Mu Librae
μ Librae (Latinised as Mu Librae) is the Bayer designation for a probable triple star[3] system in the zodiac constellation of Libra. They have a combined apparent visual magnitude of 5.32,[2] which is bright enough to be faintly visible to the naked eye. With an annual parallax shift of 13.71 mas,[1] the system is located at an estimated distance of around 240 light years.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Libra |
| Right ascension | 14h 49m 19.05130s[1] |
| Declination | −14° 08′ 56.4766″[1] |
| Apparent magnitude (V) | 5.32[2] (5.69 + 6.72[3] + 14.70[4]) |
| Characteristics | |
| Spectral type | A1pSrCrEu + A6m[3] |
| B−V color index | +0.07[2] |
| Astrometry | |
| Radial velocity (Rv) | −3.2±1.4[5] km/s |
| Proper motion (μ) | RA: −65.95[1] mas/yr Dec.: −14.54[1] mas/yr |
| Parallax (π) | 13.71 ± 0.69[1] mas |
| Distance | 240 ± 10 ly (73 ± 4 pc) |
| Absolute magnitude (MV) | 1.32±0.20[6] |
| Details | |
| μ Lib A | |
| Mass | 2.31±0.12[7] M☉ |
| Radius | 2.59[8] R☉ |
| Luminosity | 41.7[7] L☉ |
| Temperature | 9,592±260[7] K |
| Rotational velocity (v sin i) | 29.0±1.7[7] km/s |
| Age | 417[6] Myr |
| μ Lib B | |
| Radius | 2.59[8] R☉ |
| Rotational velocity (v sin i) | 32.0±6[8] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The inner pair consists of two A-type stars that, as of 2006, had an angular separation of 1.79 arc seconds along a position angle of 5.5°.[10] They have an estimated physical separation of 139 AU.[8] The primary, component A, is a visual magnitude 5.69[3] magnetic Ap star showing overabundances of the elements aluminum, strontium, chromium, and europium.[7] Hence, it has a stellar classification of A1pSrEuCr.[3] It is a photometric variable with periods of 25.3992±0.1970 d and 1.8871±0.0008 d. The surface magnetic field strength is 1,375 Gauss.[7]
The secondary, component B, is an Am star with a stellar classification of A6m.[3] It has a visual magnitude of 6.72.[3] The tertiary member, component C, is a magnitude 14.70 star at an angular separation of 12.90 arc seconds along a position angle of 294°, as of 2000.[4]
References
- van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa, 27: 11, Bibcode:1968MNSSA..27...11C.
- 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
- Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22.
- de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
- Kochukhov, O.; Bagnulo, S. (2006), "Evolutionary state of magnetic chemically peculiar stars", Astronomy and Astrophysics, 450 (2): 763, arXiv:astro-ph/0601461, Bibcode:2006A&A...450..763K, doi:10.1051/0004-6361:20054596.
- Wraight, K. T.; et al. (February 2012), "A photometric study of chemically peculiar stars with the STEREO satellites - I. Magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society, 420 (1): 757–772, arXiv:1110.6283, Bibcode:2012MNRAS.420..757W, doi:10.1111/j.1365-2966.2011.20090.x.
- Howe, K. S.; Clarke, C. J. (January 2009), "An analysis of v sin (i) correlations in early-type binaries", Monthly Notices of the Royal Astronomical Society, 392 (1): 448–454, Bibcode:2009MNRAS.392..448H, doi:10.1111/j.1365-2966.2008.14073.x.
- "mu. Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-24.
- Mason, Brian D.; et al. (October 2007), "Speckle Interferometry at the US Naval Observatory. XIII.", The Astronomical Journal, 134 (4): 1671–1678, Bibcode:2007AJ....134.1671M, doi:10.1086/521555.