G 185-32

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,[1] the stellar remnant is a ZZ Ceti variable, varying by 0.02 apparent magnitudes from the mean of 13.00.[2]

G 185-32
Observation data
Epoch J2000      Equinox J2000
Constellation Vulpecula
Right ascension  19h 37m 13.7502s[1]
Declination +27° 43′ 18.7366″[1]
Apparent magnitude (V) 13.00[2]
Characteristics
Spectral type DA4.0[3]
Apparent magnitude (J) 13.183±0.023[4]
Apparent magnitude (H) 13.213±0.029[4]
Apparent magnitude (K) 13.329±0.043[4]
B−V color index 0.17
Variable type ZZA[2]
Astrometry
Proper motion (μ) RA: 439.597±0.044[1] mas/yr
Dec.: 21.270±0.049[1] mas/yr
Parallax (π)54.7742 ± 0.0288[1] mas
Distance59.55 ± 0.03 ly
(18.257 ± 0.010 pc)
Absolute magnitude (MV)11.66
Details[5]
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

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.[6] The white dwarf designation was confirmed spectroscopically in 1970 by astronomer Jesse L. Greenstein of the California Institute of Technology.[7]

References
  1. 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.
  2. VSX (4 January 2010). "PY Vulpeculae". AAVSO Website. American Association of Variable Star Observers. Retrieved 19 October 2014.
  3. Gianninas, A.; Bergeron, P.; Ruiz, M. T. (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.
  4. Skrutskie, M. F.; et al. (2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708.Vizier catalog entry
  5. 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.
  6. 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.
  7. 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.


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