Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Apus |
Right ascension | 15h 12m 33.97907s[1] |
Declination | −72° 46′ 14.1634″[1] |
Apparent magnitude (V) | 6.02±0.01[2] |
Characteristics | |
Spectral type | B8 IV[3] |
U−B color index | −0.24[4] |
B−V color index | 0.00[4] |
Astrometry | |
Radial velocity (Rv) | −13.7±1.3[5] km/s |
Proper motion (μ) | RA: −14.107 mas/yr[1] Dec.: −16.361 mas/yr[1] |
Parallax (π) | 3.8088 ± 0.0418 mas[1] |
Distance | 856 ± 9 ly (263 ± 3 pc) |
Absolute magnitude (MV) | −1.34[6] |
Details | |
Mass | 3.72+0.09 −0.05[1] M☉ |
Radius | 6.35[7] R☉ |
Luminosity | 364+15 −14[1] L☉ |
Surface gravity (log g) | 3.48[8] cgs |
Temperature | 10,250[9] K |
Metallicity [Fe/H] | 0.00[10] dex |
Age | 202+23 −2[1] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 133981, also known as HR 5628, is a solitary, bluish-white hued star located in the southern circumpolar constellation of Apus. It has an apparent magnitude of 6.02,[2] allowing it to be faintly visible to the naked eye in ideal conditions. The object is located relatively far at a distance of 856 light years based on parallax measurements from Gaia DR3[1] but is approaching the Solar System with a heliocentric radial velocity of −13.7 km/s.[5]
HD 133981 has a stellar classification of B8 IV,[3] indicating that it is a B-type star that is evolving towards the red giant branch. Houk and Cowley (1975) gave a slightly more evolved class of B8/9 III,[13] instead indicating that it is a giant star. Some evolutionary models show that it is a star just reaching the end of the main sequence.[1] Nevertheless, it has 3.72 times the mass of the Sun[1] and 6.35 times its girth.[7] It radiates 364 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 10,250 K.[9] HD 133981 is said to be 202 million years old.[1]
HD 133981 lies in front of the distant faint galaxy LEDA 54288.[14] A debris disk has been detected around the star. It has 22.5 times the mass of the Earth and an equilibrium temperature of 27 K.[9]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
' | 1,851 AU | — | — |