Zobrazeno 1 - 10
of 22
pro vyhledávání: '"Shibata, Kazunari"'
Autor:
Ikuta, Kai, Shibata, Kazunari
Flares are intense explosions on the solar and stellar surfaces, and solar flares are sometimes accompanied by filament or prominence eruptions. Recently, a large filament eruption associated with a superflare on a solar-type star EK Dra was discover
Externí odkaz:
http://arxiv.org/abs/2401.04279
Autor:
Namekata, Kosuke, Airapetian, Vladimir S., Petit, Pascal, Maehara, Hiroyuki, Ikuta, Kai, Inoue, Shun, Notsu, Yuta, Paudel, Rishi R., Arzoumanian, Zaven, Avramova-Boncheva, Antoaneta A., Gendreau, Keith, Jeffers, Sandra V., Marsden, Stephen, Morin, Julien, Neiner, Coralie, Vidotto, Aline A., Shibata, Kazunari
Young solar-type stars frequently produce superflares, serving as a unique window into the young Sun-Earth environments. Large solar flares are closely linked to coronal mass ejections (CMEs) associated with filament/prominence eruptions, but its obs
Externí odkaz:
http://arxiv.org/abs/2311.07380
Autor:
Notsu, Yuta, Kowalski, Adam F., Maehara, Hiroyuki, Namekata, Kosuke, Hamaguchi, Kenji, Enoto, Teruaki, Tristan, Isaiah I., Hawley, Suzanne L., Davenport, James R. A., Honda, Satoshi, Ikuta, Kai, Inoue, Shun, Namizaki, Keiichi, Nogami, Daisaku, Shibata, Kazunari
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 3.5m and Small \& Moderate A
Externí odkaz:
http://arxiv.org/abs/2310.02450
Autor:
Ikuta, Kai, Namekata, Kosuke, Notsu, Yuta, Maehara, Hiroyuki, Okamoto, Soshi, Honda, Satoshi, Nogami, Daisaku, Shibata, Kazunari
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 between spot location
Externí odkaz:
http://arxiv.org/abs/2302.09249
Autor:
Namekata, Kosuke, Maehara, Hiroyuki, Honda, Satoshi, Notsu, Yuta, Nogami, Daisaku, Shibata, Kazunari
Solar flares are often accompanied by filament/prominence eruptions, sometimes leading to coronal mass ejections (CMEs). By analogy, we expect that stellar flares are also associated with stellar CMEs whose properties are essential to know the impact
Externí odkaz:
http://arxiv.org/abs/2211.05506
Autor:
Namekata, Kosuke, Maehara, Hiroyuki, Honda, Satoshi, Notsu, Yuta, Okamoto, Soshi, Takahashi, Jun, Takayama, Masaki, Ohshima, Tomohito, Saito, Tomoki, Katoh, Noriyuki, Tozuka, Miyako, Murata, Katsuhiro L., Ogawa, Futa, Niwano, Masafumi, Adachi, Ryo, Oeda, Motoki, Shiraishi, Kazuki, Isogai, Keisuke, Nogami, Daisaku, Shibata, Kazunari
Young solar-type stars are known to show frequent "superflares", which may severely influence the habitable worlds on young planets via intense radiations and coronal mass ejections. Here we report an optical spectroscopic and photometric observation
Externí odkaz:
http://arxiv.org/abs/2201.09416
Autor:
Namekata, Kosuke, Maehara, Hiroyuki, Honda, Satoshi, Notsu, Yuta, Okamoto, Soshi, Takahashi, Jun, Takayama, Masaki, Ohshima, Tomohito, Saito, Tomoki, Katoh, Noriyuki, Tozuka, Miyako, Murata, Katsuhiro L., Ogawa, Futa, Niwano, Masafumi, Adachi, Ryo, Oeda, Motoki, Shiraishi, Kazuki, Isogai, Keisuke, Seki, Daikichi, Ishii, Takako T., Ichimoto, Kiyoshi, Nogami, Daisaku, Shibata, Kazunari
Solar flares are often accompanied by filament/prominence eruptions ($\sim10^{4}$ K and $\sim 10^{10-11}$ cm$^{-3}$), sometimes leading to coronal mass ejections (CMEs) that directly affect the Earth's environment. `Superflares' are found on some act
Externí odkaz:
http://arxiv.org/abs/2112.04808
Autor:
Okamoto, Soshi, Notsu, Yuta, Maehara, Hiroyuki, Namekata, Kosuke, Honda, Satoshi, Ikuta, Kai, Nogami, Daisaku, Shibata, Kazunari
We report the latest statistical analyses of superflares on solar-type (G-type main-sequence; effective temperature is 5100 - 6000 K) stars using all of the $Kepler$ primary mission data, and $Gaia$-DR2 (Data Release 2) catalog. We updated the flare
Externí odkaz:
http://arxiv.org/abs/2011.02117
Autor:
Ikuta, Kai, Maehara, Hiroyuki, Notsu, Yuta, Namekata, Kosuke, Kato, Taichi, Notsu, Shota, Okamoto, Soshi, Honda, Satoshi, Nogami, Daisaku, Shibata, Kazunari
Starspots are thought to be regions of locally strong magnetic fields, similar to sunspots, and they can generate photometric brightness modulations. To deduce stellar and spot properties, such as spot emergence and decay rates, we implement computat
Externí odkaz:
http://arxiv.org/abs/2008.05478
Autor:
Namekata, Kosuke, Maehara, Hiroyuki, Sasaki, Ryo, Kawai, Hiroki, Notsu, Yuta, Kowalski, Adam F., Allred, Joel C., Iwakiri, Wataru, Tsuboi, Yohko, Murata, Katsuhiro L., Niwano, Masafumi, Shiraishi, Kazuki, Adachi, Ryo, Iida, Kota, Oeda, Motoki, Honda, Satoshi, Tozuka, Miyako, Katoh, Noriyuki, Onozato, Hiroki, Okamoto, Soshi, Isogai, Keisuke, Kimura, Mariko, Kojiguchi, Naoto, Wakamatsu, Yasuyuki, Tampo, Yusuke, Nogami, Daisaku, Shibata, Kazunari
We report multi-wavelength monitoring observations of an M-dwarf flare star AD Leonis with Seimei Telescope (6150--7930 {\AA}), SCAT (Spectroscopic Chuo-university Astronomical Telescope; 3700--7500 {\AA}), NICER (Neutron Star Interior Composition Ex
Externí odkaz:
http://arxiv.org/abs/2005.04336