ABSTRACT

Supernova 1987A, the closest supernova seen in nearly four centuries, and the most intensely studied, is rapidly turning into a supernova remnant as the ejecta from the explosion now strikes the circumstellar envelope shed by the star over the last million years. In this project, this process will be followed using a combination of archival, optical, infra-red and ultra-violet programs, plus space-based studies. Previous observations taken by Dr. Crotts of the three dimensional structure, velocities, density and composition will establish the nature of the pre-explosion nebula and the mass loss processes that created it, while new observations of the excitation of this nebula by the X-ray and extreme ultra-violet flux created in the collision will enable Dr. Crotts to re-analyze it once more. In addition to this study of a supernova remnant, Dr. Crotts will continue to use light echoes from the supernova explosion to explore the interstellar medium in the 30 Doradus star-formation region, to study the echo of the ultra-violet pulse from supernova shock breakout through the progenitor star's surface, and accurately to determine the distance to the Large Magellanic Cloud - a fundamental rung on the extragalactic distance ladder.

Dr. Crotts will also explore the application of his image differencing software to biomedical imaging - specifically how the image processing algorithms used to trace changes in the appearance of supernova echoes can track changes in other data sets, prominently CT-scan dye tests used for early detection of cancerous growths. The light echo data will also be used in renderings and animations as part of several public-access demonstrations of the fascinating structures revealed by light echoes.

Please report errors in award information by writing to: awardsearch@nsf.gov.