Evolutionary Timescale of the Pulsating White Dwarf G117-B15A: The Most Stable Optical Clock Known

SO Kepler; A Mukadam; DE Winget; RE Nather; TS Metcalfe; MD Reed; SD Kawaler; PA Bradley

doi:10.1086/312664

Evolutionary Timescale of the Pulsating White Dwarf G117-B15A: The Most Stable Optical Clock Known

Astrophys J. 2000 May 10;534(2):L185-L188. doi: 10.1086/312664.

Authors

SO Kepler, A Mukadam, DE Winget, RE Nather, TS Metcalfe, MD Reed, SD Kawaler, PA Bradley

PMID: 10813678
DOI: 10.1086/312664

Abstract

We observe G117-B15A, the most precise optical clock known, to measure the rate of change of the main pulsation period of this blue-edge DAV white dwarf. Even though the obtained value is only within 1 sigma, P&d2;=&parl0;2.3+/-1.4&parr0;x10-15 s s-1, it is already constraining the evolutionary timescale of this cooling white dwarf star.