TSS Bi-Monthly DSO Challenge for May/June 2023 - Hunting the Messier galaxies in the Virgo Galaxy Cluster

[kt4hx]

Very nice images Graeme, and truly appreciate you posting them. M100 is gorgeous with lots of spiral detail clearly evident. Plus the bonus galaxies of NGC 4312, NGC 4328, MCG 3-32-13 (sometimes erroneously listed as IC 783A) and MCG 3-32-11.

The M85 image is also a nice one, and as you point out clearly shows the form of an elliptical in the same view as the delicate spiral structure of NGC 4394. Then you also have the dim little presence of IC 3292 in there as well. The one thing I am trying to figure out, is what is that stellar presence just left of the core of M85, well within the galactic disk? What exact date/time did you image M85, as I would like to try and track down what that object is, since my Sky Tools 4 does not show a foreground star at that position relative to the galactic core.

Well done!

[Graeme1858]

Cheers Alan

That's a fine eye for detail you have there! The M85 subs were taken on the morning of 11/06/23 between 00:32 and 00:56 BST. The star you mention is visible in all the subs. It is shown in Stellarium but it's part of the M85 image so is not in the star database.

The Astrometry.net annotated output doesn't help much:

[kt4hx]

Thanks Graeme. Well the star does not show up in Sky Tools 4 Pro as I mentioned. However, I've seen it in older images of M85. From the notes of noted visual observer Steve Gottlieb, and also an article in Sky & Telescope about the SN 2020nlb in M85, the star in your image is 13.1 mag though I don't have a catalogue designation. I observed that SN back in July of 2020 when it was about mag 12.2, but in my notes I did not mention this other star, which seems out of character for me! I would have to guess that I must've seen it, but because I was so focused on the SN within M85 that I simply didn't mention it in my notes. Next time I visit M85 I will take a look for it however.