Nu2 Lyrae
Nu2 Lyrae, Latinized from ν2 Lyrae, or sometimes simply Nu Lyrae, is a solitary[9] star in the northern constellation of Lyra. Based upon an annual parallax shift of 14.09 mas as seen from Earth, it is located around 231 light years from the Sun. With an apparent visual magnitude of 5.23,[2] it is bright enough to be faintly visible to the naked eye.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lyra |
| Right ascension | 18h 49m 52.91721s[1] |
| Declination | +32° 33′ 03.8153″[1] |
| Apparent magnitude (V) | 5.23[2] |
| Characteristics | |
| Spectral type | A3 V[3] |
| U−B color index | +0.12[2] |
| B−V color index | +0.10[2] |
| Astrometry | |
| Proper motion (μ) | RA: −11.12[1] mas/yr Dec.: −11.90[1] mas/yr |
| Parallax (π) | 14.09 ± 0.25[1] mas |
| Distance | 231 ± 4 ly (71 ± 1 pc) |
| Absolute magnitude (MV) | +0.97[4] |
| Details | |
| Mass | 1.91[5] M☉ |
| Radius | 1.5[6] R☉ |
| Luminosity | 32[7] L☉ |
| Surface gravity (log g) | 3.89±0.14[5] cgs |
| Temperature | 8,912±303[5] K |
| Rotational velocity (v sin i) | 128[3] km/s |
| Age | 214[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a white-hued A-type main sequence star with a stellar classification of A3 V.[3] At an estimated age of 214 million years,[5] it is spinning with a projected rotational velocity of 128 km/s.[3] This is giving the star an oblate shape with an equatorial bulge that is 5% larger than the polar radius.[10] Nu2 Lyrae has an estimated 1.9[5] times the mass of the Sun and about 1.5[6] times the Sun's radius. It is radiating 32[7] times the solar luminosity from its photosphere at an effective temperature of around 8,912 K.[5]
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, S2CID 18759600.
- Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
- 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.
- 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.
- Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (3rd ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
- "* nu. Lyr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-15.
- 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, S2CID 14878976.
- van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.