View Single Post
  #4  
Old 16-11-2009, 08:55 PM
ngcles's Avatar
ngcles
The Observologist

ngcles is offline
 
Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,585
Audrey Hepburn

Hi Patrick & All,

Lovely report mate -- much enjoyed.

Dunno whether it's just me but photographically, I reckon NGC 1097 is probably one of the most beautiful galaxies in the whole sky. Strangely, for me it seems to work best in Black & White -- dunno why.

Here it is in colour on APOD:

http://apod.nasa.gov/apod/ap061201.html

and here is a plain-jane DSS image:

http://stdatu.stsci.edu/cgi-bin/dss_...e&fov=NONE&v3=

I prefer the monochrome. There are few more photogenic barred spirals in the sky -- it is, if you like the "Audrey Hepburn" of barred spirals.

I have a fond memory of it from about 4 years ago observing at Bargo. Take a look at the APOD image and at about the 1/2 way point between the core of -97 and -97A you'll see a 14th mag star embedded at the point where the spiral arm curls off the bar.

I took a look in the ep (with the 18") at x185 and something just didn't seem quite right to me. No I don't have photographic memory or anything like it but I saw that star (about mag 14) and I just thought it looked out of place. But at the same time it was in a likely spot for a supernova. No real alarm bells, but an amber light did go off in the recesses of my brain -- I'd seen -97 maybe 20 times before and it just didn't look right. Checked it at x247 nd x317 -- Hmmm ... still there and very star-like.

So went over to the lappy (no net connection) and pulled it up on megastar and then superimposed the real-sky compressed DSS image over it.

The star wasn't recorded in Megastar or on the DSS -- well actually the DSS was a little ambiguous but several of us agreed it really didn't show a star clearly. The only problem with realsky is that the data is so compressed that some things get smudged out of the mix in pixilation at small scales. There it looked like an small diffuse HII region -- but not really star like. Supernovae are common in HII regions/star clouds I thought to myself ...

Now I was starting to get a little excited. Not on megastar even as a non-star and not apparently on the DSS. The first thing I would have loved to check were the Supernova Search Charts -- but they were at home in the shed and it was nearly 12 midnight.

Hmmm ... I had to do something. Luckily we had an imager there that night so I sauntered over and asked nicely (and as casually as I could) if he could take a quick 60 second sub of 1097. Sure enough, there it was easily visible and very star-like.

So who (with a set of supernova search charts) do you wake up at 1am and ask to take a look and then take an image that can be used with some astrometric accuracy?

I tried Steve Quirk but no answer. Tried Peter Ward -- he said he would do some research take an image (if it was clear) and get back to me. A long time passed and I had to play my final card -- someone I knew as a dead-set cert would be in his dome doing imaging and had access to all the best resources. Better still, I had the direct line to the dome -- Rob McNaught.

So, within 5 seconds of making the call he had answered and 10 minutes later in his rich accent came "No, its a star -- doesn't have a USNO number he could see either and isn't even in the GSC -- but the actual plate taken at the UK Schmidt clearly shows it".

Bummer!

Almost thought I had one there.

Despite that, it is still a personal favourite!


Best,

Les D
Reply With Quote