75 citations · 1.3k across the 58 of their papers we have counts for
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Near-infrared spectra of chemically peculiar stars and applications to kilonova spectra
Nanae Domoto, Masaomi Tanaka, Wako Aoki +11
Kilonova spectra provide information on rapid neutron-capture nucleosynthesis in neutron star mergers. However, it remains challenging to identify individual elements in kilonova s…
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…
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…
Elemental abundances of 44 very metal-poor stars determined from Subaru/IRD near-infrared spectra
Wako Aoki, Timothy C. Beers, Satoshi Honda +12
Abundances of five elements, Na, Mg, Al, Si, and Sr, are investigated for 44 very metal-poor stars (-4.0 < [Fe/H] < -1.5) in the Galactic halo system based on an Local Thermodinami…
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…
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…
Photospheric nitrogen abundances and carbon 12C/13C ratios of red giant stars
Yoichi Takeda, Masashi Omiya, Hiroki Harakawa +1
Nitrogen abundances and carbon isotope ratios (12C/13C) in the atmospheres of red giants are known to be influenced by dredge-up of H-burning products and serve as useful probes to…
Sulfur and zinc abundances of red giant stars
Yoichi Takeda, Masashi Omiya, Hiroki Harakawa +1
Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants havi…
Sodium Absorption Systems toward SN Ia 2014J Originate on Interstellar Scales
K. Maeda, A. Tajitsu, K. S. Kawabata +21
Na I D absorbing systems toward Type Ia supernovae (SNe Ia) have been intensively studied over the last decade with the aim of finding circumstellar material (CSM), which is an ind…
Can surface oxygen abundances of red giants be explained by the canonical mixing theory?
Yoichi Takeda, Bun'ei Sato, Masashi Omiya +1
Extensive oxygen abundance determinations were carried out for 239 late-G/early-K giant stars of 1.5-5 M_sun by applying the spectrum-fitting technique to O I 7771-5 and [O I] 6300…
A Long-period Eccentric Substellar Companion to the Evovled Intermediate-Mass Star HD 14067
Liang Wang, Bunei Sato, Masashi Omiya +14
We report the detection of a substellar companion orbiting an evolved intermediate-mass () star HD 14067 (G9 III) using precise Doppler technique. Radial velo…