Showing posts with label reflector. Show all posts
Showing posts with label reflector. Show all posts

Wednesday, 24 November 2021

The Skull and the Silver Coin

2 November 2021, 21:45 – 23:45


Seeing: Poor
Transparency: Good – Average

Conditions: A still, windless night after a surprisingly warm sunny day (but the lawn was still very muddy from the rain of recent days). In the afternoon I walked up to North Foreland, where the countless strands of spider-silk backlit by the sun made the farmer’s fields look like they were covered with fine silver blankets. The Clear Outside forecast (which is usually pretty reliable) was confidently predicting cloud and fog after dark, but it mostly remained clear, with just a few patchy clouds gathering in the northeast. However there was a lot of moisture in the air, mostly affecting the eyepieces. The low sunlight during the day had also left me with quite the headache; it took more of an effort to concentrate on what I was seeing, so I was pretty tired by the second hour of observing.

Also of note: a couple of bright blue flashes of light somewhere to the south which I thought might have been early fireworks, but there was no follow-up sound. Perhaps a distant storm was passing through the Channel.

NGC 246 (Caldwell 56), planetary nebula, Cetus
92x + OIII filter. Large (for a PN) bulbous haze; barely visible without the filter and still quite faint even with it in place. Speckled with 3 or 4 faint stars, one of which is presumably the central illuminating star. (The three brighter stars form an isosceles triangle.) This slightly punctured, speckled appearance made it seem like a cross between the two PNs NGC 6781 and NGC 6804 in Aquila. When observing an object for the first time I try to go in “cold” with little or no prior knowledge, but in this case I was vaguely aware that NGC 246 was nicknamed the Skull Nebula. With averted vision it does indeed have a blotchy, skull-like appearance. It’s certainly a more appropriate nickname than the “Pac-Man Nebula” which, confusingly, is also the informal name for NGC 281 in Cassiopeia.

NGC 253 (Caldwell 65), the Silver Coin Galaxy, Sculptor
92x. After several previous failed attempts to spot this galaxy I wasn’t getting my hopes up, but – after careful positioning of the scope to see through a gap in the neighbours’ foliage – I finally saw it as a large, faint and rather elongated ellipse angled NE to SW. Two field stars to the south and another one north, with a few fainter stars superposed on the galaxy, including one just west of the core. Averted vision showed the galaxy brightening smoothly towards the centre, but no bright core/nucleus or other details were apparent. Although faint, it wasn’t “vanishingly” faint like some of the more challenging objects I’ve tracked down, so I’m surprised it’s taken me this long to see it. I guess the sky conditions have to be just right. Having an Ethos also helps; I’m not sure I would have spotted it in any other eyepiece.

It’s a challenge for me to see any galaxy below -20 degrees declination, so although it wasn’t visually impressive, the fact I can see NGC 253 at all demonstrates that (like M83) it must be a spectacular sight from more southerly latitudes.

While in the area I also looked for globular cluster NGC 288 (which lies a couple of degrees south of NGC 253), but I couldn’t see it with any degree of confidence. I guess it must lack the central condensation of more typical globulars, plus the obstructing foliage didn’t help.

M77, Seyfert Galaxy, Cetus
92x. As per previous observations. Small, bright galaxy with an intense star-like nucleus. The nucleus seemed blue-ish, but this may have been because I had just come from Delta Ceti (which looks very blue in the Ethos). The surrounding haze swells with averted vision. Bright field star to the east. This is one galaxy that benefits from higher magnification.

A faint point of light was just about visible in the 9x50 finder at the corresponding location, but was impossible to tell whether it was the galaxy or the adjacent field star (or a combination of both).

NGC 1055, galaxy, Cetus
92x. North of M77. Very faint streak of light forming a triangle with two bright field stars to the north. Another fainter field star on the western end of the galaxy.

NGC 488, galaxy, Pisces
92x. Faint round haze west of a bright field star. Star-like core with averted vision. Another fainter field star on SE of galaxy. Visually, this one reminded me of NGC 278 in Cassiopeia.

The PSA plots a couple of other galaxies in this region, but I was unable to see them. I then relocated to M74, but the so-called Phantom Galaxy was even fainter than usual, at which point I noticed that the eye-lens of the Ethos was starting to succumb to the condensation. With the clouds starting to encroach from the northeast, I switched to the 7mm DeLite and made a return trip to M77.

M77, Seyfert Galaxy, Cetus
171x. The oval shape of the galaxy was more pronounced at this magnification, and there was more distinction between the bright core and the nucleus embedded within it, but the poor seeing smeared out any fine detail I was hoping to see. The core still seemed slightly blue, but not as much as at 92x.

Although the DeLite has a similarly-sized eye-lens to the Ethos, I thought the raised eye-cup design might provide better protection against the condensation. Unfortunately, it wasn’t to be, so I was forced to switch eyepieces again.

After a first look at M42 for the season (just clearing the fence) and quick trips to M78 and the Pleiades, I rounded off the session with a look at one of the best open clusters of the winter.

M37, open cluster, Auriga
133x and 50x. Magnificent as usual: a water beetle with a jewelled heart. Looks best at low-to-medium powers. The 24mm Panoptic’s field is wide enough to show a bright orange-red star southwest of M37, contrasting with the pale red star at the centre of the cluster.


Other notes:
I glimpsed a few faint meteors while I was taking breaks from the eyepiece. I also heard a few more Redwings flying overhead.

Monday, 15 November 2021

Sightseeing in Cassiopeia and Perseus

8 October 2021, 20:45 – 22:45 (BST)


Seeing: Average
Transparency: Average

Conditions: A mild night with a light breeze. Patchy cloud at the start and end of the session.
With all the forecasts predicting clouds at some point, I wasn’t sure how much time I was going to get, so I kept the 13mm Ethos in the focuser for the entire session.

NGC 7789, open cluster, Cassiopeia
92x. Lovely, rich cluster – looks like a very loose globular in the Ethos. Orange star on the leading (west) side of the cluster.

NGC 457, open cluster, Cassiopeia
92x. The unmistakable Owl Cluster; this was always one of my favourites in the SP-102. Rich central spine of stars with several close doubles. Looks good in the Ethos.

NGC 436, open cluster, Cassiopeia
92x. Companion cluster to the Owl. About 15 members resolved in direct vision, with an underlying haze of unresolved stars.

Nature note: At approximately 21:20 I heard the first of several Redwings flying overhead. Winter is coming…

Double Cluster, Perseus
92x. What more can I say that I haven’t already said other than: wow! I don’t know if it’s the eyepiece design or something to do with the magnification I’m using, but star colours really seem to “pop” in the Ethos, particularly red giants and carbon stars.

NGC 957, open cluster, Perseus
92x. Elongated, almond-shaped cluster, with a mixture of bright stars and an underlying haze. Two bright stars at the east and west ends of the cluster. Not bad as clusters go, but its cause isn’t helped by its close proximity to the Double Cluster.

NGC 744, open cluster, Perseus
92x. Loose, vaguely bat-shaped cluster. (It also resembles – putting it less charitably – a concertina clothes horse.) Central diamond-shaped concentration of stars with a few close doubles. Bright star on the northern corner.

M76, “Little Dumbbell Nebula”, Perseus
92x. Seemed a little fainter at this magnification (possibly due to lower contrast). As noted previously, aligned NE-SW, with the SW lobe being the brighter of the two. The orange star noted last time out is due east. Field star west of the nebula, another one NW, and two more in a line farther out on the eastern side.

NGC 278, galaxy, Cassiopeia
92x. Small, round condensed fuzz southwest of a prominent blue field star. Bright core with averted vision; like an unresolved little globular cluster. A MEO satellite crawled through the field at around 22:15.

NGC 278 is certainly a lot easier to see than the two Andromeda satellite galaxies that also occupy this corner of Cassiopeia. Talking of which, NGC 185 was just visible as a faint featureless oval, but NGC 147 was a lot harder to see (as usual). After sweeping the area I thought I could detect a very faint glow south of a triangle of field stars – and by “very faint” I mean right on the threshold of visibility. I was going to take a breather and try again, but unfortunately the clouds returned at this point, bringing with them a thin layer of haze. When I went indoors I looked at a photo of NGC 147 in NSOG, and there it was south of a triangle of field stars, so I think maybe I did spot it at last. (But I’d like to see it again to be sure.)




I also went out the following night (9 October) from 21:00 to 22:15. I had planned to follow up on the observation of NGC 147, but it was quickly apparent that the transparency was too poor for viewing faint objects. The air temperature was also noticeably cooler, with condensation appearing on the scope from the outset. (The big eye lens of the Ethos doesn’t cope well with dew.)

So instead I switched to the back-up plan and spent an enjoyable hour observing Jupiter and its moons. The seeing was mostly poor with fleeting moments of clarity, so I didn’t go higher than 240x (5mm Nagler). However it was good enough for me to watch Europa emerging from Jupiter’s shadow at approximately 21:35, appearing first as a pinprick of light, then growing to full brightness in just a few minutes.

One brown barge was visible above the NEB, and the GRS was starting to rotate into view near the end of the session, but the seeing was deteriorating badly by this point. The metal tube of the scope was also dripping wet, so I packed up for the night.

Saturday, 6 November 2021

Autumn Favourites

29 September 2021, 20:30 – 22:45 (BST)


Seeing: Poor
Transparency: Average

Conditions: A cool, somewhat chilly night; gusty to begin with, but the wind dropped off fairly quickly. Low patchy clouds passing overhead (like fluffy icebergs), joined later on by high hazy clouds (all coming from the west). The sky wasn’t great and the moon was due to rise at 23:00, but with the forecast not looking good for the coming nights I figured I had to make the best of what I had.

After warming up with a look at M15 (at 133x), I popped in the OIII filter and had a somewhat optimistic search for the nearby planetary nebula NGC 7094 (using an article in the November 2018 S&T as a guide). It’s not plotted in the PSA or SA 2000 – and perhaps with good reason; I couldn’t see any trace of it.

I thought about swapping the Nagler for the Ethos to give myself a better chance of finding it, but I didn’t want to waste too much time on a single (very faint) object, so I pushed the scope up to Cygnus to drop in on an old favourite.

Veil Nebula, SNR, Cygnus
133x + OIII filter. 133x is really too high a magnification for this object, but quite a lot of structure was visible in both arcs, including the brighter edges of the Western Veil, and the “talons” extending from the Eastern Veil.

Before leaving the Veil, I tried a quick experiment: removing the OIII filter and holding it over the eyepiece of the 9x50 finder. The two arcs were just about visible using this method, but they were extremely faint – nowhere near as good as the view through the TV60 (15x + filter).

A quick look at NGC 7331 (Pegasus) confirmed that the sky (the part of it that was clear at least) was much better than it had been on 7 September, so I went after some galaxies before it got too cloudy.

NGC 7457, galaxy, Pegasus
133x. I couldn’t remember if I’d seen this one before (turned out I had), but it was fairly easy, showing as a soft oval glow which was brighter towards the centre. Suggestion of a stellar nucleus with averted vision. Two faint 12th magnitude field stars to the south; three brighter ones to the east.

NGC 7662 “The Blue Snowball”,  planetary nebula, Andromeda
133x. (A quick look before tackling galaxy NGC 7640.) Small and very bright, with a distinctive blue-green tinge; it almost seemed like it was sparkling. Even at 133x I could still see a hint of the darker core.

NGC 7640, galaxy, Andromeda
133x. Very faint streak of light, aligned roughly north-south, and “encaged” in a triangle of 11th magnitude field stars which make seeing the galaxy harder than it should be. An easy one to overlook; I can appreciate now why I had trouble spotting it before. The brighter core seemed “clumpy” with averted vision, with two points of light popping in and out of view. Reading about this galaxy later in NSOG I learned that one of these points is a magnitude 13.5 foreground star.

The advancing haze brought the galaxy-hunting to an end, so I pushed the telescope south for a look at Jupiter and Saturn. Sometimes a bit of haze can improve planetary viewing, but not tonight. The seeing was consistently poor with only coarse details visible.

I had expected to pack up at this point, but the sky had cleared over Cassiopeia and Perseus, allowing time for a few bonus objects.

NGC 7789, open cluster, Cassiopeia
133x. Another old favourite. Rich, large cluster with stars arranged in spiralling “petals”. As noted on previous occasions, the wider field of the Ethos gives the best view of this cluster.

There's an interesting (and very close) double nearby in the shape of Sigma Cassiopeiae. Worth revisiting at higher magnification on a night with better seeing.

M76, “Little Dumbbell Nebula”, Perseus
133x. North of Phi Persei. Easy at 133x despite its reputation, with the bi-lobed structure immediately apparent. The seeing wasn’t good enough to pick out the knots in the brighter lobe. Orange 7th magnitude star in same field 12’ to ESE. With the OIII filter the nebula seemed a little more boxy, with the faint outer loops just about visible with averted vision. The northern one was a little easier to see, but appeared patchy and discontinuous. 

Gamma Andromedae (Almach), double star, Andromeda
171x. Another favourite to round off the session. Golden primary (west), indigo-blue secondary (west); one of the most beautiful double star systems in the night sky.


Also of note: two medium-fast meteors after 10pm, both of similar brightness and both travelling on similar east-to-west trajectories about 10 or 15 minutes apart. Sporadics, or perhaps a pair of Southern Taurids?

Wednesday, 27 October 2021

The Bubble and the Veil

10 September 2021, 21:30 – 22:15 (BST)


Seeing: Average
Transparency: Average

Conditions: Cooler than the last couple of sessions (though still mild for the time of year), with a gusty wind. Cloud joining up from the west and the northeast, eventually putting an end to the session at 22:15. But the 45 minutes I did get were pretty good.

Czernik 43, open cluster, Cassiopeia
133x. About time I took some notes on this cluster given the number of times I’ve had it in the field of view. Loose, sparse cluster – hard to distinguish from the rich background of Milky Way stars. The view is currently livened up by the presence of Nova Cas 2021 right next to it.

NGC 7635, Bubble Nebula, Cassiopeia
50x + OIII filter. Seemed more “obvious” with this magnification/filter combination, but hard to define any shape on this occasion. Seemed larger too (paradoxically); perhaps I was detecting traces of the surrounding nebulosity. The clouds forced me away before I could try other combinations.

Veil Nebula, SNR, Cygnus
50x + OIII filter. Looked spectacular tonight before the clouds got in the way. The three brightest components were showing up well.

M27, planetary nebula, Vulpecula
50x + OIII filter. Very bright with this eyepiece/filter combination, but hard to make out much detail. The “spinning coin” effect seemed quite pronounced at this magnification.

The clouds were pushing in from all sides by this point, but a gap had cleared over Cygnus, allowing a quick return trip to the Veil before the sky was completely covered.

Veil Nebula, SNR, Cygnus
50x + OIII filter. Quick notes to add to previous observations. The spike of the Witch’s Broom had brighter edges with averted vision. Fleming’s Triangular Wisp is very long – starts farther north than I had previously realised. Couldn’t see any of the other, fainter sections, but I didn’t really have enough time to properly look for them.

Saturday, 23 October 2021

More Autumnal Haze

7-8 September 2021, 22:30 – 00:30 (BST)


Seeing: Poor / Average
Transparency: Poor

Conditions: Similar to the previous night; warm and hazy, with a hint of a low-lying mist. Unusually, despite there being no condensation on the scope, the pages of my notebook became very soft and difficult to write on by the end of the session. Even the pages of the PSA had lost their usual sturdiness.

Once again, the poor transparency left me scratching around for things to observe, but I started out with a look at Saturn at 171x, with Titan and a couple of the other moons showing well.

M52 was visible in 7x50 binoculars as a misty, grainy patch of light. The view in the 9x50 finder was similar, but I could more easily see the fan shape and the 8th magnitude star at its apex.

Nova Cas 2021 seems to be slowly brightening again at approximately 7th magnitude.
A test of different filters and magnifications on the Bubble Nebula proved inconclusive because of the poor conditions. Need to try again on a better night.

That was followed by an ambitious attempt to look at some galaxies.

NGC 7331, galaxy, Pegasus
171x. As per previous observations. Only the core region was showing up well tonight. Stellar nucleus visible with averted vision. I did nudge the scope southwest towards the Stephan’s Quintet area, but there wasn’t even a hint of the fuzziness I've seen before.

NGC 7479 wasn’t visible tonight (at both 171x and 133x).

I kept pushing the scope south to look for Neptune. The chart showed some more galaxies en route (including NGC 7556 in Pisces), but I couldn’t see any of them. However there was a consolation prize in the bright, red-hued carbon star TX (19) Piscium, which looked like a glowing coal at 133x. It showed well in the finder too. Possibly the highlight of the night.

Neptune itself was smeared out and mushy because of the poor seeing. I had made a note of where Triton was supposed to be, and at one point I thought I caught a glimpse of it, but I was unable to repeat the observation, so that has to go down as a non-detection.

Jupiter (at 240x) was perhaps the only thing that benefited from the haze, as it seemed to improve the contrast on the cloud belts. Unfortunately the seeing was only intermittently good (and otherwise mostly poor). Ganymede and Callisto were close together.

Nature note:
Two large frogs in the pond and several smaller ones queuing up on the exit log (I suppose you could call it a frog-jam).

Sunday, 3 October 2021

An Extra-galactic Globular

6 September 2021, 22:15 – 00:00 (BST)


Seeing: Poor

Transparency: Average

Conditions: A still night, very warm and mild for the time of year. Some high, patchy cloud which cleared as the night drew on. Thin layer of condensation on the scope by the end of the session.

After allowing time for the scope to reach equilibrium (and my eyes to dark-adapt), I started with a look at the autumn highlight globular clusters M15 and M2 at 171x, although the iffy seeing prohibited me from resolving the fine detail I was hoping for.

After a quick look at Saturn, I then paid a return visit to NGC 7814, which was very faint tonight. Supernova 2021rhu, unsurprisingly, was no longer visible.

However, NGC 404 (Mirach’s Ghost) was quite obvious at 171x, even with Mirach in the field. Mirach itself is worth looking at, as it has a distinctly reddish hue.

M32, satellite galaxy, Andromeda
171x. Small, round and very bright. Condensed core with a star-like nucleus. With prolonged examination there seemed to be just a hint of elongation along the axis pointing towards M31.

Mayall II (G1), globular cluster, Andromeda
171x. Finally tracked down the Andromeda Galaxy’s biggest and “brightest” globular cluster. I reached it via a careful and somewhat complicated star-hop from M32, but it was visible with averted vision as a tiny fuzzy spot flanked by one or two faint foreground stars. Most sources give the magnitude at somewhere around 13.7, but fortunately its light is very concentrated, which helps with its visibility.

G1 was a little more obvious at 240x (still using averted vision), but it was still very challenging. Now I know how to find it, I might try this again on a better night when M31 is nearer the zenith.


I finished off with a look at Jupiter at 240x and 342x (171x + 2x Barlow). All four Galilean moons were west of the planet. Indifferent seeing smeared out most of the fine detail, but one brown barge was visible near the western limb. The orange colour surrounding the NEB appeared to have spread farther into the EZ, and the northern polar region seemed to have a slightly blue-ish tone (compared to the southern region). I’ve noticed this before but I haven’t seen it on images, so I’m wondering if this is an illusion caused by atmospheric dispersion or contrast effects.

Nature (and other) notes:
The frogs were quite vocal tonight. Also, lots of air traffic flying east (out of the country). Oddly, I didn’t see any flying west.

Thursday, 30 September 2021

Cassiopeia through the Haze

2 September 2021, 21:40 – 23:10 (BST)


Seeing: Average / poor

Transparency: Poor – very poor

Conditions: Patchy cloud with an overlying haze; moderate breeze. The nights are drawing in quickly now. This was the first “clear-ish” evening in several weeks, but the hazy transparency that seems to bedevil autumn skies was particularly bad tonight, ruling out any plans I had of going after faint galaxies.

So instead I took a leisurely stroll along the Milky Way at 92x (Ethos 13mm), starting at M57, and visiting M71, M27, the Veil Nebula (with the OIII filter), before arriving at the rich area of sky near M52 in Cassiopeia.

The Bubble Nebula (NGC 7635) was visible in the same field as M52 at 92x (with the OIII filter). It was also visible without the filter with averted vision, although the poor transparency made it even more subtle than usual. While sweeping with the OIII filter I also stumbled across NGC 7538 (the Northern Lagoon). Nearby clusters NGC 7510 and Markarian 50 also showed well, sharing the same field of view at 92x (unfiltered).

Collinder 463, open cluster, Cassiopeia
92x. One I’ve been meaning to revisit for a while, but the poor conditions may have compromised it somewhat. Appeared as a misty patch in the finder. In the main scope it showed as a large, sprawling cluster – even in the Ethos it seemed very loose. Comprised of mostly blue-white stars, interspersed with a few red-orange stars. One for smaller wide-field scopes.

With the transparency visibly deteriorating, I gave up on deep-sky targets and rounded off the session with a look at Saturn at 240x, glimpsed through a gap in the neighbour’s jungle. The seeing wasn’t great tonight either, but the planet’s post-opposition shadow was visible on the rings, and the moon Iapetus was showing well (for once).

Sunday, 26 September 2021

Perseid Meteors and an Io Transit

12-13 August 2021, 23:00 – 02:00 (BST)


Seeing: Good to poor (and back again; sometimes in the space of a couple of minutes)

Transparency: Good / Average

Conditions: Mild, with a light breeze. The temperature dropped noticeably after midnight, and there was a thin layer of condensation on the scope by the end of the session. The transparency was quite good for the time of year (both M31 and the Double Cluster were visible to the naked eye without too much trouble), although Jupiter was so bright you could almost regard it as a source of light pollution.

Tonight the Perseids took centre-stage and they didn’t disappoint, although the first two meteors I saw were both sporadics, including a bright one flashing from the zenith towards the west. I didn’t see any fireballs, but several of them were bright enough to leave trails. In between being distracted by meteors, I found time to revisit a few telescopic targets:

RS Ophiuchi, Recurrent Nova, Ophiuchus
133x. The nova had noticeably dimmed since Tuesday night (to about 6th magnitude), but was still obvious in the finder. Through the eyepiece it had a strong red hue which was quite striking. According to the Astronomer’s Telegram service, the nova has been monitored intensively at wavelengths right across the EM spectrum, so I look forward to finding out what new discoveries have been made about this intriguing object.

I then spent a few minutes looking at M11 and M57 (again). At around 23:40 a very bright Perseid flashed south of Pegasus, leaving a long trail glowing in its wake for a second or two. A couple of minutes it was followed by two more fast meteors which also left brief trails.

M52, open cluster, Cassiopeia
133x. Expanding on previous observations. Rich, delta-shaped cluster in a busy Milky Way star-field. This shape tends to be lost in photographs but it’s quite distinct though the eyepiece. Member stars have a range of magnitudes. Bright yellow-orange star at the apex of the delta on the southwest corner. Elongated clump of stars on the northeast side of the cluster (at the back of the delta).

At around midnight I took another short break for meteor-spotting, including a super-short Perseid coming straight from the radiant near the Double Cluster. I then pointed the telescope south to revisit some targets in Aquarius.

M72, globular cluster, Aquarius
133x. Large round glow, brighter towards the centre. Two bright field stars to the east. Two stars just southeast of the cluster and a fainter one to the northeast (presumably these are field stars too). At 171x the cluster was fainter, but did appear speckly with averted vision. The core seemed to have a triangular shape (reminiscent of M71), pointing west. The effect was enhanced by what appeared to be a dark lane (running north-south) just east of the core. At 240x I could just make out little pinpricks of light winking in and out of view, but this was right on the limit of what I could see. I certainly wouldn’t regard this cluster as anywhere near “resolved”. It’s not a bad object, but I can think of a few NGC globulars visible at this time of year that are at least as good, if not better, such as NGC 6712 in Scutum.

M73, asterism, Aquarius
171x. As noted previously, four stars in a Y-shaped asterism pointing west. I hadn’t noticed this before (because the magnification wasn’t high enough) but M72 points roughly towards a very tight 10th magnitude double star, with north-south components separated by only 2 or 3 arcseconds. 171x barely splits it, but it’s a little easier at 240x. Aladin Lite lists it as HD 199524.

NGC 7009, “the Saturn Nebula”, planetary nebula, Aquarius
171x. Bright blue-green ellipse aligned east-west; compared to M72 and M73 it really does jump out. I couldn’t see any structure in the nebula (or the central star), but there was just a hint of the projections (the ansae) with averted vision, particularly on the western side. I doubt I would have noticed anything if I hadn’t already known they were there. Similar impression at 240x; this nebula holds its brightness well at high magnifications even without a filter.

It only seemed appropriate to follow the Saturn Nebula with Saturn itself (at 240x). The seeing was initially very poor in this part of the sky, but after a few minutes it stabilised, allowing a brief but very sharp view of the ringed planet. In addition to Titan, three other moons were visible: Tethys west, Dione and Rhea east.

I then switched to Jupiter, just in time to catch Io’s shadow moving onto the disc followed closely by Io itself, which surprisingly remained visible even after it had passed beyond the darker part of the limb (appearing as a bright spot against the equatorial zone). The Great Red Spot was also on show, although its colour still seemed rather subdued compared to recent years (more of a coral pink compared to its previous brick red). I increased the magnification from 240x to 343x (7mm DeLite + 2x Barlow) and the seeing was good enough for me to resolve the moons as tiny discs, with Ganymede appearing noticeably larger than the other three. The view was so good it was an effort to tear myself away from the eyepiece, but fortunately I got the laptop and the camera ready in time to capture one decent set of images before the seeing deteriorated. (South at the top to match the eyepiece view.)



Here's an attempt at a sketch in pastel showing the beginning of the transit, but even with a bit of tweaking in Photoshop I still think the result looks less like the eyepiece view than the digital image. With hindsight, perhaps watercolour or coloured pencil would be a better choice of medium for planetary sketching. 



Two more Perseids closed the show as I was packing up.

Also:
Tonight’s soundtrack came courtesy of frogs roaming in the garden, drunken revellers singing in the town, and police sirens (it was the penultimate night of Folk Week).

I also noticed several bright satellites (presumably Starlinks, although there haven’t been any launches recently) following near-identical paths from the west, disappearing into the Earth’s shadow somewhere north of the zenith. There were also a lot more planes in the sky – some travelling east, but the majority travelling west (i.e. into the country).

Friday, 27 August 2021

Saturn at Opposition

3-4 August 2021, 23:30 – 01:30 (BST)


Having spent a good portion of the day walking round Stodmarsh Nature Reserve (for the first time in forever) in dazzling sunshine, my eyes weren’t really up for the challenge of observing faint objects, so I spent most of the session in the company of the two giant planets.

I caught Jupiter just as the GRS was disappearing around the limb. Unfortunately the neighbour’s tree seems to have put on a growth spurt, so I may not get an uninterrupted view of Jupiter this year after all.

Saturn was a couple of days past opposition, with the rings still glowing brightly, and I was even able to grab a half-decent image (below):

Saturn

Titan and several moons were visible through the eyepiece, with Rhea, Dione and Tethys in a straight line just north of the planet.

I also had a quick look at NGC 7814 at 240x. Despite my eyes being nowhere near properly dark-adapted, I was still able to see Supernova 2021rhu. It was difficult to judge its brightness, but it seemed to have faded to somewhere around 13th magnitude.

Sunday, 22 August 2021

Rhubarb Supernova

16-17 July 2021, 23:45 – 01:15 (BST)


Seeing: Average

Transparency: Average/poor

Conditions: After a run of cloudy nights, a very mild, cloudless evening with a light breeze blowing from the north. (And a near first-quarter moon sinking in the west.) I spent a lot of time carefully aligning and calibrating the astrophotography rig, only to find out later (for reasons I haven’t yet figured out) that it had stopped tracking after a few minutes, leaving me with over an hour’s worth of star trails. Oddly, it started tracking again (or attempted to, given that the autoguider had long since lost its target star) on the last few frames. I suspect a loose or snagged cable is the culprit, but I haven’t been able to replicate the fault in daylight. (This is the experience I expected to have when I first attempted this type of astrophotography back in 2018, not three years in. Oh well…)

While that was in progress (or not), I revisited some summer favourites with the XT10 at 133x: M57, M56, Albireo and M27. The dumbbell’s central star was visible again (with averted vision), but not as easily as it was at 171x.

Then, with my eyes sufficiently dark-adapted, it was onto some special extragalactic targets: 

BL Lacertae, Active Galactic Nucleus / Blazar
133x. Not the most visually exciting object (it looks like a faint, inconspicuous star in a field full of stars), but at approximately 900 million light years this is the second-farthest thing I’ve seen (after quasar 3C 273). I had to consult the MSA (chart 1123) to track it down, and even then I had to make a rough sketch of the field stars to be sure I had seen it.

BL Lac usually fluctuates between magnitudes 14 and 17, which would normally put it out of range of my scope, but it’s been exhibiting a lot of activity over the last few months and is now brighter than it’s ever been, currently pushing 13th magnitude.

SN 2021rhu, Supernova in galaxy NGC 7814, Pegasus
At long last, a supernova bright enough for my scope, and in a place where I could see it. That said, I had to wait for Pegasus to clear the neighbour’s fence before I could get the XT10 on it, but even though it was still low in the sky, the supernova was immediately obvious at both 133x and 171x, shining relatively brightly against the faint haze of NGC 7814 at approximately magnitude 12.5. It appeared as an intense star-like point slightly east of the galaxy’s centre (I wasn’t able to see the galaxy’s dark lane). Quite an impressive sight considering it’s 40 million light years away (but bad news for anyone unfortunate enough to be within a few light-years of the explosion).

Apparently SN 2021rhu (with that name I can’t help but think of it as the “rhubarb supernova”) is a type 1a supernova. This is caused by a white dwarf accreting matter from a nearby companion star until electron degeneracy pressure can no longer support its mass – resulting in a rapid collapse, a runaway nuclear reaction and a spectacular explosion that rips apart the entire star.


Also: I was treated to three very bright passes of the ISS over the course of the evening. One pass was so bright I could see a halo around it.



I went out again the following night (17 July – 18 July) for another attempted imaging run which resulted in 8 minutes of perfect data followed by another hour or so of trailed images. [Insert expletives here.]

Fortunately I was able to salvage something from the session by sticking the camera on the XT10 and grabbing some data on Jupiter while a Ganymede shadow transit was in progress (below).

Ganymede Shadow Transit

Detail-wise, there wasn’t much to choose between the image and the eyepiece view (at 240x): the brown barges above the NEB showed up well, but I didn’t spot the string of white ovals in the southern hemisphere (which are just about visible in the full-size image).

I also had a look at Saturn as it emerged from behind the neighbour’s tree. Several moons were visible and lots of fine detail was briefly visible in the planet and the rings, although the seeing quickly deteriorated.

I also had another look at SN 2021rhu (at 240x). The supernova was still quite prominent despite my eyes not being properly dark-adapted. It’ll be interesting to see if it’s still visible in August once the moon has got out of the way.

Nature note
The mosquitoes were out in force on both nights; in all the years I’ve been doing astronomy I’ve never been bitten quite like that before.

Sunday, 15 August 2021

Clusters in Cygnus and Scutum

7-8 July 2021, 23:30 – 02:00 (BST)


Seeing: Average

Transparency: Average/poor

Conditions: A breezy night with patches of high cirrus passing overhead; quite cool for the time of year. England won a major football semi-final tonight for the first time in 50+ years, so there was lots of noise coming from the town centre: people singing and car horns blaring until well after 1 AM.

Light condensation building gradually over the course of the session – mostly on the atlas and the telescope tube; fortunately the optics remained unaffected up until the last few minutes.

NGC 7044, open cluster, Cygnus
133x. I’ve looked at a lot of Cygnus clusters recently, and most of them have been immediately obvious. However, at first all I could see here were two moderately bright stars embedded in a very small and very hazy knot of light. Averted vision showed another faint haze nearby, but it was unclear whether one or both of these belonged to the cluster. At 171x a few stars popped out with averted vision, and a third star joined the two brighter ones to form a triangle. Perhaps not the best object to start a session (I was expecting something brighter).

NGC 7027, planetary nebula, Cygnus
171x. Small but bright blue-green nebula with bi-lobed structure. Bright spot stood out on the western side – as noted on previous occasions.

NGC 7086, open cluster, Cygnus
133x. Rich, compact cluster (visible as a hazy patch in the finder). Stars arranged in a loose, ragged spiral. Orange star on the western side. Underlying haze of unresolved stars.

NGC 7063, open cluster, Cygnus
133x. Large, loose cluster of bright stars with a central asterism shaped a bit like a stick representation of a horse.

I then relocated to the constellation of Scutum and, after spending some time in the company of M11 (the Wild Duck Cluster), I revisited an open cluster and a globular cluster:

NGC 6664, open cluster, Scutum
133x. Large, loose and sparse collection of moderately bright stars, shaped a bit like a partially peeled banana. Slightly washed out by the glare from 4th magnitude Alpha Scuti to the west.

NGC 6712, globular cluster, Scutum
133x and 171x. Grainy round glow in a rich star field – seemed larger than I remember. Bright field star to east. Faint stars visible with averted vision; even more so at 171x, though the field is so rich it’s hard to tell which ones belong to the cluster and which belong to the Milky Way. The cluster itself appeared “lumpy” at this power, with a prominent knot of stars south of the core. I’ve been underwhelmed by this object in the past, but tonight it really came to life – the best view I’ve had to date.

I spent quite a lot of time looking at this cluster, and at one point a slow-moving MEO satellite crossed the field on a southerly trajectory, its brightness oscillating slightly as it rotated.

NGC 6934 (Caldwell 47), globular cluster, Delphinus
171x. Small, compact globular; more condensed than 6712, with a brighter core. Bright 9.5m star leading 2’ to the west. Grainy with averted vision, but harder to resolve than 6712. The most prominent members appeared to be south of the core, with another one just northeast of the core.

M27 (Dumbbell Nebula), planetary nebula, Vulpecula
171x (no filter). Large and boxy at this power; no obvious colour. Brightest field star on the western corner, with a couple more visible through the northern half of the nebula. The central illuminating star wasn’t immediately obvious against the nebulous background, but was visible with averted vision, popping in and out of view with the seeing. It's not particularly difficult, but you have to make a conscious effort to seek it out, which is probably why I haven’t seen it before. Sources seem to vary on the brightness of this star: some have it at 13th magnitude; others have it nearer 14th magnitude. Based on my observation, I would put it nearer 13 than 14.

I rounded off the session with a first look at Jupiter for the year, starting at 171x, before moving up to 240x and then 333x. (Saturn is still low and currently behind the neighbour’s fast-growing tree for most of the night, but Jupiter looks like it might just clear it.) All four Galilean moons were on view (one west, three east) and the Great Red Spot was on the meridian, looking a bit faded compared to the last time I saw it. By contrast the NEB had a very dark core and a distinct orange-brown hue. I was almost tempted to get the laptop and capture some videos, but the condensation started to interfere at this point. Bodes well for the next couple of months though.

Sunday, 25 July 2021

Goodbye Nova Herculis 2021

13-14 June 2021, 23:40 – 00:50 (BST)


Seeing: Average

Transparency: Poor

Conditions: A mild night with a light breeze. Very slight layer of condensation on the telescope tube after an hour.

All of tonight’s observations were carried out at 92x with the 13mm Ethos.

Nova Herculis 2021 (aka V1674 Her)
I was eager to see if the nova had got any brighter in the last 24 hours, but instead I found it had faded considerably by a good two magnitudes. (It was at a similar brightness to the nearby 8.5m field star HD 175919.) I didn’t notice any colour to the nova last night, but tonight it had a slight orange hue. I’ll be interested to read the explanation for this rapidly evolving nova’s behaviour once the analysis is completed, but in the meantime see:

Obviously, I’m glad I made the effort to see this nova last night rather than leave it for a day. It’s quite something to see a star change its appearance so dramatically in such a short span of time.

As well as V1674 Her, I also revisited a few other targets from last night. As expected, 61 Cygni looked lovely in the Ethos: a pair of pale orange headlights suspended in a sea of stars.

Open clusters NGC 6755 and NGC 6756 just about fit in the same fov at 92x, but I need a darker sky to really do them justice at this magnification.

But NGC 6709 did look better tonight. The Ethos gave the cluster more room to “breathe” and the v-shape formed by the brightest stars was more prominent.

NGC 6738, open cluster, Aquila
Plotted in SA 2000. Large, sparse cluster with a meandering line of stars running through the centre. Not impressive; I can see why it was left out of the PSA. Some sources don’t even recognise it as a real cluster.

NGC 6940, open cluster, Vulpecula
A long overdue return visit to this underrated cluster (its status isn’t helped by its proximity to the Veil Nebula.) Large, rich cluster of uniformly bright stars – fits nicely in the Ethos fov. A prominent red star (VG (or FG?) Vulpeculae) near the centre and a bright, close double on the western side of the cluster.

NGC 6826, “Blinking Planetary”, Cygnus
In same field as 16 Cygni in the Ethos; it’s hard to stop your eye constantly flicking from one to the other. Pale blue-green disc with a bright central star.

I rounded off the session with a look at the famous black hole Cygnus X-1, or to be more precise, its visible-light companion HDE 226868. It’s not that hard to find if you’ve got a decent map (I used chart 119 from my old copy of Uranometria). It’s the southernmost of a pair of 9th magnitude stars in a rich star-field near Eta Cygni. Like Nova Herculis 2021, this is a view to savour while you contemplate its astrophysical significance. I may not be able to see the black hole, but more I stared at that little patch of sky, the more I felt like it was staring into me.

Also, I wasn’t aware of this at the time, but Cygnus X-1 is right next to the much-photographed Tulip Nebula (Sh2-101).

Saturday, 24 July 2021

Hello Nova Herculis 2021

12-13 June 2021, 23:50 – 01:50 (BST)


Seeing: Poor

Transparency: Average / poor

Conditions: A breezy night with the occasional small patchy cloud passing by. Noticeably chillier than Thursday night. Also, some light condensation.


Nova Herculis 2021 (aka V1674 Her)
You wait ages for a nova to come along … and now another one appears, perfectly placed for summer viewing on the Hercules / Aquila border. I had the MSA (Millennium Star Atlas) bookmarked ready for this one (Volume III, chart 1222), but it turned out I didn’t need a detailed chart; the nova jumped straight out in the finder, blazing away at somewhere between magnitude 6.0 and 6.5. Through the eyepiece at 133x it appeared as an intense little point of light, dominating the surrounding star-field. Although there wasn’t much more to see, I spent a long time in the nova’s company. It’s fascinating (and a rare treat) to look at such an object and imagine the thermonuclear processes involved as a white dwarf leaches material from a companion star, culminating in an explosive eruption.

While in the area I also noticed an interesting grouping of four stars to the west: two 8th magnitude stars flanked by two fainter stars, all in a roughly east-west straight line.

NGC 6709, open cluster, Aquila
133x. Pretty cluster of moderately bright stars arranged in a rough zig-zag pattern. Fairly large and loose; as noted last year, the centre appeared somewhat empty of stars. Visible in the finder as a misty patch of light.

At around 1:10 I noticed a really bright flare from a satellite passing overhead (travelling south to north).

NGC 6755, open cluster, Aquila
133x and 171x. Faint spray of stars in a rough crescent shape, with a stream of fainter stars tailing off to the east. Brightest member on the western end of the cluster.

NGC 6756, open cluster, Aquila
Located about half a degree NNE of 6755 (plotted in the PSA but not SA 2000). 133x: An even fainter fuzzy patch, and also somewhat smaller than its neighbouring cluster. Faint stars popping out with averted vision. At 171x I could see a tight, elongated core of faint stars, surrounded by a broken almond-shape of brighter stars, like an eye. I imagine this cluster would look quite good under a properly dark sky.

Beta Lyrae, Lyra
133x. Bright white star with three companions forming a triangle around the primary.

Delta Cygni, double star, Cygnus
171x. Brilliant icy blue-white primary with a very close companion 2.4” to the south. (I’m glad I used the DeLite for this one.) Beautiful split between the two stars when the seeing allowed.

61 Cygni, double star, Cygnus
171x. Lovely pair of bright yellow-orange stars in a rich star-field (must revisit this one with the Ethos). The separation appears similar to Albireo, and (like Albireo) the split was just about visible in the 9x50 finder. Like Barnard’s Star, this pair is a relatively close neighbour to the sun at 11.4 light years.

As I’d started the session with a nova, it seemed appropriate to finish with one: a return visit to Nova Cassiopeia 2021, which appears to be holding steady at somewhere between 7th and 8th magnitude.

Thursday, 15 July 2021

Hunting Barnard’s Star

10-11 June 2021, 23:50 – 01:40 (BST)


Seeing: Good
Transparency: Average (but only during the “dark” window from 00:30 to 01:30)

Conditions: Similar to the previous night, but with two significant differences: the condensation was back, and so were the mosquitoes...

A succession of late nights (not helped by some ambiguous clear-sky forecasts) were starting to catch up with me, so I spent much of the session just ambling along the Milky Way with the 13mm Ethos (at 92x). Without wishing to sound like a spokesman for Tele Vue, all my TV eyepieces are exceptional, but the Ethos is something else – and not just because of the extra-wide field. There’s a crispness to its image which – coupled with the immersive fov and the slightly longer eye relief (compared to the Naglers) – makes for a really special viewing experience.

The only downside is that I was so wrapped up in the view, I was a bit lax about taking notes (how do you even begin to describe a 100-degree afov of the Milky Way through Cygnus and Vulpecula?), but I did record the following observations:

NGC 6910, open cluster, Cygnus
Pretty y-shaped cluster with two bright stars at either end of the “y” (one of which has an orange hue). Fainter stars showing with averted vision.

M80, globular cluster, Scorpius
As per previous observations, but now I was catching glimpses of another, fainter star roughly due west of the cluster (at 90 degrees to the bright 8.5m field star).

Barnard’s Star, Ophiuchus
Found it at last – after some previous half-hearted attempts. At a distance of six light-years, this is the Sun’s fourth-closest neighbour (after the Alpha Centauri system) and the closest one visible from the northern hemisphere. You need a good finder chart to track it down and fortunately chart A1 in SA 2000 is up to the job. Visually of course there isn’t much to see other than a magnitude 9.5 star in a fairly rich field, but it’s certainly thought-provoking and worthy of contemplation. I expected its redness would make it stand out, but what little colour I could see was subtle: a very slight orange tinge.

I followed that with some enjoyable views of M11, M71 and M27 before relocating to Cepheus. I failed to spot galaxy NGC 6951, but reflection nebula NGC 7023 and the cluster/galaxy pairing of NGC 6939 and NGC 6946 were just about visible through the midsummer murk.

I tried to compensate for the deteriorating transparency by adding the OIII filter, squeezing in views of NGC 7000, NGC 6888 and the Veil Nebula before the end of the session.

Friday, 9 July 2021

From Cygnus to Aquila (via Lyra)

9-10 June 2021, 23:50 – 01:50 (BST)


Seeing: Good
Transparency: Average within 20-30 degrees of the zenith, poor everywhere else

Conditions: Yet another still night with the temperature steadily falling from a mild start. Smell of honeysuckle on the breeze. Earlier in the evening (at around 22:30) the signs looked promising for a noctilucent cloud display low in the north, but it fizzled out before it ever really got going.

I began with a return visit to Nova Cassiopeia 2021 / V1405 Cas (at 133x) which is still binocular-bright at somewhere around 7th magnitude. After fading from its dramatic May peak, it appears to be creeping back up in brightness again. 

That was followed by a look at summer favourite Albireo before plunging into the Milky Way again.

NGC 6834, OC, Cygnus
133x. A rich cluster arranged in clumps, with an overall shape resembling a wide upturned tree or a Jewish menorah. The latter description is perhaps more apt because the cluster’s brightest stars are aligned in a row where the candle-flames would be. Lots more faint stars pop out with averted vision, breaking up the shape a little. This is one I overlooked from the previous session, but now I’ve seen it I’m glad I made the effort to track it down.

SA 2000 lists a planetary nebula (NGC 6842) near here, but I couldn’t see it, so onto the next object.

M1-92 (Minkowski 92, aka the Footprint Nebula), PPN, Cygnus
My first protoplanetary nebula (not that I have many to choose from). Interestingly, both the PSA and SA 2000 use the regular square nebula symbol for this object. I had to increase the magnification to 240x (5mm Nagler) to find it and even then it was tiny, appearing as an elongated fuzz east of a field star. The nebula itself was fairly bright and did actually resemble a footprint (albeit a very, very small one), with the western component appearing larger and brighter than the other. I might revisit this one at 333x or 428x when it’s nearer the zenith (assuming I can find it again).

While in the area I also looked for Campbell’s Hydrogen Star (PK 64+5.1). I’m pretty sure I had it in the fov, but there was no obvious sign of anything red and/or nebulous. Again, I think this is one for 333x or higher.

I had planned to explore the Milky Way with the 13mm Ethos, but with the seeing actually reasonably stable for a change, I opted to stay at high power and revisit a few well-known (and a few not-so-well known) objects.

All four components of Epsilon Lyrae (the Double-Double) showed a good split at 240x. I could also see three fainter stars and one brighter star (east) between the two pairs. 

M57 (the Ring Nebula) also looked good at 240x, near its maximum elevation. Nothing new I can write about the nebula itself on this occasion, but I was able to see (with averted vision) a couple of very faint stars on the northern side of the ring (opposite the 13m and 14.1m stars noted previously). One of these is the combined light from a multiple star, but the other is listed as magnitude 14.7, the faintest (confirmed) star I’ve yet seen with the XT10.

M56, globular cluster, Lyra
240x. Loses its shape a little at this power, but lots of stars resolved across the face of the cluster, particularly with averted vision. Bright star leading.

NGC 6826, “the Blinking Planetary”, Cygnus
Impressive view at 240x; holds brightness well. Pale blue-green disc with a bright central star. No detail within the disc that I could see, though (as I later found out) I was looking for darker areas when perhaps I should have been looking for brighter ones.

NGC 6804, planetary nebula, Aquila
240x. Faint amorphous disc, with a star on the northern edge and a fainter one near the centre. No obvious sign of nearby NGC 6803 (it must be really small), but I didn’t spend a lot of time looking for it.

NGC 6760, globular cluster, Aquila
240x. Faint (for a globular) round glow which brightens towards the centre. Averted vision shows it to be mottled with some faint stars popping into view on the outskirts – are these actual members or foreground stars?

NGC 6781, planetary nebula, Aquila
240x. Large, faint disc – too large for 240x. A better view came at 171x with the OIII filter, giving the nebula a clumpy, punctured appearance –like a balloon that’s just started deflating.

And finally, before the sky became too bright:

M8, Lagoon Nebula, Sagittarius
171x + OII, 133x. A quick look through the neighbouring garden’s rapidly increasing foliage (I don’t think I’ll be seeing many of the treasures in Sagittarius this summer, unfortunately). The finder showed a line of bright stars embedded in nebulosity. 171x + the OIII filter showed the nebulosity intensifying to a tight core that looks like it’s been pinched and twisted into the distinctive hourglass shape. There was also a suggestion of second, narrower dark area west of the main “lagoon”. At 133x (minus filter), the open cluster NGC 6530 dominated the view, the stars arranged into an angular, unwinding spiral.

Nature note
My stargazing was accompanied by the sound of frogs moving through the garden again.

Saturday, 3 July 2021

Along the Milky Way in Cygnus and Vulpecula

7-8 June 2021, 23:50 – 01:30 (BST)


Seeing: Poor
Transparency: Poor / average

Conditions: Mild (but cooling quickly), almost no wind. Some patchy high cirrus, but nothing like the forecasted amount.


Note: The previous Saturday (5 June) I took the 7x50 binoculars out for what was supposed to be a quick look, though (as is often the case) I lost track of how long I actually spent scanning the Milky Way. The North America Nebula (NGC 7000) in Cygnus is just about visible with binoculars on a good night, though it’s hard to distinguish from the very rich star field. I’ve tried previously to see if I could spot it unmagnified by holding up one of the nebula filters to my eye, but without success. This time I experimented with holding the filter over one of the eyecups of the binoculars. The OIII filter dimmed the view too much, but the brightest parts of the nebula were clearly visible through the Ultrablock filter (even when I switched over to my right eye). As expected, I wasn't able to see the Veil Nebula or the nebulosity around Gamma Cygni using this method.



Tonight I started out with another scan along the Milky Way, with the 24mm Panoptic (50x) plus the Ultrablock filter:

The North America Nebula (NGC 7000) was huge and obvious, but indistinct in shape.

The Veil Nebula was its usual ethereal, spooky self.

The Crescent Nebula (NGC 6888) was visible as a subtle arc of light (like the Veil, I think it responds better to the OIII filter, but it does seem very sensitive to viewing conditions).

M27 (the Dumbbell Nebula) was very bright and somewhat elongated.

NGC 6823, open cluster, Vulpecula
50x + Ultrablock filter. Small nest of stars overlaying a fine mist, but hard to tell if this is the nebulosity (NGC 6820) or just unresolved starlight. Switching to 133x (no filter) revealed a tight delta-shaped formation of four stars (including one red star) surrounded by a loose spray of 20+ stars. No nebulosity that I could see at this power. Note: according to Wikipedia, NGC 6820 is a reflection nebula and both it and the cluster are embedded in a much larger, fainter emission nebula, Sh 2-86 (SA 2000 plots this larger nebula, but labels it as 6820). A possible future astrophotography target. 

NGC 6830, open cluster, Vulpecula
133x. Loose formation of stars shaped like a fold-up chair. Doesn’t really jump out from the surrounding Milky Way.

Stock 1, open cluster, Vulpecula
133x. Very large and loose collection of bright blue-white stars (and one lone red star). Shows quite well in the finder. Too large for the main fov, but one or two close doubles in the cluster.

NGC 6800, open cluster, Vulpecula
133x. Another loose, large group of moderately bright stars. Unremarkable. One for smaller, wide-field scopes. Note: this is one of those rare examples of an object that’s plotted in the PSA but not in SA 2000.

NGC 6871, open cluster, Cygnus
133x. “Split” cluster in an incredibly rich star-field. Not sure where this cluster ends and the Milky Way begins, but the core area consists of a triangle of bright stars on the north side, two bright stars on the southern side, surrounded by 8 or 9 fainter stars.

NGC 6819, open cluster, Cygnus
171x. Revisiting this cluster from an earlier session. Not substantially different at this magnification, but retains its richness. Looks a bit like a globular cluster that’s slowly being peeled in half.

Sunday, 27 June 2021

Exploring Ophiuchus

1-2 June 2021, 23:45 – 02:00 (BST)


Seeing: Poor – Very Poor
Transparency: Poor to average (varied from one part of the sky to another)

Conditions: Mild again, although it started cooling noticeably from 00:45. There was no wind to speak of for much of the session, but it picked up suddenly towards the end, becoming quite breezy. No condensation. Overall the transparency was still poor, but slightly improved compared to the previous two nights.

I had planned to revisit some planetary nebulae and globular clusters at high power, but the seeing was so bad (even after allowing plenty of time for the scope to cool down) I ended up leaving the 9mm Nagler (133x) in the focuser for the entire session. After warming up with a last look at M5 before it disappears into the summer murk, I moved east to Hercules and Lyra, where the sky seemed like it might be dark enough to track down some faint targets.

NGC 6703, galaxy, Lyra
Small, faint round haze in a rich star-field in northern Lyra. Brighter core with averted vision. Plotted in SA2000 but not the PSA.

NGC 6482, galaxy, Hercules
Condensed round haze (fairly small) with a bright, star-like nucleus. Forms an isosceles triangle with two 12th magnitude field stars. 

M4, globular cluster, Scorpius
At least I could see it tonight, but the view was far from impressive. Some stars resolved when the seeing allowed, including the distinctive central bar, but most of the time it looked mushy.

M107, globular cluster, Ophiuchus
Large and faint as globulars go. Brighter towards the core, but not particularly condensed. Grainy with averted vision, but no stars popping out (the seeing didn’t help in this regard). The cluster is surrounded by five field stars which make up a distinctive kite or cruciform shape.

M14, globular cluster, Ophiuchus
Quite large and bright, but again – not particularly condensed. Speckly with averted vision. A few stars resolved on the outskirts – most prominent of these were two on the WSW side of the cluster (part of a possible chain of four or more stars leading away from the core).

NGC 6284, globular cluster, Ophiuchus
Round fuzzball with a condensed core. No stars resolved, but quite prominent despite its low altitude (-25 degrees declination).

M19, globular cluster, Ophiuchus
Large and bright; grainy with averted vision, but poor seeing prohibited resolution of individual stars.

NGC 6287, globular cluster, Ophiuchus
Faint round blur; some brightening towards the centre. Hint of graininess with averted vision.

NGC 6369, planetary nebula, Ophiuchus
Faint round disc of light, modest in size (listed at 28 arcseconds). Seemed brighter on the western side, with a hint of annularity, but the detail was smeared out by the poor seeing. At -25 degrees this is one of the most southerly planetary nebulae I’ve looked for, so I was pleasantly surprised I was able to see it without a filter.

NGC 6517, globular cluster, Ophiuchus
Faint round haze. Bright core with averted vision; seemed slightly elongated on the north-south axis.

It was at this point that the breeze started picking up, shuffling the pages of my notebook and threatening to do the same to my sky atlas. There are two other globular clusters plotted near NGC 6517 (NGC 6539 and IC 1276), but I couldn’t see either of them – presumably because of low surface brightness. But I did have better luck with another globular cluster farther north.

NGC 6535, globular cluster, Serpens Cauda
Soft round glow residing in a rich star-field. Seemed slightly misshapen on closer inspection. Not very condensed, but about half a dozen stars popped out with averted vision, the brightest one on the southwest side. If I didn’t know better I would have thought this was a very rich open cluster rather than a globular (given that in most NGC globular clusters I’m lucky if I resolve one or two stars). I’d like to see this one again under a darker sky. A nice note on which to end the session.

Friday, 18 June 2021

3 Open Clusters and 3 Globulars

31 May 2021, 00:10 – 01:20 (BST)


Seeing: Poor
Transparency: Average – Poor

A mild night to begin with, but cooled gradually over the course of the hour. Also a little breezy. As the temperature dropped, the condensation grew, collecting on the telescope tube and softening the pages of the notebook. The absence of true astronomical darkness was also apparent, making me wonder how I managed to see so much last summer (perhaps the light pollution from the town centre is starting to return to pre-2020 levels).

I started with a look at three open clusters in western Cygnus, two of which I’ve seen before (but only in passing, judging by the brevity of my notes).

NGC 6811, open cluster, Cygnus
133x. Large mass of similarly bright stars near Delta Cygni (and within the Kepler space telescope field of view); shaped vaguely like a fat spinning top, or an arrowhead. Hard to separate from the rich Milky Way background at this magnification; would probably look better in the Ethos.

NGC 6866, open cluster, Cygnus
133x. Compact group of about two dozen bright stars arranged in winding chains, with an underlying haze of fainter members. Quite pretty.

NGC 6819, open cluster, Cygnus
133x. Another compact cluster, shaped a bit like a wishbone or a pair of pliers. Comes alive with averted vision; revealed as a rich spray of faint stars with what looks like a dark lane cutting through the centre of the cluster. The wishbone suddenly becomes a flying squirrel(!), gliding through the Milky Way. Very pretty cluster; worth revisiting at a higher magnification on a better night.

M80, globular cluster, Scorpius
133x. Grainy round glow with a bright core; averted vision appears to expand the size of the cluster. 8th or 9th magnitude field star to the north-east. At 171x the impression remains much the same: a very condensed core and a few “speckles” with averted vision. The most prominent of these speckles (and the only one I was able to hold in view for a significant amount of time) was roughly halfway between the core of M80 and the aforementioned field star.

M12 and M10, globular clusters, Ophiuchus
133x. Both clusters looked a little washed-out tonight, and even increasing the magnification to 171x didn’t make much, if any, improvement to the contrast. (I think to see them at their best you really have to stay up very late on an April night.) Of the two, M10 looked better from an aesthetic point of view, appearing rounder and more condensed. M12 appeared unruly (almost “messy”) by comparison, with 2 particularly bright stars south of the core. As noted last year, the southernmost of the two is so prominent I wonder if it might be a foreground star.

With a waning gibbous moon starting to rise in the southeast, this was always going to be a truncated session, so I rounded off with a quick look at M11, which still looked superb despite the brightening sky. See my article on Love the Night Sky for more on this magnificent cluster.

With a similar forecast for the following night I took the scope out again (31 May, 23:45 to 1 June, 01:00), but, despite the moon rising half an hour later, the sky transparency was even worse. M4 (which looked so good last year) wasn’t even visible above the background glow.

Given the unfavourable conditions, I didn’t bother taking detailed notes, but I did look at M56 in Lyra, plus M80, M12 and M10 again (at 133x). I also looked at M57 and M13 at 333x (9mm Nagler + 2.5x Powermate), but the seeing wasn’t really good enough for such a high magnification.

As usual for this time of year, the sky was alive with satellites, including two bright ones which raced through the field of view while I was looking at M10 and M57.

Friday, 11 June 2021

Galaxies in Serpens Caput (and a Nova in Cassiopeia)

13-14 May 2021, 23:30 – 00:30 (BST)


Seeing: Average / Good
Transparency: Average

An unexpectedly clear night (for an hour at least), defying every forecast I’d looked at. Cool air, no wind (at ground level), light condensation on the telescope tube after a few minutes, but fortunately the lenses and mirrors stayed clear. Clouds low in the south, moving slowly north.

Anticipating that my observing time would be limited I stuck with just one eyepiece for the session: the 13mm Ethos at 92x.

M5, globular cluster, Serpens Caput
A beautiful sight with 5 Serpentis in the same field. Once again, V84 was at least as bright if not brighter than V42. Otherwise the cluster appeared much as it did on Tuesday night.

5 Serpentis was comfortably split at 92x. The companion star seemed a little brighter tonight; perhaps the transparency was better.

NGC 5921, galaxy, Serpens Caput
Small, faint fuzzy oval next to a y-shaped (or h-shaped, depending on your field orientation) pattern of field stars. Brighter towards the centre with averted vision.

NGC 5970, galaxy, Serpens Caput
Ghostly oval glow just south of a bright field star. Gradually brighter towards the centre with averted vision. Nice yellow-blue double star to the east (identified in NSOG as Otto Struve 300).

NGC 5962, galaxy, Serpens Caput
Round hazy glow with a bright core. Star-like nucleus with averted vision – seemed slightly offset to the east.

M13, globular cluster, Hercules
The 13mm Ethos doesn’t necessarily give the “best” view of globular clusters (in terms of resolving fine detail and pulling out the fainter stars), but it often gives the most beautiful, the Great Globular in Hercules being a prime example. When you see it in such a wide field that the field stop effectively disappears from view, it’s like being out there in space with it. And there’s always something new to see if you look carefully enough. For example, tonight I noticed two lines of stars running through M13 (parallel to the two 7th magnitude stars flanking the cluster). One running straight through the centre, and the other slightly offset to the southeast, adjacent to one of the arms of the propeller feature (adding to the contrast effect). 

By now the patchy clouds advancing from the south had covered nearly half the sky, pushing me farther north.

NGC 6015, galaxy, Draco
One of the galaxies I missed the other night. Appeared as an extended lenticular haze east of a field star. Brighter towards the centre with averted vision.

With the clouds pushing me still farther north, there was just time for a quick look at Nova Cassiopeiae 2021 (aka V1405 Cas), which has brightened dramatically in recent days. (See: https://skyandtelescope.org/astronomy-news/observing-news/nova-in-cassiopeia-brightens-suddenly/ )

I didn’t have a finder chart to hand so I had to identify it by comparing the field stars on my atlas to the ones visible in the finderscope. Fortunately it stood out really well at around magnitude 5.5. The Ethos showed it in the same field as rich open cluster M52. A very nice appetiser as I wait for my elusive first supernova.

At this point it seemed like the patchy clouds might leave some clear sky behind them, but then the wind abruptly reversed direction and an even thicker bank of cloud rolled across from the north, putting an end to the session.

Wednesday, 2 June 2021

Globular Clusters in Hercules and Galaxies in Draco

11-12 May 2021, 22:45 – 01:15 (BST)


Seeing: Average
Transparency: Average

A breezy night with occasional gusts. Some high cirrus cloud early on; this blew away and the sky remained clear until about 1 AM. It had been a warm day, so the temperature was relatively mild at the start of the session, but it soon fell away and became quite chilly by the end. No condensation though.

Satellites and space junk everywhere I looked (including through the eyepiece). More planes than last year too.

At this time of year I always find myself drawn irresistibly towards globular clusters (no matter how many times I’ve seen them before) so I began the session with a tour of some of the season’s best.

M5, globular cluster, Serpens Caput
133x and 171x. As per previous observations: lovely, well resolved cluster with a bright, condensed core. Its stars seemed to have a considerable spread of magnitudes, with the most prominent member lying just southeast of the core. Another slightly less bright star is offset to the SW, forming a tight triangle with two other fainter stars. Reading up on M5 the next day I learned that both of these bright stars are variables: V84 (an RV Tauri star) and V42 (a Cepheid) respectively.

Another distinctive feature was a chain of stars curling around the NE side of the cluster, like a spiral arm. Not a great deal of difference between the two magnifications, but the stars did seem to “pop out” more at 171x. No colour to the cluster (or its individual stars) that I could perceive on this occasion.

While at 171x I also had a look at the nearby double star 5 Serpentis, comprised of a bright white primary and a dim secondary roughly NE. The secondary seemed to have a pale violet/indigo(?) hue, but it was very subtle and mostly likely caused by a contrast effect with the primary.

M13, globular cluster, Hercules
171x. Tonight M13 looked like a sprawling sea monster compared to M5. No individual stars stood out from the crowd, but there was good resolution across the face of the cluster. It took me a few minutes to “get my eye in” before I could spot the Y-shaped propeller feature, but once I did it was quite obvious. Nearby galaxy NGC 6207 (with its false nucleus) also showed well at 171x.

NGC 6229, globular cluster, Hercules
171x. Small and ghostly compared to M13. With averted vision the cluster swelled in size, and the core glowed with a soft intensity. After a few minutes of observing the cluster started to look a little mottled around the centre and grainy on its outskirts, but no stars were resolved other than a very faint star trailing to the east, of which I had only fleeting glimpses. (Most likely a foreground Milky Way star.)

M92, globular cluster, Hercules
171x. A bright, underrated globular with a very condensed core. Lots of stars resolved at 171x, but the oval shape noted previously starts to break up, although the area around the core still appears somewhat elongated. Other distinctive features include two straggly arms of stars roughly trailing to the north and south, and another tighter one folding back on itself east of the core.

NGC 6543, Cat’s Eye Nebula, Draco
171x and 133x. Another late spring/summer favourite. Impression much the same as last year: vivid, pale green ellipse – slightly misshapen. The central 11th magnitude star wavered in and out of view using direct vision, sometimes holding steady for several seconds at a time depending on the seeing. The view at 133x was similar, but the green colour was more intense.

NGC 6503, galaxy, Draco
133x. (The one that Herschel missed.) As per previous observations. Extended ellipse; not much brightening towards the centre, other than a vague impression of mottling/clumpiness.

NGC 6340, galaxy, Draco
133x. Round fuzz (fainter than 6503), roughly east of a double star. Star-like nucleus with averted vision.

NGC 6643, galaxy, Draco
133x. Faint streak of light east of and parallel to two field stars. A little brighter towards the centre with averted vision. This one looked like a ghost of NGC 6503.

While in the area I noticed a very distinctive W-shaped asterism in the finder, near 44 Draconis and later identified as Kemble 2. The eyepiece view revealed a few more stars in addition to the core five, but the best view was through the 9x50 finder.

Psi Draconis, double star, Draco
133x. One I’ve been meaning to revisit for a while (I always get distracted by the Cat’s Eye Nebula). A really lovely, bright double – at 30 arcseconds, wide enough to split (barely) in the 9x50 finder. In the main scope it appeared as a pale yellow-white primary with a pale blue-white secondary.

I couldn’t find galaxies NGC 6412 or NGC 6140 for some reason, though I suspect some high hazy cloud was starting to interfere with the transparency. With more clouds gathering low in the southwest (and a fox barking very loudly from the same direction), I decided to round off the session with another old favourite at a very high magnification.

M57, Ring Nebula, Lyra
428x (7mm DeLite + 2.5x Powermate). At this magnification the target crosses the field of view so quickly you need to get the scope ahead of it to give yourself time to have a decent look. The inner part of the ring looked a little ragged at this power, but unsurprisingly there was no sign of the central star, not even a hint of a glint. I think I’d need an equatorial platform (and near-perfect conditions) to stand even a chance of picking it out from the gauzy central region.

As the bright clouds pushed across the sky there was just time for a quick return visit to M13 at the same power. The sheer volume of stars was a little too much to take in during the short time available; at this magnification it looked less like a sea monster and more like a hanging basket brimming over with bright and unruly flowers; the entire field of view clotted with ancient starlight.