G1.9+0.3

Hi,

Evidence suggests galactic sn remant G1.9+0.3 is only about 150 years old. The RA is 17h 48m 45s and Dec is −27d 10m. I don't know how accuately its distance has been measured. Assuming it is at the galactic centre this would make the apparent magntude, without extinction, of about -5.

However, interstellar extinction is severe towards the galactic, up to about 30 mags. Even the Rosse Leviathan could not see a +25 mag object!

see:
chandra.harvard.edu/photo/2008/g19/

John

Hi John,

The issue of atmospheric extinction takes on a new dimension for us in the northern hemisphere given the SNR's declination of -27 degrees. As much as I would love to tackle this object, there is no way at such a low altitude. :oops:

It's now for sure that it would have been visible to all in the 1860's but of course, the dust took care of that. There is no way you could even hope to see this now optically with ANY scope unfortunately.

So here is the record: It was thought that the last supernova to occur in the milkyway was in the year 1604 (kepler's supernova) at magnitude -2, even though it was at a distance of about 20,000 light years away !

Now we have evidence that another supernova occured in Cassiopeia in the year 1680, but was not observed either well or at all, due to dust again

Now we know that another one happened in the 1860's, so it appears that supernova happen more often than we thought, but in ordre for us to visibly see one, it's all down to location

P.S. I'm going out tonight, and all going well I will be the discoverer of one at magnitude -6 !!

Keith..

Keith..

As far as I know the expected rate for supernovae is about 2-3 per century in this galaxy. The puzzle was that observations didn't bear out anything like this rate. This latest discovery and the fact that the original optical event wasn't observed helps to support the theory.