AAVSO: American Association of Variable Star Observers

Surveying for Historical Supernovae Light Echoes in the Milky Way Field (Abstract)

Volume 42 number 2 (2014)

Doug L. Welch
Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada; welch@physics.mcmaster.ca


(Abstract only) Very luminous, transient events can produce detectable “light echoes”—light scattered by interstellar dust which can arrive much later than the direct light from an outburst. In the last 1,000 years, there have been half a dozen supernovae in the Milky Way which are capable of producing detectable light echoes. Light echo systems have already been found for Tycho (SN 1572) and Cas A. The three-dimensional distribution of light echoes provides one of the few menas for an astronomical source to be inspected from more than one viewpoint. Indications of the degree of asymmetry of supernovae are extremely valuable for understanding the details of the event itself. Amateurs are well-equipped to find the brighter light echoes and in this work I will provide practical guidance on how such surveys may be accomplished and the various science opportunities they provide.