EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky

We search for superflares from 4068 cool stars in 2+ yr of Evryscope photometry, focusing on those with high-cadence data from both Evryscope and the Transiting Exoplanet Survey Satellite (TESS). The Evryscope array of small telescopes observed 575 flares from 284 stars, with a median energy of 1034...

ver descrição completa

Detalhes bibliográficos
Autores: Howard, Ward S., Corbett, Hank, Law, Nicholas M., Ratzloff, Jeffrey K., Glazier, Amy, Fors Aldrich, Octavi, Ser Badia, Daniel del, Haislip, Joshua
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Recursos:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/207379
Acesso em linha:https://hdl.handle.net/2445/207379
Access Level:acceso abierto
Palavra-chave:Estels
Telescopis
Fotometria
Stars
Telescopes
Photometry
id ES_aee8d175e21d264352379bef136d41be
oai_identifier_str oai:diposit.ub.edu:2445/207379
network_acronym_str ES
network_name_str España
repository_id_str
spelling EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern SkyHoward, Ward S.Corbett, HankLaw, Nicholas M.Ratzloff, Jeffrey K.Glazier, AmyFors Aldrich, OctaviSer Badia, Daniel delHaislip, JoshuaEstelsTelescopisFotometriaStarsTelescopesPhotometryWe search for superflares from 4068 cool stars in 2+ yr of Evryscope photometry, focusing on those with high-cadence data from both Evryscope and the Transiting Exoplanet Survey Satellite (TESS). The Evryscope array of small telescopes observed 575 flares from 284 stars, with a median energy of 1034.0 erg. Since 2016, Evryscope has enabled the detection of rare events from all stars observed by TESS through multi-year, high-cadence continuous observing. We report around twice the previous largest number of 1034 erg high-cadence flares from nearby cool stars. We find eight flares with amplitudes of 3+ g' magnitudes, with the largest reaching 5.6 mag and releasing 1036.2 erg. We observe a 1034 erg superflare from TOI-455 (LTT 1445), a mid-M with a rocky planet candidate. We measure the superflare rate per flare-star and quantify the average flaring of active stars as a function of spectral type, including superflare rates, flare frequency distributions, and typical flare amplitudes in g'. We confirm superflare morphology is broadly consistent with magnetic reconnection. We estimate starspot coverage necessary to produce superflares, and hypothesize maximum allowed superflare energies and waiting times between flares corresponding to 100% coverage of the stellar hemisphere. We observe decreased flaring at high Galactic latitudes. We explore the effects of superflares on ozone loss to planetary atmospheres: we observe one superflare with sufficient energy to photodissociate all ozone in an Earth-like atmosphere in one event. We find 17 stars that may deplete an Earth-like atmosphere via repeated flaring. Of the 1822 stars around which TESS may discover temperate rocky planets, we observe 14.6% ± 2% emit large flares.Institute of Physics (IOP)2019info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/207379Articles publicats en revistes (Física Quàntica i Astrofísica)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció del document publicat a: https://doi.org/10.3847/1538-4357/ab2767Astrophysical Journal, 2019, vol. 881, num.1, p. 1-17https://doi.org/10.3847/1538-4357/ab2767(c) American Astronomical Society, 2019info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/2073792026-05-27T06:46:51Z
dc.title.none.fl_str_mv EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
title EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
spellingShingle EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
Howard, Ward S.
Estels
Telescopis
Fotometria
Stars
Telescopes
Photometry
title_short EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
title_full EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
title_fullStr EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
title_full_unstemmed EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
title_sort EvryFlare. I. Long-term Evryscope Monitoring of Flares from the Cool Stars across Half the Southern Sky
dc.creator.none.fl_str_mv Howard, Ward S.
Corbett, Hank
Law, Nicholas M.
Ratzloff, Jeffrey K.
Glazier, Amy
Fors Aldrich, Octavi
Ser Badia, Daniel del
Haislip, Joshua
author Howard, Ward S.
author_facet Howard, Ward S.
Corbett, Hank
Law, Nicholas M.
Ratzloff, Jeffrey K.
Glazier, Amy
Fors Aldrich, Octavi
Ser Badia, Daniel del
Haislip, Joshua
author_role author
author2 Corbett, Hank
Law, Nicholas M.
Ratzloff, Jeffrey K.
Glazier, Amy
Fors Aldrich, Octavi
Ser Badia, Daniel del
Haislip, Joshua
author2_role author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Estels
Telescopis
Fotometria
Stars
Telescopes
Photometry
topic Estels
Telescopis
Fotometria
Stars
Telescopes
Photometry
description We search for superflares from 4068 cool stars in 2+ yr of Evryscope photometry, focusing on those with high-cadence data from both Evryscope and the Transiting Exoplanet Survey Satellite (TESS). The Evryscope array of small telescopes observed 575 flares from 284 stars, with a median energy of 1034.0 erg. Since 2016, Evryscope has enabled the detection of rare events from all stars observed by TESS through multi-year, high-cadence continuous observing. We report around twice the previous largest number of 1034 erg high-cadence flares from nearby cool stars. We find eight flares with amplitudes of 3+ g' magnitudes, with the largest reaching 5.6 mag and releasing 1036.2 erg. We observe a 1034 erg superflare from TOI-455 (LTT 1445), a mid-M with a rocky planet candidate. We measure the superflare rate per flare-star and quantify the average flaring of active stars as a function of spectral type, including superflare rates, flare frequency distributions, and typical flare amplitudes in g'. We confirm superflare morphology is broadly consistent with magnetic reconnection. We estimate starspot coverage necessary to produce superflares, and hypothesize maximum allowed superflare energies and waiting times between flares corresponding to 100% coverage of the stellar hemisphere. We observe decreased flaring at high Galactic latitudes. We explore the effects of superflares on ozone loss to planetary atmospheres: we observe one superflare with sufficient energy to photodissociate all ozone in an Earth-like atmosphere in one event. We find 17 stars that may deplete an Earth-like atmosphere via repeated flaring. Of the 1822 stars around which TESS may discover temperate rocky planets, we observe 14.6% ± 2% emit large flares.
publishDate 2019
dc.date.none.fl_str_mv 2019
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/207379
url https://hdl.handle.net/2445/207379
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció del document publicat a: https://doi.org/10.3847/1538-4357/ab2767
Astrophysical Journal, 2019, vol. 881, num.1, p. 1-17
https://doi.org/10.3847/1538-4357/ab2767
dc.rights.none.fl_str_mv (c) American Astronomical Society, 2019
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) American Astronomical Society, 2019
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Institute of Physics (IOP)
publisher.none.fl_str_mv Institute of Physics (IOP)
dc.source.none.fl_str_mv Articles publicats en revistes (Física Quàntica i Astrofísica)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869416639926108160
score 15,300719

Registos relacionados