| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Crux |
| Right ascension | 12h06m 52.89900s[1] |
| Declination | −64° 36′ 49.4244″[1] |
| Apparent magnitude (V) | 4.14[2] |
| Characteristics | |
| Spectral type | F2 V[3] |
| U−B color index | +0.00[2] |
| B−V color index | +0.35[2] |
| Astrometry | |
| Radial velocity (Rv) | +9.0[4] km/s |
| Proper motion (μ) | RA: +33.88[1] mas/yr Dec.: −37.02[1] mas/yr |
| Parallax (π) | 50.62 ± 0.12 mas[1] |
| Distance | 64.4 ± 0.2 ly (19.76 ± 0.05 pc) |
| Absolute magnitude (MV) | 2.67[5] |
| Details | |
| Radius | 1.3[6] R☉ |
| Luminosity | 7[7] L☉ |
| Surface gravity (log g) | 4.01[3] cgs |
| Temperature | 6,964[5] K |
| Metallicity [Fe/H] | −0.04[3] dex |
| Rotational velocity (v sin i) | 46.1±2.3[5] km/s |
| Age | 2.53[8] Gyr |
| Other designations | |
η Cru, CD−63° 2145, GJ 9388, HD 105211, HIP 59072, HR 4616, SAO 251742.[9] | |
| Database references | |
| SIMBAD | data |
Eta Crucis (η Crucis) is a solitary[10] star in the southern constellationofCrux. It can be seen with the naked eye, having an apparent visual magnitude of 4.14m.[2] Based upon parallax measurements,[1] η Crucis is located 64 light-years from the Sun. The system made its closest approach about 1.6 million years ago when it achieved perihelion at a distance of roughly 26 light years.[11]
This is an F-type main sequence star with a stellar classification of F2 V.[3] It has 130%[6] of the Sun's radius and shines with 7[7] times the luminosity of the Sun from an outer atmosphere with an effective temperature of 6,964 K.[5] Observations of the system using the Spitzer Space Telescope show a statistically significant infrared excess of emission at a wavelength of 70 μm. This suggests the presence of a circumstellar disk. The temperature of this material is below 70 K.[8]
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.[12]
{{cite web}}: CS1 maint: postscript (link)
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