Iota Crucis

ι Crucis, Latinized as Iota Crucis, is a wide double star in the southern constellation of Crux.^[6] It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4^m.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.^[1]

Iota Crucis

Observation data Epoch J2000      Equinox J2000
Constellation	Crux
Right ascension	12h 45m 38.05019s[1]
Declination	−60° 58′ 52.7536″[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[1] km/s
Proper motion (μ)	RA: 112.968[1] mas/yr Dec.: −65.830[1] mas/yr
Parallax (π)	26.0909±0.2150 mas[1]
Distance	125 ± 1 ly (38.3 ± 0.3 pc)
Absolute magnitude (MV)	+1.86[2]
Details
ι Cru A
Radius	7.26+0.23 −0.25[1] R☉
Luminosity	24.0±0.2[1] L☉
Surface gravity (log g)	2.79±0.22[5] cgs
Temperature	4,824±44[5] K
Metallicity [Fe/H]	+0.07±0.03[5] dex
Other designations
ι Cru, CPD−60°4273, HD 110829, HIP 62268, HR 4842, SAO 252016[6]
Database references
SIMBAD	data

The primary component is an aging giant star with a stellar classification of K0 III.^[3] Having exhausted the supply of hydrogen at its core, the star has cooled and expanded off the main sequence, and now has over seven times the girth of the Sun. It is radiating 24 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,824 K.^[1]

The secondary is a magnitude 10.24 star 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,"^[7] whereas Eggleton and Tokovinin (2008) list it as a binary system.^[8] Gaia Data Release 2 gives a parallax of 1.0868±0.0391 mas for the companion, implying a distance around 1,000 pc.^[9]