Astronomy:Eta Muscae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Musca |
| Right ascension | 13h 15m 14.94123s[2] |
| Declination | −67° 53′ 40.5276″[2] |
| Apparent magnitude (V) | 4.79[3] |
| Characteristics | |
| Spectral type | B8V + sim. + K9.4XR? + A0p[4] or B7III + B7III[5] |
| B−V color index | −0.078±0.003[3] |
| Variable type | eclipsing binary |
| Astrometry | |
| Radial velocity (Rv) | −8.1±7.4[3] km/s |
| Proper motion (μ) | RA: +30.207[2] mas/yr Dec.: +17.921[2] mas/yr |
| Parallax (π) | 7.1001 ± 0.1924[2] mas |
| Distance | 405.7[6] ly (124.4[6] pc) |
| Absolute magnitude (MV) | −0.81[6] |
| Orbit[7] | |
| Period (P) | 2.3963161 d |
| Semi-major axis (a) | 14.11±0.15 R☉ |
| Eccentricity (e) | 0.00 |
| Inclination (i) | 77.40° |
| Semi-amplitude (K1) (primary) | 145.35±0.20 km/s |
| Semi-amplitude (K2) (secondary) | 145.38±0.20 km/s |
| Details[7] | |
| Eta Mus Aa | |
| Mass | 3.30±0.04 M☉ |
| Radius | 2.14±0.02 R☉ |
| Luminosity | 223.77[3] (combined) L☉ |
| Surface gravity (log g) | 4.293±0.005 cgs |
| Temperature | 12,700±100 K |
| Rotational velocity (v sin i) | 34±2 km/s |
| Eta Mus Ab | |
| Mass | 3.29±0.04 M☉ |
| Radius | 2.13±0.04 R☉ |
| Surface gravity (log g) | 4.298±0.005 cgs |
| Temperature | 12,550±300 K |
| Rotational velocity (v sin i) | 44±2 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta Muscae is a multiple[9][10] star system in the southern constellation of Musca. It is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude of 4.79.[3] The system is located around 406 light years away from the Sun.[6] It is a member of the Lower Centaurs Crux subgroup of the Sco OB2 stellar association of co-moving stars.[11]
The two main components of this system form a double-lined spectroscopic binary[12] with a period of 2.4 days in a circular orbit.[7][11] They are a detached eclipsing binary with a spectral type of B8V and a brightness that dips by 0.05 magnitude once per orbit.[13] This pair consists of two components of similar mass and type.[4]
Further away from the primary system are stars of magnitude 7.3 and 10, designated Eta Muscae B and C. It is unclear if these stars are gravitationally–bound to the main pair. Evidence for an additional component has been found with a 30-year cycle in the orbital behavior of the main pair.[9] The data suggests an orbital eccentricity of 0.29 for this suspected component, Eta Muscae D.[14]
References
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ 2.0 2.1 2.2 2.3 2.4 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V.
- ↑ 3.0 3.1 3.2 3.3 3.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 4.0 4.1 Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ Hube, Douglas P. (1970). "The radial velocities of 335 late B-type stars". Memoirs of the Royal Astronomical Society 72: 233. Bibcode: 1970MmRAS..72..233H.
- ↑ 6.0 6.1 6.2 6.3 Hubrig, S. et al. (June 2001). "Search for low-mass PMS companions around X-ray selected late B stars". Astronomy and Astrophysics 372: 152–164. doi:10.1051/0004-6361:20010452. Bibcode: 2001A&A...372..152H.
- ↑ 7.0 7.1 7.2 Eker, Z. et al. (May 2014). "The Catalogue of Stellar Parameters from the Detached Double-Lined Eclipsing Binaries in the Milky Way". Publications of the Astronomical Society of Australia 31: 23. doi:10.1017/pasa.2014.17. e024. Bibcode: 2014PASA...31...24E.
- ↑ "eta Mus". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=eta+Mus.
- ↑ 9.0 9.1 Butland, R. J.; Budding, E. (2011). "Another component in the multiple system Eta Mus". Commissions 27 and 42 of the IAU Information Bulletin on Variable Stars 6004 (6004): 1. Bibcode: 2011IBVS.6004....1B. http://www.konkoly.hu/cgi-bin/IBVS?6004.
- ↑ Medici, A.; Hubrig, S. (January 2000). "Triple System epsilon Vol and Quadruple System eta Mus: the Mass Ratio in Close Binary Systems". Information Bulletin on Variable Stars 4827: 1. Bibcode: 2000IBVS.4827....1M.
- ↑ 11.0 11.1 Hensberge, H.; Nitschelm, C.; Bouzid, Y. M.; Clausen, V. J.; David, M.; Freyhammer, M. L.; Helt, B.; Olsen, H. E. et al. (April 5–10, 2003). "η Muscae: a multiple system with a PMS component". in Lépine, Jacques; Gregorio-Hetem, Jane. Open Issues in Local Star Formation. Proceedings of the Ouro Preto Colloquium, Brazil. 299. Kluwer Academic Publishers, Dordrecht. Bibcode: 2003ASSL..299P...8H.
- ↑ Buscombe, W.; Morris, Pamela M. (1961). "Three southern spectroscopic binaries". Monthly Notices of the Royal Astronomical Society 123 (2): 183. doi:10.1093/mnras/123.2.183. Bibcode: 1961MNRAS.123..183B.
- ↑ Zasche, P. et al. (2009). "A catalog of visual double and multiple stars with eclipsing components". The Astronomical Journal 138 (2): 664–79. doi:10.1088/0004-6256/138/2/664. Bibcode: 2009AJ....138..664Z.
- ↑ Blackford, M. G. et al. (June 2016). "The AD binary in the multiple system eta Mus". Information Bulletin on Variable Stars 6171: 1. Bibcode: 2016IBVS.6171....1B.
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