Iota Crucis
Star in the constellation Crux
From Wikipedia, the free encyclopedia
ι Crucis, Latinized as Iota Crucis, is a star in the southern constellation of Crux.[7] It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4m.69.[2] This object is located 125 light-years from the Sun, based on parallax, and is drifting further away with a radial velocity of +7.5 km/s.[5]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Crux |
| Right ascension | 12h 45m 38.05167s[1] |
| Declination | −60° 58′ 52.7563″[1] |
| Apparent magnitude (V) | 4.69[2] |
| Characteristics | |
| Spectral type | K0 III[3] |
| U−B color index | +0.93[4] |
| B−V color index | +1.05[4] |
| Astrometry | |
| Radial velocity (Rv) | +7.45±0.12[5] km/s |
| Proper motion (μ) | RA: +112.266 mas/yr[1] Dec.: −65.641 mas/yr[1] |
| Parallax (π) | 26.1753±0.0952 mas[1] |
| Distance | 124.6 ± 0.5 ly (38.2 ± 0.1 pc) |
| Absolute magnitude (MV) | +1.86[2] |
| Details[6] | |
| Mass | 1.45±0.11 M☉ |
| Radius | 6.57±0.19 R☉ |
| Luminosity | 20.9±0.5 L☉ |
| Surface gravity (log g) | 2.920±0.149 cgs |
| Temperature | 4,815±60 K |
| Metallicity [Fe/H] | +0.148±0.038 dex |
| Other designations | |
| ι Cru, CPD−60°4273, HD 110829, HIP 62268, HR 4842, SAO 252016[7] | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K0 III.[3] It has 1.45 times the mass of the Sun. Having exhausted the supply of hydrogen at its core, the star has cooled and expanded off the main sequence, and now has 6.57 times the radius of the Sun. It is radiating 20.9 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,815 K.[6]
There is a magnitude 10.24 star named CPD-60 4273B (B8V) at an angular separation of 29.7″ from the primary, along a position angle of 2° as of 2015. The Washington Double Star Catalog (2001) notes this is an "optical pair, based on study of relative motion of the components,"[8] whereas Eggleton and Tokovinin (2008) list it as a binary system.[9] However, astrometric measurements by the Gaia spacecraft confirm the companion is not gravitationally bound, with a measured parallax of 1.1416±0.0162 mas implying a distance around 876 pc (2,860 ly), as well as radically different proper motions.[10]