A new sample of extremely/ultra metal-poor stars

A. E. García Pérez; N. Christlieb; S. G. Ryan; T. C. Beers; W. Aoki; M. Asplund; P. S. Barklem; M. S. Bessell; K. Eriksson; A. Frebel; B. Gustafsson; A. J. Korn; B. Nordström; J. E. Norris

doi:10.1088/0031-8949/2008/T133/014036

A new sample of extremely/ultra metal-poor stars

A. E. García Pérez, N. Christlieb, S. G. Ryan, T. C. Beers, W. Aoki, M. Asplund, P. S. Barklem, M. S. Bessell, K. Eriksson, A. Frebel, B. Gustafsson, A. J. Korn, B. Nordström, J. E. Norris

Research output: Contribution to journal › Conference article › peer-review

7 Citations (Scopus)

Abstract

A sample of 30 very metal-poor stars from the Hamburg-European Southern Observatory (ESO) objective-prism survey have been observed at high spectral resolution at the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle Spectrograph (UVES). Two of the observed stars are very interesting not only because of their very low iron content, approximately four orders of magnitude lower than the solar value, but also because we detected the neutral lithium resonance line at 670.8 nm. Hydrogen lines suggest that the two observed stars have effective temperatures around 6000-6250 K and according to isochrones, they are either on the main-sequence or on the subgiant branch, in which case they would probably be the most metal-poor dwarfs or warm subgiants with lithium detections known. These detections would allow to determine more accurately the slope of the trend of the lithium abundance with [Fe/H] than was possible with samples of unevolved stars restricted to higher metallicities.

Original language	English
Article number	014036
Journal	Physica Scripta
Volume	T133
DOIs	https://doi.org/10.1088/0031-8949/2008/T133/014036
Publication status	Published - 2008
Event	A Stellar Journey: A symposium in Celebration of Bengt Gustafsson's 65th Birthday - Uppsala, Sweden Duration: 23 Jun 2008 → 27 Jun 2008

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10.1088/0031-8949/2008/T133/014036

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title = "A new sample of extremely/ultra metal-poor stars",

abstract = "A sample of 30 very metal-poor stars from the Hamburg-European Southern Observatory (ESO) objective-prism survey have been observed at high spectral resolution at the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle Spectrograph (UVES). Two of the observed stars are very interesting not only because of their very low iron content, approximately four orders of magnitude lower than the solar value, but also because we detected the neutral lithium resonance line at 670.8 nm. Hydrogen lines suggest that the two observed stars have effective temperatures around 6000-6250 K and according to isochrones, they are either on the main-sequence or on the subgiant branch, in which case they would probably be the most metal-poor dwarfs or warm subgiants with lithium detections known. These detections would allow to determine more accurately the slope of the trend of the lithium abundance with [Fe/H] than was possible with samples of unevolved stars restricted to higher metallicities.",

author = "{Garc{\'i}a P{\'e}rez}, {A. E.} and N. Christlieb and Ryan, {S. G.} and Beers, {T. C.} and W. Aoki and M. Asplund and Barklem, {P. S.} and Bessell, {M. S.} and K. Eriksson and A. Frebel and B. Gustafsson and Korn, {A. J.} and B. Nordstr{\"o}m and Norris, {J. E.}",

year = "2008",

doi = "10.1088/0031-8949/2008/T133/014036",

language = "English",

volume = "T133",

journal = "Physica Scripta",

issn = "0031-8949",

publisher = "IOP Publishing Ltd.",

note = "A Stellar Journey: A symposium in Celebration of Bengt Gustafsson's 65th Birthday ; Conference date: 23-06-2008 Through 27-06-2008",

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TY - JOUR

T1 - A new sample of extremely/ultra metal-poor stars

AU - García Pérez, A. E.

AU - Christlieb, N.

AU - Ryan, S. G.

AU - Beers, T. C.

AU - Aoki, W.

AU - Asplund, M.

AU - Barklem, P. S.

AU - Bessell, M. S.

AU - Eriksson, K.

AU - Frebel, A.

AU - Gustafsson, B.

AU - Korn, A. J.

AU - Nordström, B.

AU - Norris, J. E.

PY - 2008

Y1 - 2008

N2 - A sample of 30 very metal-poor stars from the Hamburg-European Southern Observatory (ESO) objective-prism survey have been observed at high spectral resolution at the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle Spectrograph (UVES). Two of the observed stars are very interesting not only because of their very low iron content, approximately four orders of magnitude lower than the solar value, but also because we detected the neutral lithium resonance line at 670.8 nm. Hydrogen lines suggest that the two observed stars have effective temperatures around 6000-6250 K and according to isochrones, they are either on the main-sequence or on the subgiant branch, in which case they would probably be the most metal-poor dwarfs or warm subgiants with lithium detections known. These detections would allow to determine more accurately the slope of the trend of the lithium abundance with [Fe/H] than was possible with samples of unevolved stars restricted to higher metallicities.

AB - A sample of 30 very metal-poor stars from the Hamburg-European Southern Observatory (ESO) objective-prism survey have been observed at high spectral resolution at the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle Spectrograph (UVES). Two of the observed stars are very interesting not only because of their very low iron content, approximately four orders of magnitude lower than the solar value, but also because we detected the neutral lithium resonance line at 670.8 nm. Hydrogen lines suggest that the two observed stars have effective temperatures around 6000-6250 K and according to isochrones, they are either on the main-sequence or on the subgiant branch, in which case they would probably be the most metal-poor dwarfs or warm subgiants with lithium detections known. These detections would allow to determine more accurately the slope of the trend of the lithium abundance with [Fe/H] than was possible with samples of unevolved stars restricted to higher metallicities.

UR - http://www.scopus.com/inward/record.url?scp=70350654387&partnerID=8YFLogxK

U2 - 10.1088/0031-8949/2008/T133/014036

DO - 10.1088/0031-8949/2008/T133/014036

M3 - Conference article

SN - 0031-8949

VL - T133

JO - Physica Scripta

JF - Physica Scripta

M1 - 014036

T2 - A Stellar Journey: A symposium in Celebration of Bengt Gustafsson's 65th Birthday

Y2 - 23 June 2008 through 27 June 2008

ER -

A new sample of extremely/ultra metal-poor stars

Abstract

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