G 185-32
White dwarf in the constellation Vulpecula
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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]
| 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] |
| Distance | 59.55 ± 0.03 ly (18.257 ± 0.010 pc) |
| Absolute magnitude (MV) | 11.66 |
| Details[6] | |
| Mass | 0.64±0.10 M☉ |
| Radius | 0.0120±0.0006 R☉ |
| Surface gravity (log g) | 8.09±0.05 cgs |
| Temperature | 12381±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 | |
| SIMBAD | data |
| ARICNS | data |
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.[7] The white dwarf designation was confirmed spectroscopically in 1970 by astronomer Jesse L. Greenstein of the California Institute of Technology.[8] Observations made by John McGraw et al. during 1979 and 1980 showed that G 185-32 is a variable star.[1] It was given its variable star designation in 1985.[9]
