Supernova Theory

Science Daily reports a potential Type Ia explosion remnant in the Small Magellanic Cloud (see here for the original Chandra report) with unusual characteristics: this remnant is lobed rather than circular.

Now, it's probably a naive thought but a simple axplanation occurs to me: since Type Ia supernovae are the result of accumulated hydrogen from a companion star detonating, the variation in morphology could be explained by the nature of the companion and consequent disparities in angular momentum.

Consider a white dwarf rotating and accumulating mass from a large, nearby companion; I would expect it to be tidally locked in its rotation and thus to have relatively low angular momentum. Consequently, upon detonation the equatorial matter would spread easily. Now consider another white dwarf whose companion star is farther away/lower mass... it might not have been spun down and so might possess considerably more angular momentum (even though it would probably take longer to accumulate the necessary critical mass) so when it does eventually go bang equatorial matter experiences a smaller deflection, perhaps leading to confinement and more effective channelling of the explosion towards the poles.

What does the companion to this star look like? Don't know... unfortunately. However this is at least a testable hypothesis.

If you object to this line of reasoning please say so!

Banging Stuff

Update 21st Feb 2010... More recent work suggests the majority of Type 1A's are caused by the collision of white dwarfs... see here for details.