S Crucis

S Crucis
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Crux
Right ascension 12h 54m 21.99728s
Declination −58° 25 50.2146
Apparent magnitude (V) 6.22 - 6.92
Characteristics
Spectral type F6-G1Ib-II
Variable type δ Cep
Astrometry
Radial velocity (Rv)−6.10 (−21.1 - 5.9) km/s
Proper motion (μ) RA: −9.480 mas/yr
Dec.: 3.987 mas/yr
Parallax (π)1.0215±0.0448 mas
Distance3,200 ± 100 ly
(980 ± 40 pc)
Absolute magnitude (MV)-3.27
Details
Radius37.9 R
Surface gravity (log g)1.2 - 1.9 cgs
Temperature5,517 - 6,482 K
Metallicity [Fe/H]−0.07 - 0.16 dex
Age116 Myr
Other designations
CD−57°4766, HD 112044, HIP 62986, HR 4895, SAO 240362
Database references
SIMBADdata

S Crucis is a star in the constellation Crux. A Cepheid variable, its apparent magnitude ranges from 6.22 to 6.92 over 4.68997 d. It is a yellow-white supergiant that pulsates between spectral types F6Ib-II and G1Ib-II.

S Crucis is a pulsating variable star of the δ Cephei type, a Classical Cepheid variable. Its mean radius is 37.9 R and that radius varies by up to 4.1 R during its 4.7-day pulsation cycle. Over the same cycle, the effective temperature varies between 5,517 K and 6,482 K. The star is thought to be 116 million years old; it has exhausted its core hydrogen and left the main sequence.