Wolf 489

Coordinates: 13^h 36^m 31.81^s, +03° 40′ 45.9″

Wolf 489

Observation data Epoch J2000[1]      Equinox J2000[1]
Constellation	Virgo
Right ascension	13^h 36^m 31.81^s[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
Distance	26.9 ± 0.8 ly (8.2 ± 0.2 pc)
Absolute magnitude (MV)	15.08[2][4][note 1]
Details
Mass	0.55 ± 0.03[2] M☉
Radius	0.013[2][note 2] R☉
Surface gravity (log g)	7.95 ± 0.02[2] cgs
Temperature	5030 ± 120[2] K
Age	5.19[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
SIMBAD	data

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.

Distance

Wolf 489, probably, is the 12th closest white dwarf, or, possibly, 9th–14th (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

Source	Paper	Parallax, mas	Distance, pc	Distance, ly	Ref.
Woolley (1970)	Woolley et al., 1970	135 ± 12	7.4 ± 0.7	24.2 ± 2.1	[5]
GJ, 3rd version	Gliese, Jahreiss, 1991	122.2 ± 3.9	8.18 ± 0.26	26.69 ± 0.85	[6]
YPC, 4th edition	van Altena et al., 1995	121.4 ± 3.4	8.24 ± 0.23	26.87 ± 0.75	[4]

Physical parameters

Wolf 489's mass is 0.55 ± 0.03 Solar masses,^[2] its surface gravity is 10^{7.95 ± 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)

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)