
Originally Posted by
Tog_
Any chance the remaining "nebula" would be visible naked eye? If so, any idea for how long?
Just wild guessing, but I would say yes if, by luck, a strong light echo takes place after about 5 months so that the apparent angular size is greater than the resolution of our eyes (1 arcminute). After 5 months, the size for the light echo would only be about 2 arcminutes, which is still very small.

Originally Posted by
Don Alexander
The ultraviolet flash will rise to peak in about 12 hours or so and fade within 2 days. Roughly, Betelgeuse could get as bright as Venus, and turn extremely blue, as most of the energy is released in the UV.
Is this a spike within the spectrum, or more of a BB distribution?
Still it should exceed the brightness of the full moon by one or two magnitudes, and this as a point source!! This will mean it will actually be dangerous to look at, the surface brightness will be close to that of the sun.
Yes, it will be very bright. Assuming the brightness reaches about -17, it will have an apparent surface brightness about 1/6th that of the Sun. [Sun has about 800 sq. arcminutes but is about 5000x the brightness.] But even this is still very bright.
We know time flies, we just can't see its wings.