Learning Centre

Do A-type stars flare?

 |  Login

Show simple item record

dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.author Pedersen, M. G.
dc.contributor.author Antoci, V.
dc.contributor.author Korhonen, H.
dc.contributor.author White, T. R.
dc.contributor.author Jessen-Hansen, J.
dc.contributor.author Lehtinen, J.
dc.contributor.author Nikbakhsh, S.
dc.contributor.author Viuho, J.
dc.date.accessioned 2017-05-31T06:02:38Z
dc.date.available 2017-05-31T06:02:38Z
dc.date.issued 2017
dc.identifier.citation Pedersen , M G , Antoci , V , Korhonen , H , White , T R , Jessen-Hansen , J , Lehtinen , J , Nikbakhsh , S & Viuho , J 2017 , ' Do A-type stars flare? ' Monthly Notices of the Royal Astronomical Society , vol 466 , no. 3 , pp. 3060-3076 . DOI: 10.1093/mnras/stw3226 en
dc.identifier.issn 0035-8711
dc.identifier.issn 1365-2966
dc.identifier.other PURE UUID: 68440772-5bf0-446d-b3fe-28ca859f462d
dc.identifier.other PURE ITEMURL: https://research.aalto.fi/en/publications/do-atype-stars-flare(68440772-5bf0-446d-b3fe-28ca859f462d).html
dc.identifier.other PURE LINK: http://www.scopus.com/inward/record.url?scp=85018249442&partnerID=8YFLogxK
dc.identifier.other PURE FILEURL: https://research.aalto.fi/files/13308582/Nikbakhsh_et_al_stw3226.pdf
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/26513
dc.description.abstract For flares to be generated, stars have to have a sufficiently deep outer convection zone (F5 and later), strong large-scale magnetic fields (Ap/Bp-type stars) or strong, radiatively driven winds (B5 and earlier). Normal A-type stars possess none of these and therefore should not flare. Nevertheless, flares have previously been detected in the Kepler light curves of 33 A-type stars and interpreted to be intrinsic to the stars. Here, we present new and detailed analyses of these 33 stars, imposing very strict criteria for the flare detection. We confirm the presence of flare-like features in 27 of the 33 A-type stars. A study of the pixel data and the surrounding field of view reveals that 14 of these 27 flaring objects have overlapping neighbouring stars and five stars show clear contamination in the pixel data. We have obtained high-resolution spectra for 2/3 of the entire sample and confirm that our targets are indeed A-type stars. Detailed analyses revealed that 11 out of 19 stars with multiple epochs of observations are spectroscopic binaries. Furthermore, and contrary to previous studies, we find that the flares can originate from a cooler, unresolved companion. We note the presence of Hα emission in eight stars. Whether this emission is circumstellar or magnetic in origin is unknown. In summary, we find possible alternative explanations for the observed flares for at least 19 of the 33 A-type stars, but find no truly convincing target to support the hypothesis of flaring A-type stars. en
dc.format.extent 17
dc.format.extent 3060-3076
dc.format.mimetype application/pdf
dc.language.iso en en
dc.relation.ispartofseries Monthly Notices of the Royal Astronomical Society en
dc.relation.ispartofseries Volume 466, issue 3 en
dc.rights openAccess en
dc.subject.other Astronomy and Astrophysics en
dc.subject.other Space and Planetary Science en
dc.subject.other 115 Astronomy and space science en
dc.title Do A-type stars flare? en
dc.type A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä fi
dc.description.version Peer reviewed en
dc.contributor.department Aarhus University
dc.contributor.department School services, CHEM
dc.contributor.department Max-Planck-Institut fur Sonnen system forschung
dc.contributor.department Department of Radio Science and Engineering
dc.contributor.department University of Copenhagen
dc.contributor.department Department of Electronics and Nanoengineering en
dc.subject.keyword Binaries: spectroscopic
dc.subject.keyword Circumstellar matter
dc.subject.keyword Stars: activity
dc.subject.keyword Stars: flare
dc.subject.keyword Stars: magnetic field
dc.subject.keyword Astronomy and Astrophysics
dc.subject.keyword Space and Planetary Science
dc.subject.keyword 115 Astronomy and space science
dc.identifier.urn URN:NBN:fi:aalto-201705315128
dc.identifier.doi 10.1093/mnras/stw3226
dc.type.version publishedVersion

Files in this item

Files Size Format View

There are no open access files associated with this item.

This item appears in the following Collection(s)

Show simple item record

Search archive

Advanced Search

article-iconSubmit a publication