The GW Vir Instability Strip in Light of New Observations of PG 1159 Stars: Discovery of Pulsations in the Central Star of A72 and Variability of RX J0122.9-7521

被引：5

作者：

Sowicka, Paulina ^{[1
]}

Handler, Gerald ^{[1
]}

Jones, David ^{[2
,3
,4
]}

Caldwell, John A. R. ^{[5
]}

van Wyk, Francois ^{[6
]}

Paunzen, Ernst ^{[7
]}

Bakowska, Karolina ^{[8
]}

de Arriba, Luis Peralta ^{[9
,10
]}

Suarez-Andres, Lucia ^{[10
]}

Werner, Klaus ^{[11
]}

Karjalainen, Marie ^{[12
]}

Holdsworth, Daniel L. ^{[13
]}

机构：

[1] Polish Acad Sci, Nicolaus Copernicus Astron Ctr, Ul Bartycka 18, PL-00716 Warsaw, Poland

[2] Inst Astrofis Canarias, E-38205 San Cristobal la Laguna, Tenerife, Spain

[3] Univ La Laguna, Dept Astrofis, E-38206 San Cristobal la Laguna, Tenerife, Spain

[4] Nord Opt Telescope, Rambla Jose Ana Fernandez Perez 7, E-38711 Brena Baja, Spain

[5] McDonald Observ, 82 Mt Locke Rd, Ft Davis, TX 79734 USA

[6] South African Astron Observ, POB 9, ZA-7935 Cape Town, South Africa

[7] Masaryk Univ, Fac Sci, Dept Theoret Phys & Astrophys, Kotlarska 2, Brno, Czech Republic

[8] Nicolaus Copernicus Univ, Inst Astron, Fac Phys Astron & Informat, Ul Grudziadzka 5, PL-87100 Torun, Poland

[9] CSIC INTA, Ctr Astrobiol CAB, Camino Bajo Castillo S-N, E-28692 Madrid, Spain

[10] Isaac Newton Grp Telescopes, E-38700 Santa Cruz De La Palma, La Palma, Spain

[11] Eberhard Karls Univ Tubingen, Inst Astron & Astrophys, Kepler Ctr Astro & Particle Phys, Sand 1, D-72076 Tubingen, Germany

[12] Czech Acad Sci, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic

[13] Univ Cent Lancashire, Jeremiah Horrocks Inst, Preston PR1 2HE, Lancs, England

来源：

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES | 2023年 / 269卷 / 01期

基金：

美国国家科学基金会;

关键词：

PRE-WHITE-DWARFS; EARTH TELESCOPE OBSERVATIONS; FAR-ULTRAVIOLET SPECTRA; POST-AGB STARS; PG-1159; STAR; EVOLUTIONARY MODELS; OLD PLANETARIES; HYDROGEN-RICH; HS 2324+3944; MASS-LOSS;

D O I：

10.3847/1538-4365/acfbe4

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the results of new time-series photometric observations of 29 pre-white dwarf stars of PG 1159 spectral type, carried out in the years 2014-2022. For the majority of stars, a median noise level in Fourier amplitude spectra of 0.5-1.0 mmag was achieved. This allowed the detection of pulsations in the central star of planetary nebula A72 (Abell 72), consistent with g modes excited in GW Vir stars, and variability in RX J0122.9-7521 that could be due to pulsations, binarity, or rotation. For the remaining stars from the sample that were not observed to vary, we placed upper limits for variability. After combination with literature data, our results place the fraction of pulsating PG 1159 stars within the GW Vir instability strip at 36%. An updated list of all known PG 1159 stars is provided, containing astrometric measurements from the recent Gaia DR3 data, as well as information on physical parameters, variability, and nitrogen content. Those data are used to calculate luminosities for all PG 1159 stars to place the whole sample on the theoretical Hertzsprung-Russell diagram for the first time in that way. The pulsating stars are discussed as a group, and arguments are given that the traditional separation of GW Vir pulsators in "DOV" and "PNNV" stars is misleading and should not be used.

引用

页数：23