Beta Muscae

Beta Muscae
Location of β Musca (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Musca
Right ascension 12h 46m 16.80410s[1]
Declination –68° 06′ 29.2164″[1]
Apparent magnitude (V) 3.05 (3.51 + 4.01)[2]
Characteristics
Spectral type B2 V + B3 V[2]
U−B color index –0.766[3]
B−V color index –0.198[3]
Astrometry
Radial velocity (Rv)+42[4] km/s
Proper motion (μ) RA: –41.97[1] mas/yr
Dec.: –8.89[1] mas/yr
Parallax (π)9.55 ± 0.41 mas[1]
Distance340 ± 10 ly
(105 ± 4 pc)
Absolute magnitude (MV)−2.06[5]
Orbit[6]
Period (P)194.28 yr
Semi-major axis (a)0.969″
Eccentricity (e)0.598
Inclination (i)37.1°
Longitude of the node (Ω)349.4°
Periastron epoch (T)1857.50
Argument of periastron (ω)
(secondary)		209.0°
Details
β Mus A
Mass7.35[7] M☉
Luminosity1,892[5] L☉
Age15.1 ± 1.2[8] Myr
β Mus B
Mass6.40[7] M☉
Other designations
β Mus, CPD−67 2064, HD 110879, HIP 62322, HR 4844, SAO 252019[9]
Database references
SIMBADdata

Beta Muscae, Latinized from β Muscae, is a binary star in the southern circumpolar constellation of Musca. With a combined apparent visual magnitude of 3.07,[2] it is the second brightest star (or star system) in the constellation. Judging by the parallax results, it is located at a distance of roughly 340 ± 13 light-years (105 ± 4 parsecs) from the Earth.[1]

This is a binary star system with a period of about 194 years at an orbital eccentricity of 0.6.[6] As of 2007, the two stars had an angular separation of 1.206 arcseconds at a position angle of 35°.[7] The components are main sequence stars of similar size and appearance. The primary component, β Muscae A, has an apparent magnitude of 3.51, a stellar classification of B2 V,[2] and about 7.35 times the Sun's mass.[7] The secondary component, β Muscae B, has an apparent magnitude of 4.01, a stellar classification of B3 V,[2] and is about 6.40 times the mass of the Sun.[7]

This is a confirmed member of the Scorpius–Centaurus association,[2][7] which is a group of stars with similar ages, locations, and trajectories through space, implying that they formed together in the same molecular cloud. Beta Muscae is considered a runaway star system as it has a high peculiar velocity of 43.9 km s−1 relative to the normal galactic rotation. Runaway stars can be produced through several means, such as through an encounter with another binary star system. Binary systems form a relatively small fraction of the total population of runaway stars.[10]

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  7. ^ a b c d e f Cite error: The named reference aaa474_1_77 was invoked but never defined (see the help page).
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