HOW TO RECOGNISE SUPERNOVAS
LOOKING UP SOME EXAMPLES OF SUPERNOVAS AND THEIR REMANENTS JUST TO TRAIN MY EYES TO THIS NEW FASCINATING TASK OF BUBBLING, I HAVE FOUND THIS ONE THAS IS SUPOSERD TO BE A SUPERNOVA REMANEN....
MY QUESTION IS HOW HAS BEEN INFERED THAT'S A SUPERNOVA AFTER A LONG PERIOD AFTE THE EXPLOSION?
I don't think this is a supernova shell, as far as I know they tend to have smoother shapes and this images has two peculiar 'antennae' at the top.
Identifying supernovae long after they have occurred is only possible for the very few that happened close by in our own galaxy.
A few things can help in identifying a supernova:
- the most easy thing to see is the shock that is going through the interstellar medium. The size of the shell gives an estimate of how long ago the supernova occurred, if you can determine the distance.
- sometimes after the supernova explosion there is still a remnant, such as a neutron star
- and if you're lucky, the supernova was observed by astronomers and you can find it in historic records.
In the case of the crab nebula, there is an impressive shell, and a pulsar has been found (the supernova remnant), and chinese astronomers observed a supernova in that specific location in the year 1054.