Theta2 Crucis

For other stars with the name θ Crucis, see Theta Crucis.
θ2 Crucis

A light curve for Theta2 Crucis, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Crux
Right ascension 12h 04m 19.22008s[2]
Declination −63° 09′ 56.5167″[2]
Apparent magnitude (V) 4.70 - 4.74[3]
Characteristics
Spectral type B3 V[4]
U−B color index −0.61[5]
B−V color index −0.08[5]
Variable type β Cep[3]
Astrometry
Radial velocity (Rv)+16.3[6] km/s
Proper motion (μ) RA: −18.467[2] mas/yr
Dec.: +0.467[2] mas/yr
Parallax (π)4.7314 ± 0.1276 mas[2]
Distance690 ± 20 ly
(211 ± 6 pc)
Absolute magnitude (MV)−2.35[7]
Orbit[8]
Period (P)3.428 d
Eccentricity (e)0.00
Periastron epoch (T)2419604.367 JD
Semi-amplitude (K1)
(primary)		51.3 km/s
Details
Mass5.9[2] M☉
Radius6.9[2] R☉
Luminosity1,935[2] L☉
Surface gravity (log g)3.55[2] cgs
Temperature15,361[2] K
Metallicity [Fe/H]+0.20[2] dex
Rotational velocity (v sin i)23[9] km/s
Age18.5[10] Myr
Other designations
θ2 Cru, CD−62°610, HD 104841, HIP 58867, HR 4603, SAO 251717[11]
Database references
SIMBADdata

Theta2 Crucis, Latinized from θ2 Crucis, is a spectroscopic binary star in the constellation Crux. This pair of stars complete an orbit every 3.4280 days and they have a low orbital eccentricity that is close to 0.0.[12] Theta2 Crucis is located at about 690 light-years from the Sun.

Since a member of the system is a β Cephei-type variable star, the magnitude is not fixed but varies slightly between +4.70 and +4.74. The period of this variability is 0.0889 days.[3] The system is categorized as is a blue-white B-type main sequence star with a stellar classification of B3 V,[4] although it has also been classified as a subgiant.[13] Evolutionary models show it at a late stage of its main sequence life.[2]

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  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Pourbaix2004 was invoked but never defined (see the help page).
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  10. ^ Cite error: The named reference tetzlaff2011 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
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  13. ^ Cite error: The named reference skiff2014 was invoked but never defined (see the help page).