$\mathsf{\eta}$ Car: the optical features at the 2003.5 low-excitation event
| Autor: | Christiaan Sterken, W. H. Allen, A. M. van Genderen, William Liller |
|---|---|
| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | Astronomy and Astrophysics |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | UBV and BVR photometry of η Car during the 2003.5 low-excitation event – the considered periastron passage of a binary – is presented. The light and colour curves show a number of features, which were also seen at previous periastron passages: a light maximum of long duration with a superimposed flare-like event which is temporarily interrupted by an eclipse-like dip, and a steep decline in the $U-B$ color index. The R brightness reached a minimum at the time of mid X-ray totality, probably implying that the H α emission line reached a minimum. The source of the optical flare-like event is probably not the same as the one causing the the X-ray radiation. It is tempting to consider the epoch of the R minimum and the mid- X ray totality – which roughly coincides with the UBV minimum – as the central moment of the 2003.5 low-excitation event. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|