Eta Crucis

η Crucis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Crux
Right ascension 12h 06m 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]
Distance64.4 ± 0.2 ly
(19.76 ± 0.05 pc)
Absolute magnitude (MV)2.67[5]
Details
Radius1.3[6] R☉
Luminosity7[7] L☉
Surface gravity (log g)4.01[3] cgs
Temperature6,964[5] K
Metallicity [Fe/H]−0.04[3] dex
Rotational velocity (v sin i)46.1±2.3[5] km/s
Age2.53[8] Gyr
Other designations
η Cru, CD−63° 2145, GJ 9388, HD 105211, HIP 59072, HR 4616, SAO 251742.[9]
Database references
SIMBADdata

Eta Crucis (η Crucis) is a solitary[10] star in the southern constellation of Crux. 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]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcrv1953 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference vonEiff2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference cadars was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Beichman2006 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference aa575_A35 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).