K2 Ultracool Dwarfs Survey – VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs
| dc.contributor.author | Paudel, Rishi R. | |
| dc.contributor.author | Gizis, J. E. | |
| dc.contributor.author | Mullan, D. J. | |
| dc.contributor.author | Schmidt, S. J. | |
| dc.contributor.author | Burgasser, A. J. | |
| dc.contributor.author | Williams, P. K. G. | |
| dc.date.accessioned | 2020-10-21T17:40:05Z | |
| dc.date.available | 2020-10-21T17:40:05Z | |
| dc.date.issued | 2020-05-06 | |
| dc.description.abstract | KeplerK2 long cadence data are used to study white light flares in a sample of 45 L dwarfs. We identified 11 flares on 9 L dwarfs with equivalent durations of (1.3–198) h and total (UV/optical/IR) energies of ≥0.9 × 10³² erg. Two superflares with energies of >10³³ erg were detected on an L5 dwarf (VVV BD001): this is the coolest object so far on which flares have been identified. The larger superflare on this L5 dwarf has an energy of 4.6 × 10³⁴ erg and an amplitude of >300 times the photospheric level: so far, this is the largest amplitude flare detected by the Kepler/K2 mission. The next coolest star on which we identified a flare was an L2 dwarf: 2MASS J08585891+1804463. Combining the energies of all the flares which we have identified on 9 L dwarfs with the total observation time which was dedicated by Kepler to all 45 L dwarfs, we construct a composite flare frequency distribution (FFD). The FFD slope is quite shallow (−0.51 ± 0.17), consistent with earlier results reported by Paudel et al. for one particular L0 dwarf, for which the FFD slope was found to be −0.34. Using the composite FFD, we predict that, in early- and mid-L dwarfs, a superflare of energy 10³³ erg occurs every 2.4 yr and a superflare of energy 10³⁴ erg occurs every 7.9 yr. Analysis of our L dwarf flares suggests that magnetic fields of ≥0.13–1.3 kG are present on the stellar surface: such fields could suppress Type II radio bursts. | en_US |
| dc.description.sponsorship | The material in this paper is based upon work supported by the National Aeronautics and Space Administration (NASA) under award Nos. NNX15AV64G, NNX16AE55G, and NNX16AJ22G. RRP acknowledges support from the University of Delaware Dissertation Fellowship program. Some/all of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23. This work made use of the http://gaia-kepler.fun cross-match data base created by Megan Bedell. Software: PYTHON, IPYTHON (Perez & Granger 2007), ASTROPY (Astropy Collaboration 2013), MATPLOTLIB (Hunter 2007), NUMPY (Oliphant 2015), LIGHTKURVE (Vin´ıcius et al. 2018), K2SC (Aigrain et al. 2016), JUPYTER (Kluyver et al. 2016) | en_US |
| dc.description.uri | https://academic.oup.com/mnras/article-abstract/494/4/5751/5831082? | en_US |
| dc.format.extent | 10 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m2lioc-1jk6 | |
| dc.identifier.citation | Paudel, R. R.; Gizis, J. E.; Mullan, D. J.; Schmidt, S. J.; Burgasser, A. J.; Williams, P. K. G.; K2 Ultracool Dwarfs Survey – VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs; Monthly Notices of the Royal Astronomical Society, Volume 494, Issue 4, June 2020, Pages 5751–5760; https://academic.oup.com/mnras/article-abstract/494/4/5751/5831082? | en_US |
| dc.identifier.uri | https://doi.org/10.1093/mnras/staa1137 | |
| dc.identifier.uri | http://hdl.handle.net/11603/19943 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Oxford University Press | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Faculty Collection | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | This article is published in Monthly Notices of the Royal Astronomical Society ©: 2020 The Author(s), Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. | |
| dc.title | K2 Ultracool Dwarfs Survey – VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs | en_US |
| dc.type | Text | en_US |