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.