Huan-Yu Teng   Bun’ei Sato   Masayuki Kuzuhara   Takuya Takarada   Masashi Omiya   Hiroki Harakawa   Hideyuki Izumiura   Eiji Kambe   Mesut Yilmaz   Ilfan Bikmaev   Selim O Selam   Timothy D Brandt   Guang-Yao Xiao   Michitoshi Yoshida   Yoichi Itoh   Hiroyasu Ando   Eiichiro Kokubo   Shigeru Ida   
Publications of the Astronomical Society of Japan 2023年9月
Abstract
In this study, we revisit 32 planetary systems around evolved stars observed within the framework of the Okayama Planet Search Program (OPSP) and its collaborative framework of the East Asian Planet Search Network to search for addition...
Huan-Yu Teng   Bun'ei Sato   Masanobu Kunitomo   Takuya Takarada   Masashi Omiya   Hiroki Harakawa   Guang-Yao Xiao   Yu-Juan Liu   Hideyuki Izumiura   Eiji Kambe   Michitoshi Yoshida   Yoichi Itoh   Hiroyasu Ando   Eiichiro Kokubo   Shigeru Ida   
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN 75(1) 169-176 2023年2月
We report the detection of a giant planet orbiting the G-type giant star HD 167768 from radial velocity measurements using the High Dispersion Echelle Spectrograph (HIDES) at Okayama Astrophysical Observatory (OAO). HD 167768 has a mass of 1.08(-0...
“Changing-look active galactic nuclei” (CLAGNs) are known to change their apparent types between types 1 and 2, usually accompanied by a drastic change in their luminosity on timescales of years. However, it is still unclear whether mat...
Huan-Yu Teng   Bun'ei Sato   Takuya Takarada   Masashi Omiya   Hiroki Harakawa   Makiko Nagasawa   Ryo Hasegawa   Hideyuki Izumiura   Eiji Kambe   Michitoshi Yoshida   Yoichi Itoh   Hiroyasu Ando   Eiichiro Kokubo   Shigeru Ida   
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN 74(6) 1309-1328 2022年12月
We report the discovery of a triple-giant-planet system around an evolved star HD 184010 (HR 7421, HIP 96016). This discovery is based on observations from Okayama Planet Search Program, a precise radial velocity survey, undertaken at Okayama Astr...
Mai Yamashita   Yoichi Itoh   Yumiko Oasa   
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN 74(6) 1295-1308 2022年12月
Zero-age main-sequence (ZAMS) stars are considered to have enormous starspots and show strong chromospheric emission lines because of their strong surface magnetic field. We discuss the dynamo activities of ZAMS stars with respect to their periodi...