Ny 2 sagittarii

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Star
ν 2 sagittarii (main component)
ν 2 Sagittarii in the constellation Sagittarius
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Sagittarius
Right ascension +18 h 55 m 7.14 s
declination −2240 ° 16.8185 ′
Apparent brightness +4.98 mag
Typing
B − V color index +1.32 
Spectral class Ib-II
Astrometry
Radial velocity −109.6 km / s
parallax 11.91 ± 0.52  mas
distance 270 ± 10  ly
84 ± 4  pc
Visual absolute brightness M vis +0.38 mag
Proper movement 
Rec. Share: −109.04  mas / a
Dec. portion: −35.25  mas / a
Physical Properties
Dimensions 1.44  M ☉
radius 85  R ☉
Luminosity

120  L ☉

Effective temperature 4244 ± 57  K
Metallicity [Fe / H] −0.13
Age 4.52 billion  a
Other names
and catalog entries
Bayer name ν 2 Sagittarii
Flamsteed name 35 Sgr
Bonn survey BD −22 ° 4915
Bright Star Catalog HR 7120 [1]
Henry Draper Catalog HD 175190 [2]
Hipparcos catalog HIP 92845 [3]
SAO catalog SAO 187445 [4]

Ny 2 Sagittarii ( ν 2  Sagittarii ) is a binary star system in the ecliptic - constellation Sagittarius , Latin Sagittarius . With an apparent brightness of +4.98 mag , it is barely visible to the naked eye. With an annual parallax of 11.91 milli-  arcseconds , the system is about 270  light-years away from us. Ny 2 Sagittarii has a high peculiar speed of 86.0 (−14.4, +11.6) km / s and is very likely a so-called fast runner .

The spectrum of the main component shows a spectral type K1 Ib-II, which indicates a developed bright giant or supergiant . It is a faint barium star that shows an increased excess of s-process elements in its outer atmosphere . This material most likely came from an earlier mass transfer of the companion, who is now a white dwarf . The main component is estimated to be 1.4 times the solar mass and an extent of 85 times the solar radius .

See also

Individual evidence

  1. ^ A b c d F. van Leeuwen: Validation of the new Hipparcos reduction , Astronomy and Astrophysics , 2007, Volume 474, Edition 2, Pages 653-664, arXiv 0708.1752
  2. ↑ a b c d e f g h i R. Earle Luck: Abundances in the Local Region. I. G and K Giants , Astronomical Journal (2015), Volume 150 Issue 3, Page 88, arXiv 1507.01466
  3. ^ A b c N. Tetzlaff, R. Neuhäuser, MM Hohle: A catalog of young runaway Hipparcos stars within 3 kpc from the Sun , Monthly Notices of the Royal Astronomical Society , January 2011, Volume 410, Issue 1, pages 190-200 , arXiv 1007.4883
  4. ↑ E. Anderson, Ch. Francis, XHIP: An extended hipparcos compilation , Astronomy Letters (2012), Volume 38, Issue 5, page 331, arXiv 1108.4971
  5. ↑ a b L. E. Pasinetti Fracassini, L. Pastori, S. Covino, A. Pozzi; Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS) , Astronomy and Astrophysics (2001), Volume 376, Pages 521-524, arXiv astro-ph / 0012289
  6. ↑ C. Soubiran, J.-F. Le Campion, G. Cayrel de Strobel, A. Caillo; The PASTEL catalog of stellar parameters , Astronomy and Astrophysics , June 2010, Volume 515, Page A111, arXiv 1004.1069
  7. ^ PP Eggleton, AA Tokovinin: A catalog of multiplicity among bright stellar systems , Monthly Notices of the Royal Astronomical Society, September 2008, Volume 389, Issue 2, pages 869-879, arXiv 0806.2878
  8. ↑ AE Gomez, X. Luri, S. Grenier, L. Prevot, MO Mennessier, F, Figueras, J. Torra: Absolute magnitudes and kinematics of barium stars , Astronomy and Astrophysics (1997), Volume 319, Page 881, Bibcode 1997A & A ... 319..881G