HD 73389

This article is about e² Carinae. For e¹ Carinae, see HD 73390. For E Carinae, see V345 Carinae.

Not to be confused with ε Carinae.

HD 73389 is a binary star^[3] system in the constellation Carina. It has the Bayer designation e² Carinae; HD 73389 is the identifier from the Henry Draper Catalogue. This system is visible to the naked eye as a point of light with a combined apparent visual magnitude of +4.84.^[2] Based on parallax measurements, it is located at a distance of approximately 225 light years from the Sun. The system is drifting further away with a radial velocity of +25.6 km/s.^[1]

HD 73389

Observation data Epoch J2000      Equinox J2000
Constellation	Carina
Right ascension	08h 35m 19.70886s[1]
Declination	−58° 00′ 33.2714″[1]
Apparent magnitude (V)	+4.84[2] (5.08 + 8.02)[3]
Characteristics
Spectral type	K0III[4]
B−V color index	0.981±0.041[2]
Astrometry
Radial velocity (Rv)	+25.62±0.13[1] km/s
Proper motion (μ)	RA: +52.848±0.555[1] mas/yr Dec.: +28.117±0.491[1] mas/yr
Parallax (π)	14.5139±0.2692 mas[1]
Distance	225 ± 4 ly (69 ± 1 pc)
Absolute magnitude (MV)	0.68[2]
Details
A
Radius	11.13+1.11 −0.39[1] R☉
Luminosity	64.4±1.4[1] L☉
Temperature	4,903+87 −229[1] K
Other designations
e2 Car, CPD−57°1591, GC 11797, HD 73389, HIP 42134, HR 3414, SAO 236106, CCDM J08353-5801[5]
Database references
SIMBAD	data

The visual magnitude 5.08 primary, component A, is an aging K-type giant star with a stellar classification of K0III.^[4] With the supply of hydrogen at its core exhausted, it has cooled and expanded to 11 times the Sun's radius.^[1] It is radiating 64 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,903 K.^[1] The secondary companion, component B, has a visual magnitude of 8.02 and is located at an angular separation of 0.30″ along a position angle of 207° from the primary, as of 2015.^[6]