A4 Vertaisarvioitu artikkeli konferenssijulkaisussa
Flares in A-type stars?
Tekijät: Pedersen MG, Antoci V, Korhonen H
Toimittaja: Kosovichev GA, Hawley SL, Heinzel P
Konferenssin vakiintunut nimi: Symposium of the International-Astronomical-Union
Julkaisuvuosi: 2016
Journal: Proceedings of the International Astronomical Union
Kokoomateoksen nimi: Solar and stellar flares and their effects on planets
Tietokannassa oleva lehden nimi: SOLAR AND STELLAR FLARES AND THEIR EFFECTS ON PLANETS
Lehden akronyymi: IAU SYMP P SERIES
Vuosikerta: 11
Numero: S320
Aloitussivu: 150
Lopetussivu: 152
Sivujen määrä: 3
ISBN: 978-1-10713-757-8
ISSN: 1743-9213
DOI: https://doi.org/10.1017/S1743921316002179
Tiivistelmä
Stellar flares are known to originate from magnetic reconnection in the atmospheres of late-type stars or through radiatively driven wind instabilities in early-type stars. Situated right between these two groups, the A-type stars are not expected to support either of the two mechanisms. However, recent studies report flare features in the Kepler light curves of 32 A-type stars, contradicting theory. We investigate the stars reported in literature, setting strong constraints on the detection criteria. Although significantly fewer, we conclude that flare-like features are present. To determine the origin we obtained high-resolution spectra from the Nordic Optical Telescope (NOT) for the ten brightest, flaring A-type stars for 3-4 epochs. Here we present the preliminary results of these spectroscopic observations, with respect to spectral classification and binarity.
Stellar flares are known to originate from magnetic reconnection in the atmospheres of late-type stars or through radiatively driven wind instabilities in early-type stars. Situated right between these two groups, the A-type stars are not expected to support either of the two mechanisms. However, recent studies report flare features in the Kepler light curves of 32 A-type stars, contradicting theory. We investigate the stars reported in literature, setting strong constraints on the detection criteria. Although significantly fewer, we conclude that flare-like features are present. To determine the origin we obtained high-resolution spectra from the Nordic Optical Telescope (NOT) for the ten brightest, flaring A-type stars for 3-4 epochs. Here we present the preliminary results of these spectroscopic observations, with respect to spectral classification and binarity.
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