1996/04/05 by R. Silvotti, Silvotti, R.
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9604030
4 pages, uuencoded (LaTeX file + 3 .eps figures), accepted by Astronomy and Astrophysics Letters
arxiv created 1996/04/05 · openalex publication_date 1996/04/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/24 · openalex updated_date 2026/07/28
HS ,2324+3944 is a peculiar PG ,1159 star, with a high amount of H in its\natmosphere (Dreizler et al. 1995). Its location in the \log T rm eff --\n\log g plane is well inside the GW Vir instability strip. In this paper I\nreport the results of two photoelectric observations of HS ,2324+39, which\nclearly show that the luminosity of this star presents periodical variations\nwith a period of (2140 \± 11) s. This photometric behaviour is most easily\nexplained by the presence of non-radial oscillations. Therefore HS ,2324+39 is\na new member of the GW Vir group, and is characterized by the longest pulsation\nperiod found among these stars. Moreover HS ,2324+39 appears to be the first\npulsating PG ,1159 star with a high H abundance in its atmosphere (H/He = 2 by\nnumber, Dreizler et al. 1995). Were the pulsation mechanism based on the C/O\ncyclic ionization (Starrfield et al. 1984) at work, the H abundance should drop\nto zero sharply in the driving regions. Such a strong decrease of hydrogen\nlooks quite unlikely; for this reason the presence of pulsations in HS ,2324+39\nseems to be a very interesting phenomenon.\n