2018ApJ...859..114B


Query : 2018ApJ...859..114B

2018ApJ...859..114B - Astrophys. J., 859, 114-114 (2018/June-1)

Chemical composition of two bright, extremely metal-poor stars from the SDSS MARVELS pre-survey.

BANDYOPADHYAY A., SIVARANI T., SUSMITHA A., BEERS T.C., GIRIDHAR S., SURYA A. and MASSERON T.

Abstract (from CDS):

SDSS J082625.70+612515.10 (V = 11.4; [Fe/H] = -3.1) and SDSS J134144.60+474128.90 (V = 12.4; [Fe/H] = -3.2) were observed with the SDSS 2.5m telescope as part of the SDSS MARVELS spectroscopic pre-survey and identified as extremely metal-poor (EMP; [Fe/H] < -3.0) stars during the high-resolution follow-up using the Hanle Echelle Spectrograph (HESP) on the 2.0-m Himalayan Chandra Telescope. In this paper, the first science results using HESP, we present a detailed analysis of their chemical abundances. Both stars exhibit under-abundances in their neutron capture elements, while one of them (SDSS J134144.60+474128.90) is clearly enhanced in carbon. Lithium was also detected in this star at a level of about A(Li) = 1.95. The spectra were obtained over a span of 6-24 months, and indicate that both stars could be members of binary systems. We compare the elemental abundances derived for these two stars along with other carbon-enhanced metal-poor (CEMP) and EMP stars, in order to understand the nature of their parent supernovae. We find that CEMP-no stars and EMP-dwarfs show a very similar trend in their lithium abundances at various metallicities. We also find indications of CEMP-no stars having larger abundances of Cr and Co at given metallicities compared to EMP stars.

Abstract Copyright: © 2018. The American Astronomical Society. All rights reserved.

Journal keyword(s): stars: abundances - stars: carbon - stars: chemically peculiar - stars: early-type - stars: neutron - stars: Population III

Simbad objects: 4

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Number of rows : 4
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 TYC 4127-341-1 * 08 26 25.6935781560 +61 25 15.190708260   12.31 11.25     ~ 2 0
2 GrW 170817 GWE 13 09 48.0850 -23 22 53.343           ~ 2683 0
3 LSPM J1341+4741 Pe* 13 41 44.6114760816 +47 41 28.905615168   11.86 11.44     ~ 10 0
4 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 16269 0

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