G 185-32, also known by the variable star designation PY Vulpeculae, is a white dwarf in the constellation Vulpecula. Located approximately 18.3 parsecs (60 ly) distant,[2] the stellar remnant is a ZZ Ceti variable, varying by 0.02 apparent magnitudes from the mean of 13.00.[3]

G 185-32

A light curve for PY Vulpeculae, adapted from McGraw et al. (1981)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Vulpecula
Right ascension 19h 37m 13.7502s[2]
Declination +27° 43′ 18.7366″[2]
Apparent magnitude (V) 13.00[3]
Characteristics
Spectral type DA4.0[4]
Apparent magnitude (J) 13.183±0.023[5]
Apparent magnitude (H) 13.213±0.029[5]
Apparent magnitude (K) 13.329±0.043[5]
B−V color index 0.17
Variable type ZZA[3]
Astrometry
Proper motion (μ) RA: 439.597±0.044[2] mas/yr
Dec.: 21.270±0.049[2] mas/yr
Parallax (π)54.7742 ± 0.0288 mas[2]
Distance59.55 ± 0.03 ly
(18.257 ± 0.010 pc)
Absolute magnitude (MV)11.66
Details[6]
Mass0.64±0.10 M
Radius0.0120±0.0006 R
Surface gravity (log g)8.09±0.05 cgs
Temperature12381±186 K
Other designations
PY Vul, EGGR 277, LSPM J1937+2743, USNO-B1.0 1177-00513805, WD 1935+276, USNO 352, WD 1935+27, NLTT 48026, GJ 1241, PG 1935+276.
Database references
SIMBADdata
ARICNSdata

Observational history

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This star was first noticed during a survey for high proper motion stars by Henry L. Giclas, at Lowell Observatory, who listed it as a suspected white dwarf.[7] The white dwarf designation was confirmed spectroscopically in 1970 by astronomer Jesse L. Greenstein of the California Institute of Technology.[8]

References

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  1. ^ McGraw, J. T.; Fontaine, G.; Dearborn, G. S. P.; Gustafson, J.; Lacombe, P.; Starrfield, S. G. (November 1981). "Two new variable white dwarfs : G 185-32 and G 191-16". The Astrophysical Journal. 250: 349–354. Bibcode:1981ApJ...250..349M. doi:10.1086/159381. Retrieved 26 May 2022.
  2. ^ a b c d e f 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.
  3. ^ a b c VSX (4 January 2010). "PY Vulpeculae". AAVSO Website. American Association of Variable Star Observers. Retrieved 19 October 2014.
  4. ^ Gianninas, A.; et al. (2011). "A Spectroscopic Survey and Analysis of Bright, Hydrogen-Rich White Dwarfs". The Astrophysical Journal. 743 (2). 138. arXiv:1109.3171. Bibcode:2011ApJ...743..138G. doi:10.1088/0004-637X/743/2/138.
  5. ^ a b c Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331. Vizier catalog entry
  6. ^ Bédard, A.; et al. (2017). "Measurements of Physical Parameters of White Dwarfs: A Test of the Mass–Radius Relation". The Astrophysical Journal. 848 (1). 11. arXiv:1709.02324. Bibcode:2017ApJ...848...11B. doi:10.3847/1538-4357/aa8bb6.
  7. ^ Giclas, Henry L.; et al. (1966). "Lowell proper motions VIII : proper motion survey of the Northern Hemisphere with the 13-inch photographic telescope of the Lowell Observatory". Lowell Observatory Bulletin. 6 (132): 233–247. Bibcode:1966LowOB...6..233G.
  8. ^ Greenstein, Jesse L. (1970). "Some New White Dwarfs with Peculiar Spectra. VI". Astrophysical Journal Letters. 162: L55–L59. Bibcode:1970ApJ...162L..55G. doi:10.1086/180622.