Spotting a wave from 1 billion light-years away
Well that's it for today's high score. Nobody's going to do better than that.
Well done Kepler & team !
The Kepler space telescope is best known for its planet-hunting prowess, but in a paper just accepted by the Astrophysical Journal it's racked up another first: sighting a shockwave ripping a star apart as it goes supernova. Called by boffins the “shock breakout”, the shockwave is the “bounce” that happens when the star …
Any closer than 100 Light-years would be worrysome. Anything closer than 30 Ly is probable extinction-level event. Luckily there are no red supergiants within 100 Ly of Earth at present. Betelgeuse will be spectacular but safe when it explodes some time well within the next million years.
"Any closer than 100 Light-years would be worrysome."
As I said, nobody noticed the effects of Vela Junior, which was at ~60 light years. The ~300pc claim sounds like the dubious Firestone paper which predicts atmospheric effects many orders of magnitude stronger than we would observe in reality.
(good name for a band?)
<quote>It's an important part of our understanding of how heavy elements form, because supernovae provide the energy that assembles hydrogen and helium into heavier atoms</quote>
Not quite true - the sun produces a large number of heavier atoms in its normal operation (depending o the size of the sun). Supernovae provide the energy to produce the really heavy atoms.
I think (but may be wrong) that stars normal fusion process can create atoms up to iron, above that and fusion is not generating energy so the star's fusion engine stalls and collapses. That final supernova burst is what powers the creation of heavier atoms (and, of course, releases all of the stuff above hydrogen/helium that we need to exist out in to space so eventually planets form, life arises, porn is created, etc...).
This table claims that "large" stars can conventionally synthesize some trans-ferrous elements, all the way up to Ytterbium. Apparently that happens via the s process (slow neutron capture; some neutrons decay into protons, transforming a heavy isotope of one element into the next element with one fewer neutron).
Normal fusion process only makes the first few elements. The bigger ones start getting made as the massive star goes through a series of partial collapses, ending with the really heavy ones that only get made in the supernova explosion itself.
Oh and, PLEASE EL REG INDICATE WHEN A PICTURE IS AN ARTISTS IMPRESSION AND NOT AN ACTUAL IMAGE
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