Any ideas what this is..?

[Lee_P]

I've just finished editing a photo of M39, and have spotted a strange red object at the top-right, near the border. I can't work out what it is. It's very small. Perhaps a planetary nebula? Or maybe an error introduced in the processing? Astrometry.net didn't highlight it, alas. I think it's somewhere between M39 and the Cocoon Nebula.

It's bugging me, so any help identifying it would be appreciated!

 

[Lee_P]

In case you can't see it...

 

 

[Tim]

It looks very much to me like a stacked hot pixel to be honest. 

There are plenty of small and unlisted 'features' out there, but they don't normally glow as red as that. Take a good look at each individual exposure and see if you can identify a pattern.

 

[Tim]

Here's a much deeper exposure, with no trace of anything else but stars

[Tim]

Or is there a match? Hmmm, just overlaying your image with this one in Registar.

[Lee_P]

The plot thickens. I'm looking at the original frames and can't find a hot pixel (or anything) in the location.

[Tim]

And thickens even more....... There is a match on that image with yours. It doesn't show as red as yours, but there is definitely a correlation. 

 

[Lee_P]

The colour difference could easily be due to me playing about with saturation levels.

[Tim]

To make it easier to see, here they are oriented the same way. Astrometry normally finds the known things. When I eventually get round to mounting my SCT again, i'll take a deep image of this at long focal length, f14 or f20 and see what shows up.

Nice find, well spotted  

[Lee_P]

Thanks, I wonder what it'll look like when you take a better look...

[Tim]

OK, if i'm not going mad (no guaranteed  ), you've bagged a picture of PK93 -2.1

Here's a close up, very pretty it is too:

http://app4value.com/moonlite/planetaries/pln9321_full/

[Lee_P]

That looks like it! Especially in this photo: http://www.astrophotos.net/pages/PLANETARY/Pk 93-2.1.htm

How did you find it? Any ideas why Astrometry didn't pick up on it?

[Tim]

Here's that pic overlaid on yours, with full credits to the original imager of course

 

 

[Lee_P]

That's very neat. I'm glad I over-did the saturation though, or I'd never have seen it!

[Tim]

I dont use astrometry very often, can't help you with that i'm afraid.

Cartes du ciel lists the Pk objects, so I just found a close one to M39, found an image of it, then overlaid using Registar.

I love stuff like this, most of my imaging these days is just taking very deep exposures and then just enjoying the really faint stuff  Must get round to making some final images out of it all one of these days

[Lee_P]

Well you've solved the mystery. Thanks!

[Waldemar]

That was great guys !!! Thank you. I love these kind of 'little' gems.

and congratulations with your keen eye!