Results 1 to 10 of about 167,710 (319)

Boron in Very Metal-Poor Stars [PDF]

The Astrophysical Journal, 1998
We have observed the B I 2497 A line to derive the boron abundances of two very metal-poor stars selected to help in tracing the origin and evolution of this element in the early Galaxy: BD +23 3130 and HD 84937. The observations were conducted using the
Alonso A., Bengt Edvardsson, Bengt Gustafsson, Blackwell D. E., Carlsson M., Dan Kiselman, David L. Lambert, Edvardsson B., Edvardsson B., Garcia Lopez R. J., Gratton R., Hobbs L. M., J. Garcia Lopez, Johansson S. G., Kiselman D., Kiselman D., Molaro P., Molaro P., Nissen P. E., O'Brian T. R., O'Brian T. R., Pavlenko Ya. V., Pavlenko Ya. V., Pavlenko Ya. V., Rafael Rebolo, Terasawa N.   +25 more
core   +3 more sources

THE BEST AND BRIGHTEST METAL-POOR STARS [PDF]

The Astrophysical Journal, 2014
28 pages, 6 figures, and 4 tables in emulateapj format; accepted for publication in ...
Schlaufman, Kevin, Casey, Andrew
openaire   +4 more sources

Extremely metal-poor stars in SDSS fields [PDF]

Astronomische Nachrichten, 2011
Some insight on the first generation of stars can be obtained from the chemical composition of their direct descendants, extremely metal-poor stars (EMP), with metallicity less than or equal to 1/1000 of the solar metalllicity. Such stars are exceedingly
Adelman-McCarthy, Barklem, Behara, Bonifacio, Bonifacio, Caffau, Carney, Castelli, Castelli, Cayrel, Cohen, Edvardsson, François, Kurucz, Lai, Ludwig, Ludwig, Marigo, Mashonkina, Nissen, Piau, Robin, Sbordone, Sbordone, Sbordone, Schlegel, Spite, Spite, Stehlé, Tafelmeyer, Tolstoy, York   +31 more
core   +10 more sources

Lithium abundances in metal-poor stars [PDF]

Astronomy & Astrophysics, 2007
Aims. Lithium abundances for 19 metal-poor stars are determined using high-resolution spectroscopy. The abundances of stars on the lithium plateau are discussed. Methods. All abundance results are derived from NLTE statistical equilibrium calculations and spectrum synthesis methods. Results.
J. R. Shi, T. Gehren, H. W. Zhang, J. L. Zeng, G. Zhao   +4 more
openaire   +2 more sources

Beryllium abundances in metal-poor stars [PDF]

Monthly Notices of the Royal Astronomical Society, 2008
We have determined beryllium abundances for 25 metal-poor stars based on the high resolution and high signal-to-noise ratio spectra from the VLT/UVES database.
Allen, Allende Prieto, Alonso, Alonso, Anders, Anstee, Anstee, Asplund, Asplund, Balachandran, Barklem, Bell, Boesgaard, Boesgaard, Boesgaard, Cavallo, Chmielewski, Dekker, Duncan, ESA, Fuhrmann, Fulbright, Fulbright, G. Zhao, García López, García Pérez, Gilmore, Gratton, Higdon, Hinkle, J. R. Shi, Johnson, Jonsell, K. F. Tan, King, Kiselman, Kiselman, Korn, Kurucz, Kurucz, Magain, Molaro, Nissen, Nissen, Parizot, Parizot, Parizot, Pasquini, Pasquini, Pasquini, Primas, Primas, Ramaty, Rebolo, Reeves, Shetrone, Shi, Smiljanic, Suzuki, Takeda, Thomas, Tolstoy, Valle, Wiese, Yi   +64 more
core   +2 more sources

Extremely Metal-Poor Stars. VII. The Most Metal-Poor Dwarf, CS 22876-032 [PDF]

The Astrophysical Journal, 2000
We report high-resolution, high-signal-to-noise, observations of the extremely metal-poor double-lined spectroscopic binary CS 22876-032. The system has a long period : P = 424.7 $\pm$ 0.6 days.
Arpigny C., Baumuller D., Beers T. C., Ikuta C., John E. Norris, Lehmann-Filhes R., Molaro P., Nissen P. E., Primas F., Russell H. N., Ryan S. G., Schuster W. J., Schuster W. J., Sean G. Ryan, Timothy C. Beers   +14 more
core   +3 more sources

Sulphur abundances in metal-poor stars [PDF]

Astronomy & Astrophysics, 2005
We investigate the debated "sulphur discrepancy" found among metal-poor stars of the Galactic halo with [Fe/H] < -2. This discrepancy stems in part from the use of two different sets of sulphur lines, the very weak triplet at 8694-95 A and the stronger ...
A. J. Korn, Alonso, Bagnulo, Caffau, Chen, Fuhrmann, Israelian, Korn, N. Ryde, Nissen, Pfeiffer, Ryde, Takada-Hidai, Takada-Hidai   +13 more
core   +2 more sources

X-Shooter GTO: evidence for a population of extremely metal-poor, alpha-poor stars [PDF]

, 2013
The extremely metal-poor stars are the direct descendants of the first generation stars. They carry the chemical signature of the pristine Universe at the time they formed, shortly after the Big Bang.
Bonifacio, P., Caffau, E., Cayrel, R., Francois, P., Hammer, F., Hill, V., Ludwig, H. -G., Molaro, P., Monaco, L., Plez, B., Randich, S., Sbordone, L., Spite, F., Spite, M., Zaggia, S.   +14 more
core   +22 more sources

Metal-poor Stars in the MW Disk: Resonant Cooling of Vertical Oscillations of Halo Stars in Barred Galaxies [PDF]

The Astrophysical Journal Letters
Using numerical simulations of a barred disk galaxy embedded in nonspinning and spinning dark matter (DM) halos, we present a novel mechanism of “cooling” the vertical oscillations of DM particles, which acquire disk kinematics.
Xingchen Li, Isaac Shlosman, Daniel Pfenniger, Clayton Heller   +3 more
doaj   +2 more sources

Oxygen Abundances in Metal‐poor Stars [PDF]

The Astrophysical Journal, 2003
We present oxygen abundances derived from both the permitted and forbidden oxygen lines for 55 subgiants and giants with [Fe/H] values between -2.7 and solar with the goal of understanding the discrepancy in the derived abundances. A first attempt, using \teff{} values from photometric calibrations and surface gravities from luminosities, obtained ...
Fulbright, Jon. P., Johnson, Jennifer A.
openaire   +2 more sources