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]

NU Pavonis

A visual band light curve for NU Pavonis, plotted from data published by Tabur et al. (2009)[1]
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]
Distance460 ± 30 ly
(142 ± 9 pc)
Absolute magnitude (MV)−0.86[3]
Details
Radius204±29[7] R
Luminosity7,412[3] L
Surface gravity (log g)0.87[8] cgs
Temperature3,516±275[7] K
Other designations
NU Pav, CD−59° 7361, FK5 3598, HD 189124, HIP 98608, HR 7625, SAO 246389[9]
Database references
SIMBADdata

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

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  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ 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.
  9. ^ "NU Pav". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 September 2018.