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.

Globular Clusters in Ophiuchus and Sagittarius

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.)

The Southernmost Messier Object

14 June 2020, 00:30 – 03:30

Conditions: Mild, still (no wind), hazy and humid – heavy condensation. Cloud increasing over the course of the session.

Seeing: Average / poor
Transparency: Poor

I don’t normally observe in the two weeks either side of the summer solstice because the sky doesn’t get reasonably dark until gone midnight – and it doesn’t stay dark for very long. However, if I’m to do justice to the Scorpius/Sagittarius region I figured I should at least try to observe some of the brighter objects this month rather than tackle them all in a mad scramble in July or August. (And of course there’s no guarantee the skies will be clear then anyway.)

Also, encouraged by my glimpse of M7 last time out, I had the TV60 set up on the Super Polaris mount. However I hadn’t taken into consideration just how much the trees and plants can grow in barely a month, so I was contending with foliage as well as the neighbour’s fence. Fortunately, the TV60 is easier to move from side to side than the XT10.

After warming up with a look at M13 in both scopes (it appeared hazy and a little washed-out tonight, despite being nearly overhead), I switched to the main target for the evening.

M7, open cluster, Scorpius, 40x (TV60 + 9mm Nagler)
The scope was almost horizontal, but I was able to get just enough clearance over the neighbour’s fence to centre M7 in the field of view. The object itself appeared faint and washed out, but enough stars were visible to at least give a sense of a very large, splashy open cluster. The brightest stars seemed to form a distorted x-shape with a double star at the centre (although the atmospheric distortion and low magnification made it hard to split). There was also a haze of unresolved stars, plus an incomplete ring of brighter stars surrounding the central cluster. Even if M7 were high enough to be visible in the XT10, the TV60 would still be a better choice of scope to view it simply because of the larger field of view (2 degrees in the 9mm Nagler). By comparison, M6 – which is itself a fairly large cluster – appeared more traditionally condensed at the same magnification.

I also had the XT10 set up in the garden, but another thing I hadn’t taken into consideration was how bad the condensation would be tonight. I had planned to use the 13mm Ethos, but unfortunately the eye-lens misted over while I was looking at M7, so I swapped it out for the 9mm Nagler. The sky was getting hazier too, so I stuck to only the brightest objects. (The fainter stuff could wait for a better night.)

M21, open cluster, Sagittarius
133x. Loose, bright cluster, a little north of M20. Star pattern at centre in the shape of a teacup, or a backwards “3”.

M23, open cluster, Sagittarius
133x. Rich, large cluster. Uniformly bright stars filling the fov. Bright star to north. Concentration of fainter stars at western end of cluster.

M25, open cluster, Sagittarius
133x. Bright, large cluster, with a distinctive “D” shaped pattern of stars at the centre. Unlike M23, the stars come in a mixture of brightnesses.

With the condensation worsening and the sky already starting to brighten, it was almost time to pack up. However while taking the TV60 indoors I noticed that Jupiter and Saturn were starting to emerge from behind the tree, so I (carefully) moved the XT10 and changed the 9mm Nagler for the 7mm DeLite.

Jupiter, 171x: the seeing was variable but in the fleeting moments that it steadied, the DeLite gave a very sharp, comfortable view. All four Galilean moons were on view and I could see the Great Red Spot moving onto the disc, showing its familiar brick-red colour when the seeing allowed.

Saturn, 171x: Titan and three faint moons were visible, despite the brightening sky. Saturn was its usual exquisite self with the Cassini Division showing well in moments of good seeing, as well as the shadow of the planet on the rings, and the dusky equatorial band.

Summer Clusters and Nebulae

18-19 May 2020, 23:45 – 2:30

Conditions: Breezy, relatively mild (first night I haven’t needed my winter coat). After a day dominated by high cirrus, the sky cleared suddenly, with just a few lingering vapour trails crossing the sky. Cloudy later on.

Seeing: Average - poor
Transparency: Poor - average

The nights are so short now that it doesn’t get reasonably dark until after 11pm, which makes for a lot of hanging around in the evening when (like tonight) the clear-sky forecast is ambiguous. With the sky near the northern horizon staying noticeably light, and vapour trails drifting overhead, the seeing and transparency varied considerably from minute to minute and from one part of the sky to another.

After warming up with M12 and M10 (both clusters looked a little hazy tonight), I tracked down another lesser-known globular in Ophiuchus:

NGC 6426, globular cluster, Ophiuchus
133x. Very faint hazy patch; a little condensed with averted vision. Unimpressive.

NGC 6572, planetary nebula, Ophiuchus
133x and 171x. Small, very bright oval disc; almost stellar at 133x. Stands out largely because of its strong green-blue colour. At 171x, the central star or core region (it was hard to tell exactly what I was seeing) overwhelms the surrounding nebulosity in direct vision. In averted vision the opposite is true: the outer nebulosity becomes the dominant feature.

NGC 6633, open cluster, Ophiuchus
133x. Follow-up from previous observation. Loose cluster of bright stars elongated roughly N-S. As noted previously, shows well in finder. Small “arrowhead” asterism of about 8 stars separated from main cluster on western (leading) side. Quite large, but a bit more “telescope-friendly” than the nearby IC clusters 4665 and 4756.

IC 4756, open cluster, Serpens
133x. Not as bright as IC 4665 and NGC 6633, but a very rich, very large cluster – best suited for smaller wide-field scopes.

NGC 6791, open cluster, Lyra
133x. Faint, extended haze. Starts to resolve with averted vision, giving at least a sense of its richness. Not much, if any, improvement on my previous observation, but I am slowly warming to this cluster.

M56, globular cluster, Lyra
133x. A little washed-out compared to previous observation. The triangular core was less apparent tonight, but I did notice a bright star leading the cluster and a long “x” shape of stellar arms.

M57, The Ring Nebula, Lyra
171x. Additional prep work for sketch (first draft below). The transparency must have been good in this part of the sky because I could just about detect a faint 14th magnitude star east of the ring (just beyond the brighter 13th magnitude star).

At 1:20 I was distracted by the unmistakable sight of the ISS passing high overhead.

After quick looks at M27, M4 and M80 I was irresistibly drawn to an old favourite:

M11, the Wild Duck Cluster, Scutum
133x. After all these years it still boggles me that I don’t have to travel any further than my back garden to see something as breathtakingly beautiful as this cluster. I have mixed feelings about the bucket list approach to life, but if you insist on such a checklist, seeing M11 through a telescope should probably be on it.

At around 2 AM the clouds returned with reinforcements, but after I’d taken the scope indoors – wouldn’t you know it – the sky suddenly cleared again from the south, and now it was remarkably free of haze. With only about half an hour of usable dark left, it wasn’t worth carrying it back out again, so all remaining observations were carried out with 7x50 binoculars and the naked eye (the most important instrument of all!).

M24, star-cloud, Sagittarius
I don’t recall ever seeing M24 with the naked eye before (the Milky Way in Sagittarius is always a little washed out from my location), but tonight it was visible as a hazy patch, a little smaller than the Scutum star-cloud further to the north. The binoculars revealed it to be sprinkled with stars, the brightest ones forming a distinctive almond shape.

This part of the sky (the steam rising from the spout of the Sagittarius teapot) is rich in bright clusters and nebulae, many of which showed up well in the binoculars (particularly M8, the Lagoon Nebula). Also visible in the binoculars were M12, M10, M11 and M27.

The binoculars resolved several more stars in M6 tonight, giving a much better view than 17 May. I also got my first glimpse of M7, which was just visible as a faint hazy patch very low in the south. I propped my elbow against a door-frame to steady the view and over time a few faint stars began to pop out. Averted vision also showed the cluster to be larger than was first apparent. From the same vantage point I could also see the bright stars Lambda Scorpii (Shaula), Upsilon Scorpii (Lesath) and G Scorpii through the binoculars (but not with the naked eye), all three of which culminate at less than 2 degrees above the horizon from my location. I don’t think I’ll be able to get the XT10 on M7, but it might be possible in the TV60.