Light curves for GT Muscae. The upper panel (adapted from Murdoch et al.[1]) shows the long-term variability after a model of the eclipsing binary variability has been removed. The orbital period of HD 101379 is shown in red. The lower panel shows TESS data,[2] in which the eclipses (both primary and secondary) are clearly visible. The orbital period of HD 101380 is shown in red. | |
Observation data Equinox J2000.0]] (ICRS) | |
---|---|
Constellation | Musca |
Right ascension | 11h 39m 29.56610s[3] |
Declination | −65° 23′ 52.0995″[3] |
Apparent magnitude (V) | 4.96 - 5.23[4] |
Characteristics | |
Spectral type | A: G5/8III+F, B: A0V+A2V[4] |
Variable type | Algol + RS CVn[5] |
Astrometry | |
Proper motion (μ) | RA: −29.762±0.561[3] mas/yr Dec.: 5.783±0.504[3] mas/yr |
Parallax (π) | 8.3972 ± 0.5075[3] mas |
Distance | 390 ± 20 ly (119 ± 7 pc) |
Orbit[6] | |
Primary | A (HD 101379) |
Companion | B (HD 101380) |
Period (P) | 96.8±2.4 yr |
Semi-major axis (a) | 0.276″±0.004″ |
Eccentricity (e) | 0.634±0.015 |
Inclination (i) | 60.9±2° |
Longitude of the node (Ω) | 259.8±1.5° |
Periastron epoch (T) | 2452778±110 |
Argument of periastron (ω) (secondary) | 92.4±1.5° |
Orbit[1] | |
Primary | Aa |
Companion | Ab |
Period (P) | 61.448±0.007 d |
Eccentricity (e) | 0.032±0.013 |
Periastron epoch (T) | 2444929±6 |
Argument of periastron (ω) (secondary) | 238±24° |
Semi-amplitude (K1) (primary) | 12.7±0.2 km/s |
Orbit[4] | |
Primary | Ba |
Companion | Bb |
Period (P) | 2.75459 d |
Other designations | |
Database references | |
SIMBAD | data |
GT Muscae, also known as 12 Muscae, is a variable star about 400 light years from the Earth, in the constellation Musca.[3] It is a 5th magnitude star, so it should be faintly visible to the naked eye of an observer far from city lights.[3] It is a quadruple star system, consisting of a spectroscopic binary containing an RS Canum Venaticorum variable (RS CVn) star (HD 101379), orbiting an eclipsing binary (HD 101380).[1] It varies in brightness from magnitude 4.96 to 5.23.[4] GT Muscae is a very active X-ray source.[9]
In 1929, Willem van den Bos discovered that GT Muscae is a visual double star, whose A (HD 101379) and B (HD 101380) components were separated by 0.2 arc seconds at the time he observed it.[8] Examining photographic plates in 1964, Wolfgang Strohmeier et al. discovered that GT Muscae is a variable star.[10] In 1979, based on spectroscopic features, Edward Weiler and Robert Stencel listed GT Muscae as a likely RS CVn variable.[11] Eclipses of the HD 101380 pair were first reported by Andrew Collier Cameron in his 1982 PhD thesis, in which he also determined that pair's orbital period.[12] The entire star system was given the variable star designation GT Muscae in 1988.[13]
Strong, variable, 5 GHz radio emission from GT Muscae, indicative of flares, was detected in 1982 and was interpreted as indicating high levels of chromospheric and coronal activity.[14]
GT Muscae was detected in the early observations of the Uhuru X-ray satellite, originally denoted as 2U 1134–161, later renamed 4U 1137–65.[15][16] Michael Garcia et al. identified HD 101379 as the source seen by Uhuru, in 1980.[17] During the 2010-2019 decade, GT Muscae showed the most X-ray flare activity of any star in the sky, producing flares with energies as high as ~1038 ergs.[9]
Original source: https://en.wikipedia.org/wiki/GT Muscae.
Read more |