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arXiv · 1609.09097

The First Six Outbursting Cool DA White Dwarf Pulsators

Keaton J. Bell·J. J. Hermes·M. H. Montgomery·D. E. Winget·N. P. Gentile Fusillo·R. Raddi·B. T. Gänsicke
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Abstract

Extensive observations from the Kepler spacecraft have recently revealed a new outburst phenomenon operating in cool pulsating DA (hydrogen atmosphere) white dwarfs (DAVs). With the introduction of two new outbursting DAVs from K2 Fields 7 (EPIC 229228364) and 8 (EPIC 220453225) in these proceedings, we presently know of six total members of this class of object. We present the observational commonalities of the outbursting DAVs: (1) outbursts that increase the mean stellar flux by up to 15%, last many hours, and recur irregularly on timescales of days; (2) effective temperatures that locate them near the cool edge of the DAV instability strip; and (3) rich pulsation spectra with modes that are observed to wander in amplitude/frequency.

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Keaton J. Bell, J. J. Hermes, M. H. Montgomery, D. E. Winget, N. P. Gentile Fusillo, R. Raddi, B. T. Gänsicke. 2016-09-28. The First Six Outbursting Cool DA White Dwarf Pulsators. https://arxiv.org/abs/1609.09097

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