Solar flares are caused by the sudden release of magnetic energy stored near sunspots. They release 10(29) to 10(32) ergs of energy on a timescale of hours(1). Similar flares have been observed on many stars, with larger 'superflares' seen on a va...
Y. Moritani D. Nogami A. T. Okazaki A. Imada E. Kambe S. Honda O. Hashimoto K. Ichikawa
CIRCUMSTELLAR DYNAMICS AT HIGH RESOLUTION 464 285-+ 2012年 [査読有り]
The famous Be/X-ray binary A 0535 + 262/V725 Tau stayed in outburst phase from 2008 to 2011, emitting several X-ray outbursts including the two giant outbursts in November/December 2009 and February 2011. We carried out a high-dispersion spectrosc...
Proceedings of the International Astronomical Union 8(293) 393-395 2012年 [査読有り]
We present the results of an extensive survey of superflares on late-type stars (G, K, and M-type main sequence stars) using the Kepler satellite data. Wefound about 6,800 superflares on late-type stars from the data of about 120,000 stars observe...
Y. Moritani D. Nogami A. T. Okazaki A. Imada E. Kambe S. Honda O. Hashimoto Y. Ishino Y. Suzuki J. Tanaka
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 405(1) 467-476 2010年6月 [査読有り]
We report on optical high-dispersion spectroscopic monitoring observations of the Be/X-ray binary A0535+26/V725 Tau, carried out from 2005 November to 2009 March. The main aim of these monitoring observations is to study spectral variabilities in ...
Yuta Notsu Adam F. Kowalski Hiroyuki Maehara Kosuke Namekata Satoshi Honda Teruaki Enoto Kenji Hamaguchi Isaiah Tristan Suzanne L. Hawley James R. A. Davenport Soshi Okamoto Kai Ikuta Daisaku Nogami Kazunari Shibata
2021年7月
Flares are releases of magnetic energy in the stellar atmosphere, and they have strong emissions from radio to X-rays. During some M dwarf flares, chromospheric line profiles show blue asymmetries, although red asymmetries are more commonly observ...
Solar and stellar flares are caused by the sudden release of magnetic energy on the surfaces. In the case of the Sun, mass ejections often accompany solar flares and affect the Earth’s environment. Active solar-type stars (G-type main-sequence sta...
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自然・環境科学研究所