HD 69863

This article is about C Carinae. For c Carinae, see HD 76728.

HD 69863 is a binary star^[11] system in the southern constellation of Carina. It is visible to the naked eye as a dim point of light with a combined apparent visual magnitude of 5.16.^[6] The system is located at a distance of about255 light years from the Sun based on parallax.^[1][3] The dual nature of this system was announced in 1832 by German astronomer Carl Rümker.^[12] As of 2015, the pair had an angular separation of 4.10″ along a position angle of 70°.^[2]

HD 69863

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Carina
A
Right ascension	08h 15m 16.42864s[1]
Declination	−62° 54′ 56.5007″[1]
Apparent magnitude (V)	5.27[2]
B
Right ascension	08h 15m 16.47622s[3]
Declination	−62° 54′ 54.8700″[3]
Apparent magnitude (V)	7.62[2]
Characteristics
Spectral type	A2V[4] + F2V[5]
B−V color index	0.086±0.003[6]
Astrometry
Radial velocity (Rv)	4.0±3.7[6] km/s
Absolute magnitude (MV)	0.71[6]
A
Proper motion (μ)	RA: −26.674[1] mas/yr Dec.: -12.060[1] mas/yr
Parallax (π)	12.5410±0.1714 mas[1]
Distance	260 ± 4 ly (80 ± 1 pc)
B
Proper motion (μ)	RA: −20.911[3] mas/yr Dec.: -14.466[3] mas/yr
Parallax (π)	12.7714±0.0329 mas[3]
Distance	255.4 ± 0.7 ly (78.3 ± 0.2 pc)
Details
A
Mass	2.10+0.20 −0.17[7] M☉
Luminosity	42[8] L☉
Surface gravity (log g)	3.90±0.14[7] cgs
Temperature	8774+601 −210[1] K
Rotational velocity (v sin i)	191[9] km/s
B
Radius	1.43+0.12 −0.08[3] R☉
Luminosity	3.966±0.016[3] L☉
Temperature	6806+203 −258[3] K
Age	635±88[7] Myr
Other designations
RMK8, C Carinae, CPD−62°985, HD 69863, HIP 40429, HR 3260, CCDM J08153-6255[10]
A: GC 11275, SAO 250164
B: GC 11276, SAO 250165
Database references
SIMBAD	data

The brighter primary, designated component A, has a visual magnitude of 5.27^[2] and is an A-type main-sequence star with a stellar classification of A2V.^[4] It is 635^[7] million years old and is spinning with a projected rotational velocity of 191 km/s.^[9] The star has 2.1 times the mass of the Sun.^[7]

The magnitude 7.62^[2] companion, component B, is a F-type main-sequence star with a class of F2V.^[5] It is radiating four^[3] times the luminosity of the Sun from its photosphere at an effective temperature of 6,806 K.^[3] The system is a source for X-ray emission, which is most likely coming from the secondary.^[13]