BPS CS22892-052

from Wikipedia, the free encyclopedia
Star
BPS CS22892-052
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Aquarius
Right ascension 22 h 17 m 1.66 s
declination -16 ° 39 ′ 27.1 ″
Apparent brightness (13.20 ± 0.01) mag
Typing
B − V color index (0.83) 
R − I index (0.87) 
Spectral class KIIvw
Astrometry
Radial velocity (13) km / s
parallax (0.19 ± 0.04)  mas
distance (17,000)  ly
(5,000)  pc
Proper movement 
Rec. Share: (12.32 ± 0.06)  mas / a
Dec. portion: (−6.49 ± 0.06)  mas / a
Physical Properties
Other names
and catalog entries
2MASS catalog 2MASS J22170165-1639271 [1]
Other names BPS CS 22892-0052, HE 2214-1654

BPS CS22892-052 (Snedens Star) is an old population-II - Star in the Halo of the Milky Way . It belongs to the rare class of the ultra-metal-poor stars ( metallicity [Fe / H] = - 3.1), and in turn to the rare sub-class with an abundance of r-process elements.

It was discovered by Tim C. Beers and co-workers with the Curtis Schmidt telescope at the Cerro Tololo Inter-American Observatory in Chile . Detailed high-resolution spectroscopic studies since around 1995 (with Chris Sneden of the University of Texas at Austin as the lead observer) have made it possible to determine the abundances of 53 elements in this star (only more could be measured on the sun).

All frequencies for elements heavier than barium (Z = 56) show the pattern of the elements formed by the r-process in the solar system. By comparing the frequencies of a stable element such as europium (Z = 63) and a radioactive element such as thorium (Z = 90) observed in the star with the calculated frequencies of these elements in a type II supernova explosion (as reported by the groups of Karl-Ludwig Kratz in Mainz and Friedrich-Karl Thielemann in Basel) results in an age of around 13 billion years for this star, which was formed only a little later than the Big Bang . Corresponding ages were determined for other ultra-metal-poor stars such as CS31082-001 or BD + 17 ° 3248 .

literature

  • BEERS TC, PRESTON GW, SHECTMAN SA, A search for stars of very low metal abundance. I. , Astron. J., 90, 2089-2102 (1985)
  • BEERS TC, PRESTON GW, SHECTMAN SA, A search for stars of very low metal abundance. II. , Astron. J., 103, 1987-2034 (1992)
  • Kratz, Karl-Ludwig; Bitouzet, Jean-Philippe; Thielemann, Friedrich-Karl; Moeller, Peter; Pfeiffer, Bernd, Isotopic r-process abundances and nuclear structure far from stability - Implications for the r-process mechanism , Astrophysical Journal , vol. 403, no. 1, p. 216-238 (1993)
  • Sneden, Christopher; McWilliam, Andrew; Preston, George W .; Cowan, John J .; Burris, Debra L .; Armosky, Bradley J., The Ultra - Metal-poor, Neutron-Capture - rich Giant Star CS 22892-052 , Astrophysical Journal v.467, p.819 (1996)
  • Cowan, John J .; Pfeiffer, B .; Kratz, K.-L .; Thielemann, F.-K .; Sneden, Christopher; Burles, Scott; Tytler, David; Beers, Timothy C., R-Process Abundances and Chronometers in Metal-poor Stars The Astrophysical Journal, Volume 521, Issue 1, pp. 194-205 (1999)

Web links

Individual evidence

  1. ↑ a b c d e f g h BPS CS 22892-0052. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed October 27, 2019 .