Article · Wikipedia archive · Last revised Jul 2, 2026

GD 358

GD 358 is a variable white dwarf star of the DBV type. Like other pulsating white dwarfs, its variability arises from non-radial gravity wave pulsations within the star itself. GD 358 was discovered during the 1958–1970 Lowell Observatory survey for high proper motion stars in the Northern Hemisphere. Although it did not have high proper motion, it was noticed that it was a very blue star, and hence might be a white dwarf. Greenstein confirmed this in 1969.

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GD 358

A white-light light curve for GD 358, adapted from Winget et al. (1982)1
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Hercules
Right ascension 16h 47m 19.02s2
Declination +32° 28′ 31.9″2
Apparent magnitude (V) 13.652
Characteristics
Evolutionary stage white dwarf3
Spectral type DBV23
B−V color index -0.12
Variable type DBV3
Astrometry
Proper motion (μ) RA: 62 mas/yr
Dec.: -1622 mas/yr
Parallax (π)23.2012±0.0298 mas4
Distance140.6 ± 0.2 ly
(43.10 ± 0.06 pc)
Absolute magnitude (MV)+10.335
Details6
Mass0.584+0.025
−0.019 M☉
Radius0.0132±0.0004 R☉
Radius9,170+300
−290 km
Luminosity0.061±0.002 L☉
Surface gravity (log g)7.964+0.048
−0.043 cgs
Temperature24,967±200 K
Other designations
EGGR 239, V777 Her, PG 1645+325, WD 1645+325.
Database references
SIMBADdata

GD 358 is a variable white dwarf star of the DBV type. Like other pulsating white dwarfs, its variability arises from non-radial gravity wave pulsations within the star itself.7 GD 358 was discovered during the 1958–1970 Lowell Observatory survey for high proper motion stars in the Northern Hemisphere.8 Although it did not have high proper motion, it was noticed that it was a very blue star, and hence might be a white dwarf.9 Greenstein confirmed this in 1969.10

In 1968, Arlo U. Landolt discovered the first intrinsically variable white dwarf when he found that HL Tau 76 varied in brightness with a period of approximately 749.5 seconds, or 12.5 minutes.11 By the middle of the 1970s, a number of additional variable white dwarfs had been found, but, like HL Tau 76, they were all white dwarfs of spectral type DA, with hydrogen-dominated atmospheres.121314 In 1982, calculations by Don Winget and his coworkers suggested that helium-atmosphere DB white dwarfs with surface temperatures around 19,000 K should also pulsate.15 Winget then searched for such stars and found that GD 358 was a variable DB, or DBV, white dwarf.1 This was the first prediction of a class of variable stars before their observation.16, p. 89. In 1985, this star was given the variable-star designation V777 Herculis, which is also another name for this class of variable stars.17; 18

Notes and references

  1. Winget, D. E.; Robinson, E. L.; Nather, R. E.; Fontaine, G. (1982-11-01). "Photometric observations of GD 358 : OB white dwarfs do pulsate". The Astrophysical Journal. 262: L11–L15. Bibcode:1982ApJ...262L..11W. doi:10.1086/183902. ISSN 0004-637X.
  2. "GD 358". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 12, 2007.
  3. McCook, George P.; Sion, Edward M. (1999). "A Catalog of Spectroscopically Identified White Dwarfs". The Astrophysical Journal Supplement Series. 121 (1): 1. Bibcode:1999ApJS..121....1M. doi:10.1086/313186. III/210
  4. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  5. Limoges, M. -M; Bergeron, P.; Lépine, S. (2015). "Physical Properties of the Current Census of Northern White Dwarfs within 40 pc of the Sun". The Astrophysical Journal Supplement Series. 219 (2): 19. arXiv:1505.02297. Bibcode:2015ApJS..219...19L. doi:10.1088/0067-0049/219/2/19. S2CID 118494290.
  6. Córsico, A. H.; Uzundag, M.; Kepler, S. O.; Silvotti, R.; Althaus, L. G.; Koester, D.; Baran, A. S.; Bell, K. J.; Bischoff-Kim, A.; Hermes, J. J.; Kawaler, S. D.; Provencal, J. L.; Winget, D. E.; Montgomery, M. H.; Bradley, P. A.; Kleinman, S. J.; Nitta, A. (2022). "Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS. III. Asteroseismology of the DBV star GD 358". Astronomy & Astrophysics. 659: A30. arXiv:2111.15551. Bibcode:2022A&A...659A..30C. doi:10.1051/0004-6361/202142153. S2CID 244729212.
  7. Winget, D E (1998-12-14). "Asteroseismology of white dwarf stars". Journal of Physics: Condensed Matter. 10 (49): 11247–11261. Bibcode:1998JPCM...1011247W. doi:10.1088/0953-8984/10/49/014. ISSN 0953-8984. S2CID 250749380.
  8. Giclas, H. L.; Burnham, R.; Thomas, N. G. (1971). Lowell proper motion survey Northern Hemisphere. The G numbered stars. 8991 stars fainter than magnitude 8 with motions > 0".26/Year. Bibcode:1971lpms.book.....G. I/79
  9. Giclas, Henry L.; Burnham, Robert; Thomas, Norman Gene (1967). "A list of white dwarf suspects II : Special objects of small proper motion from the Lowell survey". Lowell Observatory Bulletin. 7 (141): 49. Bibcode:1967LowOB...7...49G.
  10. Greenstein, Jesse L. (1969). "The Lowell Suspect White Dwarfs". The Astrophysical Journal. 158: 281. Bibcode:1969ApJ...158..281G. doi:10.1086/150191.
  11. Landolt, Arlo U. (1968). "A New Short-Period Blue Variable". The Astrophysical Journal. 153: 151. Bibcode:1968ApJ...153..151L. doi:10.1086/149645.
  12. Robinson, E. L.; McGraw, J. T. (1976). "Observations of variable white dwarfs: One new variable and 35 nonvariables". The Astrophysical Journal. 207: L37. Bibcode:1976ApJ...207L..37R. doi:10.1086/182173.
  13. Hesser, J. E.; Lasker, B. M.; Neupert, H. E. (1976). "High-frequency stellar oscillations. XI. The ZZ Ceti star BPM 30551". The Astrophysical Journal. 209: 853. Bibcode:1976ApJ...209..853H. doi:10.1086/154784.
  14. McGraw, J. T. (1976). "BPM 31594: A new southern-hemisphere variable white dwarf". The Astrophysical Journal. 210: L35. Bibcode:1976ApJ...210L..35M. doi:10.1086/182297.
  15. Winget, D. E.; Van Horn, H. M.; Tassoul, M.; Fontaine, G.; Hansen, C. J.; Carroll, B. W. (1982). "Hydrogen-driving and the blue edge of compositionally stratified ZZ Ceti star models". The Astrophysical Journal. 252: L65. Bibcode:1982ApJ...252L..65W. doi:10.1086/183721.
  16. Kawaler, Steven D. (1997). "White Dwarf Stars". Stellar Remnants. Saas-Fee Advanced Courses. Vol. 25. pp. 1–95. doi:10.1007/3-540-31628-0_1. ISBN 3-540-61520-2.
  17. Kholopov, P. N.; Samus, N. N.; Kazarovets, E. V.; Perova, N. B. (1985). "The 67th Name-List of Variable Stars". Information Bulletin on Variable Stars. 2681: 1. Bibcode:1985IBVS.2681....1K.
  18. Fontaine, G.; Wesemael, F. (2000). White Dwarfs. Bibcode:2000eaa..bookE1894F.