82 citations · 674 across the 46 of their papers we have counts for
49 papers
Photometric and Spectroscopic Observations of Comet 2P/Encke's Nucleus in the Mid-Infrared Wavelength Region
Takafumi Ootsubo, Hideyo Kawakita, Jun-ichi Watanabe +2
We observed comet 2P/Encke with the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on the Subaru telescope on UT 2003 November 12.3, when the comet was at heliocentric and ge…
High-resolution optical spectroscopy reveals the distinctive volatile composition of the interstellar comet 3I/ATLAS
K. Aravind, E. Jehin, C. Opitom +9
Comets preserve volatile material from the early stages of planetary-system formation. The discovery of the interstellar comet 3I/ATLAS enables a direct comparison between a comet…
IFU Observations of Comet 3I/ATLAS = C/2025 N1 (ATLAS) using the Hobby-Eberly Telescope with the VIRUS Instrument
Anita Cochran, Gregory Zeimann, Emmanuel Jehin +2
We observed interstellar object 3I/ATLAS = C/2025 N1 (ATLAS) on 9 December 2025 UT with the VIRUS spectrograph on the Hobby-Eberly Telescope. VIRUS is a low spectral resolving powe…
Opposition effect of comet 28P/Neujmin observed with Subaru Hyper Suprime-Cam
Takafumi Ootsubo, Hideyo Kawakita, Tadafumi Takata +8
We present an observational study of the nucleus of comet 28P/Neujmin at a heliocentric distance exceeding 10 au, where coma contamination is effectively minimized. Observations we…
A post-perihelion constraint on the CO/HO ratio of interstellar comet 3I/ATLAS from [O I] forbidden lines
Yoshiharu Shinnaka, Ko Tsujimoto, Hideyo Kawakita +3
We present high-resolution optical spectroscopy of interstellar comet 3I/ATLAS (C/2025 N1) obtained with the High Dispersion Spectrograph mounted on the Subaru Telescope on UT 2026…
Coma Volatile Composition and Thermal Physics in Comet C/2022 E3 (ZTF) Measured Near Closest Approach to Earth with NASA-IRTF
Nathan X. Roth, Michael A. DiSanti, Boncho P. Bonev +9
The 2023 perihelion passage of comet C/2022 E3 (ZTF) afforded an opportunity to measure the abundances and spatial distributions of coma volatiles in an Oort cloud comet at high sp…
Considerations on the process of target selection for the Comet Interceptor mission
C. Snodgrass, E. Mazzotta Epifani, C. Tubiana +27
Comet Interceptor is an ESA science mission with payload contributions from ESA Member States and with an international participation by JAXA. It is the first mission that is being…
Infrared Compositional Measurements in Comet C/2017 K2 (Pan-STARRS) at Heliocentric Distances Beyond 2.3 AU
Chemeda Ejeta, Erika Gibb, Michael A. DiSanti +11
Comet C/2017 K2 (Pan-STARRS) provided a rare opportunity to investigate the evolution of coma composition and outgassing patterns over a transitional heliocentric distance (Rh) ran…
[N I] 10400/10410 Å Lines as Possible Disk Wind Tracers in a Young Intermediate-Mass Star
Haruki Katoh, Chikako Yasui, Yuji Ikeda +10
In this study, we performed high-resolution near-infrared (NIR) spectroscopy (R = 28,000; -1.35 m) with a high signal-to-noise ratio on HD 200775, a very young (${\sim…
First Result for Dark Matter Search by WINERED
Wen Yin, Taiki Bessho, Yuji Ikeda +10
The identity of dark matter has been a mystery in astronomy, cosmology, and particle theory for about a century. Bessho, Ikeda, and Yin (2022), three of the current authors, propos…
A High-Resolution Non-Detection of Escaping Helium In The Ultra-Hot Neptune LTT 9779b: Evidence for Weakened Evaporation
Shreyas Vissapragada, Patrick McCreery, Leonardo A. Dos Santos +16
The recent discovery of ``ultra-hot'' ( day) Neptunes has come as a surprise: some of these planets have managed to retain gaseous envelopes despite being close enough to th…
WARP: The Data Reduction Pipeline for the WINERED spectrograph
Satoshi Hamano, Yuji Ikeda, Shogo Otsubo +8
We present a data reduction pipeline written in Python for data obtained with the near-infrared cross-dispersed echelle spectrograph, WINERED, which yields a 0.911.35 m spect…
The globular cluster VVV CL002 falling down to the hazardous Galactic centre
D. Minniti, N. Matsunaga, J. G. Fernandez-Trincado +15
Context. The Galactic centre is hazardous for stellar clusters because of the strong tidal force. Supposedly, many clusters were destroyed and contributed stars to the crowded stel…
Shock Excitation in Narrow Line Regions Powered by AGN Outflows
Misaki Mizumoto, Hiroaki Sameshima, Naoto Kobayashi +10
Outflows in the Active Galactic Nucleus (AGN) are considered to play a key role in the host galaxy evolution through transfer of a large amount of energy. A Narrow Line Region (NLR…
Metallicities of Classical Cepheids in the Inner Galactic Disk
N. Matsunaga, D. Taniguchi, S. S. Elgueta +14
Metallicity gradients refer to the sloped radial profile of metallicities of gas and stars and are commonly seen in disk galaxies. A well-defined metallicity gradient of the Galact…
Astrophysical calibration of the oscillator strengths of YJ-band absorption lines in classical Cepheids
S. S. Elgueta, N. Matsunaga, M. Jian +13
Newly-developed spectrographs with increased resolving powers, particularly those covering the near-IR range, allow the characterization of more and more absorption lines in stella…
Survey of near-infrared diffuse interstellar bands in and bands. I. Newly identified bands
Satoshi Hamano, Naoto Kobayashi, Hideyo Kawakita +12
We searched for diffuse interstellar bands (DIBs) in the 0.911.33 m region by analyzing the near-infrared (NIR) high-resolution ( and 28,000) spectra of 31 redden…
A Very Metal-poor RR Lyrae Star with a Disk Orbit Found in the Solar Neighborhood
Noriyuki Matsunaga, Akinori Itane, Kohei Hattori +28
Metal-deficient stars are important tracers for understanding the early formation of the Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have report…
Detection of Be II in the Classical Nova V5669 Sgr (Nova Sagittarii 2015 No.3)
Akira Arai, Akito Tajitsu, Hideyo Kawakita +1
We report the new detection of Be II in the ultraviolet spectra of V5669 Sgr during its early decline phase ( and d). We identified three blue-shifted absorption sys…
The similarity of the interstellar comet 2I/Borisov to solar system comets from high resolution optical spectroscopy
C. Opitom, E. Jehin, D. Hutsemékers +11
2I/Borisov - hereafter 2I - is the first visibly active interstellar comet observed in the solar system, allowing us for the first time to sample the composition of a building bloc…
Absorption Lines in the 0.91-1.33 m Spectra of Red Giants for Measuring Abundances of Mg, Si, Ca, Ti, Cr, and Ni
K. Fukue, N. Matsunaga, S. Kondo +13
Red giants show a large number of absorption lines in both optical and near-infrared wavelengths. Still, the characteristics of the lines in different wave passbands are not necess…
Mid-infrared observations of the nucleus of comet P/2016 BA14 (PANSTARRS)
Takafumi Ootsubo, Hideyo Kawakita, Yoshiharu Shinnaka
We present mid-infrared observations of comet P/2016 BA14 (PANSTARRS), which were obtained on UT 2016 March 21.3 at heliocentric and geocentric distances of 1.012 au and 0.026 au,…
Effective temperatures of red supergiants estimated from line-depth ratios of iron lines in the YJ bands, 0.97--1.32 micron
Daisuke Taniguchi, Noriyuki Matsunaga, Mingjie Jian +10
Determining the effective temperatures (Teff) of red supergiants (RSGs) observationally is important in many fields of stellar physics and galactic astronomy, yet some significant…
Mg II and Fe II fluxes of luminous quasars at z ~ 2.7 and evaluation of the Baldwin effect in the flux-to-abundance conversion method for quasars
Hiroaki Sameshima, Yuzuru Yoshii, Noriyuki Matsunaga +12
To investigate the chemical abundance of broad-line region clouds in quasars at high redshifts, we performed near-infrared spectroscopy of six luminous quasars at z ~ 2.7 with the…