Survey of active solar-type stars with the wide-filed photometric observations and archival data

2016 Fiscal Year Final Research Report

• Project/Area Number: 26800096
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Maehara Hiroyuki 国立天文台, 岡山天体物理観測所, 専門研究職員 (40456851)
• Research Collaborator: Shibata Kazunari 京都大学, 大学院理学研究科, 教授 (70144178) ; Nogami Daisaku 京都大学, 大学院理学研究科, 准教授 (20332728) ; Honda Satoshi 兵庫県立大学, 天文科学センター, 特任助教 (20425408)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 恒星フレア

Outline of Final Research Achievements

Previous studies by using the data from Kepler suggest that a part of solar-type stars with the rotation period comparable to the Sun (~25 days) show much higher magnetic activity (e.g., superflares). We studied the rotation period distribution of the solar-type stars with high X-ray luminosity from grand-based photometric and spectroscopic observations. We found that some of active solar-type stars have the rotation velocity of < 5 km/s.
We also studied the statistical properties of superflares on active solar-type stars by using the Kepler 1-min cadence data. We found a clear correlation between the duration of flares and the energy released by flares. This correlation can be explained if we assume that flares are caused by the magnetic reconnection.

Free Research Field

光赤外線天文学