Flares in A-type stars?. Issue Volume 11:Issue S320(2015) (9th September 2016)

• Record Type: Journal Article
• Authors: Pedersen, May G.; Antoci, Victoria; Korhonen, Heidi
• Editors: Kosovichev, A.G.; Hawley, S.L.; Heinzel, P.
• Is Part Of: Proceedings of the International Astronomical Union. Volume 11:Issue S320(2015)
• Page Start: 150
• Page End: 152
• Publication Date: 2016-09-09
• Subjects: stars: activity, -- stars: flare, -- binaries: spectroscopic; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921316002179
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: 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.