Night of the Globular Clusters

14 -15 April 2020, 23:30 – 02:45

Conditions: Slight breeze, hazy bands of cloud receding low in the southeast.

Seeing: Poor
Transparency: Average

I was in the mood for something different after all those faint galaxies, so I started a bit later than usual with a session devoted (mostly) to globular clusters. All observations carried out at 133x with the 9mm Nagler. In the XT10 this eyepiece seems to hit the sweet spot for framing and resolving globulars; also, sticking to one magnification for the entire session makes it easier to compare one cluster to another.

M13, globular cluster, Hercules
What better place to start? (I returned to this cluster several times during the session as it rose higher in the sky.) Stunning as always, and for the first time I clearly saw the dark Y-shaped “propeller feature” adjacent to the core. Like the nearby galaxy NGC 6207, I suspect it’s one of those things that becomes fairly obvious after you’ve seen it once. No overall colour to the cluster that I could see – at least not on this occasion.

M92, globular cluster, Hercules
Smaller than M13, but an impressive globular in its own right. Well resolved. Oval shape. Slight blue tinge.

NGC 6229, globular cluster, Hercules
The “baby bear” of the three Hercules globulars. Small, condensed, quite bright. Grainy, but no stars resolved.

M104, Sombrero Galaxy, Virgo
A “stop-off” on the way to M68. Long, saucer-shaped galaxy with central bulge and bright stellar core. Dark lane clearly seen offset to the south.

M68, globular cluster, Hydra
Large, faint misty patch of light, all but washed out by its low altitude and atmospheric haze. With averted vision it seemed a little mottled, but that was all I could make out. A tough object – I lost it a couple of times and had trouble relocating it.

NGC 4565, Needle Galaxy, Coma Berenices
Very long and thin compared to M104, extending almost halfway across the field of view. Star-like nucleus embedded in slightly bulging core. Dark lane cutting across core; with averted vision it can be seen extending further out across the galaxy.

NGC 5634, globular cluster, Virgo
Small, round unresolved fuzzball, not very condensed. Faint star to west, bright one to east.

M5, globular cluster, Serpens Caput
A lovely, rich condensed cluster, rivalling M13. Well resolved most of the way to the core. (It’s such a stunning cluster I completely forgot to check for colour.) Stars appear “swept back” to the east. Particularly prominent star just southeast of the core. Further away, just out of the field to the southeast, lies a bright and closely paired double star (5 Serpentis).

M83, Southern Pinwheel Galaxy, Hydra
Took a while to track down, and when I did it was literally grazing the neighbour’s fence (culminating at less than 9 degrees above the horizon!). The galaxy itself was just visible as a condensed fuzzy core, with a distinctive line of 3 stars to the south and east. Averted vision revealed a very faint surrounding haze. A minor miracle that I’m able to see a galaxy this far south (I only searched for it on a whim because the haze had cleared and all the neighbours’ lights were off). That I was able to see it all illustrates that it must be a spectacular object when viewed from more southerly latitudes.

M12, globular cluster, Ophiuchus
Unusual, spidery cluster with a pear-shaped core and two long straight “arms” of stars forming a flattened “X” shape. Also a seemingly detached clump of stars to the west and a bright (foreground?) star southeast of the core, reminiscent of the one in M5. A straggly cluster, quite well resolved, with lots of intriguing detail.

M10, globular cluster, Ophiuchus
A more “conventional” globular than M12, appearing as a rich, condensed ball of stars. Most distinctive features are a wavy arm of stars to the north and an opposing one extending south (like the integral sign or the f-hole on a violin). Well resolved.

M56, globular cluster, Lyra
Small, condensed globular residing in a rich Milky Way field. Bright star to west. Distinctive triangular core. Resolved fairly well with averted vision.

M14, globular cluster, Ophiuchus
Large, grainy, condensed cluster. Very few stars resolved – not sure if this was due to haze, interstellar dust extinction, or tiredness creeping in.

M107, globular cluster, Ophiuchus
A relatively faint, condensed cluster, smaller than M14. Grainy with averted vision. Again, possible haze/dust/tiredness affecting the view.

IC 4665, open cluster, Ophiuchus
Loose, boxy cluster of bright, blue-white stars of similar magnitude. Too large to fully appreciate at 133x, but looked very good in the finderscope and in 7x50 binoculars.

As tempting as it was to wait around for Scorpius (another constellation typically lost to the midsummer continuous twilight) to clear the neighbour’s tree, I’d been outside for over three hours, so I called it a night.

Late Summer Clusters

6-7 August 2018, 23:00 – 01:00 BST

Tonight I set up the TV-60 and the Super Polaris for imaging M52 and NGC 457 (open clusters in Cassiopeia). While that was in progress I revisited some of last night’s targets and also sought out the following objects:

M2, globular cluster in Aquarius
Appeared as a circular fuzzball, possibly affected by haze and cloud. Some resolution with averted vision and one bright (foreground?) star offset from core. Easier to find than I expected, but needs revisiting under better conditions.

M92, globular cluster in Hercules
Every bit as impressive as M3 and M15, despite being on the “brighter” side of the sky tonight. Resolved nicely with a bright condensed core (albeit not as condensed as M15). It appeared to be a little elongated along one axis, almost oval–shaped.

NGC 129, open cluster in Cassiopeia
Loose arrangement of stars, but still obvious.

NGC 436, open cluster in Cassiopeia
Small cluster near NGC 457 (below the "feet" of the Owl Cluster). It was one of those clusters that hovered on the threshold of resolution in the 4-inch scope (which, in a way, made it more fascinating), but now with full resolution it seems a little disappointing – not as many stars as I was expecting.

M34, open cluster in Perseus
Large, bright and loose – more impressive than M39 in Cygnus, but I still think it looks better with a wider, more contrasty field.

First night out with the new scope

18 – 19 May 2018, 22:30 – 02:00 BST

The sky was a little hazy and never completely dark, so for the most part I stuck to the bright showpiece objects. Best views came with the 9 mm Nagler – darker sky, better contrast. The scope took a good hour to cool down, but when it did the views were spectacular.

M13, great globular cluster in Hercules
In a word: wow! After switching from the 24 mm Panoptic to the 9 mm Nagler, pinpoint stars were resolved (in direct and averted vision) right across the face of the cluster, giving an impressive sense of scale and distance. After a while I could perceive chains of stars curving out from the centre. The first night was supposed to be a whistle-stop tour of some old favourites but I couldn’t tear myself away from this object. The longer I looked, the better the view got. I've viewed M13 many times with the 4-inch scope but now for the first time I could see it as a proper cluster of stars and not just a grainy snowball hovering on the threshold of resolution. (The photo above really doesn't do the spectacle justice.) At one point a satellite (space junk?) glided right across the middle of the cluster, followed a minute or two later by a second object travelling on the same path.

M57, Ring Nebula in Lyra
Very bright outer "donut", gauzy central region, brighter edge on one of the long sides. Faint star clearly seen adjacent to nebula.

M5, globular cluster in Serpens
Easier to find than I thought it would be. Smaller, more condensed than M13, but the XT10 resolved it well despite it being in a brighter part of the sky. Relatively bright star just off centre. It seemed (and I’ve thought this before with the Vixen SP-102) that although M13 is bigger and brighter overall, the brightest stars in M5 are brighter than the brightest ones in M13.

M81 and M82, pair of galaxies in Ursa Major
Not well-placed for observing now, but I couldn't resist looking at the Great Bear's famous galaxy pair. M81 showed a bright condensed core and not much else (I’ve no doubt the outer structure will be more evident on a better night). M82 was a surprisingly long streak of light (making me look forward to the likes of NGC 891, etc.) and the bisecting dark lane was clearly visible.

Despite its low altitude this year, Jupiter in the XT10 was as good as I’ve ever seen it. It was dazzlingly bright with the 9 mm Nagler, but the best view came with the 5 mm Nagler. Alt-Az tracking wasn’t any problem either, although it helped that it was near the meridian. Fleeting moments of good seeing revealed plenty of fine detail in and around the belts, with a noticeable “kink” in the NEB. The GRS was immediately obvious and – once my eye had adjusted to the brightness – its brick red hue stood out. All four Galilean moons were visible, but with no obvious signs of colour or resolution.

Veil Nebula, supernova remnant in Cygnus
I switched back to the 24 mm Panoptic for this one. As I anticipated, the sky wasn’t dark enough to see it with direct vision, but when I added the Ultrablock filter it immediately popped out. The Witch’s Broom (running through 52 Cyg) looked like a funnel cloud frozen in space, tapering to a sharp point. I had to sweep to find the other section, but again it popped out from the dark background, showing the distinct “chicken-bone” shape familiar from photographs, and a suggestion of a braided structure.

M27, Dumbbell Nebula in Vulpecula
Very bright with or without the Ultrablock. Appeared sharper on one side and ever so slightly bluer than M57. I need to spend more time on this object, but it's already clear that the XT10 is going to be an excellent scope for high-magnification viewing of planetary nebulae.

M71, globular cluster in Sagitta
Quick look, partly resolved. Loose for a globular.

NGC 6939, open cluster in Cepheus
Partially resolved, triangular shape. Appearance much the same as the photo I took recently.

Albireo, double star in Cygnus
One of the northern sky's showpiece doubles. Improved as it gained altitude; looked better at 50x, but perhaps the brightness was overwhelming the colours a little.

M51 and NGC 5195, Whirlpool Galaxy and companion in Canes Venatici
Again, not well placed, but both galaxies showed bright cores. A hint of spiral arm structure in M51, with a star superimposed over the face of the galaxy (definitely not a supernova).

Other impressions: lots of satellites/space junk seen passing through the field of view, often in pairs (According to Stellarium the brighter ones were from the GlobalStar family). The night included a very bright ISS passage - almost overhead - and visible most of the way down to the horizon.