PG 1159-035

PG 1159-035 is the prototypical PG 1159 star after which the class of PG 1159 stars was named. It was discovered in the Palomar-Green survey of ultraviolet-excess stellar objects^[9] and, like the other PG 1159 stars, is in transition between being the central star of a planetary nebula and being a white dwarf.^[4]

PG 1159-035

A light curve for GW Virginis, adapted from Winget et al. (1985)[1]
Observation data Epoch J2000.0 (ICRS)      Equinox J2000.0 (ICRS)
Constellation	Virgo
Right ascension	12h 01m 45.9731s[2]
Declination	−03° 45′ 40.629″[2]
Apparent magnitude (V)	14.9[3]
Characteristics
Evolutionary stage	PG 1159[4]
Spectral type	DOQZ1[5]
Variable type	GW Vir[3]
Astrometry
Proper motion (μ)	RA: −14.495[2] mas/yr Dec.: −3.207[2] mas/yr
Parallax (π)	1.6905±0.0642 mas[2]
Distance	1,930 ± 70 ly (590 ± 20 pc)
Details
Mass	0.63[6] M☉
Radius	0.0254 ± 0.005[7] R☉
Luminosity (bolometric)	200[7] L☉
Surface gravity (log g)	7.59[6] cgs
Temperature	136,000[6] K
Other designations
GW Vir, GW Virginis, 2E 2572, WD 1159-034[8]
Database references
SIMBAD	data

The luminosity of PG 1159-035 was observed to vary in 1979,^[10] and it was given the variable star designation GW Virginis (abbreviation GW Vir) in 1985.^[11] Variable PG 1159 stars may be called GW Vir stars, or the class may be split into DOV and PNNV stars.^[12][13] The variability of PG 1139-035, like that of other GW Vir stars, arises from non-radial gravity wave pulsations within itself.^[14] Its light curve was observed intensively by the Whole Earth Telescope over a 264-hour period in March 1989, and over 100 of its vibrational modes have been found in the resulting vibrational spectrum, with periods ranging from 300 to 1,000 seconds.^{[15] [16]}