao-Ran Yu +2
In order to explore the generic properties of a backreaction model for explaining the accelerated expansion of the Universe, we exploit two metrics to describe the late time Univer…
Cosmological neutrino simulations at extreme scale
J. D. Emberson, Hao-Ran Yu, Derek Inman +8
Constraining neutrino mass remains an elusive challenge in modern physics. Precision measurements are expected from several upcoming cosmological probes of large-scale structure. A…