DRAA: Supernova Light Echoes - Observing in Four Dimensions

Presented by Prof. Doug Welch, Department of Physics & Astronomy, McMaster University

Scattered-light echoes from luminous transients (supernovae, luminous blue variables/supernova impostors) are unique in their ability to preserve an observable record of the state of a transient in outburst for centuries. Unlike conventional (i.e. intentional) time-series records, the presence of interstellar dust on the light echo ellipsoid from a given outburst allows photometric and spectroscopic study at any epoch where the scattered-light signal reaches a useful signal-to-noise threshold.

Additionally, dust located at different positions on an outburst's light-echo ellipsoid will preserve a record of the hemispheric emission of light from the outburst as seen from each dust location, allowing the degree of asymmetry of an outburst to be studied.

A more recent application of scattered-light echoes employs the fact that multiple outbursts of high-amplitude, unstable, luminous variables each produce their own light-echo ellipsoids and dust located on such ellipsoids provides an opportunity for multiple outbursts to be studied at the same (modern) epoch.

This talk will provide a brief summary of the evolution of light echoes from use as a tool to map out interstellar dust around luminous events to their richer and more recent use of investigating the outbursts themselves. Important findings from observations of scattered-light echoes regarding SN1987A, Cas A, and Eta Car will be highlighted and near-term prospects for new work and new observational opportunities will be presented.

Who can attend: Everyone
Fee: Free
Registration: Not required
Organized by: Durham Region Astronomical Association
Location: Whitby Public Library - Central Library, Meeting Room 1 A/B, 405 Dundas St W, Whitby, ON  L1N 6A1

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