First detection of dust clouds around R CrB variable stars

Abstract

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.

Published in Astronomy and Astrophysics (A&A 428,L13-L16 (2004))

References in corpus (3)

• The MACHO Project LMC Variable Star Inventory: X. The R Coronae Borealis Stars
• Winds in R Coronae Borealis Stars
• EROS 2 photometry of probable R Coronae Borealis stars in the Small Magellanic Cloud

Cited by in corpus (10)

• The Circumstellar Environment of R Coronae Borealis: White Dwarf Merger or Final Helium Shell Flash?
• R Coronae Borealis stars in the Galactic Bulge discovered by EROS-2
• Dust around R Coronae Borealis stars: I. Spitzer/IRS observations
• New R Coronae Borealis stars discovered in OGLE-III Galactic Bulge fields from their mid- and near- infrared properties
• R Coronae Borealis at the 2003 Light Minimum
• Direct imaging of a massive dust cloud around R Coronae Borealis
• A snapshot of the inner dusty regions of a RCrB-type variable
• VLTI observations of the dust geometry around R Coronae Borealis stars
• High-resolution spectroscopy of the R Coronae Borealis and Other Hydrogen Deficient Stars
• Spectropolarimetry of R Coronae Borealis in 1998--2003: Discovery of Transient Polarization at Maximum Brightness