Sneden's Star

{{Starbox observe

| epoch = J2000

| constell = Aquarius

| ra = {{RA|22|17|01.65585}}

| dec = {{DEC|−16|39|27.0519}}

| appmag_v = 13.21

}}

{{Starbox character

| type = giant

| class = KIIvw

| b-v = 0.78

| u-b =

| variable =

}}

{{Starbox astrometry

| radial_v = +13.0

| prop_mo_ra = 12.321

| prop_mo_dec = −6.493

| parallax = 0.1868

| p_error = 0.0440

| parallax_footnote =

| absmag_v = −0.23

}}

{{Starbox detail

| age_gyr = {{val|14.2|3}}

| metal_fe = −3.19

| mass = 1.13

| radius = 13.8

| gravity = 1.15

| rotation =

| luminosity = 158

| temperature = 4,690

}}

{{Starbox catalog

| names = BPS CS 22892-0052, HE 2214-1654

}}

{{Starbox reference

| Simbad = BPS+CS22892-0052

}}

BPS CS22892-0052 (Sneden's Star) is an old population II star located at a distance of {{convert|4.7|kpc|light-year|abbr=off|lk=on}} in the Milky Way's galactic halo. It belongs to a class of ultra-metal-poor stars (metallicity [Fe/H]=-3.1), specifically the very rare subclass of neutron-capture (r-process) enhanced stars. It was discovered by Tim C. Beers and collaborators with the Curtis Schmidt telescope at the Cerro Tololo Inter-American Observatory in Chile. Extended high-resolution spectroscopic observations since around 1995 (with Chris Sneden from the University of Texas at Austin as the leading observer) allowed observers to determine the abundances of 53 chemical elements in this star, as of December 2005 only second in number to the Sun.

From barium (Z=56) on, all elements show the pattern of the r-process contribution to the abundances of the elements in the Solar System. Comparing the observed abundances for a stable element such as europium (Z=63) and the radioactive element thorium (Z=90) to calculated abundances of an r-process in a type II supernova explosion (as from the universities at Mainz and Basel groups of Karl-Ludwig Kratz and Friedrich-Karl Thielemann) have allowed observers to determine the age of this star to be about 14 billion years. Similar ages have been derived for other ultra-metal-poor stars (CS31082-001, BD+17°3248 and HE 1523-0901) from thorium-to-uranium ratios.{{cn|date=June 2025}}

References

{{reflist|refs=

{{cite simbad

| title=BPS CS 22892-0052 | access-date=2021-03-29 }}

{{cite journal |bibcode=2003ApJ...591..936S |title=The Extremely Metal-poor, Neutron Capture-rich Star CS 22892-052: A Comprehensive Abundance Analysis |last1=Sneden |first1=Christopher |last2=Cowan |first2=John J. |last3=Lawler |first3=James E. |last4=Ivans |first4=Inese I. |last5=Burles |first5=Scott |last6=Beers |first6=Timothy C. |last7=Primas |first7=Francesca |last8=Hill |first8=Vanessa |last9=Truran |first9=James W. |last10=Fuller |first10=George M. |last11=Pfeiffer |first11=Bernd |last12=Kratz |first12=Karl-Ludwig |journal=The Astrophysical Journal |date=2003 |volume=591 |issue=2 |page=936 |doi=10.1086/375491 |arxiv=astro-ph/0303542 }}

{{cite journal |bibcode=2023A&A...679A.110G |title=TITANS metal-poor reference stars. II. Red giants and CEMP stars |last1=Giribaldi |first1=R. E. |last2=Van Eck |first2=S. |last3=Merle |first3=T. |last4=Jorissen |first4=A. |last5=Krynski |first5=P. |last6=Planquart |first6=L. |last7=Valentini |first7=M. |last8=Chiappini |first8=C. |last9=Van Winckel |first9=H. |journal=Astronomy and Astrophysics |date=2023 |volume=679 |pages=A110 |doi=10.1051/0004-6361/202347208 |arxiv=2308.10118 }}

{{cite journal

| title=Extremely Metal-poor Stars. IV. The Carbon-rich Objects

| display-authors=1 | last1=Norris | first1=John E.

| last2=Ryan | first2=Sean G. | last3=Beers | first3=Timothy C.

| journal=The Astrophysical Journal

| volume=488 | issue=1 | pages=350–363 | date=October 1997

| doi=10.1086/304695 | bibcode=1997ApJ...488..350N | s2cid=121307016 }}

{{cite journal

| title=A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-poor Stars

| display-authors=1 | last1=Roederer | first1=Ian U.

| last2=Preston | first2=George W. | last3=Thompson | first3=Ian B.

| last4=Shectman | first4=Stephen A. | last5=Sneden | first5=Christopher

| last6=Burley | first6=Gregory S. | last7=Kelson | first7=Daniel D.

| journal=The Astronomical Journal

| arxiv=1403.6853 | bibcode=2014AJ....147..136R

| doi=10.1088/0004-6256/147/6/136 | s2cid=119249291 }}

{{Cite journal|last1=Anders|first1=F.|last2=Khalatyan|first2=A.|last3=Chiappini|first3=C.|last4=Queiroz|first4=A. B.|last5=Santiago|first5=B. X.|last6=Jordi|first6=C.|last7=Girardi|first7=L.|last8=Brown|first8=A. G. A.|last9=Matijevic|first9=G.|last10=Monari|first10=G.|last11=Cantat-Gaudin|first11=T.|date=2019-08-01|title=Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18|bibcode=2019A&A...628A..94A|journal=Astronomy and Astrophysics|volume=628|pages=A94|doi=10.1051/0004-6361/201935765|arxiv=1904.11302|issn=0004-6361|doi-access=free}}

{{Cite journal|last1=Stassun|first1=Keivan G.|last2=Oelkers|first2=Ryan J.|last3=Paegert|first3=Martin|last4=Torres|first4=Guillermo|last5=Pepper|first5=Joshua|last6=De Lee|first6=Nathan|last7=Collins|first7=Kevin|last8=Latham|first8=David W.|last9=Muirhead|first9=Philip S.|last10=Chittidi|first10=Jay|last11=Rojas-Ayala|first11=Bárbara|date=2019-10-01|title=The Revised TESS Input Catalog and Candidate Target List|bibcode=2019AJ....158..138S|journal=The Astronomical Journal|volume=158|issue=4 |pages=138|doi=10.3847/1538-3881/ab3467|arxiv=1905.10694 |issn=0004-6256|hdl=1721.1/124721|s2cid=166227927 |hdl-access=free |doi-access=free }}

{{cite journal |bibcode=1992AJ....103.1987B |title=A Search for Stars of Very Low Metal Abundance. II |last1=Beers |first1=Timothy C. |last2=Preston |first2=George W. |last3=Shectman |first3=Stephen A. |journal=The Astronomical Journal |year=1992 |volume=103 |page=1987 |doi=10.1086/116207 |s2cid=121564385 }}

}}

Sources

Beers T.C., Preston G.W., Shectman S.A., A search for stars of very low metal abundance. I., Astron. J., 90, 2089-2102 (1985)
Beers T.C., Preston G.W., Shectman S.A., 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)

External links

[https://web.archive.org/web/20050118210353/http://dkcmzc.chemie.uni-mainz.de/~pfeiffer/ages.html R-Process Cosmo-Chronometers]
[https://web.archive.org/web/20070319100858/http://dkcmzc.chemie.uni-mainz.de/~pfeiffer/cs228.html image]
[http://aladin.u-strasbg.fr/AladinPreview?-c=22+17+01.50-16+39+26.0&ident=BPS+CS+22892-0052&submit=Aladin+previewer Image Sneden's Star]

Category:K-type bright giants

Category:Asymptotic-giant-branch stars

Category:Population II stars

Category:Aquarius (constellation)