Musca
The pattern of the brightest stars resembles that of Ursa Minor, in that the stars form a pattern reminiscent of a bowl with a handle. Lying south-southeast of Acrux in neighbouring Crux is Alpha Muscae. It is the brightest star in the constellation with an apparent magnitude of 2.7. Lying around 310 light-years away, it is a blue-white star of spectral type B2IV-V that is around 4520 times as luminous and 8 times as massive as the Sun. The star is a Beta Cephei variable with about 4.7 times the Sun's diameter, and pulsates every 2.2 hours, varying by 1% in brightness. A nearby star of magnitude 13 may or may not be a companion star. Marking the fly's tail is Gamma Muscae, a blue-white star of spectral type B5V that varies between magnitudes 3.84 and 3.86 over a period of 2.7 days. It is a variable of a different type, classed as a slowly pulsating B star, a type of variable. It is around five times as massive as our Sun.
NGC 5316
There are 570 probable member stars within the angular radius of the cluster and 262 within the central part of the cluster. The tidal radius of the cluster is 6.0 - 8.1 parsecs (19 - 26 light years) and represents the average outer limit of NGC 5316, beyond which a star is unlikely to remain gravitationally bound to the cluster core. The brightest member of the cluster (lucida) is star No. 31 (mag. 9.40). Star 31 has significantly more barium than the rest of the group and the Ba II line is visually stronger than the rest of the cluster. The turn-off mass of the cluster is estimated to be at 5.0 . The hottest stars of the cluster are of spectral type B5–B7. NGC 5316 has metallicity nearly the same as the solar one ([Fe/H] = −0.02 ± 0.05).