EMB News - 1987 supernova images
1987 supernova images |
Thu, Feb 22, 2007 |
On February 22, 2007, astronomers Thomas Morris and Philipp Podsiadlowski announced simulation results which support a common hypothesis that the merger of two stars and the orbital movements that preceded it may have generated the distinctive triple-ring system of Supernova 1987A. The expansion velocity of the rings suggests they were produced about 20,000 years before the supernova explosion itself, possibly the result of a star with five Solar-masses being merged into a larger 15-Solar mass, red giant star and colliding with its core. As smaller star spirals in towards the red giant's core, it stirs up the red giant's atmosphere and gives more angular momentum of the red giant's gas which helps to flatten it into a disk. The friction of the smaller star's through the red giant also heats up the star's atmosphere in its vicinity, which causes it to expand outwards in all directions although much of this outflow is deflected by the outer part of the disk and channelled to eventually produce two large rings above and below it. Moreover, the stellar merger produces a single star spinning so fast that it throws off gas at its equator to form a third, inner ring (Podsiadlowski et al, 2007; simulation images; and David Shiga, New Scientist, February 22, 2007 -- more below). |