S Muscae

S Muscae is a classical (δ) Cepheid variable star in the constellation Musca about 2,600 light years away.

S Muscae
Location of S Muscae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Musca
Right ascension 12h 12m 47.01834s
Declination 70° 09 06.4363
Apparent magnitude (V) 6.394 (5.89 - 6.49)
Characteristics
Spectral type F6Ib (F6-G0) + B5V
U−B color index +0.66
B−V color index +1.00
Variable type δ Cepheid
Astrometry
Radial velocity (Rv)1.91 km/s
Proper motion (μ) RA: 7.79 mas/yr
Dec.: 0.60 mas/yr
Parallax (π)1.99 ± 0.84 mas
Distance863 pc
Absolute magnitude (MV)4.01
Orbit
Period (P)504.9 ± 0.07
Semi-major axis (a)794 AU
Eccentricity (e)0.08 ± 0.002
Inclination (i)32 ± 1°
Semi-amplitude (K1)
(primary)
14.7 ± 0.2 km/s
Details
Mass6.2 M
Radius65.1 R
Luminosity3,467 L
Metallicity+0.18
companion
Mass5.3 M
Temperature17,000 K
Other designations
S Mus, HR 4645, SAO 251791, CD69°977, GSC 09231-00752, HD 106111, GC 16679, HIP 59551, AAVSO 1207-69
Database references
SIMBADdata

S Muscae is a yellow supergiant ranging between spectral types F6Ib and G0Ib and magnitudes 5.89 to 6.49 over a period of 9.66 days. It is a luminous star around six times as massive as the Sun and 65.1 times the radius of the Sun. It is a binary star with a blue-white main sequence star companion likely to be of spectral type B3V to B5V with a mass of just over five solar masses, one of the hottest and brightest companions of a Cepheid known. The two stars orbit each other every 505 days.

S Muscae has been found to lie within the faint star cluster ASCC 69.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.