The First Six Outbursting Cool DA White Dwarf Pulsators
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.- Publication:
-
20th European White Dwarf Workshop
- Pub Date:
- March 2017
- DOI:
- 10.48550/arXiv.1609.09097
- arXiv:
- arXiv:1609.09097
- Bibcode:
- 2017ASPC..509..303B
- Keywords:
-
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 6 pages, 2 figures, 1 table. To appear in the ASP Conference Series proceedings of "20th European Workshop on White Dwarfs," held at the University of Warwick, UK on July 25-29th, 2016