Wolf 489

Wolf 489 (WD 1334+039, LHS 46, G 062-053, Gliese 518) is a nearby degenerate star (white dwarf) of spectral class DZ10.0[2][3]), the single known component of the system, located in the constellation Virgo.

Wolf 489 aka big wolf 489
Observation data
Epoch J2000[1]      Equinox J2000[1]
Constellation Virgo
Right ascension  13h 36m 31.81s[1]
Declination +03° 40′ 45.″[1]
Apparent magnitude (V) 14.66[2]
Characteristics
Spectral type DZ10.0[2][3]
Apparent magnitude (B) 15.59[1]
Apparent magnitude (V) 14.63[1]
Apparent magnitude (R) 14.0[1]
Apparent magnitude (I) 14.1[1]
Apparent magnitude (J) 13.06[1]
Apparent magnitude (H) 12.82[1]
Apparent magnitude (K) 12.69[1]
Astrometry
Proper motion (μ) RA: -3706[3] mas/yr
Dec.: -1149[3] mas/yr
Parallax (π)121.4 ± 3.4[4] mas
Distance26.9 ± 0.8 ly
(8.2 ± 0.2 pc)
Absolute magnitude (MV)15.08[2][4][note 1]
Details
Mass0.55 ± 0.03[2] M☉
Radius0.013[2][note 2] R☉
Surface gravity (log g)7.95 ± 0.02[2] cgs
Temperature5030 ± 120[2] K
Age5.19[3][note 3] Gyr
Other designations
WD 1334+039,[2][3] Wolf 489,[1] Gliese 518,[1] LHS 46,[2] LFT 1023,[1] LTT 13961,[1] NLTT 34618,[1] G 062-053,[4] G 62-53,[1] G 64-4,[1] EGGR 100,[1] 2MASS J13363181+0340458,[1] USNO-B1.0 0936-00229354[1]
Database references
SIMBADdata

Distance

Wolf 489, probably, is the 129th closest white dwarf, or, possibly, 129th–214th (see Gliese 293, GJ 1087, Gliese 915, GJ 1276 and Gliese 318). Its trigonometric parallax from YPC (Yale Parallax Catalog) is 121.4 ± 3.4 mas,[4] corresponding to a distance 8.24 ± 0.23 pc, or 26.87 ± 0.75 ly.

Wolf 489 parallax data
SourcePaperParallax, masDistance, pcDistance, lyRef.
Woolley (1970)Woolley et al., 1970135 ± 127.4 ± 0.724.2 ± 2.1[5]
GJ, 3rd versionGliese, Jahreiss, 1991122.2 ± 3.98.18 ± 0.2626.69 ± 0.85[6]
YPC, 4th editionvan Altena et al., 1995121.4 ± 3.48.24 ± 0.2326.87 ± 0.75[4]

Physical parameters

Wolf 489's mass is 0.55 ± 0.03 Solar masses,[2] its surface gravity is 107.95 ± 0.02 (8.91 · 107) cm·s−2,[2] or approximately 91 000 of Earth's, corresponding to a radius 9089 km, or 143% of Earth's.

Wolf 489's temperature is 5030 ± 120 K[2] (comparable with that of early K-type main sequence stars); its cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star) is 5.19 Gyr.[3] Despite its official classification as "white dwarf", Wolf 489 is not actually white due to low temperature, and should appear the same color as K-type main sequence stars, often referred to as "orange dwarfs".

Notes
  1. From apparent magnitude and parallax.
  2. From surface gravity and mass.
  3. White dwarf cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star)

See also

References
  1. "GJ 518 -- White Dwarf". Centre de Données astronomiques de Strasbourg. Retrieved 2011-11-02.
  2. Holberg, J. B.; Sion; Oswalt; McCook; Foran; Subasavage (2008). "A NEW LOOK AT THE LOCAL WHITE DWARF POPULATION". The Astronomical Journal. 135: 1225–1238. Bibcode:2008AJ....135.1225H. doi:10.1088/0004-6256/135/4/1225.
  3. Sion, Edward M.; Holberg; Oswalt; McCook; Wasatonic (2009). "THE WHITE DWARFS WITHIN 20 PARSECS OF THE SUN: KINEMATICS AND STATISTICS". The Astronomical Journal. 138: 1681–1689. arXiv:0910.1288. Bibcode:2009AJ....138.1681S. doi:10.1088/0004-6256/138/6/1681.
  4. Yale Trigonometric Parallaxes, Fourth Edition (van Altena+ 1995)
  5. Stars within 25 pc of the Sun (Woolley+ 1970)
  6. Nearby Stars, Preliminary 3rd Version (Gliese+ 1991)
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