Yuta Notsu Adam F. Kowalski Hiroyuki Maehara Kosuke Namekata Kenji Hamaguchi Teruaki Enoto Isaiah I. Tristan Suzanne L. Hawley James R. A. Davenport Satoshi Honda Kai Ikuta Shun Inoue Keiichi Namizaki Daisaku Nogami Kazunari Shibata
The Astrophysical Journal 961(2) 189-189 2024年1月
Abstract
We conducted the time-resolved simultaneous optical spectroscopic and photometric observations of mid-M-dwarf flare stars YZ CMi, EV Lac, and AD Leo. Spectroscopic observations were obtained using Apache Point Observatory 3.5 m and Smal...
Kai Ikuta Kosuke Namekata Yuta Notsu Hiroyuki Maehara Soshi Okamoto Satoshi Honda Daisaku Nogami Kazunari Shibata
The Astrophysical Journal 948(1) 64-64 2023年5月 [査読有り]
Abstract
Starspots and stellar flares are indicators of stellar magnetic activity. The magnetic energy stored around spots is thought to be the origin of flares, but the connection is not completely understood. To investigate the relation betwee...
The Astrophysical Journal 948(1) 9-9 2023年4月 [査読有り]
Abstract
Stellar coronal mass ejections (CMEs) have recently received much attention for their impacts on exoplanets and stellar evolution. Detecting prominence eruptions, the initial phase of CMEs, as the blueshifted excess component of Balmer ...
The Astrophysical Journal 945(1) 61-61 2023年3月 [査読有り]
<jats:title>Abstract</jats:title>
<jats:p>Active M-type stars are known to often produce superflares on the surface. Radiation from stellar (super)flares is important for exoplanet habitability, but the mechanisms are not well understood. In this...
Haining Li Wako Aoki Tadafumi Matsuno Qianfan Xing Takuma Suda Nozomu Tominaga Yuqin Chen Satoshi Honda Miho N. Ishigaki Jianrong Shi Jingkun Zhao Gang Zhao
The Astrophysical Journal 931(2) 147-147 2022年6月 [査読有り]
Abstract
We present homogeneous abundance analysis of over 20 elements for 385 very metal-poor (VMP) stars based on the LAMOST survey and follow-up observations with the Subaru Telescope. It is the largest high-resolution VMP sample (including 3...
Kosuke Namekata Takahito Sakaue Kyoko Watanabe Ayumi Asai Hiroyuki Maehara Yuta Notsu Shota Notsu Satoshi Honda Takako T. Ishii Kai Ikuta Daisaku Nogami Kazunari Shibata
Astrophysical Journal 851(2) 2017年12月
Recently, many superflares on solar-type stars have been discovered as white-light flares (WLFs). The statistical study found a correlation between their energies (E) and durations (τ): τ ∝ E0.39, similar to those of solar hard/soft X-ray flares, ...
Yousuke Utsumi Masaomi Tanaka Nozomu Tominaga Michitoshi Yoshida Sudhanshu Barway Takahiro Nagayama Tetsuya Zenko Kentaro Aoki Takuya Fujiyoshi Hisanori Furusawa Koji S. Kawabata Shintaro Koshida Chien-Hsiu Lee Tomoki Morokuma Kentaro Motohara Fumiaki Nakata Ryou Ohsawa Kouji Ohta Hirofumi Okita Akito Tajitsu Ichi Tanaka Tsuyoshi Terai Naoki Yasuda Fumio Abe Yuichiro Asakura Ian A. Bond Shota Miyazaki Takahiro Sumi Paul J. Tristram Satoshi Honda Ryosuke Itoh Yoichi Itoh Miho Kawabata Kumiko Morihana Hiroki Nagashima Tatsuya Nakaoka Tomohito Ohshima Jun Takahashi Masaki Takayama Wako Aoki Stefan Baar Mamoru Doi Francois Finet Nobuyuki Kanda Nobuyuki Kawai Ji Hoon Kim Daisuke Kuroda Wei Liu Kazuya Matsubayashi Katsuhiro L. Murata Hiroshi Nagai Tomoki Saito Yoshihiko Saito Shigeyuki Sako Yuichiro Sekiguchi Yoichi Tamura Masayuki Tanaka Makoto Uemura Masaki S. Yamaguchi
Publications of the Astronomical Society of Japan 69(6) 2017年12月
The first detected gravitational wave from a neutron star merger was
GW170817. In this study, we present J-GEM follow-up observations of SSS17a, an
electromagnetic counterpart of GW170817. SSS17a shows a 2.5-mag decline in the -band from 1.7 da...
Masaomi Tanaka Yousuke Utsumi Paolo A. Mazzali Nozomu Tominaga Michitoshi Yoshida Yuichiro Sekiguchi Tomoki Morokuma Kentaro Motohara Kouji Ohta Koji S. Kawabata Fumio Abe Kentaro Aoki Yuichiro Asakura Stefan Baar Sudhanshu Barway Ian A. Bond Mamoru Doi Takuya Fujiyoshi Hisanori Furusawa Satoshi Honda Yoichi Itoh Miho Kawabata Nobuyuki Kawai Ji Hoon Kim Chien-Hsiu Lee Shota Miyazaki Kumiko Morihana Hiroki Nagashima Takahiro Nagayama Tatsuya Nakaoka Fumiaki Nakata Ryou Ohsawa Tomohito Ohshima Hirofumi Okita Tomoki Saito Takahiro Sumi Akito Tajitsu Jun Takahashi Masaki Takayama Yoichi Tamura Ichi Tanaka Tsuyoshi Terai Paul J. Tristram Naoki Yasuda Tetsuya Zenko
Publications of the Astronomical Society of Japan 69(6) 2017年12月
Recent detection of gravitational waves from a neutron star (NS) merger event
GW170817 and identification of an electromagnetic counterpart provide a unique
opportunity to study the physical processes in NS mergers. To derive properties
of ejected...
Tomoki Morokuma Masaomi Tanaka Yasuyuki T. Tanaka Ryosuke Itoh Nozomu Tominaga Poshak Gandhi Elena Pian Paolo Mazzali Kouji Ohta Emiko Matsumoto Takumi Shibata Hinako Akimoto Hiroshi Akitaya Gamal B. Ali Tsutomu Aoki Mamoru Doi Nana Ebisuda Ahmed Essam Kenta Fujisawa Hideo Fukushima Shuhei Goda Yuya Gouda Hidekazu Hanayama Yasuhito Hashiba Osamu Hashimoto Kenzo Hayashida Yuichiro Hiratsuka Satoshi Honda Masataka Imai Kanichiro Inoue Michiko Ishibashi Ikuru Iwata Hideyuki Izumiura Yuka Kanda Miho Kawabata Kenji Kawaguchi Nobuyuki Kawai Mitsuru Kokubo Daisuke Kuroda Hiroyuki Maehara Hiroyuki Mito Kazuma Mitsuda Ryota Miyagawa Takeshi Miyaji Yusuke Miyamoto Kumiko Morihana Yuki Moritani Kana Morokuma-Matsui Kotone Murakami Katsuhiro L. Murata Takahiro Nagayama Kazuki Nakamura Tatsuya Nakaoka Kotaro Niinuma Takafumi Nishimori Daisaku Nogami Yumiko Oasa Tatsunori Oda Tomohito Ohshima Yoshihiko Saito Shuichiro Sakata Shigeyuki Sako Yuki Sarugaku Satoko Sawada-Satoh Genta Seino Kazuo Sorai Takao Soyano Francesco Taddia Jun Takahashi Yuhei Takagi Katsutoshi Takaki Koji Takata Ken'Ichi Tarusawa Makoto Uemura Takahiro Ui Riku Urago Kazutoshi Ushioda Jun-Ichi Watanabe Makoto Watanabe Satoshi Yamashita Kenshi Yanagisawa Yoshinori Yonekura Michitoshi Yoshida
Publications of the Astronomical Society of Japan 69(5) 2017年10月
We present monitoring campaign observations at optical and near-infrared (NIR) wavelengths for a radio-loud active galactic nucleus (AGN) at z = 0.840, SDSS J110006.07+442144.3 (hereafter, J1100+4421), which was identified during a flare phase in ...
Tadafumi Matsuno Wako Aoki Timothy C. Beers Young Sun Lee Satoshi Honda
Astronomical Journal 154(2) 2017年8月
We present elemental abundances for eight unevolved extremely metal-poor (EMP) stars with Teff 5500 K, among which seven have [Fe H] -3.5. The sample is selected from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Expl...
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