Falling Stars and Grazing Planets

A short update to round off the 2020 log. The weather during December was mostly unsuitable for observing, with a couple of notable exceptions.

The Geminid meteor shower put on a really fine display on the night of Saturday 12 December to Sunday 13 December, despite this being a good 24 hours before the shower peaked. (The actual night of the peak was clouded out.) I went outside a little before midnight and lasted about 90 minutes before the cold drove me back indoors, seeing at least 30 meteors (including one sporadic) during that time. I didn’t observe any fireballs, but I did notice a strange effect during the first half-hour whereby the meteors appeared to arrive in pairs. After a gap of two or three minutes, one would flash through Orion or Taurus, quickly followed by another one on almost the same path. Then another gap of two or three minutes before the next pair. My attempts to photograph the Geminids were less successful; they seemed to know exactly when I had the shutter open, and the one meteor I did “catch” in the act wasn’t bright enough to register on the sensor.

The day of the Great Conjunction between Jupiter and Saturn was also clouded out, but on the evening before closest approach (Sunday 20 December) there was a period between about 16:00 and 16:30 where the clouds cleared briefly in the southwest. Viewing conditions were pretty terrible, but I was able to see both planets (plus several moons and an interloper star) in the same field of view at several magnifications all the way up to 240x (i.e. within a third of a degree). Sadly both planets slipped behind a tree just as I was about to start an imaging run (using the ZWO ASI120MM at 1,000 mm), but I don’t think the results would have been that great anyway. Seeing the conjunction in the scope was good enough. (The image above is a quick consolation shot taken with the TV60, showing the relative size/brightness of the two planets.)


Nature note:
With the dusk gathering, and while I was scanning the gaps in the clouds with my binoculars, one of the local sparrowhawks floated over the garden, heading towards the local park (where I presume it has a roost).

A Gap in the Clouds

8 December 2020, 17:30 – 19:00

Conditions: Cold, clear, still (for once). Sky crawling with satellites. Very damp and muddy from recent rain. Smell of smoke in the air.

Seeing: All over the place – mostly poor but occasionally excellent

Transparency: Average / poor


The run of bad weather continues; the strong winds blow in a new batch of clouds almost as soon as the old ones have cleared, giving me barely enough time to observe with binoculars, let alone a telescope. Tonight’s 90-minute window felt like a luxury by comparison.


NGC 189, open cluster, Cassiopeia

133x. A pick-up from a previous session. (This is the first entry in O’Meara’s Hidden Treasures, but it’s not plotted in either the PSA or SA 2000.) Faint spray of stars in the rough shape of a Christmas star (appropriate for the time of year), though if you include the straight chain of stars trailing to the west it start to look more like a magic wand. Smaller than the nearby cluster NGC 225; would probably look better in a darker sky.

NGC 7293, Helix Nebula, Aquarius

50x + OIII filter. Very faint and ghostly tonight, even with the filter. Double-ring structure just about visible with some effort. Not a patch on last year’s viewings. It was at this point I had to concede that the low surface brightness objects on my target list (NGC 253, NGC 246, etc.) would have to wait for another night.

Mars: At 240x (plus the BCB filter) Mars was small and distinctly gibbous, but Syrtis Major was clearly visible. Increasing the magnification to 333x (same filter) made it easier to define the somewhat ragged outline of Syrtis Major, but the diminished SPC was hard to see. Looked as if there was a bright cloud extending from the Hellas region to the morning limb.


I also attempted (very optimistically) to track down IC 289 (a PN in Cassiopeia) and NGC 1275 (a galaxy in Perseus which has eluded me on several occasions) but the transparency wasn’t improving – if anything it was getting worse. Even M77 (one of the brighter Messier galaxies) was disappointingly faint. With the clouds gathering and the condensation increasing, I rounded off the session by popping the Ethos in the focuser and taking a quick look at – what else? – the magnificent Double Cluster.

Nature Note:

A fox casually trotting through the garden during the daytime, causing some anxiety among the local gulls.

Mars and the Moon

28 November 2020, 19:00 – 20:00

Conditions: Quite cold (as you’d expect for the time of the year). Light film of condensation on the telescope.

Seeing: Good / excellent

Transparency: N/A


My run of good luck with the weather had to come to an end eventually, and so it proved with the months of October and November being pretty much a wash-out as far as deep-sky observing was concerned. The few windows of clear sky I did get were devoted to observing and imaging Mars, and fortunately I able to get just enough data to assemble a crude albedo map.

Tonight however was all about observing, with the seeing remaining unusually steady for once.


Mars: Good views at all magnifications from 171x up to 428x. Gibbous phase starting to become more obvious now. SPC tiny, but still bright. The albedo features were of much lower contrast than previous viewings, even with the Baader CB filter in place; but I was looking at the Tharsis / Solis Lacus region – the site of a recent major dust storm. There was a large – and prominent – bright yellowish haze near the limb (over Argyre?), plus a less obvious fainter haze further north.


The Moon: Nearly full, very bright. Viewed at 171x and 428x (with the Baader ND filter). As usual, the amount of detail on view was almost overwhelming, particularly at the higher magnification, but a few observations worthy of mention include:

At least three Plato craterlets “twinkling” in and out of view when the seeing allowed.

Mons Rümker region near the terminator, just a few days before the Chang’e 5 mission landed to collect samples.

Rimae Sirsalis showing particularly well (at 428x it looked more like a canyon than a rille).

Mare Humboldtianum visible close to the northern limb (the best view I’ve had of this elusive libration feature).


Nature note:
Tonight's soundtrack: The gentle “tseep” of winter thrushes passing overhead, and the not so gentle clattering of a fox jumping over the fence into the garden. Its eyes lit up when I shone the torch at it, but it didn’t leave until I cleared my throat.

Open Clusters in Cassiopeia

21 – 22 September 2020, 21:45 – 01:00

Conditions: Mild to begin with, but soon turning chilly. No wind. Condensation increasing over the course of the session.

Seeing: Average
Transparency: Poor

Again, with a couple of hours to spare before Mars reached a usable altitude, and the transparency no better than the previous night, I filled the time by touring some of Cassiopeia’s many open clusters.


M52, open cluster, Cassiopeia

133x. Rich, vaguely delta-shaped cluster with a bright star on the eastern corner.

Also of note: between 21:50 and 21:55 BST, while looking at this cluster I spotted an unusually slow-moving satellite of about 8th or 9th magnitude, winking into view every three seconds. It was travelling west to east, and passed just south of M52, taking about a minute to cross the field of view. Later, when I was back indoors, I used a quick back-of-the-envelope calculation to estimate it was on a 12-hour orbit. This puts it squarely in the Medium Earth Orbit (MEO) range; the first time (as far as I can remember) that I’ve observed one of these satellites.

NGC 7790, open cluster, Cassiopeia

133x. Compact cluster of about 20 faint stars with an underlying unresolved haze. Quite a nice view. In the same field of view to the NW was an even smaller triangular cluster of about 6 stars plus an unresolved haze – what I assume to be NGC 7788.

I looked (rather optimistically, it has to be said) for the galaxy IC 10, but couldn’t see it. However I did spot a very close double star nearby, just to the north.

NGC 129, open cluster, Cassiopeia

133x. Large, loose cluster with a mixture of bright and faint stars. No underlying haze that I could see.

NGC 225, open cluster, Cassiopeia

133x. Large cluster of about 20 to 30 similarly bright stars.

King 14, open cluster, Cassiopeia

133x. Faint stars plus haze in a rich star field, just NW of 15 (Kappa) Cas. It's a nice field in the Nagler, but the cluster doesn’t really jump out.

NGC 7789, open cluster, Cassiopeia

133x. Not so well resolved tonight as on previous occasions, but still wonderfully rich. Looked like a hazy “swarm” of stars.

NGC 559 (Caldwell 8), open cluster, Cassiopeia

133x. Small, hazy, rectangular cluster with bright stars on each corner; the brightest stars on the eastern side formed a triangle. More stars popped out with averted vision.

NGC 663 (Caldwell 10), open cluster, Cassiopeia

133x. Rich, large, lots of bright stars, plus that distinctive horseshoe shape. Always impressive.

NGC 659, open cluster, Cassiopeia

133x. Small, arrowhead-shaped cluster near NGC 663. Fainter stars of similar brightness plus two bright ones (are these foreground stars?).

IC 1747, planetary nebula, Cassiopeia

I added the 2.5x Powermate to boost the magnification to 333x, but before heading to Mars, I paid a return visit to this little planetary nebula. There wasn’t much to see other than a faint little disc – but at least it was an obvious disc as opposed to a bloated star. With averted vision it seemed slightly brighter on the western side, but this feature (if real) was very subtle.

Mars: 333x. The seeing wasn’t quite as good tonight as it had been over the weekend, but the Sinus Sabaeus region was still showing well, with just a hint of Syrtis Major on the evening limb.

Nebulae in Cepheus and Cassiopeia

20 – 21 September 2020, 21:45 – 01:00

Conditions: Chilly, breezy. Light condensation appearing as the temperature dropped.

Seeing: Good
Transparency: Poor

With Mars now larger than the magic 20-arcsecond threshold, deep-sky observing (and indeed deep-sky astrophotography) will be playing second fiddle to the red planet for the next couple of months. (The autumn constellations will be back next year; Mars won’t be this good again until 2030-something.) That said, the nights are getting longer, so I was able to get a couple of hours of observing before Mars took centre stage.

I started with a short wander around Cygnus at 133x, during which I stumbled across 27 Cyg – a close double in a dark nebula (B146). The transparency in this part of the sky was very poor (the Crescent Nebula was disappointing – even with the filter it was barely visible ), so I relocated to Cepheus.


NGC 7538, emission nebula, Cepheus

133x + OIII filter. Initial impression was of an amorphous patch of light, like a puff of smoke, surrounding a pair of 11th magnitude stars. Averted vision showed some detail in the form of mottling, including what looked like a dark lane or rift on the eastern side of the nebula. Not a showpiece object by any means, but not bad given the middling conditions. Switching up to 171x plus the Ultrablock filter gave much the same view, but larger and fainter – although the two central stars were easier to see. The nebula was just barely visible without the filters.

IC 1470, emission nebula, Cepheus

133x + OIII filter. I never know quite what to expect when tracking down obscure IC-designated nebulae. Sometimes they’re surprisingly bright; other times they’re all but invisible. However this object was fairly easy to spot as a quite small, fuzzy round patch of light. The core appeared stellar with averted vision. Increasing the magnification to 171x (no filter) showed a star embedded in a wide, fan-shaped nebula, a bit like a comet. (It reminded me of Hubble’s Variable Nebula, NGC 2261.) The Ultrablock filter offered a little improvement: the central star became harder to see, while the nebula itself seemed more triangular and harder-edged.

A quick look at the eye-catching clusters NGC 7510 and Mrk 50 (see last year's notes on these) and then onto another nebula.

NGC 7635, Bubble Nebula (Caldwell 11), Cassiopeia

171x + Ultrablock gave the best view, though it wasn’t nearly as good as my previous look at this object (perhaps the Ethos plus the OIII filter would be a better combination). Bright star associated with a nebula of indistinct shape; with averted vision it looked a little bit like one half of a Yin-Yang symbol.

NGC 40, “Bow-Tie Nebula” (Caldwell 2), planetary nebula, Cepheus

171x + Ultrablock filter. While reading up on this nebula (after my observation on 16 September), I found some reports claiming it responds better to narrowband filters than OIII. Now I’ve tried both I do think the Ultrablock filter gives a slightly better view than the OIII, but this nebula is bright enough that it doesn’t really need it. The two arcs were a little easier to see (with averted vision), but of course it helps when you already know where they are.


Mars: The combination of the 9mm Nagler and the 2.5x Powermate (giving a magnification of 333x) seemed to hit the sweet spot tonight, giving me my finest view yet. The SPC was a brilliant little oval and the Sinus Meridiani (home of the Mars Opportunity rover) and Sinus Sabaeus regions were showing particularly well. I could also see a blue haze over the north polar region and brighter patches along the morning limb. I swapped the eyepiece for a camera and captured some videos, resulting in the image below: