69 citations · 297 across the 16 of their papers we have counts for
9 papers · 1 filter
The age and metallicity dependence of the near-infrared absolute magnitude and colour of red clump stars
Hiroki Onozato, Yoshifusa Ita, Yoshikazu Nakada
Understanding the age and metallicity dependence of the absolute magnitude and colour of red clump (RC) stars is crucial for validating the accuracy of stellar evolution models and…
The Thirty Millimeter Telescope
Yoshifusa Ita, Takashi Ichikawa, Hironori Tsutsui +11
A near-infrared telescope with an effective aperture diameter of thirty millimeters has been developed. The primary objective of the development is to observe northern bright stars…
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…
Long-Term Near-Infrared Brightening of Non-Variable OH/IR Stars
Takafumi Kamizuka, Yoshikazu Nakada, Kenshi Yanagisawa +8
Non-variable OH/IR stars are thought to have just left the asymptotic giant branch (AGB) phase. In this conventional picture, they must still show strong circumstellar extinction c…
Optical and X-ray observations of stellar flares on an active M dwarf AD Leonis with Seimei Telescope, SCAT, NICER and OISTER
Kosuke Namekata, Hiroyuki Maehara, Ryo Sasaki +24
We report multi-wavelength monitoring observations of an M-dwarf flare star AD Leonis with Seimei Telescope (6150--7930 Å), SCAT (Spectroscopic Chuo-university Astronomical Telesco…
The Age and Metallicity Dependence of the Near-Infrared Magnitudes of Red Clump Stars
Hiroki Onozato, Yoshifusa Ita, Yoshikazu Nakada +1
Red clump (RC) stars are widely used as an excellent standard candle. To make them even better, it is important to know the dependence of their absolute magnitudes on age and metal…
Discovery of carbon-rich Miras in the Galactic bulge
Noriyuki Matsunaga, John W. Menzies, Michael W. Feast +4
Only one carbon-rich (C-rich, hereinafter) Mira variable has so far been suggested as a member of the Galactic bulge and this is in a symbiotic system. Here we describe a method fo…
V5852 Sgr: An Unusual Nova Possibly Associated with the Sagittarius Stream
E. Aydi, P. Mróz, P. A. Whitelock +16
We report spectroscopic and photometric follow-up of the peculiar nova V5852~Sgr (discovered as OGLE-2015-NOVA-01), which exhibits a combination of features from different nova cla…
A Study of Mid-Infrared Sources that Dramatically Brightened
Hiroki Onozato, Yoshifusa Ita, Kenji Ono +5
We present results of near-infrared photometric and spectroscopic observations of mid-infrared (MIR) sources that dramatically brightened. Using IRAS, AKARI, and WISE point source…