16 Librae
16 Librae is a star in the constellation Libra. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.49.[2] An annual parallax shift of 37.17[1] mas yields a distance estimate of 87.7 light years. It is moving further from the Sun with a radial velocity of +26 km/s.[4]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Libra |
| Right ascension | 14h 57m 11.00009s[1] |
| Declination | −04° 20′ 47.2547″[1] |
| Apparent magnitude (V) | 4.49[2] |
| Characteristics | |
| Spectral type | F2 V[3] |
| U−B color index | +0.05[2] |
| B−V color index | +0.32[2] |
| Astrometry | |
| Radial velocity (Rv) | +26.3±0.6[4] km/s |
| Proper motion (μ) | RA: −96.98[1] mas/yr Dec.: −153.40[1] mas/yr |
| Parallax (π) | 37.17 ± 0.32 mas[1] |
| Distance | 87.7 ± 0.8 ly (26.9 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.32[5] |
| Details | |
| 16 Lib A | |
| Mass | 1.47[6] M☉ |
| Luminosity | 9.77[5] L☉ |
| Surface gravity (log g) | 3.99[6] cgs |
| Temperature | 7,187±244[6] K |
| Metallicity [Fe/H] | −0.13[7] dex |
| Rotational velocity (v sin i) | 113.3[8] km/s |
| Age | 660[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary F-type main-sequence star with a stellar classification of F2 V.[3] It is an estimated 660[6] million years old and is spinning rapidly with a projected rotational velocity of 113 km/s.[8] The star has 1.47[6] times the mass of the Sun and is radiating nearly 10[5] times the Sun's luminosity from its photosphere at an effective temperature of about 7,187 K.[6]
16 Librae has a common proper motion companion located at an angular separation of 22.8 arc seconds along a position angle of 297°, as of 1999. Designated component B, this is a red dwarf star with a class of about M6 and an infrared J-band magnitude of 12.19.[10]
References edit
- ^ a b c d e f van Leeuwen, F. (November 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, S2CID 18759600.
- ^ a b c d Ducati, J. R. (2002), "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system", CDS/ADC Collection of Electronic Catalogues, 2237, Bibcode:2002yCat.2237....0D.
- ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
- ^ a b 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, S2CID 59451347, A61.
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ Casagrande, L.; et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics, 530: A138, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
- ^ a b Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377[permanent dead link]
- ^ "16 Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-30.
- ^ Scholz, R. -D. (March 2016), "Overlooked wide companions of nearby F stars", Astronomy & Astrophysics, 587: 8, arXiv:1601.01896, Bibcode:2016A&A...587A..51S, doi:10.1051/0004-6361/201527965, S2CID 118348424, A51