| Issue |
A&A
Volume 428, Number 1, December II 2004
|
|
|---|---|---|
| Page(s) | L13 - L16 | |
| Section | Letters | |
| DOI | https://doi.org/10.1051/0004-6361:200400095 | |
| Published online | 23 November 2004 | |
Letter to the Editor
First detection of dust clouds around R CrB variable stars*
Observatoire de la Côte d'Azur, Dpt Cassiopée, CNRS - UMR 6202, BP 4229, 06304 Nice Cedex 4, France e-mail: [laverny;mekarnia]@obs-nice.fr
Received:
6
September
2004
Accepted:
23
October
2004
From VLT/NACO diffraction-limited images of RY Sgr, we report the first direct detection of heterogeneities in the circumstellar envelope of a R Coronae Borealis variable star. Several bright and very large dust clouds are seen in various directions at several hundred stellar radii from RY Sgr, revealing high activity for the ejection of stellar material by R CrB variables. These observations do support the current interpretation that optically thick dust clouds are formed around the surface of this type of variable stars and, when passing between the star and the observer, produce the huge and sudden declines characterizing these objects in visible light. This is the first direct confirmation of a scenario proposed about 70 years ago.
Key words: stars: AGB and post-AGB / stars: variables: general / stars: individual: RY Sgr / stars: mass-loss / stars: circumstellar matter / techniques: high angular resolution
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.