Pulsation in the white dwarf HE 1017−1352: confirmation of the class of hot DAV stars. (4th June 2020)

• Record Type: Journal Article
• Authors: Romero, Alejandra D; Antunes Amaral, L; Kepler, S O; Fraga, L; Kurtz, D; Shibahashi, H
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 497:Number 1(2020)
• Page Start: L24
• Page End: L29
• Publication Date: 2020-06-04
• Subjects: stars: interiors -- stars: variables: general -- white dwarfs; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/slaa106
• Languages: English
• ISSNs: 1745-3933

Abstract

ABSTRACT: We report the detection of periodic variations on the $T_\mathrm{eff}\simeq 32\, 000$ K DA white dwarf star HE 1017−1352. We obtained time series photometry using the 4.1-m Southern Astrophysical Research telescope on three separate nights for a total of 16.8 h. From the frequency analysis, we found four periods of 605, 556, 508, and 869 s with significant amplitudes above the 1/1000 false alarm probability detection limit. The detected modes are compatible with low harmonic degree g-mode non-radial pulsations with radial order higher than ∼9. This detection confirms the pulsation nature of HE 1017−1352 and thus the existence of the new pulsating class of hot DA white dwarf stars. In addition, we detect a long period of 1.52 h, compatible with a rotation period of DA white dwarf stars.