η Carinae: The optical flare-like events during low-excitation passages

Autor: Christiaan Sterken, A. M. van Genderen, W. H. Allen
Rok vydání: 2003
Předmět:
Zdroj: Astronomy and Astrophysics
ISSN: 1432-0746
0004-6361
DOI: 10.1051/0004-6361:20030688
Popis: The 1992.5 and 1998.0 low-excitation events of the possible binary in the core of Carinae show a conspicuous flare-like event in optical and near-ultraviolet light. These events last a couple of months and have a light amplitude of 0: 1-0: m 2 in V. Considering the presence of a dense (bi-polar) stellar wind, one explanation could be that some type of a hot area is created by an increased mass flow from the S Dor primary near the hypothetical periastron. These flare-like events are terminated by sharp dips. The magnitude dierences between the underlying light source and the central light ("Component A") are derived. It turns out that they are fainter than Component A by2: 5. The luminosity could be of the order of 10 5 L. It was possible to derive two new continuum values in the near-UV, reinforcing the impression derived from the HST fluxes that Component A has a very strong radiation peak in the Balmer continuum. This can probably be explained by the strong emission of the stellar wind.
Databáze: OpenAIRE