Precision asteroseismology of the pulsating white dwarf GD 1212 using a two-wheel-controlled Kepler spacecraft

TL;DR

This study demonstrates the potential of two-wheel-controlled Kepler spacecraft for asteroseismology by detecting numerous pulsation modes and long-period signals in the white dwarf GD 1212, revealing new insights into stellar oscillations.

Contribution

First application of two-wheel Kepler data to pulsating white dwarfs, enabling detection of long-period signals and multiple pulsation modes previously inaccessible from ground observations.

Findings

Detected at least 19 pulsation modes in GD 1212.

Identified long-period signals up to 14.5 hours.

Proved two-wheel Kepler's capability for asteroseismology.

Abstract

We present a preliminary analysis of the cool pulsating white dwarf GD 1212, enabled by more than 11.5 days of space-based photometry obtained during an engineering test of the two-reaction-wheel-controlled Kepler spacecraft. We detect at least 19 independent pulsation modes, ranging from 828.2-1220.8 s, and at least 17 nonlinear combination frequencies of those independent pulsations. Our longest uninterrupted light curve, 9.0 days in length, evidences coherent difference frequencies at periods inaccessible from the ground, up to 14.5 hr, the longest-period signals ever detected in a pulsating white dwarf. These results mark some of the first science to come from a two-wheel-controlled Kepler spacecraft, proving the capability for unprecedented discoveries afforded by extending Kepler observations to the ecliptic.