The Case for Asymmetric Dust Around a C-Rich AGB star

Abstract

JHKL observations of the mass-losing carbon Mira variable IRAS 15194-5115 (II Lup) extending over about 18 years are presented and discussed. The pulsation period is 575 days and has remained essentially constant over this time span. The star has undergone an extensive obscuration minimum during this time. This is complex and, like such minima in similar objects, e.g. R For, does not fit the model predictions of a simple long term periodicity. Together with the high resolution observations of Lopez et al. the results suggest that the obscuration changes are due to the formation of dust clouds of limited extent in the line-of-sight. This is an RCB-type model. The effective reddening law at J and H is similar to that found for R For.

arXiv comment8 pages, 2 figures, accepted for publication in MNRAS

References in corpus (8)

• Obscured Asymptotic Giant Branch Variables in the Large Magellanic Cloud and the Period-Luminosity Relation
• Reprocessing the Hipparcos data for evolved stars III Revised Hipparcos period-luminosity relationship for galactic long-period variable stars
• Dust-enshrouded Asymptotic Giant Branch Stars in the Solar Neighbourhood
• Smoke Signals From IRC +10216: 1. Milliarcsecond Proper Motions of the Dust
• Dust Formation Above Cool Magnetic Spots in Evolved Stars
• The light curve of the semiregular variable L2 Puppis: I. A recent dimming event from dust
• Dust formation in winds of long-period variables. V. The influence of micro-physical dust properties in carbon stars
• Three-component modeling of C-rich AGB star winds. II. The effects of drift in long-period variables

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