dc.contributor.author |
Pandey, G |
|
dc.contributor.author |
Kameswara Rao, N |
|
dc.contributor.author |
Jeffery, C. S |
|
dc.contributor.author |
Lambert, D. L |
|
dc.date.accessioned |
2014-10-21T05:50:57Z |
|
dc.date.available |
2014-10-21T05:50:57Z |
|
dc.date.issued |
2014-10-01 |
|
dc.identifier.citation |
The Astrophysical Journal, Vol. 793, No. 2, 76 |
en |
dc.identifier.issn |
0004-637X |
|
dc.identifier.uri |
http://hdl.handle.net/2248/6660 |
|
dc.description |
Restricted Access |
en |
dc.description.abstract |
DY Cen has shown a steady fading of its visual light by about one magnitude in the last 40 yr, suggesting a secular increase in its effective temperature. We have conducted non-local thermodynamic equilibrium (LTE) and LTE abundance analyses to determine the star's effective temperature, surface gravity, and chemical composition using high-resolution spectra obtained over two decades. The derived stellar parameters for three epochs suggest that DY Cen has evolved at a constant luminosity and has become hotter by about 5000 K in 23 yr. We show that the derived abundances remain unchanged for the three epochs. The derived abundances of the key elements, including F and Ne, are as observed for the extreme helium stars resulting from a merger of a He white dwarf with a C-O white dwarf. Thus DY Cen by chemical composition appears to also be a product of a merger of two white dwarfs. This appearance seems to be at odds with the recent suggestion that DY Cen is a single-lined spectroscopic binary. |
en |
dc.language.iso |
en |
en |
dc.publisher |
IOP Publishing |
en |
dc.relation.uri |
http://iopscience.iop.org/0004-637X/793/2/76/ |
en |
dc.rights |
© IOP Publishing |
en |
dc.subject |
Stars: abundances |
en |
dc.subject |
Stars: atmospheres |
en |
dc.subject |
Stars: chemically peculiar |
en |
dc.subject |
Stars: evolution |
en |
dc.subject |
Stars: fundamental parameters |
en |
dc.subject |
Stars: individual (DY Cen) |
en |
dc.title |
On the Binary Helium Star DY Centauri: Chemical Composition and Evolutionary State |
en |
dc.type |
Article |
en |