HD 83446

This article is about M Velorum. For m Velorum, see HD 85622.

HD 83446 is a probable astrometric binary^[10] star system in the constellation Vela. It is visible to the naked eye with an apparent visual magnitude of 4.34.^[1] Based upon an annual parallax shift of 30.5 mas,^[2] it is located 107.1 light years from the Sun. The system is moving further away with a heliocentric radial velocity of +18 km/s.^[6]

HD 83446

Observation data Epoch J2000      Equinox J2000
Constellation	Vela[1]
Right ascension	09h 36m 49.53851s[2]
Declination	−49° 21′ 18.0873″[2]
Apparent magnitude (V)	4.34[1]
Characteristics
Evolutionary stage	main sequence[3]
Spectral type	A7 V[4]
B−V color index	0.173±0.005[1]
Variable type	δ Sct[5]
Astrometry
Radial velocity (Rv)	+17.8±0.5[6] km/s
Proper motion (μ)	RA: −130.55[2] mas/yr Dec.: +42.98[2] mas/yr
Parallax (π)	30.4562±0.1933 mas[2]
Distance	107.1 ± 0.7 ly (32.8 ± 0.2 pc)
Absolute magnitude (MV)	1.79[1]
Details
Mass	1.8+0.11 −0.09[7] M☉
Luminosity	15.99[1] L☉
Surface gravity (log g)	4.3±0.14[7] cgs
Temperature	8,331±283[7] K
Rotational velocity (v sin i)	155[8] km/s
Age	453+256 −278[7] Myr
Other designations
M Vel, CD−48°4836, FK5 2768, HD 83446, HIP 47175, HR 3836, SAO 221344[9]
Database references
SIMBAD	data

The visible component is an A-type main-sequence star with a stellar classification of A7 V.^[4] Observations with the BRITE constellation led to this star's identification as a Delta Scuti variable with pulsation frequencies of 31.0806 and 34.2098 cycles per day, corresponding to periods of 46.3 and 42.1 minutes, respectively.^[5] It has a high rate of spin with a projected rotational velocity of 155 km/s, which is giving the star an oblate shape with an equatorial bulge that is 6% larger than the polar radius.^[8] The star is roughly 453^[7] million years old with 1.8^[7] times the mass of the Sun. It is radiating 16^[1] times the Sun's luminosity from its photosphere at an effective temperature of 8,331 K.^[7]