Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Orion |
Right ascension | 05h 55m 09.53049s [1] |
Declination | −04° 10′ 07.0653″ [1] |
Apparent magnitude (V) | 14.488 [2] |
Characteristics | |
Spectral type | DZ11.8 [2] |
Apparent magnitude (B) | 15.49 [3] |
Apparent magnitude (V) | 14.488 [2] |
Apparent magnitude (RKC) | 13.99 [4] |
Apparent magnitude (IKC) | 13.51 [4] |
Apparent magnitude (J) | 13.05 ± 0.03 [4] |
Apparent magnitude (H) | 12.86 ± 0.03 [4] |
Apparent magnitude (KS) | 12.78 ± 0.03 [4] |
B−V color index | 1.0 [3] [2] |
Astrometry | |
Proper motion (μ) | RA: 535.249 mas/yr [1] Dec.: −2,317.011 mas/yr [1] |
Parallax (π) | 155.2373±0.0175 mas [1] |
Distance | 21.010 ± 0.002 ly (6.4418 ± 0.0007 pc) |
Absolute magnitude (MV) | 15.44 ± 0.03 [4] |
Details [2] | |
From Holberg etal. (2008) | |
Mass | 0.45±0.01 M☉ |
Radius | 0.014 [2] [note 1] R☉ |
Surface gravity (log g) | 7.80±0.02 [2] cgs |
Temperature | 4,270±70, [2] K |
Age | 6.42 [5] [note 2] Gyr |
Details [4] | |
From Subasavage etal. (2009) | |
Mass | 0.80±0.01 M☉ |
Radius | 0.010 R☉ |
Surface gravity (log g) | 8.35±0.01 cgs |
Temperature | 5,180±70 K |
Age | 6.82±0.02 [note 2] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
LP 658-2 is a degenerate (white dwarf) star in the constellation of Orion, [3] the single known object in its system. It has an apparent visual magnitude of approximately 14.488. [2]
According to a 2009 paper, it is the eighth closest known white dwarf to the Sun (after Sirius B, Procyon B, van Maanen's star, Gliese 440, 40 Eridani B, Stein 2051 B and GJ 1221). [6] Its trigonometric parallax from the CTIOPI (Cerro Tololo Inter-American Observatory (CTIO) Parallax Investigation) 0.9 m telescope program, published in 2009, is 0.15613 ± 0.00084 arcsec, [4] corresponding to a distance 6.40 ± 0.03 pc, or 20.89 ± 0.11 ly. Also, previous less precise parallax measurements of LP 658-2 present in YPC (Yale Parallax Catalog) and among results of CTIOPI 1.5 m telescope program:
LP 658-2 parallax measurements
Source | Paper | Parallax, mas | Distance, pc | Distance, ly | Ref. |
---|---|---|---|---|---|
YPC | van Altena et al., 1995 | 155.0 ± 2.1 | 6.45 ± 0.09 | 21.04 ± 0.29 | [7] |
CTIOPI 1.5 m | TSN-14 (Costa et al., 2005) | 156.93 ± 2.67 | 6.37 ± 0.11 | 20.78 ± 0.35 | [8] |
CTIOPI 0.9 m | TSN-21 (Subasavage et al., 2009) | 156.13 ± 0.84 | 6.40 ± 0.03 | 20.89 ± 0.11 | [4] |
There are two sets of published physical parameters of LP 658-2, significantly differing from each other: one from Holberg et al. 2008 and Sion et al. 2009, the other from Subasavage et al. 2009.
Despite it being classified as a "white" dwarf, it appears yellowish white rather than white, due to temperature, cooler than the Sun's and comparable with that of a K-type main sequence star.