SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER. I. STATISTICAL PROPERTIES OF SUPERFLARES

Shibayama, Takuya; Notsu, Shota; Notsu, Yuta; Nagao, Takashi; Maehara, Hiroyuki; Honda, Satoshi; Ishii, Takako T.; Nogami, Daisaku; Shibata, Kazunari

doi:10.1088/0067-0049/209/1/5

Title: SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER. I. STATISTICAL PROPERTIES OF SUPERFLARES

Full Record
Other Related Research

Abstract

By extending our previous study by Maehara et al., we searched for superflares on G-type dwarfs (solar-type stars) using Kepler data for a longer period (500 days) than that (120 days) in our previous study. As a result, we found 1547 superflares on 279 G-type dwarfs, which is much more than the previous 365 superflares on 148 stars. Using these new data, we studied the statistical properties of the occurrence rate of superflares, and confirmed the previous results, i.e., the occurrence rate (dN/dE) of superflares versus flare energy (E) shows a power-law distribution with dN/dE∝E {sup –α}, where α ∼ 2. It is interesting that this distribution is roughly similar to that for solar flares. In the case of the Sun-like stars (with surface temperature 5600-6000 K and slowly rotating with a period longer than 10 days), the occurrence rate of superflares with an energy of 10{sup 34}-10{sup 35} erg is once in 800-5000 yr. We also studied long-term (500 days) stellar brightness variation of these superflare stars and found that in some G-type dwarfs the occurrence rate of superflares was extremely high, ∼57 superflares in 500 days (i.e., once in 10 days). In the case of Sun-like stars, themore »« less

Authors:

Shibayama, Takuya; Notsu, Shota; Notsu, Yuta; Nagao, Takashi ^[1]; Maehara, Hiroyuki; Honda, Satoshi; Ishii, Takako T.; Nogami, Daisaku; Shibata, Kazunari ^[2]

Department of Astronomy, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)
Kwasan and Hida Observatory, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

Publication Date:: Fri Nov 01 00:00:00 EDT 2013

OSTI Identifier:: 22273279

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal, Supplement Series

Additional Journal Information:: Journal Volume: 209; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0067-0049

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; BRIGHTNESS; DWARF STARS; ROTATION; STARSPOTS; STELLAR FLARES; VARIATIONS

Citation Formats


                    Shibayama, Takuya, Notsu, Shota, Notsu, Yuta, Nagao, Takashi, Maehara, Hiroyuki, Honda, Satoshi, Ishii, Takako T., Nogami, Daisaku, and Shibata, Kazunari. SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER. I. STATISTICAL PROPERTIES OF SUPERFLARES.  United States: N. p., 2013. 
        Web.  doi:10.1088/0067-0049/209/1/5.

Copy to clipboard


                    Shibayama, Takuya, Notsu, Shota, Notsu, Yuta, Nagao, Takashi, Maehara, Hiroyuki, Honda, Satoshi, Ishii, Takako T., Nogami, Daisaku, & Shibata, Kazunari. SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER. I. STATISTICAL PROPERTIES OF SUPERFLARES.  United States.  https://doi.org/10.1088/0067-0049/209/1/5

Copy to clipboard


                    Shibayama, Takuya, Notsu, Shota, Notsu, Yuta, Nagao, Takashi, Maehara, Hiroyuki, Honda, Satoshi, Ishii, Takako T., Nogami, Daisaku, and Shibata, Kazunari. 2013.  
        "SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER. I. STATISTICAL PROPERTIES OF SUPERFLARES".  United States.  https://doi.org/10.1088/0067-0049/209/1/5.

Copy to clipboard


                    
@article{osti_22273279,

  title        = {SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER. I. STATISTICAL PROPERTIES OF SUPERFLARES},

  author       = {Shibayama, Takuya and Notsu, Shota and Notsu, Yuta and Nagao, Takashi and Maehara, Hiroyuki and Honda, Satoshi and Ishii, Takako T. and Nogami, Daisaku and Shibata, Kazunari},

  abstractNote = {By extending our previous study by Maehara et al., we searched for superflares on G-type dwarfs (solar-type stars) using Kepler data for a longer period (500 days) than that (120 days) in our previous study. As a result, we found 1547 superflares on 279 G-type dwarfs, which is much more than the previous 365 superflares on 148 stars. Using these new data, we studied the statistical properties of the occurrence rate of superflares, and confirmed the previous results, i.e., the occurrence rate (dN/dE) of superflares versus flare energy (E) shows a power-law distribution with dN/dE∝E {sup –α}, where α ∼ 2. It is interesting that this distribution is roughly similar to that for solar flares. In the case of the Sun-like stars (with surface temperature 5600-6000 K and slowly rotating with a period longer than 10 days), the occurrence rate of superflares with an energy of 10{sup 34}-10{sup 35} erg is once in 800-5000 yr. We also studied long-term (500 days) stellar brightness variation of these superflare stars and found that in some G-type dwarfs the occurrence rate of superflares was extremely high, ∼57 superflares in 500 days (i.e., once in 10 days). In the case of Sun-like stars, the most active stars show a frequency of one superflare (with 10{sup 34} erg) in 100 days. There is evidence that these superflare stars have extremely large starspots with a size about 10 times larger than that of the largest sunspot. We argue that the physical origin of the extremely high occurrence rate of superflares in these stars may be attributed to the existence of extremely large starspots.},

  doi          = {10.1088/0067-0049/209/1/5},

  url          = {https://www.osti.gov/biblio/22273279},
  journal      = {Astrophysical Journal, Supplement Series},

  issn         = {0067-0049},

  number       = 1,

  volume       = 209,

  place        = {United States},

  year         = {Fri Nov 01 00:00:00 EDT 2013},

  month        = {Fri Nov 01 00:00:00 EDT 2013}

}

Copy to clipboard

Journal Article:

https://doi.org/10.1088/0067-0049/209/1/5

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Superflare occurrence and energies on G-, K-, and M-type dwarfs

Journal Article Candelaresi, S.; Hillier, A.; Maehara, H.; ... - Astrophysical Journal

Kepler data from G-, K-, and M-type stars are used to study conditions that lead to superflares with energies above 10{sup 34} erg. From the 117,661 stars included, 380 show superflares with a total of 1690 such events. We study whether parameters, like effective temperature or rotation rate, have any effect on the superflare occurrence rate or energy. With increasing effective temperature we observe a decrease in the superflare rate, which is analogous to the previous findings of a decrease in dynamo activity with increasing effective temperature. For slowly rotating stars, we find a quadratic increase of the mean occurrencemore »« less
https://doi.org/10.1088/0004-637X/792/1/67
A STUDY OF VARIABILITY IN THE FREQUENCY DISTRIBUTIONS OF THE SUPERFLARES OF G-TYPE STARS OBSERVED BY THE KEPLER MISSION

Journal Article Wu, Chi-Ju; Ip, Wing-Huen; Huang, Li-Ching - Astrophysical Journal

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,more »« less
https://doi.org/10.1088/0004-637X/798/2/92
K2 Ultracool Dwarfs Survey. II. The White Light Flare Rate of Young Brown Dwarfs

Journal Article Gizis, John; Paudel, Rishi; Mullan, Dermott; ... - Astrophysical Journal

We use Kepler K2 Campaign 4 short-cadence (one-minute) photometry to measure white light flares in the young, moving group brown dwarfs 2MASS J03350208+2342356 (2M0335+23) and 2MASS J03552337+1133437 (2M0355+11), and report on long-cadence (thirty-minute) photometry of a superflare in the Pleiades M8 brown dwarf CFHT-PL-17. The rotation period (5.24 hr) and projected rotational velocity (45 km s{sup −1}) confirm 2M0335+23 is inflated (R⩾0.20 R{sub ⊙}) as predicted for a 0.06 M{sub ⊙}, 24 Myr old brown dwarf βPic moving group member. We detect 22 white light flares on 2M0335+23. The flare frequency distribution follows a power-law distribution with slope −α=−1.8±0.2 overmore »« less
https://doi.org/10.3847/1538-4357/AA7DA0
Discovery of extreme, roughly daily superflares on the recurrent nova V2487 Oph

Journal Article Schaefer, Bradley; Pagnotta, Ashley; Zoppelt, Seth - Monthly Notices of the Royal Astronomical Society

ABSTRACT V2487 Oph is a recurrent nova with detected eruptions in 1900 and 1998. Startlingly, V2487 Oph shows flares, called ‘Superflares’, with up to 1.10 mag amplitude, fast rises of under one-minute, always with an initial impulsive spike followed by a roughly exponential tail, typically one-hour durations, and with random event times averaging once-per-day. The typical flare energy E is over 1038 erg, while the yearly energy budget is 1041 erg. V2487 Oph Superflares obey three relations; the number distribution of flare energies scales as E−2.34 ± 0.35, the waiting time from one flare to the next is proportional to E ofmore »« less
https://doi.org/10.1093/mnras/stac443
SUPERFLARES ON SOLAR-TYPE STARS OBSERVED WITH KEPLER II. PHOTOMETRIC VARIABILITY OF SUPERFLARE-GENERATING STARS: A SIGNATURE OF STELLAR ROTATION AND STARSPOTS

Journal Article Notsu, Yuta; Shibayama, Takuya; Notsu, Shota; ... - Astrophysical Journal

We performed simple spot-model calculations for quasi-periodic brightness variations of solar-type stars showing superflares using Kepler photometric data. Most of the superflare stars show quasi-periodic brightness modulations with a typical period of one to a few tens of days. Our results indicate that these brightness variations can be explained by the rotation of a star with fairly large starspots. Using the results of the period analysis, we investigated the relation between the energy and frequency of superflares and the rotation period. Stars with relatively slower rotation rates can still produce flares that are as energetic as those of more rapidlymore »« less
https://doi.org/10.1088/0004-637X/771/2/127

Similar Records