Astronomy:LP 658-2
Coordinates: 
05h 55m 09.53s, −04° 10′ 07.1″
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 55m 09.53s[1] |
| Declination | −04° 10′ 07.1″[1] |
| Apparent magnitude (V) | 14.488[2] |
| Characteristics | |
| Spectral type | DZ11.8[2] |
| Apparent magnitude (B) | 15.49[1] |
| Apparent magnitude (V) | 14.488[2] |
| Apparent magnitude (RKC) | 13.99[3] |
| Apparent magnitude (IKC) | 13.51[3] |
| Apparent magnitude (J) | 13.05 ± 0.03[3] |
| Apparent magnitude (H) | 12.86 ± 0.03[3] |
| Apparent magnitude (KS) | 12.78 ± 0.03[3] |
| B−V color index | 1.0[1][2] |
| Astrometry | |
| Proper motion (μ) | RA: 535.249±0.017[4] mas/yr Dec.: −2317.011±0.015[4] mas/yr |
| Parallax (π) | 155.2373 ± 0.0175[4] mas |
| Distance | 21.010 ± 0.002 ly (6.4418 ± 0.0007 pc) |
| Absolute magnitude (MV) | 15.44 ± 0.03[3] |
| 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[3] | |
| 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,[1] the single known object in its system. It has an apparent visual magnitude of approximately 14.488.[2]
Distance
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).[7] 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,[3] 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 | [6] |
| CTIOPI 0.9 m | TSN-21 (Subasavage et al., 2009) | 156.13 ± 0.84 | 6.40 ± 0.03 | 20.89 ± 0.11 | [3] |
Physical parameters
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.
Color
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.
Notes
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "GJ 223.2". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=GJ+223.2.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Holberg, J. B.; Sion, E. M.; Oswalt, T.; McCook, G. P.; Foran, S.; Subasavage, John P. (1 April 2008). "A new look at the local white dwarf population". The Astronomical Journal 135 (4): 1225–1238. doi:10.1088/0004-6256/135/4/1225. Bibcode: 2008AJ....135.1225H.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Subasavage, John P.; Jao, Wei-Chun; Henry, Todd J.; Bergeron, P.; Dufour, P.; Ianna, Philip A.; Costa, Edgardo; Méndez, René A. (1 June 2009). "The solar neighborhood. XXI. Parallax results from the CTIOPI 0.9 m program: 20 new members of the 25 parsec white dwarf sample". The Astronomical Journal 137 (6): 4547–4560. doi:10.1088/0004-6256/137/6/4547. Bibcode: 2009AJ....137.4547S.
- ↑ 4.0 4.1 4.2 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ Sion, Edward M.; Holberg, J. B.; Oswalt, Terry D.; McCook, George P.; Wasatonic, Richard (1 December 2009). "The white dwarfs within 20 parsecs of the Sun: kinematics and statistics". The Astronomical Journal 138 (6): 1681–1689. doi:10.1088/0004-6256/138/6/1681. Bibcode: 2009AJ....138.1681S.
- ↑ 6.0 6.1 van Altena, W. F.; Lee, J. T.; Hoffleit, E. D. (1995). The General Catalogue of Trigonometric [Stellar] Parallaxes (4th ed.). New Haven, CT: Yale University Observatory. Bibcode: 1995gcts.book.....V. VizieR entry.
- ↑ Table 1 in Sion et al. 2009
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