SIMBAD references

We have obtained a 150x150" map of the 1.3mm emission around the carbon star CW Leo. Emission is detected at the 3σ level out to a distance of 50" from the central star. From model calculations we find that the dust density distribution is described by an approximate r^–2 law superposed on which are possible density enhancements at about 5 and 20" distance from the star. This could imply phases of enhanced mass loss lasting up to several hundred years duration over the last few 1000 years. The major uncertainty in a quantitative analysis is in the contribution of molecular lines. The density enhancement at 5" is consistent with a recent phase of increased mass loss as inferred from CO data.