BPS CS31082-001
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Star BPS CS31082-001 |
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| AladinLite | |||||||||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | whale | ||||||||
| Right ascension | 01 h 29 m 31.13 s | ||||||||
| declination | –16 ° 00 ′ 45.5 ″ | ||||||||
| Apparent brightness | (11.64 ± 0.02) mag | ||||||||
| Typing | |||||||||
| B − V color index | (0.79) | ||||||||
| U − B color index | (0.10) | ||||||||
| R − I index | (0.48) | ||||||||
| Astrometry | |||||||||
| Radial velocity | (139.09 ± 0.85) km / s | ||||||||
| parallax | (0.48 ± 0.05) mas | ||||||||
| distance | (7,000) ly (2,000) pc |
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| Proper movement | |||||||||
| Rec. Share: | (11.75 ± 0.09) mas / a | ||||||||
| Dec. portion: | (−42.71 ± 0.04) mas / a | ||||||||
| Physical Properties | |||||||||
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Other names and catalog entries |
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BPS CS31082-001 (Cayrels Star) is an old population-II - Star in the Halo of the Milky Way . It belongs to the rare class of ultrametallic stars ( metallicity [Fe / H] = - 2.9), and in turn to the rare subclass 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 . Roger Cayrel and co-workers used the Very Large Telescope (VLT) of the European Southern Observatory in Paranal , Chile for high-resolution optical spectroscopy for elemental abundances determined.
The ratio of thorium -232 to uranium -238 enabled the age to be determined. This star is around 12.5 billion years old, one of the oldest known.
Compared to other ultra-low-metal , r-process -enriched stars (such as CS22892-052 , BD + 17 ° 3248 ), CS31082-001 has higher abundances of actinides (Th, U), but an astonishingly low content of lead (Pb).
literature
- TC Beers, GW Preston, SA Shectman: A search for stars of very low metal abundance. I. In: Astron. J. Volume 90, 1985, pp. 2089-2102.
- TC Beers, GW Preston, SA Shectman: A search for stars of very low metal abundance. II. In: Astron. J. Volume 103, 1992, pp. 1987-2034.
- R. Cayrel, V. Hill, TC Beers, B. Barbuy, M. Spite, F. Spite, B. Plez, J. Andersen, P. Bonifacio, P. François, P. Molaro, B. Nordström, F. Primas : Measurement of stellar age from uranium decay. In: Nature. Vol. 409, No. 6821, 2001, pp. 691-692.
- H. Schatz, R. Toenjes, B. Pfeiffer, TC Beers, JJ Cowan, V. Hill, K.-L. Kratz: Thorium and Uranium Chronometres applied to CS 31082-001. In: Astrophysical Journal. Volume 579, 2002, pp. 628-638.
Web links
- R-Process Cosmo-Chronometers ( Memento from April 15, 2012 in the Internet Archive )
Individual evidence
- ↑ a b c d e f g h BPS CS 31082-0001. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed October 27, 2019 .