NU Pavonis (N-U, not "nu") is a variable star in the southern constellation of Pavo. With a nominal apparent visual magnitude of 4.95,[3] it is a faint star but visible to the naked eye. The distance to NU Pav, as determined from its annual parallax shift of 7.0 mas[2] as seen from Earth's orbit, is around 460 light years. It is moving closer with a heliocentric radial velocity of −10 km/s.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pavo |
| Right ascension | 20h 01m 44.74682s[2] |
| Declination | −59° 22′ 33.1864″[2] |
| Apparent magnitude (V) | 4.95[3] |
| Characteristics | |
| Spectral type | M6 III[4] |
| B−V color index | 1.356±0.011[3] |
| Variable type | SRb[5] |
| Astrometry | |
| Radial velocity (Rv) | −10.3±2.8[6] km/s |
| Proper motion (μ) | RA: +20.385[2] mas/yr Dec.: −26.769[2] mas/yr |
| Parallax (π) | 7.0208 ± 0.4464 mas[2] |
| Distance | 460 ± 30 ly (142 ± 9 pc) |
| Absolute magnitude (MV) | −0.86[3] |
| Details | |
| Radius | 204±29[7] R☉ |
| Luminosity | 7,412[3] L☉ |
| Surface gravity (log g) | 0.87[8] cgs |
| Temperature | 3,516±275[7] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging red giant with a stellar classification of M6 III,[4] currently on the asymptotic giant branch. It is a semiregular variable star of sub-type SRb that ranges in magnitude from 4.91 down to 5.26 with a period of 60 days.[7] The star has expanded to 204[7] times the Sun's radius and is radiating 7,412[3] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,516 K.[7] Far-ultraviolet emission has been detected from these coordinates, which may be coming from a companion star.[8]
References
edit- ^ Tabur, V.; Bedding, T. R.; Kiss, L. L.; Moon, T. T.; Szeidl, B.; Kjeldsen, H. (December 2009). "Long-term photometry and periods for 261 nearby pulsating M giants". Monthly Notices of the Royal Astronomical Society. 400 (4): 1945–1961. arXiv:0908.3228. Bibcode:2009MNRAS.400.1945T. doi:10.1111/j.1365-2966.2009.15588.x.
- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
- ^ a b c d e f 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 Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ 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.
- ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b c d e Arroyo-Torres, B.; et al. (June 2014), "VLTI/AMBER observations of cold giant stars: atmospheric structures and fundamental parameters", Astronomy & Astrophysics, 566: 11, arXiv:1404.7384, Bibcode:2014A&A...566A..88A, doi:10.1051/0004-6361/201323264, S2CID 16778588, A88.
- ^ a b Ortiz, Roberto; Guerrero, Martín A. (2016), "Ultraviolet emission from main-sequence companions of AGB stars", Monthly Notices of the Royal Astronomical Society, 461 (3): 3036, arXiv:1606.09086, Bibcode:2016MNRAS.461.3036O, doi:10.1093/mnras/stw1547, S2CID 118619933.
- ^ "NU Pav". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 September 2018.