I received an email from Brian Skiff this morning on another mailing list who alerts southern observers that CBET circular 1065 announces the discovery of a possible supernova in the relatively nearby spiral NGC 5530 in Lupus. The discovery was by Rev Bob Evans (his forty-somethingth? -- I've lost count).
Evans puts the magnitude at +13.5 -- likely within visual reach of 10-12" 'scopes (maybe even 8"??). A CCD image position by Steve Quirk places the candidate at 14 18 27.92 -43 23 12.9 (J2000). This is 24" west and 25" north of the galaxy nucleus in the NW end of the halo.
As noted by Brian Skiff, there is a well known superimposition star on the face of the galaxy at a similar distance from the core but to the NE. That star has a V mag of 12.1 -- so it is likely somewhat brighter than the supernova candidate at this stage.
Looking back on an old 10" observation I made nearly 10 years ago from suburbia, that superimposition star is pretty easy to see, the galaxy has quite low surface brightness, and appears about 2.5' x 1.5' in PA 135. NGC 5530 is only about 1 degree NW from the bright, interesting PNe IC 4406, near the Lupus-Centaurus border.
The new object is yet to be confirmed as a supernova so its type at this stage is not known. Obviously at this stage it is also unknown whether it will get brighter or is already on the fade.
Congratulations Bob!!
Les Dalrymple
Contributing Editor AS&T
Last edited by ngcles; 14-09-2007 at 10:48 AM.
Reason: Typo
It just amazes me that Bob can memorise an area so well that he can detect any change. I have trouble remembering the star patterns from night to night when simply tracking asteroids but whole galaxy fields are something else!!
Yep he is an absolutely phenomenal observer and has a memory anyone would envy.
I hardly know Bob, but when I and some observing friends were up at a friend's property near Mudgee earlier this year, Bob and Steve Quirk happened to call in for a yak.
We got to talking about what I'd been observing the previous night (around NGC 6752 -- some pretty obscure) and then, without batting an eyelid Bob performed a perfectly executed "information dump" on everything I'd seen -- sizes, brightness, distances from other objects, PAs, appearance etc and a few more I hadn't seen. It took me an 1/2 hour to research and grade that observing list using a P.C, a database and planetarium software -- some of it I'd never seen before. Bob rattled it off like it was the names of the grand kids.
A while later we were looking at an old survey plate from the AAO (these plates are not labelled and have no information on them) with a light-box and after a scan for a few seconds, he was able to identify the four brightest galaxies (they were all at the mag 11 level) immediately and correctly and then identify nearly all the smaller ones that surround them and supply all sorts of interesting facts on them. Incredible!
Bob as an observer is playing in a whole different league to the rest of us. His ability to memorise this stuff is, in my experience, "one-of -a-kind".
The new object is yet to be confirmed as a supernova so its type at this stage is not known. Obviously at this stage it is also unknown whether it will get brighter or is already on the fade.
Today's circular from the Central Bureau (CBET 1068) confirms Evans' discovery as a supernova - SN 2007it. It's a type II supernova, described as young.
I observed the Supernova last night with the 25" scope of ARGO NAVIS (BILL)and my 16" at CAMBROON, the supernova was the fainter of the two stars, the galaxy was very faint, because of the moon and being low down by the time we decided to observe it.
Yep, we saw it last night at Linden. One of the people present was photographing it for Bob so we all had a squiz. Can't believe he can know that area so well that he can detect a change. Its amazing!!
I have just come in from observing this galaxy/supernova. I estimate that it is slightly brighter than last night, about 13mag, comparing it to the 12.5mag star at the opposite end of the galaxy.
I was able to see it with a 21mm eyepiece, 87xmag even though the 4 day old moon was not too far away.
best view was with a 13mm nagler+ 2xbarlow=282x mag.
unfortunatly the moon and the brighter evenings are going to make observing this supernova difficult in the future.
I have just come in from observing this galaxy/supernova. I estimate that it is slightly brighter than last night, about 13mag, comparing it to the 12.5mag star at the opposite end of the galaxy.
I was able to see it with a 21mm eyepiece, 87xmag even though the 4 day old moon was not too far away.
best view was with a 13mm nagler+ 2xbarlow=282x mag.
unfortunatly the moon and the brighter evenings are going to make observing this supernova difficult in the future.
Observed the Supernova again last night 29/09/08 17:00 through some cloud and lightening flashes from the N/NW, the galaxy was about 20 deg high.
The Supernova was easely seen with the same equipment as above post.
I would estimate that it has faded by about a couple of tenths of a magnitude
but was still seen in the 21mm plossl a little later on as the night progressed and the clouds went away from the southwest.
The galaxy seemed more prominant than my last observation even though the seeing wasn't as good.
I observed about another 30 galaxies before the Moonglow halted any more Supernova searching
