Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Orion |
Right ascension | 05h 56m 25.45999s [2] |
Declination | +05° 21′ 48.4432″ [2] |
Apparent magnitude (V) | 14.105 [3] |
Characteristics | |
Spectral type | DAP8.9 [4] |
Apparent magnitude (B) | 14.69 [5] |
Apparent magnitude (V) | 14.10 [5] |
Apparent magnitude (R) | 14.0 [5] |
Apparent magnitude (I) | 13.6 [5] |
Apparent magnitude (J) | 12.930 ± 0.022 [5] |
Apparent magnitude (H) | 12.720 ± 0.025 [5] |
Apparent magnitude (K) | 12.653 ± 0.024 [5] |
Astrometry | |
Radial velocity (Rv) | −414.02±10.41 [2] km/s |
Proper motion (μ) | RA: -444.685 mas/yr [2] Dec.: -925.140 mas/yr [2] |
Parallax (π) | 123.1989±0.0170 mas [2] |
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 | |
V1201 Ori, GJ 1087, EG GR 290, G 99-47, G 102-40, G 106-15, LHS 212, LTT 17891, NLTT 15834, WD 0553+053, 2MASS J05562547+0521486, USNO-B1.0 0953-00073703 [5] | |
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 the 10th-closest known white dwarf, the next closest after LP 658-2 and GJ 3991 B. [7]
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. [8]