Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Grus |
Right ascension | 22h 16m 26.54790s [1] |
Declination | −41° 37′ 37.8266″ [1] |
Apparent magnitude (V) | 5.10 [2] |
Characteristics | |
Spectral type | G8 III [3] |
B−V color index | +0.92 [2] |
Astrometry | |
Radial velocity (Rv) | +12.50 [4] km/s |
Proper motion (μ) |
RA: −14.788
[1]
mas/
yr Dec.: −15.530 [1] mas/ yr |
Parallax (π) | 13.1578 ± 0.1559 mas [1] |
Distance | 248 ± 3
ly (76.0 ± 0.9 pc) |
Absolute magnitude (MV) | +0.56 [5] |
Details | |
Radius | 9.97+0.32 −0.20 [1] R☉ |
Luminosity | 56.37±0.78 [1] L☉ |
Temperature | 5009+52 −79 [1] K |
Other designations | |
Database references | |
SIMBAD | data |
Mu2 Gruis, Latinized from μ2 Gruis, is a yellow-hued star or star system in the southern constellation of Grus. It is a suspected astrometric binary, showing a variation in proper motion due to gravitational acceleration. [7] Mu2 Gruis is visible to the naked eye with an apparent visual magnitude of 5.10. [2] The distance to this system, as determined using an annual parallax shift of 13.2 mas as seen from the Earth, [1] is around 248 light years. It is drifting further away with a heliocentric radial velocity of +12.5 km/s. [4]
The primary component is an evolved giant star with a stellar classification of G8 III. [3] It is a periodic variable star, showing a change in brightness with an amplitude of 0.004 magnitude at the rate of 7.50983 times per day. [8] With the supply of hydrogen at its core exhausted, the star has cooled and expanded until now it has 10 times the radius of the Sun. It is radiating 56 [1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 5,009 K. [1]