Determining the Cooling Curve of the Unique Extreme Amplitude Dwarf Nova V386 Ser Containing an Accreting, Pulsating White Dwarf.
Abstract
V386 Ser is a relatively rare close binary containing a well-studied (at quiescence) accreting, pulsating white dwarf that underwent its first known extreme amplitude dwarf nova outburst in January, 2019, and we request a short COS observation to measure the temperature of the white dwarf as soon as possible after the outburst. Since 2004, it has been pulsating at a period of 609 sec, which is known to be a triplet with a spacing indicating a puzzling extremely slow rotation for an accreting white dwarf. The only other pulsating white dwarf that went into a superoutburst and has been followed up with HST is GW Lib. That data revealed an unusually long and non-monotonic cooling time as well as changing modes of pulsation during its decline. However, the monitoring of GW Lib only started 3 yrs past its outburst. V386 Ser presents the unique opportunity to obtain the optimum measurement of the heating within a few months of the outburst when the accretion disk has dissipated enough to view the white dwarf. Obtaining this measurement in the UV with COS will constrain the cooling curve (hence the amount of accretion that took place) and how possible spinup from this accretion impacts the pulsation structure in the interior versus atmospheric rotation.
- Publication:
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HST Proposal
- Pub Date:
- March 2019
- Bibcode:
- 2019hst..prop15703S