S Crucis

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.^[2] It is a yellow-white supergiant that pulsates between spectral types F6Ib-II and G1Ib-II.^[2]

S Crucis

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Crux
Right ascension	12h 54m 21.99728s[1]
Declination	−58° 25′ 50.2146″[1]
Apparent magnitude (V)	6.22 - 6.92[2]
Characteristics
Spectral type	F6-G1Ib-II[2]
Variable type	δ Cep[2]
Astrometry
Radial velocity (Rv)	−6.10[3] (−21.1 - 5.9)[4] km/s
Proper motion (μ)	RA: −9.480[1] mas/yr Dec.: 3.987[1] mas/yr
Parallax (π)	1.0215±0.0448 mas[1]
Distance	3,200 ± 100 ly (980 ± 40 pc)
Absolute magnitude (MV)	-3.27[5]
Details
Radius	37.9[6] R☉
Surface gravity (log g)	1.2 - 1.9[4] cgs
Temperature	5,517 - 6,482[4] K
Metallicity [Fe/H]	−0.07 - 0.16[4] dex
Age	116[7] Myr
Other designations
CD−57°4766, HD 112044, HIP 62986, HR 4895, SAO 240362[8]
Database references
SIMBAD	data

Light curve of the classical Cepheid variable S Crucis recorded by NASA's Transiting Exoplanet Survey Satellite (TESS)

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.^[6] Over the same cycle, the effective temperature varies between 5,517 K and 6,482 K.^[4] The star is thought to be 116 million years old; it has exhausted its core hydrogen and left the main sequence.^[7]