Eta Crucis

η Crucis
Location of Mimosa (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Crux
Right ascension 12h 06m 52.89814s
Declination −64° 36 49.4305
Apparent magnitude (V) 4.14
Characteristics
Spectral type F2 V
U−B color index +0.00
B−V color index +0.35
Astrometry
Radial velocity (Rv)+13.13±0.26 km/s
Proper motion (μ) RA: +34.270 mas/yr
Dec.: −36.902 mas/yr
Parallax (π)50.7919±0.1049 mas
Distance64.2 ± 0.1 ly
(19.69 ± 0.04 pc)
Absolute magnitude (MV)2.67
Details
Mass1.51±0.04 M
Radius1.854±0.005 R
Luminosity6.901+0.027
−0.029
 L
Surface gravity (log g)4.01±0.00 cgs
Temperature6,830 K
Metallicity [Fe/H]−0.04 dex
Rotational velocity (v sin i)46.1±2.3 km/s
Age1.63±0.29 Gyr
Other designations
η Cru, CD−63°2145, GJ 455.2, GJ 9388, HD 105211, HIP 59072, HR 4616, SAO 251742
Database references
SIMBADdata

Eta Crucis (η Crucis) is a solitary star in the southern constellation of Crux. It can be seen with the naked eye, having an apparent visual magnitude of 4.14m. Based upon parallax measurements, η Crucis is located at a distance of 64 light-years. The system made its closest approach about 1.6 million years ago when it achieved perihelion at a distance of roughly 26 light years.

This is an F-type main sequence star with a stellar classification of F2 V. It has 151% of the Sun's mass, 185% of the Sun's radius and shines with 6.9 times the luminosity of the Sun from its outer atmosphere with an effective temperature of 6,830 K.

Eta Crucis has a pair of visual companions. Component B is a magnitude 11.80 star located at an angular separation of 48.30 along a position angle of 300°, as of 2010. Component C has a magnitude of 12.16 and lies at an angular separation of 35.50″ along a position angle of 194°, as of 2000.