Beta Muscae

Stellar classification



  • X 286
  • Y -33
  • Z 184
→ Sol: 342

Object type

  • Double or multiple star
  • Star
  • Infra-Red source
  • Spectroscopic binary
  • UV-emission source
simbad:* bet Mus


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, 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.

This is a binary star system with a period of about 194 years at an orbital eccentricity of 0.6. As of 2007, the two stars had an angular separation of 1.206 arcseconds at a position angle of 35°. 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, and about 7.35 times the Sun's mass. The secondary component, β Muscae B, has an apparent magnitude of 4.01, a stellar classification of B3 V, and is about 6.40 times the mass of the Sun.

This is a confirmed member of the Scorpius-Centaurus Association, 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.

This article uses material from the Wikipedia article "Beta Muscae", which is released under the Creative Commons Attribution-Share-Alike License 3.0.