White dwarf star in the constellation Orion
LP 658-2 Observation dataEpoch 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−Vcolor index 1.0[ 3] [ 2] Astrometry Proper motion (μ)RA: mas /yr [ 1] Dec.: mas /yr [ 1] Parallax (π)155.2373± 0.0175 mas [ 1] Distance 21.010 ± 0.002 ly pc ) Absolute magnitude (MV )15.44 ± 0.03[ 4] Details[ 2] From Holberg etal. (2008) Mass ± 0.01M ☉ Radius 0.014[ 2] [ note 1] R ☉ Surface gravity (log g )± 0.02[ 2] cgs Temperature ± 70[ 2] K Age 6.42[ 5] [ note 2] Gyr Details[ 4] From Subasavage etal. (2009) Mass ± 0.01M ☉ Radius 0.010 R ☉ Surface gravity (log g )± 0.01cgs Temperature ± 70K Age ± 0.02[ note 2] Gyr Other designations HL 4,GJ 223.2GJ 9193 ,EG GR 45G 99-44G 106-12LHS 32LP 658-2NLTT 15811WD 0552-041[ 3] Database references SIMBAD data
LP 658-2 is a degenerate (white dwarf )star in theconstellation ofOrion ,[ 3] apparent visual magnitude of approximately 14.488.[ 2]
According to a 2009 paper, it is the eighth closest known white dwarf to the Sun (afterSirius B ,Procyon B ,van Maanen's star ,Gliese 440 ,40 Eridani B ,Stein 2051 B andGJ 1221 ).[ 6] trigonometric parallax from the CTIOPI (Cerro Tololo Inter-American Observatory (CTIO) Parallax Investigation) 0.9 m telescope program, published in 2009, is 0.15613 ± 0.00084arcsec ,[ 4] pc , or 20.89 ± 0.11ly . 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]
Physical parameters [ edit ] There are two sets of published physical parameters of LP 658-2, significantly differing from each other: one fromHolberg et al. 2008 andSion et al. 2009 , the other fromSubasavage 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 aK-type main sequence star .
^ From surface gravity and mass. ^a b White dwarf cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star) ^a b c d Vallenari, A.; et al. (Gaia collaboration) (2023)."Gaia Data Release 3. Summary of the content and survey properties" .Astronomy and Astrophysics .674 : A1.arXiv :2208.00211 Bibcode :2023A&A...674A...1G .doi :10.1051/0004-6361/202243940 S2CID 244398875 . Gaia DR3 record for this source atVizieR .^a b c d e f g h i 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.Bibcode :2008AJ....135.1225H .doi :10.1088/0004-6256/135/4/1225 ^a b c d "GJ 223.2" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2011-01-17 .^a b c d e f g h i 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.arXiv :0902.0627 Bibcode :2009AJ....137.4547S .doi :10.1088/0004-6256/137/6/4547 .S2CID 14696597 . ^ 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.arXiv :0910.1288 Bibcode :2009AJ....138.1681S .doi :10.1088/0004-6256/138/6/1681 .S2CID 119284418 . ^ Table 1 inSion et al. 2009 ^ 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 .^ Costa, Edgardo; Méndez, René A.; Jao, W.-C.; Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Ianna, Philip A.;Bartlett, Jennifer (July 2005)."The solar neighborhood. XIV. Parallaxes from the Cerro Tololo Inter-American Observatory Parallax Investigation—First results from the 1.5 m telescope program" .The Astronomical Journal .130 (1):337– 349.Bibcode :2005AJ....130..337C .doi :10.1086/430473
