From the Lagoon to the Eagle

24 – 25 June 2020, 23:30 – 3:00

Conditions: Warm and breezy.

Seeing: Terrible
Transparency: Poor

Once again I set up two telescopes in the garden, but this time, instead of the TV-60 on the Super Polaris mount, I brought my old Vixen 4-inch refractor (below) out of retirement to see if the extra aperture would help me catch those last remaining Messier globulars. As it turned out, the sky transparency was too poor to spot them (if only I’d had this idea before the previous session). The XT10 was, once again, coupled with the 13mm Ethos.

I warmed up with a look at M13 and M11 in both scopes. I didn’t take notes as the conditions were too poor to make a fair comparison. Neither cluster was at its best tonight. That was followed by a dive back into the wonders of Sagittarius.

M23, open cluster, Sagittarius
92x. As noted before: a rich cluster of uniformly bright stars, but better-framed at this lower magnification. The stars seemed to form the outline of a flattened starfish or a magic lantern (although the fluctuating seeing may have been a factor in my interpretation). Bright star north of the cluster.

M8, Lagoon Nebula, Sagittarius
92x. M8 is so large that even the Ethos barely contains it, but it’s a wonderfully complex region at this magnification. Despite the less than ideal conditions, even the unfiltered view clearly showed the key components: the bright star cluster NGC 6530, the nebulosity to the west, and the wide dark lane (the “laguna”) dividing the two. A little further west, the bright star 7 Sgr completes the line up, giving M8 the extended shape which is so distinctive in finders and binoculars. The nebulosity filled out considerably with the addition of the Ultrablock filter, revealing another patch to the south extending along the other side of the laguna into NGC 6530, and a large fainter band of nebulosity to the north, all separated by dark lanes. The brightest segment (the one clearly visible without a filter) was transformed into a dense mottled patch of nebulosity. It’s a shame with it being so low in the sky that I don’t get more time to savour M8, but any view is better than no view at all.

M20, Trifid Nebula, Sagittarius
92x + Ultrablock filter. Considerably smaller and fainter than M8, but shows well with averted vision. Nebulosity split by three dark lanes converging on a tight double star.

M6 and M7, open clusters, Scorpius
42x (SP-102 + 24mm Panoptic, giving a 1.5-degree field)
Both clusters were well-framed in the Vixen and showed a respectable number of stars, although they suffered from the haze and poor seeing. The butterfly shape of M6 was more apparent tonight, and the ring of stars surrounding the core region of M7 gave it a stretched-out appearance, like a spider’s web slowly being pulled apart.

Back to the XT10, and back to the nebulae:

M17, Omega/Swan Nebula, Sagittarius
92x + Ultrablock filter. As noted before: very bright, distinctive swan-shaped nebula. Mottled with averted vision but a lot of the fine detail I’ve seen previously was lost to the deteriorating seeing.

M16, Eagle Nebula, Serpens
92x + Ultrablock filter. Loose, sinuous cluster (NGC 6611) embedded in a faint haze, the size of which increased dramatically with averted vision. The most prominent section was a large band of nebulosity south of the cluster extending SW to NE, filling a large part of the field of view. The edges of the nebula tapered off smoothly into the background sky and it was hard to make out any dark features or other structure.

M24, star-cloud, Sagittarius
92x. As noted last time out, a staggeringly rich star-field, “squared-off” by surrounding dark nebulae. A little smeared-out by the poor seeing, but still a sight to behold.

M25, open cluster, Sagittarius
92x. As pre previous observation: rich, large cluster, well-framed in the Ethos. D-shaped asterism at centre.

I also revisited M22 but, unsurprisingly, the poor sky conditions had turned it into a shadow of the magnificent cluster I saw last time out. Jupiter and Saturn were also afflicted by the mushy seeing.

As noted earlier, I failed to spot M69 and M70 with the Vixen, but M54 was just about visible at 42x.

Nature note:
I had to be careful where I was treading tonight because there were lots of froglets (plus several adult frogs) on the move, as well as all the usual snails and slugs.