More lead stars

@article{Eck2003MoreLS,
  title={More lead stars},
  author={Sophie Van Eck and Stephane Goriely and A. Jorissen and Bertrand Plez},
  journal={Astronomy and Astrophysics},
  year={2003},
  volume={404},
  pages={291-299}
}
The standard model for the operation of the s-process in asymptotic giant branch (AGB) stars predicts that low-metallicity ([Fe/H] ≲ -1) AGB stars should exhibit large overabundances of Pb and Bi as compared to other s-elements. The discovery of the first three such "lead stars" (defined as stars enriched in s-elements with [Pb/hs] ≳1, hs being any of Ba. La or Ce) among CH stars has been reported in a previous paper (Van Eck et al. 2001). Five more CH stars (with [Fe/H] ranging from -1.5 to -2… 

Figures and Tables from this paper

The S-process in metal - poor stars: Abundances for 22 neutron - capture elements in CS 31062-050
The CH star CS 31062-050 ([Fe/H] = -2.42) is one of the most useful stars yet discovered for evaluating the s-process in metal-poor stars. It is very abundant in heavy elements (e.g., [La/Fe] = 2.2),
The s-Process in Low Metallicity Stars. II. Interpretation of High-Resolution Spectroscopic Observations with AGB models
High-resolution spectroscopic observations of a hundred metal-poor Carbon and s-rich stars (CEMP-s) collected from the literature are compared with the theoretical nucleosynthesis models of
The Missing Lead: Developments in the Lead (Pb) Discrepancy in Intrinsically s-Process Enriched Single Post-AGB Stars
Lead (Pb) is predicted to have large over-abundances with respect to other s-process elements in Asymptotic Giant Branch (AGB) stars, especially of low metallicities. However, our previous abundance
The origin of the lead-rich stars in the Galactic halo: investigation of model parameters for the s-process
Several stars at the low-metallicity extreme of the Galactic halo show large spreads of lead and associated 'heavy' s-process elements ([Pb/hs]). Theoretically, an s-process pattern should be
s‐Process in low‐metallicity stars – I. Theoretical predictions
A large sample of carbon enhanced metal-poor stars enriched in s-process elements (CEMP-s) have been observed in the Galactic halo. These stars of low mass (M � 0.9 M� ) are located on the
First stars X. The nature of three unevolved Carbon-Enhanced Metal-Poor stars ⋆
Context. On the order of 20% of the very metal-poor stars in the Galaxy exhibit large carbon enhancements. It is important to establish which astrophysical sites and processes are responsible for the
First stars IV. CS 29497-030: Evidence for operation of the s-process at very low metallicity
We present an abundance analysis of the very metal-poor, carbon-enhanced star CS 29497-030. Our results indicate that this unusually hot turno star (Te = 6650 K, logg= 3.5) has a metallicity (Fe/H)=
Study of the abundance features of the metal-poor star HD 94028
Recent work has found that the metal-poor star HD 94028 shows interesting abundance features. The s-process material (e.g., Ba, La, Ce, and Pb) and r-process material (e.g., Eu, Os, Pt) are mildly
Enrichment of Very Metal Poor Stars with Both r-Process and s-Process Elements from 8-10 M☉ Stars
Recent spectroscopic studies have revealed the presence of numerous carbon-enhanced, metal-poor stars with [Fe/H] < -2.0 that exhibit strong enhancements of s-process elements. These stars are
Binary properties of CH and Carbon-Enhanced Metal-Poor stars
The HERMES spectrograph installed on the 1.2-m Mercator telescope has been used to monitor the radial velocity of 13 low-metallicity carbon stars, among which seven carbon-enhanced metal-poor (CEMP)
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 37 REFERENCES
Discovery of three lead-rich stars
TLDR
Analysis shows that three metal-poor stars are more enriched in lead than in any other element heavier than iron, and excellent agreement between the observed and predicted abundances reinforces current understanding of the detailed operation of the s-process deep in the interiors of AGB stars.
Extremely Metal-poor Stars. IV. The Carbon-rich Objects
Abundances are presented for some 20 elements in three extremely metal-poor, carbon-rich stars. All have [Fe/H] < -2.5. Based on their high proper motions and spectroscopic gravities two of them have
The Incidence of Binaries among Very Metal-poor Carbon Stars
We have monitored the radial velocities of seven very metal-poor stars with abnormally strong CH G bands. On the basis of their colors four are giants (gCH) and three are subgiants (sgCH). Three of
Neutron capture elements in s-process-rich, very metal-poor stars
We report abundance estimates for neutron capture elements, including lead (Pb), and nucleosynthesis models for their origin, in two carbon-rich, very metal-poor stars, LP 625-44 and LP 706-7. These
The CH Stars. III. Heavy Element Abundances
The s-process abundances in seven CH giants have been derived. Large enhancement of s-process elements relative to solar values are found, [s/Fe]=+1.0 to +2.0. In addition, the heavy s-process peak
A Subaru/High Dispersion Spectrograph Study of Lead (Pb) Abundances in Eight s-Process Element-rich, Metal-poor Stars
We report the abundances of neutron-capture elements in eight carbon-rich, metal-poor (� 2:7 �½ Fe=H ��� 1:9) stars observed with the Subaru Telescope High Dispersion Spectrograph. The derived
The Binary Nature of the Barium and CH Stars. III. Orbital Parameters
Results are presented from a 10-year program to monitor the velocity variations of Ba II and CH stars, showing that all Ba II and CH stars are binaries. Radial-velocity observations for Ba II and CH
Nucleosynthesis of s-elements in zero-metal AGB stars
Contrary to previous expectations, recent evolutionary models of zero-metallicity stars show that the development of mixing episodes at the beginning of the AGB phase allows low- and
Detection of Lead in the Carbon-rich, Very Metal-poor Star LP 625-44: A Strong Constraint on s-Process Nucleosynthesis at Low Metallicity.
TLDR
The detection of Pb makes it possible, for the first time, to compare model predictions of s-process nucleosynthesis in AGB stars with observations of elements between Sr and Pb, and the Pb abundance is significantly lower than the prediction of recent models.
Stellar Iron Abundances: Non-LTE Effects
We report new statistical equilibrium calculations for Fe I and Fe II in the atmosphere of late-type stars. We used atomic models for Fe I and Fe II having, respectively, 256 and 190 levels, as well
...
1
2
3
4
...