Nu1 Sagittarii

Nu1 Sagittarii
Diagram showing star positions and boundaries of the Sagittarius constellation and its surroundings


Location of ν1 Sagittarii (circled)

Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagittarius
Right ascension 18h 54m 10.17695s[1]
Declination −22° 44′ 41.4247″[1]
Apparent magnitude (V) +4.86[2]
Characteristics
Spectral type G2/K1 Ib/II + B9.2p[3]
U−B color index +1.34[2]
B−V color index +1.43[2]
Astrometry
Proper motion (μ) RA: +2.59[1] mas/yr
Dec.: −8.41[1] mas/yr
Parallax (π)2.90 ± 0.30[1] mas
Distanceapprox. 1,100 ly
(approx. 340 pc)
Absolute magnitude (MV)−3.91[4]
Other designations
ν1 Sgr, 32 Sgr, BD−22° 4907, HD 174974, HIP 92761, HR 7116, SAO 187426, WDS J18542-2245[5]
Database references
SIMBADdata

Nu1 Sagittarii (ν1 Sagittarii) is a triple star[6] system lying approximately 1,100 light years from Earth. The primary, component A, is a spectral type K1 bright giant which has an apparent magnitude of +4.86. It is a microvariable with a frequency of 0.43398 cycles per day and an amplitude of 0.0078 magnitude.[7] In 1982 it was found to have a hotter companion, a rapidly rotating B9 type star.[8] The pair form a spectroscopic binary with a period of around 370 days.[6] A magnitude +10.8 companion, component B,[9] is orbiting further out at an angular separation of 2.5 arcseconds from the primary.[6]

References

  1. 1 2 3 4 5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752 Freely accessible, doi:10.1051/0004-6361:20078357.
  2. 1 2 3 Lutz, T. E.; Lutz, J. H. (June 1977), "Spectral classification and UBV photometry of bright visual double stars", Astronomical Journal, 82: 431–434, Bibcode:1977AJ.....82..431L, doi:10.1086/112066.
  3. ↑ Parsons, Sidney B.; Ake, Thomas B. (1998), "Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. V. The Entire IUE Sample", The Astrophysical Journal Supplement Series, 119: 83, Bibcode:1998ApJS..119...83P, doi:10.1086/313152.
  4. ↑ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440.
  5. ↑ "nu01 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-06.
  6. 1 2 3 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, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878 Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x.
  7. ↑ Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331: 45, Bibcode:2002MNRAS.331...45K, arXiv:astro-ph/0112194 Freely accessible, doi:10.1046/j.1365-8711.2002.05150.x.
  8. ↑ Kondo, Y.; et al. (August 1982), "The early-type component in ν1 Sagittarii", Astronomical Society of the Pacific, Publications, 94: 647−649, Bibcode:1982PASP...94..647K, doi:10.1086/131037.
  9. ↑ Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22.
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