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Alpha Gruis
Star in the constellation Grus / From Wikipedia, the free encyclopedia
Alpha Gruis is the brightest star in the southern constellation of Grus. It is officially named Alnair;[1] Alpha Gruis is the star's Bayer designation, which is Latinized from α Gruis and abbreviated α Gru. With an magnitude of 1.74, it is one of the brightest stars in the sky and one of the fifty-eight stars selected for celestial navigation. Alpha Gruis is a single, B-type main-sequence star located at a distance of 31 pc.
Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Grus |
Pronunciation | /ælˈnɛər/[1] |
Right ascension | 22h 08m 13.98473s[2] |
Declination | −46° 57′ 39.5078″[2] |
Apparent magnitude (V) | +1.74[3] |
Characteristics | |
Spectral type | B6 V[4] |
U−B color index | −0.47[3] |
B−V color index | −0.13[3] |
Astrometry | |
Radial velocity (Rv) | +11.8[5] km/s |
Proper motion (μ) | RA: +126.69[2] mas/yr Dec.: −147.47[2] mas/yr |
Parallax (π) | 32.29 ± 0.21 mas[2] |
Distance | 101.0 ± 0.7 ly (31.0 ± 0.2 pc) |
Absolute magnitude (MV) | −0.721±0.031[6] |
Details | |
Mass | 3.82[7] M☉ |
Radius | 3.7[8][lower-alpha 1] R☉ |
Luminosity | 520[9] L☉ |
Surface gravity (log g) | 3.76±0.11[10] cgs |
Temperature | 14,245±484[7] K |
Metallicity [Fe/H] | −0.13±0.02[11] dex |
Rotational velocity (v sin i) | 215[12][7] km/s |
Age | 100[13] Myr |
Other designations | |
Database references | |
SIMBAD | data |
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