Hey, BA, you may be interested in this topic:
This is an interesting article. I'm not sure but think it may have some BA in it. It says:
"When the upgrade is complete the telescope will be able to see three times more detail in the supernova wreckage than it could
before. Only the Hubble Space Telescope will be able to do better."
Is that correct?! I've read that the Kecks and the VLT in Chilie are now rivaling and possibly exceding Hubble for clarity.
Does anybody have an answer?
Title: On the Progenitor of Supernova 1987A
Authors: M. Parthasarathy, David Branch, E. Baron, David J. Jeffery
A previously unpublished ultralow-dispersion spectrum of Sanduleak -69 202, the stellar progenitor of SN 1987A, is presented and the uncertain presupernova evolution of Sanduleak -69 202 is discussed.
Read more (460kb, PDF)
This was an interestng paper in that the implication seems to be that the clues that a blue super giant is about to explode are very subtle, if detectable at all.
Forming opinions as we speak
Just more proof that we have a gold mine of archival astronomy data, whose usefulness may not become apparent for decades, even centuries. You can perhaps see why there is now a concerted effort to preserve thousands of old photographic plates dating back to the turn of the last century...
Physorg.com: Rethinking last century's closest, brightest supernova
Also: UC Berkeley press releaseOngoing observations of the exploded star, called supernova 1987A, provided important tests for theories of how stars die, but it also raised some new questions. Principal among these was how a bizarre, triple-ring nebula surrounding the supernova - ejected by the star a few thousand years before it exploded - originated. Astronomers devised a complicated theory that, within a relatively short period of time, the original star, a red supergiant, merged with a companion and started spinning rapidly, then underwent a transition to a blue supergiant, and finally exploded.
University of California, Berkeley, astronomer Nathan Smith has proposed a different theory for the origin of the nebula, arguing instead that SN1987A's progenitor star may have been in a class of unstable blue supergiant stars, called luminous blue variables, which eject material from their surfaces in recurring, volcano-like eruptions before they finally die in a supernova explosion.
Which basically confirms that its either a new class of supernova, or the original concept will have to be expanded a bit.
They don't seem to be the stock model Type II.