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Beta2 Sagittarii
Star in the constellation Sagittarius / From Wikipedia, the free encyclopedia
Beta2 Sagittarii (β2 Sagittarii, abbreviated Beta2 Sgr, β2 Sgr) is a star in the zodiac constellation of Sagittarius. It is visible to the naked eye, having an apparent visual magnitude of +4.29.[2] Based upon an annual parallax shift of 24.31 mas as seen from Earth,[1] it is located 134 light-years from the Sun.
For other stars with this Bayer designation, see β Sagittarii.
Quick Facts Constellation, Right ascension ...
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Sagittarius |
Right ascension | 19h 23m 13.13745s[1] |
Declination | −44° 47′ 59.2051″[1] |
Apparent magnitude (V) | +4.29[2] |
Characteristics | |
Spectral type | F2/3 V[3] or F2 III[4] |
U−B color index | +0.07[2] |
B−V color index | +0.34[2] |
Astrometry | |
Radial velocity (Rv) | +19.0[5] km/s |
Proper motion (μ) | RA: +93.45[1] mas/yr Dec.: −54.09[1] mas/yr |
Parallax (π) | 24.31 ± 0.19 mas[1] |
Distance | 134 ± 1 ly (41.1 ± 0.3 pc) |
Absolute magnitude (MV) | +1.20[6] |
Details | |
Mass | 1.43[7] M☉ |
Luminosity | 20[8] L☉ |
Surface gravity (log g) | 3.57[7] cgs |
Temperature | 7,035±239[7] K |
Metallicity [Fe/H] | −0.54[5] dex |
Rotational velocity (v sin i) | 155[9] km/s |
Age | 933[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Close
Based upon variations in its proper motion, this is a probable astrometric binary system.[11] As such, its two components would be designated Beta2 Sagittarii A (officially named Arkab Posterior /ˈɑːrkæb pɒˈstɪəriər/, the traditional name of the system)[12][13] and B.