White Dwarf Variability With gPhoton: Pulsators

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Daniel B. Caton PhD, Director of Observatories, Professor (Creator)
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/

Abstract: We present results from a search for short time-scale white dwarf variability using gPhoton, a time-tagged data base of GALEX photon events and associated software package. We conducted a survey of 320 white dwarf stars in the McCook–Sion catalogue, inspecting each for photometric variability with particular emphasis on variability over time-scales less than ~30 ?min. From that survey, we present the discovery of a new pulsating white dwarf: WD 2246-069. A Ca?ii K line is found in archival ESO spectra and an IR excess is seen in WISE W1 and W2 bands. Its independent modes are identified in follow-up optical photometry and used to model its interior structure. Additionally, we detect UV pulsations in four previously known pulsating ZZ Ceti-type (DAVs). Included in this group is the simultaneous fitting of the pulsations of WD 1401-147 in optical, near-ultraviolet and far-ultraviolet bands using nearly concurrent Whole Earth Telescope and GALEX data, providing observational insight into the wavelength dependence of white dwarf pulsation amplitudes.

Additional Information

Michael A Tucker, Scott W Fleming, Ingrid Pelisoli, Alejandra Romero, Keaton J Bell, S O Kepler, Daniel B Caton, John Debes, Michael H Montgomery, Susan E Thompson, Detlev Koester, Chase Million, Bernie Shiao, White dwarf variability with gPhoton: pulsators, Monthly Notices of the Royal Astronomical Society, Volume 475, Issue 4, April 2018, Pages 4768–4780, https://doi.org/10.1093/mnras/stx3297. Publisher version of record available at: https://academic.oup.com/mnras/article/475/4/4768/4772883
Language: English
Date: 2018
techniques: photometric, stars: oscillations, white dwarfs, ultraviolet: stars

Email this document to