M57 et al.

[xilman]

The wee hours of this morning produced the first half-way decent images from the new camera. A total of 36 30-second unfiltered subs were taken centred on the 15th-magnitude barred spiral IC1296. A portion of the co-added image is shown here.

IC1296 is the galaxy in the middle. Its nucleus is somewhat over-exposed but the arms show up nicely, as do a few H-II regions and a large star forming region.

At top-right is a much fainter galaxy, 2MASX J18530959+3305385, for which I have not been able to find a visual magnitude. It appears to be a nearly edge-on spiral, it's very red, and its bright nucleus shows up nicely. The other point source below the nucleus is a faint star in our galaxy.

At bottom left is the Ring Nebula, aka M57. The ring is completely invisible through gross over-exposure. What is visible is the extremely faint and low contrast, shell of fluorescing gas around the bright nebula. This is very rarely seen in published images,

[Spherical Cow]

Wow- very nice indeed. The new camera is working well.

Questions: the 15th mag galaxy you mention; is my label below aimed at the right object?

And the faint foreground star you mention; is that labeled right, or do you mean the very small object, almost attached to the 15th mag galaxy. Almost like a bulge at the bottom.

And, the fuzziness I've labeled as a partially obscure galaxy: real, or within the range of background variability, do you think? Or an artifact of processing?

The Ring Nebula is great with the outer shell like this. I'm surprised we don't see more composite images, with the outer shell overlaid on an image of the Ring that's not over-exposed.

Great stuff- thanks.

Norm

[xilman]

Originally Posted by Spherical Cow

Wow- very nice indeed. The new camera is working well.

Questions: the 15th mag galaxy you mention; is my label below aimed at the right object?

And the faint foreground star you mention; is that labeled right, or do you mean the very small object, almost attached to the 15th mag galaxy. Almost like a bulge at the bottom.

And, the fuzziness I've labeled as a partially obscure galaxy: real, or within the range of background variability, do you think? Or an artifact of processing?

The Ring Nebula is great with the outer shell like this. I'm surprised we don't see more composite images, with the outer shell overlaid on an image of the Ring that's not over-exposed.

Great stuff- thanks.

Norm

Not really. Since that image was posted something else interesting has turned up so an annotated version the full stack of images is given here. Apologies for the cruddy appearance --- I'm no artist.

M57 and IC 1296 are labelled as such. Note that IC 1296 is the 15th magnitude object.

The other objects are indicated with arrows but no text to avoid cluttering. The elongated fuzzy object next along from M57 and IC 1296 is a 16-17 mag spiral; its disk is tilted relative to us. Its bright central nucleus shows up as a stellar-appearing point. Towards the 7 o'clock edge of the galaxy is another stellar point. That truly is a star.

The curious object is the star indicated by the fourth arrow. You may wish to trog over to Aladin and type in the coordinates "18:53:03 33:07:25" then zoom in until the FOV is a few arc minutes. You will not see anything at the position of the marked star! SWMBO spotted this one when I showed her my image and the DSS2 version for comparison.

There was no asteroid within 5 arc minutes brighter than 24th magnitude when the image was taken. Comparison with the GAIA catalogue suggests the newcomer is close to mag 17.9 in Gaia's g-band. The limiting mag of my image is around 20.5 to 21.

A follow-up image taken by Nick James in the UK last night did not confirm the object but his observation was taken through thin cirrus, didn't go as deep (around mag 19.5) and the transient position lay firmly on a diffraction spike from the bright star nearby. I was unable to take follow-up observations last night but will try to do so again tonight. If anyone else reading this can reach mag 20 or so, please give it a try!

[Spherical Cow]

Fascinating- Hope you have good skies tonight. Would be great to see that shifted a bit in position. A very distant asteroid; maybe a TNO.

Great work by SWMBO- (I always enjoyed Rumpole; those were good shows.)

Norm

[xilman]

Originally Posted by Spherical Cow

Fascinating- Hope you have good skies tonight. Would be great to see that shifted a bit in position. A very distant asteroid; maybe a TNO.

Great work by SWMBO- (I always enjoyed Rumpole; those were good shows.)

Norm

Turned out to be a false alarm. No-one else could image it. My best guess is that it was a ghost of some bright star (beta Lyr perhaps?) out of the field of view.

It was a very plausible transient. One of the people who imaged it, a very highly regarded guy, described my image as rather convincing.