32 Eridani

32 Eridani
Location of 32 Eridani (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Eridanus
Right ascension 03h 54m 17.50181s
Declination −02° 57′ 17.0397″
Apparent magnitude (V) 4.45
Observation data
Epoch J2000      Equinox J2000
Constellation Eridanus
32 Eridani A
Right ascension 03h 54m 17.50s
Declination −02° 57′ 17.0″
Apparent magnitude (V) 4.79
32 Eridani B
Right ascension 03h 54m 17.41s
Declination −02° 57′ 10.3″
Apparent magnitude (V) 6.14
Characteristics
32 Eridani A
Evolutionary stage giant star
Spectral type G8III
32 Eridani B
Evolutionary stage main sequence
Spectral type A1V
Astrometry
A
Proper motion (μ) RA: +26.330 mas/yr
Dec.: +0.079 mas/yr
Parallax (π)9.4562±0.1108 mas
Distance345 ± 4 ly
(106 ± 1 pc)
B
Proper motion (μ) RA: +26.878 mas/yr
Dec.: +1.007 mas/yr
Parallax (π)9.6777±0.0623 mas
Distance337 ± 2 ly
(103.3 ± 0.7 pc)
Position (relative to 32 Eridani A)
Component32 Eridani B
Epoch of observation2021
Angular distance6.90
Position angle349°
Details
32 Eridani A
Mass1.29 M
Radius14.6 R
Luminosity138 L
Surface gravity (log g)2.63 cgs
Temperature4,970 K
Metallicity [Fe/H]−0.16 dex
Rotational velocity (v sin i)2.7 km/s
Age706 Myr
32 Eridani B
Mass2.36 M
Radius2.32 R
Luminosity36 L
Temperature9,294 K
Rotational velocity (v sin i)180 km/s
Age461 Myr
Other designations
32 Eri, HIP 18255
32 Eridani A: HD 24555, HR 1212
32 Eridani B: HD 24554, HR 1211
Database references
SIMBADdata
A
B

32 Eridani (abbreviated 32 Eri) is a binary star in the constellation of Eridanus. The two stars are designated HD 24555 (32 Eridani A) and HD 24554 (32 Eridani B). They share a single entry in the Hipparcos catalogue, HIP 18255, but have separate entries in the Bright Star Catalogue, HR 1212 and HR 1211.

32 Eridani is visible to the naked eye as a single star with an apparent magnitude of 4.45. Individually, 32 Eridani A shines at magnitude 4.79 while 32 Eridani B has a magnitude of 6.14. As of 2021, the pair had an angular separation of about 6.90 arcseconds with a position angle of 349°.

Based on measurements of parallax by the Gaia mission, the system lies at a distance of about 340 light-years (22,000,000 AU) from Earth.

The primary component, 32 Eridani A, is an evolved yellow giant star of spectral type G8III. It has a radius about 15 times that of the Sun and a luminosity around 138 times solar, with an effective temperature of about 4,970 K.

The secondary component, 32 Eridani B, is a main-sequence star of spectral type A1V. It has a surface temperature of roughly 9,294 K and rotates rapidly with a projected rotational velocity of about 180 km/s, giving the star a noticeably flattened shape due to its rotation.