22 – 23 June 2020, 23:30 – 3:30
Conditions: Very mild, light wind with occasional gusts. No clouds and no condensation tonight.
Seeing: Good
Transparency: Quite good considering the time of year
Once again I set up two scopes in the garden: the XT10 with the 13mm Ethos (92x) and the TV60 with the 9mm Nagler (40x). The XT10 was balanced on my observing table, enabling it to point a little further south than usual (and also so I could observe while sitting down).
After warming up with views of M13, M57, M56 and Albireo, I turned my attention south to a selection of globular clusters.
M19, globular cluster, Ophiuchus
92x. Bright, condensed globular, about the same declination as Antares. Speckled appearance with averted vision. One star resolved north of the core, another one east of the core.
NGC 6284, globular cluster, Ophiuchus
92x. Small, condensed blur, a little north of M19. Swells in size with averted vision. Faint star east of core.
NGC 6293, globular cluster, Ophiuchus
92x. Another small, condensed blur. No resolution, but the core seemed particularly bright.
M62, globular cluster, Ophiuchus
92x. Large, condensed blur (one of the Messier globulars below -30 degrees). Bright core, a little grainy with averted vision.
NGC 6316, globular cluster, Ophiuchus
92x. Very faint round blur, east of M19 and M62, and about midway between them in terms of declination (-28 degrees). Condensed with averted vision. There were also a few stars superimposed over the top, surrounding the core; I assume these are foreground stars and not true cluster members.
M9, globular cluster, Ophiuchus
92x. Bright, asymmetric globular. Starts to resolve with averted vision, but really needs a darker sky to get the best out of it. Apparent dark patches southwest of core.
NGC 6342, globular cluster, Ophiuchus
92x. Faint, condensed blur, south of M9. Brighter core with averted vision. Faint star SW of core.
NGC 6356, globular cluster, Ophiuchus
92x. Bright, condensed globular, northwest of M9 and only a little smaller and fainter than its M-designated neighbour. No resolution, but some faint stars visible on the outskirts of the cluster.
M6, open cluster, Scorpius
92x (and skimming the neighbour's fence!). Better-framed at this magnification (than at 133x), but still a little too large for the fov. More stars visible, giving it an almost “chunky” appearance. On this occasion its overall outline reminded me a little of M24.
M7, open cluster, Scorpius: 40x (TV60 + 9mm Nagler)
A slightly better view tonight, reinforcing my initial impressions: a large, loose cluster with the dozen brightest stars arranged in a wavy x-shape.
NGC 6520, open cluster, Sagittarius
92x. I picked this up by accident while sweeping the area south of M8. A compact and very distinctive open cluster comprised of bright, colourful stars overlying a rich unresolved haze. Prominent orange star near the centre. This cluster stood out well despite its low altitude (-28 degrees declination).
M21, open cluster, Sagittarius
92x. Rich cluster with bright stars; not particularly condensed. Bright pair near centre.
M28, globular cluster, Sagittarius
92x. Bright, condensed globular. Grainy appearance. Hint of resolution with averted vision. Somewhat overshadowed by its illustrious neighbour…
M22, globular cluster, Sagittarius
92x. Very large “flattened” globular – spectacular in the Ethos. A few dozen stars resolved in direct vision; countless more with averted vision. Appeared to be a dark lane or rift on the western side. Tonight at least, it surpassed even M13 in visual splendour.
M24, star-cloud, Sagittarius
92x. Incredibly rich star-field. Even in the Ethos it covers several fields of view, but this is probably the best eyepiece for appreciating this region’s grandeur and sheer density of stars. I could easily spend an entire session here. The dark dust clouds which give M24 its distinctive sharp-edged appearance are conspicuous by their relative absence of stars. I know this region is actually a window into a deeper part of the galaxy, but the impression I get is of an iceberg of stars caught in the process of calving off from the Milky Way.
M18, open cluster, Sagittarius
92x. Bright little cluster; not particularly rich, but the brightest stars seem to form the shape of a pointy toadstool, or a partially opened umbrella.
M54, globular cluster, Sagittarius
92x. Small, round condensed blur. Prominent bright core, but not even a hint of resolution. Apparently gravitationally bound to the Sagittarius Dwarf Elliptical Galaxy (SagDEG).
M69, M70 and M55 (the only Messiers I haven’t yet observed) eluded me tonight. M69 and M70 are only a couple of degrees lower than M54, but that’s a lot of atmosphere to look through, making them too faint for the TV60. They also don't quite clear the fence as viewed from the XT10 - even with it balanced on a table. At -31 degrees, M55 should be viewable in the XT10, but – being further east than the other objects – the sky was too bright by the time it emerged from behind the tree. However, as a consolation, the conditions were just right for viewing the planets (with the 7mm DeLite).
Jupiter, 171x: Possibly my best view yet of the giant planet. Some sustained moments of excellent seeing revealed superfine detail, including festoons trailing from the notably turbulent NEB. Io’s shadow was visible as a perfect little dark spot on the NEB, and I was able to follow Io itself as it nudged across the darkened Jovian limb to begin its own transit. I did briefly add the 2.5x Powermate to increase the magnification to 428x, but the seeing wasn’t quite that good.
Saturn, 171x: Same detail as noted in the previous session, but holding steady for longer. The Cassini Division showed particularly well. Again, despite the brightening sky, Titan, Tethys, Dione and Rhea were clearly visible, along with a nearby faint star masquerading as a moon; I’d have to do a same-night comparison with the 5mm Nagler to be sure, but the DeLite does seem to control light-scatter better than any other eyepiece I’ve looked through.
Mars, 171x: First telescopic view of the red planet for this year. The seeing wasn’t quite as good here (it was still only just clearing the neighbour’s rooftop), but the gibbous phase was obvious along with some vague dark markings that showed a little better when I added the Baader Contrast Booster filter*. Disc still small at 11 arcseconds, but the best is yet to come (barring another dust storm like the one in 2018).
(* I bought the BCB years ago for the Vixen SP-102; I had no idea it was useful as a Mars filter until I read about it recently on Cloudy Nights.)
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