Thread: warning for supernova near earth ?

i was reading this in wikepedia: Near-Earth supernova - Wikipedia, the free encyclopedia

there are not any likely stars close to earth but if there were is a warning possible ? if a warning is possible how soon before supernova explosion ?

would there be anything that people could do if a warning was possible ?

i read about this supernova in 1006: SN 1006 - Wikipedia, the free encyclopedia

it was 7200 ly from earth and brightest astonomical event of all:

SN 1006 was a supernova, widely seen on Earth beginning in the year 1006; the Earth was about 7,200 light years away from the supernova. It was the brightest apparent magnitude stellar event in recorded history, reaching an estimated −7.5 visual magnitude^[3] (over ten times as bright as Venus). First appearing in the constellation of Lupus between April 30 and May 1, 1006, this "guest star" was described by observers in China, Japan, Iraq, Egypt, and Europe,^[4] and possibly recorded in North American petroglyphs

I have read these articles, and as long as the star is 80-100 light years away (80-100 based of numerous websites) it should not affect us... So you can look at the stars near us and determine if they are massive enough to make a supernova

If a warning was possible I don't think there is much we can do, and we wouldn't know until the light (and this means radioactivity) reached us, so a warning doesn't seem possible to me.

Originally Posted by MindlessMath

I have read these articles, and as long as the star is 80-100 light years away (80-100 based of numerous websites) it should not affect us... So you can look at the stars near us and determine if they are massive enough to make a supernova

yes. i have read these articles too. i am more interested if any preliminary EMR is emitted prior to the actual blast. something like a warning.

Originally Posted by MindlessMath

If a warning was possible I don't think there is much we can do, and we wouldn't know until the light (and this means radioactivity) reached us, so a warning doesn't seem possible to me.

you are probably correct i think.

if by radioactivity you mean gamma rays then yes but other types of radiation (alpha and beta) are particles which travel at much less than than c. i don't know if supernova blast would eject much alpha or beta radioactivity. maybe none. i do not know really. i am just guessing but i think alpha and beta radioactivity, if ejected, would not be harmful over interstellar distances.