Publications (23)
Solar twins in Gaia DR3 GSP-Spec II. Age distribution and its implications for the Sun's migration
Takuji Tsujimoto, Daisuke Taniguchi, Alejandra Recio-Blanco +2
Solar twins are among the most powerful tracers of Galactic disk evolution owing to their unique property of sharing nearly solar metallicities ([Fe/H] ~ 0) while spanning a wide r…
UBVRI photometry of Betelgeuse over 23 years since 1999
Yojiro Ogane, Osamu Ohshima, Daisuke Taniguchi +1
We report the results of our continuous UBVRI-band photometry of Betelgeuse from 1999 to 2022 using the same photometric system. There are two advantages in our observation: (1) we…
The Great Dimming of Betelgeuse seen by the Himawari-8 meteorological satellite
Daisuke Taniguchi, Kazuya Yamazaki, Shinsuke Uno
Betelgeuse, one of the most studied red supergiant stars, dimmed in the optical by ~1.2 mag between late 2019 and early 2020, reaching an historical minimum called "the Great Dimmi…
Pressure-induced two-step spin crossover in double-layered elastic model
Daisuke Taniguchi, Jun Okabayashi, Chisa Hotta
We study the two-step spin crossover in a double-layered elastic model based on transition metal complexes each taking high spin (HS) and low spin (LS) states. Here, only the simpl…
Discovery of WINERED-HVS1: A metal-rich hyper-velocity star candidate ejected from the Galactic center
Kohei Hattori, Daisuke Taniguchi, Takuji Tsujimoto +4
We report the discovery of a metal-rich red giant star, WINERED-HVS1, which is a candidate for a hyper-velocity star (HVS). Its past trajectory suggests that this star may have bee…
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…
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…
Detection of diffusion anisotropy from an individual short particle trajectory
Kaito Takanami, Daisuke Taniguchi, Sawako Enoki +3
In parallel with advances in microscale imaging techniques, the fields of biology and materials science have focused on precisely extracting particle properties based on their diff…
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 spec…
Method to Estimate the Effective Temperatures of Late-Type Giants using Line-Depth Ratios in the Wavelength Range 0.97-1.32m
Daisuke Taniguchi, Noriyuki Matsunaga, Naoto Kobayashi +7
The effective temperature, one of the most fundamental atmospheric parameters of a star, can be estimated using various methods, and here we focus on the method using line-depth ra…
Kinematical and dynamical properties of recently discovered bulge and disc star clusters with WINERED
Ilaria Petralia, Dante Minniti, José G. Fernández-Trincado +8
Context. Galactic globular clusters are a very important tool in explaining the characteristics of the Milky Way. Therefore it is essential to determine the kinematical and dynamic…
Solar twins in Gaia DR3 GSP-Spec I. Building a large catalog of Solar twins with ages
Daisuke Taniguchi, Patrick de Laverny, Alejandra Recio-Blanco +2
[Abbreviated] Context. Solar twins, stars whose stellar parameters (Teff, log g, and [M/H]) are very close to the Solar ones, offer a unique opportunity to investigate Galactic arc…
FeI lines in 0.91-1.33 m spectra of red giants for measuring the microturbulence and metallicities
Sohei Kondo, Kei Fukue, Noriyuki Matsunaga +16
For a detailed analysis of stellar chemical abundances, high-resolution spectra in the optical have mainly been used, while the development of near-infrared (NIR) spectrograph has…
Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97--1.32 Micron
Noriyuki Matsunaga, Daisuke Taniguchi, Mingjie Jian +13
Stellar absorption lines of heavy elements can give us various insights into the chemical evolution of the Galaxy and nearby galaxies. Recently developed spectrographs for the near…
High-Precision Near-Infrared Abundances of Solar Analogs in the YJ Bands
Noriyuki Matsunaga, Takuji Tsujimoto, Daisuke Taniguchi +12
We present a near-infrared abundance analysis of 46 solar analogs with known ages, observed with the WINERED WIDE-mode spectrograph at a resolution of . Using an e…
MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project I. Establishment of an abundance analysis procedure for red supergiants and its evaluation with nearby stars
Daisuke Taniguchi, Noriyuki Matsunaga, Naoto Kobayashi +11
[Abbreviated] Context. Given their high luminosities (L>~10^4Lsun), red supergiants (RSGs) are good tracers of the chemical abundances of the young stellar population in the Milky…
Stellar population astrophysics (SPA) with the TNG: Measurement of the He I 10830Ã line in the open cluster Stock 2
Mingjie Jian, Xiaoting Fu, Noriyuki Matsunaga +10
The precise measurement of stellar abundances plays a pivotal role in providing constraints on the chemical evolution of the Galaxy. However, before spectral lines can be employed…
Possible progression of mass flow processes around young intermediate-mass stars based on high-resolution near-infrared spectroscopy. I. Taurus
Chikako Yasui, Satoshi Hamano, Kei Fukue +12
We used the WINERED spectrograph to perform near-infrared high-resolution spectroscopy (resolving power ,000) of 13 young intermediate-mass stars in the Taurus star-forming…
Correction of near-infrared high-resolution spectra for telluric absorption at 0.90-1.35 microns
Hiroaki Sameshima, Noriyuki Matsunaga, Naoto Kobayashi +15
We report a method of correcting a near-infrared (0.90-1.35 m) high-resolution () spectrum for telluric absorption using the corresponding spectrum of a tell…
Clues to growth and disruption of two neighbouring spiral arms of the Milky Way
Natsuki Funakoshi, Noriyuki Matsunaga, Daisuke Kawata +3
Studying the nature of spiral arms is essential for understanding the formation of the intricate disc structure of the Milky Way. The European Space Agency's Gaia mission has provi…
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…
Line-depth ratios as indicators of effective temperature and surface gravity
Noriyuki Matsunaga, Mingjie Jian, Daisuke Taniguchi +1
The analysis of stellar spectra depends upon the effective temperature (Teff) and the surface gravity (log g). However, the estimation of log g with high accuracy is challenging. A…
The effect of surface gravity on line-depth ratios in the wavelength range 0.97-1.32 μm
Mingjie Jian, Daisuke Taniguchi, Noriyuki Matsunaga +10
A line-depth ratio (LDR) of two spectral lines with different excitation potentials is expected to be correlated with the effective temperature (). It is possible t…