Fundamental Parameters and Abundances of Metal-Poor Stars: The SDSS Standard BD +17 4708

Details Fundamental Parameters and Abundances of Metal-Poor Stars: The SDSS Standard BD +17 4708 Fundamental Parameters and Abundances of Metal-Poor Stars: The SDSS Standard BD +17 4708

2006-08-25

arxiv.org/abs/astro-ph/0608559v1

Astron.Astrophys. 459 (2006) 613-625

Astronomy and Astrophysics

Astrophysics

A&A in press

Scientific paper

10.1051/0004-6361:20065647

The atmospheric parameters and iron abundance of the Sloan Digital Sky Survey (SDSS) spectrophotometric standard star BD +17 4708 are critically examined using up-to-date Kurucz model atmospheres, LTE line formation calculations, and reliable atomic data. We find Teff = 6141+-50 K, log g = 3.87+-0.08, and [Fe/H]=-1.74+-0.09. The line-of-sight interstellar reddening, bolometric flux, limb-darkened angular diameter, stellar mass, and the abundances of Mg, Si, and Ca are also obtained. This star is a unique example of a moderately metal-poor star for which the effective temperature can be accurately constrained from the observed spectral energy distribution (corrected for reddening). Such analysis leads to a value that is higher than most spectroscopic results previously reported in the literature (~5950 K). We find that the ionization balance of Fe lines is satisfied only if a low Teff (~5950 K) is adopted. With our preferred Teff (6141 K), the mean iron abundance we obtain from the FeII lines is lower by about 0.15 dex than that from the FeI lines, and therefore, the discrepancy between the mean iron abundance from FeI and FeII lines cannot be explained by overionization by UV photons as the main non-LTE effect. We also comment on non-LTE effects and the importance of inelastic collisions with neutral H atoms in the determination of oxygen abundances in metal-poor stars from the 777 nm OI triplet. (Abridged)

Affiliated with

Also associated with

No associations

Rating

Fundamental Parameters and Abundances of Metal-Poor Stars: The SDSS Standard BD +17 4708 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Fundamental Parameters and Abundances of Metal-Poor Stars: The SDSS Standard BD +17 4708, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fundamental Parameters and Abundances of Metal-Poor Stars: The SDSS Standard BD +17 4708 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-112155