Star in the constellation Orion
G 99-47
Observation dataEpoch J2000 [ 2] Equinox J2000 [ 2]
Constellation
Orion
Right ascension
05h 56m 25.47s [ 2]
Declination
+05° 21′ 48.6″[ 2]
Apparent magnitude (V)
14.105[ 3]
Characteristics
Spectral type
DAP8.9[ 4]
Apparent magnitude (B)
14.69[ 2]
Apparent magnitude (V)
14.10[ 2]
Apparent magnitude (R)
14.0[ 2]
Apparent magnitude (I)
13.6[ 2]
Apparent magnitude (J)
12.930 ± 0.022[ 2]
Apparent magnitude (H)
12.720 ± 0.025[ 2]
Apparent magnitude (K)
12.653 ± 0.024[ 2]
Astrometry Proper motion (μ) RA: -444.685[ 5] mas /yr Dec.: -925.140[ 5] mas /yr Parallax (π)123.1989 ± 0.0170 mas [ 5] Distance 26.474 ± 0.004 ly (8.117 ± 0.001 pc ) Absolute magnitude (MV )14.59[ 3] [ 6] [ note 1]
Details Mass 0.71 ± 0.03[ 3] M ☉ Radius 0.011[ 3] [ note 2] R ☉ Surface gravity (log g )8.20 ± 0.05[ 3] cgs Temperature 5790 ± 110[ 3] K Age 3.97[ 4] [ note 3] Gyr
Other designations WD 0553+053,
[ 3] [ 4] V 1201 Ori,
[ 2] LHS 212,
[ 3] LTT 17891,
[ 2] NLTT 15834,
[ 2] G 099-047,
[ 6] GJ 1087,
[ 2] G 102-40,
[ 2] G 106-15,
[ 2] EGGR 290,
[ 2] 2MASS J05562547+0521486,
[ 2] USNO-B1.0 0953-00073703, Gaia DR2 3320184202856027776
[ 2]
Database references SIMBAD data
G 99-47 (V1201 Orionis) is a nearby degenerate star (white dwarf ) of spectral class DAP8 (DAP8.9,[ 4] or DAP8.7[ 3] ), the single known component of the system, located in the constellation Orion . G 99-47 is probably the tenth closest white dwarf, followed by Gliese 293 , Gliese 518 and Gliese 915 .
The mass of G 99-47 is 0.71± 0.03 Solar masses ;[ 3] its surface gravity is 108.20 ± 0.05 (1.58 · 108 ) cm·s−2 ,[ 3] or approximately 162 000 of Earth's , corresponding to a radius 7711 km, or 121% of Earth's . Its temperature is 5790 ± 110 K ,[ 3] almost like the Sun 's; its cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star) is 3.97 Gyr .[ 4] Due almost equal to the Sun's temperature, GJ 1087 should appear almost the same white color as the Sun. The white dwarf has a strong magnetic field, with measured vertical component near surface equal to 560 T .[ 7]
See also
Notes
^ From apparent magnitude and parallax.
^ From surface gravity and mass.
^ White dwarf cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star)
References
^ Brinkworth, Carolyn S.; Burleigh, Matthew R.; Lawrie, Katherine; Marsh, Thomas R.; Knigge, Christian (August 2013). "Measuring the Rotational Periods of Isolated Magnetic White Dwarfs" . The Astrophysical Journal . 773 (1): 47. Bibcode :2013ApJ...773...47B . doi :10.1088/0004-637X/773/1/47 . hdl :2381/37593 . S2CID 56285149 .
^ a b c d e f g h i j k l m n o p q r s t "V* V1201 Ori -- White Dwarf" . Centre de Données astronomiques de Strasbourg . Retrieved 2011-11-01 .
^ a b c d e f g h i j k l
Holberg, J. B.; Sion; Oswalt; McCook; Foran; Subasavage (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 . S2CID 122855486 .
^ a b c d e
Sion, Edward M.; Holberg; Oswalt; McCook; Wasatonic (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 .
^ a b c Brown, A. G. A. ; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties" . Astronomy & Astrophysics . 649 : A1. arXiv :2012.01533 . Bibcode :2021A&A...649A...1G . doi :10.1051/0004-6361/202039657 . S2CID 227254300 . (Erratum: doi :10.1051/0004-6361/202039657e ) . Gaia EDR3 record for this source at VizieR .
^ a b Yale Trigonometric Parallaxes, Fourth Edition (van Altena+ 1995)
^ Bagnulo, Stefano; Landstreet, John D. (2020), "Discovery of six new strongly magnetic white dwarfs in the 20 pc local population", Astronomy & Astrophysics , 643 : A134, arXiv :2010.05795 , Bibcode :2020A&A...643A.134B , doi :10.1051/0004-6361/202038565 , S2CID 222290583