Iota Cancri

ι Cancri
Location of ι Cancri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cancer
ι Cnc A
Right ascension 08h 46m 41.81988s
Declination +28° 45 35.6190
Apparent magnitude (V) 4.02
ι Cnc B
Right ascension 08h 46m 39.98118s
Declination +28° 45 54.1932
Apparent magnitude (V) 6.57
Characteristics
Spectral type G8IIIa Ba0.2 + A2V
Astrometry
ι Cnc A
Radial velocity (Rv)15.74 ± 0.13 km/s
Proper motion (μ) RA: -21.58 ± 0.75 mas/yr
Dec.: -45.69 ± 0.56 mas/yr
Parallax (π)9.85±0.61 mas
Distance330 ± 20 ly
(102 ± 6 pc)
Absolute magnitude (MV)0.79
ι Cnc B
Radial velocity (Rv)25.00 ± 1.5 km/s
Proper motion (μ) RA: -22.74 ± 3.45 mas/yr
Dec.: -46.36 ± 2.56 mas/yr
Parallax (π)11.69 ± 2.75 mas
Distanceapprox. 280 ly
(approx. 90 pc)
Details
ι Cnc A
Mass3.43 M
Radius21 R
Luminosity204 L
Surface gravity (log g)2.5 cgs
Temperature4,954 K
Metallicity [Fe/H]0.14 dex
Rotational velocity (v sin i)170 km/s
ι Cnc B
Luminosity14.39 L
Temperature8,786 K
Age263 Myr
Other designations
48 Cancri
Iota Cancri A: HR 3475, HD 74739, BD+29°1824, HIP 43103, SAO 80416
Iota Cancri B: HR 3474, HD 74738, BD+29°1823, HIP 43100, SAO 80415
Database references
SIMBADdata

Iota Cancri (ι Cnc, ι Cancri) is a double star in the constellation Cancer approximately 300 light years from Earth.

The two stars of ι Cancri are separated by 30 arcseconds, changing only slowly. Although no orbit has been derived, the two stars show a large common proper motion and are assumed to be gravitationally related.

The brighter star, ι Cancri A, is a yellow G-type giant with an apparent magnitude of +4.02. It is a mild barium star, thought to be formed by mass transfer of enriched material from an asymptotic giant branch star onto a less evolved companion. No such donor has been detected in the ι Cancri system, but it is assumed that there is an unseen white dwarf.

The fainter of the two stars, ι Cancri B, is a white A-type main sequence dwarf with an apparent magnitude of +6.57. It is a shell star, surrounded by material expelled by its rapid rotation.