An Extra-galactic Globular

6 September 2021, 22:15 – 00:00 (BST)

Seeing: Poor

Transparency: Average

Conditions: A still night, very warm and mild for the time of year. Some high, patchy cloud which cleared as the night drew on. Thin layer of condensation on the scope by the end of the session.

After allowing time for the scope to reach equilibrium (and my eyes to dark-adapt), I started with a look at the autumn highlight globular clusters M15 and M2 at 171x, although the iffy seeing prohibited me from resolving the fine detail I was hoping for.

After a quick look at Saturn, I then paid a return visit to NGC 7814, which was very faint tonight. Supernova 2021rhu, unsurprisingly, was no longer visible.

However, NGC 404 (Mirach’s Ghost) was quite obvious at 171x, even with Mirach in the field. Mirach itself is worth looking at, as it has a distinctly reddish hue.

M32, satellite galaxy, Andromeda

171x. Small, round and very bright. Condensed core with a star-like nucleus. With prolonged examination there seemed to be just a hint of elongation along the axis pointing towards M31.

Mayall II (G1), globular cluster, Andromeda

171x. Finally tracked down the Andromeda Galaxy’s biggest and “brightest” globular cluster. I reached it via a careful and somewhat complicated star-hop from M32, but it was visible with averted vision as a tiny fuzzy spot flanked by one or two faint foreground stars. Most sources give the magnitude at somewhere around 13.7, but fortunately its light is very concentrated, which helps with its visibility.

G1 was a little more obvious at 240x (still using averted vision), but it was still very challenging. Now I know how to find it, I might try this again on a better night when M31 is nearer the zenith.

I finished off with a look at Jupiter at 240x and 342x (171x + 2x Barlow). All four Galilean moons were west of the planet. Indifferent seeing smeared out most of the fine detail, but one brown barge was visible near the western limb. The orange colour surrounding the NEB appeared to have spread farther into the EZ, and the northern polar region seemed to have a slightly blue-ish tone (compared to the southern region). I’ve noticed this before but I haven’t seen it on images, so I’m wondering if this is an illusion caused by atmospheric dispersion or contrast effects.

Nature (and other) notes:

The frogs were quite vocal tonight. Also, lots of air traffic flying east (out of the country). Oddly, I didn’t see any flying west.