A STUDY OF VARIABILITY IN THE FREQUENCY DISTRIBUTIONS OF THE SUPERFLARES OF G-TYPE STARS OBSERVED BY THE KEPLER MISSION

Journal Article · Sat Jan 10 04:00:00 EST 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/798/2/92· OSTI ID:22364644

Wu, Chi-Ju; Ip, Wing-Huen ^[1]; Huang, Li-Ching ^[2]

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1. Graduate Institute of Space Science, National Central University, Taoyuan 32001, Taiwan (China)
2. Institute of Astronomy, National Central University, Taoyuan 32001, Taiwan (China)

The energy and time profiles of 4944 superflares from 77 G-type stars with well-defined light curve periodicities from the Kepler measurements have been analyzed in detail. The total value of the power-law index of the flare frequency distribution as a function of energy (dN/dE ∝ E {sup –γ}) between 5 × 10{sup 34} and 10{sup 36} erg is on average γ = 2.04 ± 0.17, which is in agreement with previous results. The γ values of eight stars with frequent flaring activity vary between 1.59 ± 0.06 and 2.11 ± 0.19, suggesting a possible diversity of energy release effects. In general, stars with shorter rotation periods tend to have larger γ values. There is an indication that the flare energy is saturated at about 2 × 10{sup 37} erg. For a few large superflares of this energy range, it is found that their temporal behaviors could be characterized by a transition from single impulsive flares to long-duration flares composed of several flares.

• OSTI ID: 22364644
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 798; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DIAGRAMS
ENERGY DEPENDENCE
INDEXES
ROTATION
STARS
STATISTICS
STELLAR FLARES
VISIBLE RADIATION