G 99-47

Coordinates: 05^h 56^m 25.47^s, +05° 21′ 48.6″

G 99-47 (V1201 Orionis) is a nearby degenerate star (white dwarf) of spectral class DAP8 (DAP8.9, or DAP8.7), the single known component of the system, located in the constellation Orion.

Distance

G 99-47 is probably the tenth closest white dwarf (or possibly the 9th–12th: see Gliese 293, Gliese 518 and Gliese 915). Its trigonometric parallax from the Yale Parallax Catalog is 0.1250 ± 0.0036 arcsec, corresponding to a distance 8.00 ± 0.23 pc, or 26.09 ± 0.75 ly.

Parallax data

Physical parameters

G 99-47's mass is 0.71 ± 0.03 Solar masses; its surface gravity is 10^{8.20 ± 0.05} (1.58 · 10⁸) cm·s⁻², or approximately 162 000 of Earth's, corresponding to a radius 7711 km, or 121% of Earth's.

Its temperature is 5790 ± 110 K, 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. Due almost equal to the Sun's temperature, GJ 1087 should appear almost the same color as the Sun.