Analyzing the images of comet C/2007 W1 (Boattini) obtained during the past nights, we found evidence of a dust tail in comet Boattini (click on the image below for a biger version):
This detail appeas as a broad fan-like structure, nearly 3 arcmin long, extending toward South-West; it almost overlap the long and narrow ion tail that has been observed since before perihelion. The dust tail becames readily visible after a simple Azimuthal Median Subtraction routine, that enhances any deviation from a "normalized" profile of the coma. Probably it was present also in our previous shots of the comet, however its visibility was strongly hampered because of the poor observing conditions (comet very low in the sky in the morning twilight).
Currently the solar elongation of C/2007 W1 is increasing, so we expect that this detail will be soon picked-up by a number of other observers, without any particular image-processing routine. Observers with CCDs are encouraged to follow-up its development, possibly using some red or infrared filters, in order to reduce the contribution of the gas coma and the ion tail.
G. Muler, G. Sostero and E. Guido