SIMBAD references

We report deep B and V-band images of IRC+10216 which reveal its extended circumstellar envelope in dust scattered, ambient Galactic light. The envelope is detected out to ∼200" from the central star and its structure records the mass-loss history over the past ∼8,000yr. The envelope is roughly spherically symmetric but is composed of a series of discrete, incomplete, concentric shells. The shells are thin (∼1"-2") and separated by ∼5"-20", which corresponds to ∼200-800yr. The shells suggest that some process modulates the mass-loss of the star on this time scale. The presence of shells also means that models of the extended envelope which have been based on smooth distributions of the circumstellar material need to be re-examined.