Doppler imaging of the helium-variable star a Centauri
نویسندگان
چکیده
منابع مشابه
Centauri : Helium Dwarf Nova Mimicking a WZ Sge - Type
We observed the long-term behavior of the helium dwarf nova V803 Cen, and clarified the existence of at least two distinct states (a state with 77-d supercycles and a standstill-like state) that interchangeably appeared with a time-scale of 1–2 yr. We also conducted a time-resolved CCD photometry campaign during the bright outburst in 2003 June. The overall appearance of the outburst closely re...
متن کاملCentauri : Helium Dwarf Nova Mimicking a WZ Sge - Type Superoutburst
We observed long-term behavior of the helium dwarf nova V803 Cen, and clarified the existence of at least two distinct states (state with 77-d supercycles and standstill-like state) which interchangeably appeared with a time-scale of 1–2 yr. We also conducted a time-resolved CCD photometry campaign during the bright outburst in 2003 June. The overall appearance of the outburst closely resemble ...
متن کاملDetection of variable Si II , Mn II and Fe II emission lines in the magnetic Bp star a Centauri ⋆
Context. The nature of non-variable high-excitation emission lines detected in the optical spectra of normal late-B type and chemically peculiar HgMn and PGa stars is still poorly understood. Aims. To better understand the origin of the weak emission lines in B type stars it is especially important to investigate the spectra of a variety of stars to search for correlations between the emergence...
متن کاملStellar and circumstellar activity of the Be star μ Centauri ?
After the description and time series analysis of the variability of the circumstellar and stellar lines, respectively, in Papers I and II of this series, this paper sets out to model the stellar variability in terms of multimode nonradial pulsation (nrp), but also adds another 109 echelle spectra to the database, obtained in 1999. While the near-circumstellar emission has faded further, the si...
متن کاملThe extended star formation history of ω Centauri ⋆
For the first time, the abundances of a large sample of subgiant and turn-off region stars in ω Centauri have been measured, the data base being medium resolution spectroscopy from FORS2 at the VLT. Absolute iron abundances were derived for ∼400 member stars from newly defined line indices with an accuracy of ±0.15 dex. The abundances range between −2.2 <[Fe/H]< −0.7 dex, resembling the large m...
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ژورنال
عنوان ژورنال: Astronomy and Astrophysics
سال: 2010
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201014157