HD 115444 - a barium star of extreme Population II
- 1. Cambridge Univ. (UK). Observatories
- 2. Uppsala Univ. (Sweden). Astronomiska Observatoriet
Description
The star HD 115444 is shown to be a very metal-poor red giant. A model atmosphere analysis based on colours, energy distributions and moderate-resolution spectrograms has been performed differentially with respect to HD 122563. The following parameters result for HD 115444: Tsub(eff) = 4800 K, log g = 1.6, M/H = -2.95, xisub(t) = 2.6 km s-1. The star is therefore one of the most metal-poor stars known to exist. However, its s-element abundances are high relative to iron in comparison with the Sun, and even more so in comparison with other extreme Population II giants. Europium, which is considered to be mainly an r-process element, is also significantly enhanced. The C/Fe ratio seems relatively normal, while N is probably enhanced as it is in HD 122563. Some possible implications of the pattern of abundances in HD 115444 are discussed. (author)
Additional details
Publishing Information
- Journal Title
- Mon. Not. R. Astron. Soc.
- Journal Volume
- 198
- Journal Issue
- 2
- Series
- Mon. Not. R. Astron. Soc.
- Journal Page Range
- 637-658
- ISSN
- 0035-8711
INIS
- Country of Publication
- United Kingdom
- Country of Input or Organization
- United Kingdom
- INIS RN
- 13673364
- Subject category
- S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
- Descriptors DEI
- CARBON; CHEMICAL COMPOSITION; COLOR; ELEMENT ABUNDANCE; ENERGY SPECTRA; EUROPIUM; IRON; METALS; NITROGEN; PHOTOMETRY; R PROCESS; RADIAL VELOCITY; RED GIANT STARS; S PROCESS; SPECTROPHOTOMETRY; STAR MODELS; STELLAR ATMOSPHERES; ULTRAHIGH TEMPERATURE
- Descriptors DEC
- ATMOSPHERES; ELEMENTS; GIANT STARS; MATHEMATICAL MODELS; NONMETALS; OPTICAL PROPERTIES; ORGANOLEPTIC PROPERTIES; PHYSICAL PROPERTIES; QUANTITY RATIO; RARE EARTHS; SPECTRA; STAR EVOLUTION; STARS; TRANSITION ELEMENTS; VELOCITY