Exploring Sagittarius

17 - 18 July 2020, 23:30 – 1:45

Conditions: Muggy, mild, breezy. Patchy cloud. Light condensation increasing over the duration of the session.

Seeing: Poor
Transparency: Average / poor

Comet C/2020 F3 NEOWISE has moved further into the evening sky, appearing a little faded since the previous weekend but still a relatively easy naked-eye object. Binocular view still good: the tail seemed longer, perhaps because I was seeing it against a darker sky.

Eyepieces used tonight were the 9mm Nagler (133x) and the 7mm DeLite (171x). The XT10 was balanced on the improvised “Observing table + bricks” platform again.

NGC 6522, globular cluster, Sagittarius
133x. Small, condensed fuzz with star-like core. Near Gamma Sgr. The low altitude and poor seeing made it hard to be certain but the core seemed to double with averted vision, possibly due to a foreground star nearby. Couldn’t confirm neighbouring globular NGC 6528.

M69, globular cluster, Sagittarius
133x. Definitely saw it tonight – visible as a soft round blur just south of an 8th magnitude star (which helps a lot when tracking it down). A little condensed with averted vision. In the brief window of time I had to look at it I was able to make out 2 or 3 speckles of individual starlight – possibly foreground stars, but overall this globular remained very faint.

M70 is harder to locate because there is no comparative star nearby. Again, I’m not confident I saw it this time – confirmation will have to wait for a better night. Likewise, M55 was right on the threshold of visibility; I think I glimpsed it with averted vision along with a few speckles of starlight, but I want to see it again to be sure.

I moved the XT10 to a less precarious spot and looked at Jupiter and Saturn at 171x. Both planets were visibly “rippling” with the seeing, so I abandoned my plan to do some imaging and returned to a couple of deep-sky objects.

M75, globular cluster, Sagittarius
Currently not far away from Saturn in the sky and quite obvious at 171x (though I suppose most DSOs would seem obvious after struggling with the previous three). Small, bright, condensed – swells in size with averted vision. Hint of graininess, but no stars popping out. Suggestion of dark area on the eastern side.

NGC 6818, “Little Gem Nebula”, planetary nebula, Sagittarius
171x. Small, fairly bright green-grey disc, slightly oval. Shows well at this magnification. Suggestion of darker centre. Oddly, with averted vision it seemed more blue-grey than green-grey.