An energetic stellar outburst accompanied by circumstellar light echoes.

摘要: Some classes of stars, including novae and supernovae, undergo explosive outbursts that eject stellar material into space. In 2002, the previously unknown variable star V838 Monocerotis brightened suddenly by a factor approximately 10(4). Unlike supernova or nova, it did not explosively its outer layers; rather, simply expanded to become cool supergiant with moderate-velocity wind. Superluminal light echoes were discovered as from outburst propagated surrounding, pre-existing circumstellar dust. Here we report high-resolution imaging polarimetry those echoes, which allow us set direct geometric distance limits object. At >6 kpc, Mon at maximum brightness was temporarily brightest in Milky Way. The presence dust implies previous eruptions have occurred, spectra show be binary system. When combined high luminosity unusual behaviour, these characteristics indicate represents hitherto type outburst, for no completely satisfactory physical explanation.