75 citations · 421 across the 15 of their papers we have counts for
15 papers
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 Discovery and Follow-up of Four Transiting Short-period Sub-Neptunes Orbiting M dwarfs
Y. Hori, A. Fukui, T. Hirano +100
Sub-Neptunes with are intermediate in size between rocky planets and Neptune-sized planets. The orbital properties and bulk compositions of transiting sub-Neptunes pr…
Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program
Taichi Uyama, Charles Beichman, Masayuki Kuzuhara +32
The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late…
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…
Silicon and Strontium abundances of very metal-poor stars determined from near-infrared spectra
Wako Aoki, Timothy C. Beers, Satoshi Honda +19
Silicon and Strontium are key elements to explore the nucleosynthesis and chemical evolution of the Galaxy by measurements of very metal-poor stars. There are, however, only a few…
Zodiacal Exoplanets in Time (ZEIT) XIII: Planet Orbits and Atmospheres in the V1298 Tau System, a Keystone in Studies of Early Planetary Evolution
E. Gaidos, T. Hirano, C. Beichman +16
Studies of planetary systems of stars in star-forming regions and young clusters open a window on the formative stages of planetary evolution. We obtained high-cadence high-resolut…
First Detection of Hydroxyl Radical Emission from an Exoplanet Atmosphere: High-dispersion Characterization of WASP-33b using Subaru/IRD
Stevanus K. Nugroho, Hajime Kawahara, Neale P. Gibson +23
We report the first detection of a hydroxyl radical (OH) emission signature in the planetary atmosphere outside the solar system, in this case, in the day-side of WASP-33b. We anal…
Neutral metals in the atmosphere of HD149026b
Masato Ishizuka, Hajime Kawahara, Stevanus K. Nugroho +3
Recent progress in high-dispersion spectroscopy has revealed the presence of vaporized heavy metals and ions in the atmosphere of hot Jupiters whose dayside temperature is larger t…
Precision radial velocity measurements by the forward-modeling technique in the near-infrared
Teruyuki Hirano, Masayuki Kuzuhara, Takayuki Kotani +15
Precision radial velocity (RV) measurements in the near-infrared are a powerful tool to detect and characterize exoplanets around low-mass stars or young stars with higher magnetic…
Zodiacal Exoplanets in Time. XI. The Orbit and Radiation Environment of the Young M Dwarf-Hosted Planet K2-25b
E. Gaidos, T. Hirano, D. J. Wilson +20
M dwarf stars are high-priority targets for searches for Earth-size and potentially Earth-like planets, but their planetary systems may form and evolve in very different circumstel…
Limits on the Spin-Orbit Angle and Atmospheric Escape for the 22 Myr-old Planet AU Mic b
Teruyuki Hirano, Vigneshwaran Krishnamurthy, Eric Gaidos +19
We obtained spectra of the pre-main sequence star AU Microscopii during a transit of its Neptune-sized planet to investigate its orbit and atmosphere. We used the high-dispersion n…
Zodiacal Exoplanets in Time. X. The Orbit and Atmosphere of the Young "Neptune Desert"-Dwelling Planet K2-100b
E. Gaidos, T. Hirano, A. W. Mann +17
We obtained high-resolution infrared spectroscopy and short-cadence photometry of the 600-800 Myr Praesepe star K2-100 during transits of its 1.67-day planet. This Neptune-size obj…
Evidence for Spin-orbit Alignment in the TRAPPIST-1 System
Teruyuki Hirano, Eric Gaidos, Joshua N. Winn +21
In an effort to measure the Rossiter-McLaughlin effect for the TRAPPIST-1 system, we performed high-resolution spectroscopy during transits of planets e, f, and b. The spectra were…
Fiber mode scrambler for the Subaru infrared Doppler instrument (IRD)
Masato Ishizuka, Takayuki Kotani, Jun Nishikawa +4
We report the results of fiber mode scrambler experiments for the Infra-Red Doppler instrument (IRD) on the Subaru 8.2-m telescope. IRD is a fiber-fed, high precision radial veloci…
Constraining accretion signatures of exoplanets in the TW Hya transitional disk
Taichi Uyama, Takayuki Tanigawa, Jun Hashimoto +4
We present a near-infrared direct imaging search for accretion signatures of possible protoplanets around the young stellar object (YSO) TW Hya, a multi-ring disk exhibiting eviden…