GT Muscae
 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 Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| 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 mas[3] |
| 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 |
| 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 |
| Details[7] | |
| A | |
| Mass | 1.1±0.3 M☉ |
| Radius | 16.6±1 R☉ |
| Luminosity | 126 L☉ |
| Surface gravity (log g) | 1.89±0.05 cgs |
| Temperature | 4,744±125 K |
| 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.[10]
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.[9] Examining photographic plates in 1964, Wolfgang Strohmeier et al. discovered that GT Muscae is a variable star.[11] In 1979, based on spectroscopic features, Edward Weiler and Robert Stencel listed GT Muscae as a likely RS CVn variable.[12] 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.[13] The entire star system was given the variable star designation GT Muscae in 1988.[14]
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.[15]
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.[16][17] Michael Garcia et al. identified HD 101379 as the source seen by Uhuru, in 1980.[18] 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.[10]
References
[edit]- ^ a b c Murdoch, K. A.; Hearnshaw, J. B.; Kilmartin, P. M.; Gilmore, A. C. (October 1995). "A photometric and orbital analysis of GT Muscae". Monthly Notices of the Royal Astronomical Society. 276 (3): 836–846. Bibcode:1995MNRAS.276..836M. doi:10.1093/mnras/276.3.836. Retrieved 26 January 2023.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 24 January 2023.
- ^ a b c d e f g Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d "GT Mus". The International Variable Star Index. AAVSO. Retrieved 26 January 2023.
- ^ Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
- ^ "11395-6524 B 1705AB (GT Mus)". Washington Double Star Catalog. US Naval Observatory. Retrieved 28 January 2023.
- ^ Kallinger, T.; Beck, P. G.; Hekker, S.; Huber, D.; Kuschnig, R.; Rockenbauer, M.; Winter, P. M.; Weiss, W. W.; Handler, G.; Moffat, A. F. J.; Pigulski, A.; Popowicz, A.; Wade, G. A.; Zwintz, K. (2019-04-01). "Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE-Constellation". Astronomy & Astrophysics. 624: A35. arXiv:1902.07531. Bibcode:2019A&A...624A..35K. doi:10.1051/0004-6361/201834514. ISSN 0004-6361.
- ^ "12 Mus -- RS CVn Variable". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-01-26.
- ^ a b van den Bos, W. H. (October 1929). "New southern double stars, ninth list". Bulletin of the Astronomical Institutes of the Netherlands. 5: 125–134. Bibcode:1929BAN.....5..125V. Retrieved 27 January 2023.
- ^ a b Sasaki, Ryo; Tsuboi, Yohko; Iwakiri, Wataru; Nakahira, Satoshi; Maeda, Yoshitomo; Gendreau, Keith; Corcoran, Michael F.; Hamaguchi, Kenji; Arzoumanian, Zaven; Markwardt, Craig B.; Enoto, Teruaki; Sato, Tatsuki; Kawai, Hiroki; Mihara, Tatehiro; Shidatsu, Megumi; Negoro, Hitoshi; Serino, Motoko (March 2021). "The RS CVn-type Star GT Mus Shows Most Energetic X-Ray Flares Throughout the 2010s". The Astrophysical Journal. 910 (1): 25. arXiv:2103.16822. Bibcode:2021ApJ...910...25S. doi:10.3847/1538-4357/abde38. S2CID 232427851.
- ^ Strohmeier, W.; Knigge, R.; Ott, H. (September 1964). "Bright Southern BV-Stars". Information Bulletin on Variable Stars. 66 (1): 1. Bibcode:1964IBVS...66....1S. Retrieved 27 January 2023.
- ^ Weiler, E. J.; Stencel, R. E. (September 1979). "Southern RS CVn systems. Candidate list". Astronomical Journal. 84: 1372–1373. Bibcode:1979AJ.....84.1372W. doi:10.1086/112553. Retrieved 27 January 2023.
- ^ Collier Cameron, Andrew (1982). Late-type Ca II emission-line stars in the Southern Hemisphere. University of Canterbury. Bibcode:1982PhDT.......163C. doi:10.26021/7260. Retrieved 28 January 2023.
- ^ Kholopov, P. N.; Samus, N. N.; Kazarovets, B. V.; Frolov, M. S.; Kireeva, N. N. (April 1989). "The 69th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 3323 (1): 1. Bibcode:1989IBVS.3323....1K. Retrieved 27 January 2023.
- ^ Collier, A. C.; Haynes, R. F.; Slee, O. B.; Wright, A. E.; Hillier, D. J. (September 1982). "A coordinated radio and Half survey of southern RS CVn systems and related objects". Monthly Notices of the Royal Astronomical Society. 200 (4): 869–880. Bibcode:1982MNRAS.200..869C. doi:10.1093/mnras/200.4.869. Retrieved 28 January 2023.
- ^ Giacconi, R.; Murray, S.; Gursky, H.; Kellogg, E.; Schreier, E.; Tananbaum, H. (December 1972). "The Uhuru catalog of X-ray sources". Astrophysical Journal. 178: 281–308. Bibcode:1972ApJ...178..281G. doi:10.1086/151790. Retrieved 27 January 2023.
- ^ Forman, W.; Jones, C.; Cominsky, L.; Julien, P.; Murray, S.; Peters, G.; Tananbaum, H.; Giacconi, R. (December 1978). "The fourth Uhuru catalog of X-ray sources". Astrophysical Journal Supplement Series. 38: 357–412. Bibcode:1978ApJS...38..357F. doi:10.1086/190561.
- ^ Garcia, M.; Baliunas, S. L.; Conroy, M.; Johnston, M. D.; Ralph, E.; Roberts, W.; Schwartz, D. A.; Tonry, J. (September 1980). "Optical identification of H 0123+07.5 and 4U 1137-65 : hard X-ray emission from RS CVn systems". Astrophysical Journal. 240: L107–L110. Bibcode:1980ApJ...240L.107G. doi:10.1086/183334. Retrieved 28 January 2023.
