K2 Ultracool Dwarfs Survey. III. White Light Flares Are Ubiquitous in M6-L0 Dwarfs
| dc.contributor.author | Paudel, Rishi R. | |
| dc.contributor.author | Gizis, John E. | |
| dc.contributor.author | Mullan, D. J. | |
| dc.contributor.author | Schmidt, Sarah J. | |
| dc.contributor.author | Burgasser, Adam J. | |
| dc.contributor.author | Williams, Peter K. G. | |
| dc.contributor.author | Berger, Edo | |
| dc.date.accessioned | 2022-02-09T15:26:14Z | |
| dc.date.available | 2022-02-09T15:26:14Z | |
| dc.date.issued | 2018-05-04 | |
| dc.description.abstract | We report the white light are rates for 10 ultracool dwarfs (UCDs) using Kepler K2 short cadence data. Among our sample stars, two have spectral type M6, three are M7, three are M8 and two are L0. Most of our targets are old low mass stars. We identify a total of 283 flares in all of the stars in our sample, with Kepler energies in the range log Eᴋₚ ~(29 - 33.5) erg. Using the maximum-likelihood method of line fi tting, we fi nd that the flare frequency distribution (FFD) for each star in our sample follows a power law with slope -𝛼 in range -(1.3-2.0). We fi nd that cooler objects tend to have shallower slopes. For some of our targets, the FFD follows either a broken power law, or a power law with an exponential cutoff. For the L0 dwarf 2MASS J12321827-0951502, we find a very shallow slope (-𝛼 = -1.3) in the Kepler energy range (0.82-130)✕10³⁰ erg: this L0 dwarf has flare rates which are comparable to the rates of high energy flares in stars of earlier spectral types. In addition, we report photometry of two super flares: one on the L0 dwarf 2MASS J12321827-0951502 and another on the M7 dwarf 2MASS+J08352366+1029318. In case of 2MASS J12321827-0951502, we report a flare brightening by a factor of ~144 relative to the quiescent photospheric level. Likewise, for 2MASS J08352366+1029318, we report a flare brightening by a factor of ~60 relative to the quiescent photospheric level. These two super flares have bolometric (UV/optical/infrared) energies 3.6 ✕10³³ erg and 8.9 ✕10³³ erg respectively, while the FWHM time scales are very short, ~2 minutes. We fi nd that the M8 star TRAPPIST-1 is more active than the M8.5 dwarf: 2M03264453+1919309, but less active than another M8 dwarf (2M12215066-0843197). | en_US |
| dc.description.sponsorship | We thank Rachel Osten, Eric D. Feigelson and James R. A. Davenport for their valuable suggestions on some methods and statistical tools used for flare analysis and FFD fitting. The material is based upon work supported by NASA under award Nos. NNX15AV64G, NNX16AE55G and NNX16AJ22G. P.K.G.W. and E.B. acknowledge support for this work from the National Science Foundation through Grant AST-1614770. 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. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.3847/1538-4357/aab8fe | en_US |
| dc.format.extent | 19 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.genre | preprints | en_US |
| dc.identifier | doi:10.13016/m2o6ru-kmdn | |
| dc.identifier.citation | Paudel, Rishi R. et al. K2 Ultracool Dwarfs Survey. III. White Light Flares Are Ubiquitous in M6-L0 Dwarfs. The Astrophysical Journal 858 (May 4, 2018), no. 1. https://doi.org/10.3847/1538-4357/aab8fe. | en_US |
| dc.identifier.uri | https://arxiv.org/ct?url=https%3A%2F%2Fdx.doi.org%2F10.3847%2F1538-4357%2Faab8fe&v=e2eb9d3a | |
| dc.identifier.uri | http://hdl.handle.net/11603/24156 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | IOP | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology | |
| dc.rights | © 2017. The American Astronomical Society. All rights reserved | en_US |
| dc.title | K2 Ultracool Dwarfs Survey. III. White Light Flares Are Ubiquitous in M6-L0 Dwarfs | en_US |
| dc.type | Text | en_US |
| dcterms.creator | https://orcid.org/0000-0002-8090-3570 | en_US |