Nu2 Sagittarii

From the Science Archives, the open-project database of science information
Jump to navigation Jump to search


Nu2 Sagittarii
Diagram showing star positions and boundaries of the Sagittarius constellation and its surroundings
Cercle rouge 100%.svg
Location of ν2 Sagittarii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagittarius
Right ascension 18h 55m 07.14098s[1]
Declination −22° 40′ 16.8185″[1]
Apparent magnitude (V) +4.98[2]
Characteristics
Spectral type K1 Ib–II[3]
B−V color index +1.32[2]
Astrometry
Radial velocity (Rv)−109.6[2] km/s
Proper motion (μ) RA: −109.04[1] mas/yr
Dec.: −35.25[1] mas/yr
Parallax (π)11.91 ± 0.52[1] mas
Distance270 ± 10 ly
(84 ± 4 pc)
Absolute magnitude (MV)+0.38[4]
Details
ν2 Sgr A
Mass1.44[2] M
Radius85[5] R
Diameter85[5] D
Luminosity120[2] L
Surface gravity (log g)1.03[6] cgs
Temperature4,244±57[2] K
Metallicity [Fe/H]−0.13[6] dex
Age4.52[2] Gyr
Other designations
ν2 Sgr, 35 Sgr, BD−22° 4915, HD 175190, HIP 92845, HR 7120, SAO 187445[7]
Database references
SIMBADdata

Nu2 Sagittarii (ν2 Sagittarii) is a binary star[8] system in the zodiac constellation of Sagittarius. It is faintly visible to the naked eye, having an apparent visual magnitude of +4.98.[2] Based upon a small annual parallax shift of 11.91 mas as seen from Earth,[1] this system is located around 270 light years from the Sun. Nu2 Sagittarii has a high peculiar velocity of 86.0+11.6
−14.4
 km/s
and is most likely a runaway star system.[3]

The spectrum of the primary component displays a stellar classification of K1 Ib–II,[3] indicating this is a K-type star with a mixed luminosity class of an evolved bright giant/supergiant star. It is a mild barium star, showing an enhanced abundance of s-process elements in its outer atmosphere. This material was most likely acquired during a previous mass transfer from its now white dwarf companion.[9] The primary has an estimated 1.4[2] times the mass of the Sun and has expanded to 85[5] times the Sun's radius.

References[edit]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 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.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal 150 (3): 88, arXiv:1507.01466, Bibcode 2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88.
  3. 3.0 3.1 3.2 Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, arXiv:1007.4883, Bibcode 2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x.
  4. 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.
  5. 5.0 5.1 Pasinetti Fracassini, L. E. et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy & Astrophysics 367: 521–24, arXiv:astro-ph/0012289, Bibcode 2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  6. 6.0 6.1 Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, arXiv:1004.1069, Bibcode 2010A&A...515A.111S, doi:10.1051/0004-6361/201014247.
  7. Lua error in Module:Citation/CS1 at line 379: attempt to call method 'match' (a nil value).
  8. 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.
  9. Gomez, A. E. et al. (1997), "Absolute magnitudes and kinematics of barium stars", Astronomy and Astrophysics 319: 881, Bibcode 1997A&A...319..881G.


Add your comment
The Science Archives welcomes all comments. If you do not want to be anonymous, register or log in. It is free.


As a reminder, article comments are only for discussions on how to improve the article. Please direct other comments to a user's talk page. Please be formal and do not use excessive uppercase. Please be advised you may receive an automatic block if you break the article comments policy. For information regarding what is acceptable/not acceptable in article comments, please message Icons-flag-ru.png Joey (talk), Natalia (talk), Icons-flag-fr.png ynoss (talk), or Icons-flag-ca.png Daniel (older account/talk).