Double Stars (and Galaxies) in the Moonlight

2 December 2019, 18:15 – 20:30 GMT

Not quite as chilly as Friday – at least not to begin with, but my feet were seriously cold after two hours. Negligible wind. No clouds until 20:30, but some patches of haze from what I think were lingering vapour trails (they were visible at sunset and didn’t look like they were going anywhere fast - unlike the planes that created them).

Transparency: Slightly better than Friday but some interference from six-day old moon (improving as it sank towards the horizon). I was able to see M74 through the scope so it couldn’t have been that bad.
Seeing: Good

The session began with a long-overdue first look at the Moon through the 13mm Ethos (with the Baader ND filter) and it didn’t disappoint. Wonderful, field-filling view with crisp detail right across the lunar surface. The image rippled a little bit (because the moon was low in the sky and near the rooftops), but the field was so large I could easily switch my attention to an unaffected part of the disc without having to touch the scope. Shadows were deep and very black, and (perhaps most impressively) the Ethos controlled the light scatter better than any other eyepiece I’ve looked through. I’ll be interested to see if this observation holds up at fuller phases. Notable features included the Theophilus crater group, Posidonius and the Messier A and B crater pair. The earthshine stood out clearly against the black sky and I was even treated to a bonus occultation at 18:26 of the 7.4mag star HIP 107610 (HD 207208) in Capricornus.

With the sky still relatively bright I exchanged the Ethos for the 5mm Nagler and observed a few double stars, including Polaris, Gamma Arietis and Almach (Gamma Andromedae). Zeta Persei looked much the same as it did on Friday, but the higher magnification revealed a few more faint stars in the background.

Omicron Persei wasn’t split, but it did look elongated, with the companion roughly due east of the primary. I noticed a small cluster of stars a few arcminutes south of Omicron, corresponding with the star forming region IC 348.

NGC 404 (Mirach’s Ghost), galaxy, Andromeda
Faint, but obvious at 240x. Clear brightening towards the core, even with Mirach still in the field of view.

Uranus
Similar view as Friday – tiny little green-grey disc. Titania suspected at 133x, but not at 240x.

M77, Seyfert Galaxy, Cetus
Viewed at 133x – obvious despite moonlight. Very bright nucleus; size of galaxy swells with averted vision. Could easily be mistaken for comet by unwary observer. Bright field star to west. Holds brightness well at 240x but no real increase in detail other than an extended core region (distinct from the nucleus).

Alpha Piscium (Alrescha), double star, Pisces
Very close double (1.8” separation), but clean split at 240x. Bright companion due west. Some occasional colour fringing where the diffraction rings overlapped, but the stars themselves looked white to me.

M74, spiral galaxy, Pisces
Viewed at 133x. Very faint, but not what I would class as difficult (at least compared to some of the Caldwell objects). Given the moonlight and the condensation I was surprised I could see it at all. Brighter towards the core with averted vision. With prolonged observation there almost seemed to be an impression of spiral structure, but I think this was an illusion caused by the 3 field stars east of the core and another one to the west.

At this point a combination of cloud, condensation and cold drove me back indoors.

Perseus – Taurus Border

29 November 2019, 18:30 – 20:30 GMT

The first clear night in over a month(!), although there were some clouds passing over during the evening (moving from west to east to begin with; direction changing to north to south by the end).
A cold evening, temperature dropping steadily.

Transparency: average to poor
Seeing: very good, extremely steady once the scope had cooled down

Observations at 92x (Ethos 13mm) unless otherwise stated.

Zeta Persei, double? star, Perseus
Lovely multiple star system, labelled as Atik in the PSA (although other sources attribute this name to nearby Omicron Persei). Bright blue-white primary with close faint companion to the south and a fainter one further west. Two more stars of equal brightness further south (probably not physically associated with the main grouping).

Uranus
Distinct grey-green disc holding steady even at 333x (9mm Nagler + 2.5x Powermate). One moon suspected with averted vision to north; still present when I dropped down to 240x (5mm Nagler), although it was constantly flitting in and out of view, making it hard to be sure. A look at the S&T app later on confirmed there was a moon in that location and that I had most likely seen Titania.

NGC 1579, emission/reflection nebula, Perseus
Very faint, extended patch of light near field star. (Poor transparency made it tough to find, needed careful star-hopping to be sure I was looking in the right place.) Seemed mottled with averted vision. No improvement with OIII filter (if anything it made it even fainter).

NGC 1514, Crystal Ball Nebula, Taurus
Observation with the Ethos 13mm and Astronomik OIII filter. Delicate cocoon of light surrounding bright central star; quite large as planetary nebulae go. Flanked by two field stars. Seemed to have two or three dark bands cutting across the nebula. Somewhat faint without the filter. Not the best view I’ve had of it, but still a lovely sight.

By now the cloud cover was increasing overhead, so I spent the rest of the session looking for NGC 253 (the Silver Coin Galaxy) way down south in Sculptor. Unsurprisingly, that part of the sky was too bright for me to say I saw it with any degree of confidence. I think on an exceptional night (or an early morning in late August or September perhaps) I might be able to spot it, but any galaxy south of -15 degrees is always going to be a challenge from my location.

Star Clusters in Cassiopeia

22 October 2019, 20:00 – 21:45 BST

Cool evening, getting colder as the night progressed. No wind.
Transparency: poor to average (improved slightly towards the end of the session)
Seeing: started out good, but suddenly deteriorated from about 21:15 onwards (opposite direction to the transparency)

NGC 7789, open cluster, Cassiopeia
Stumbled upon it while sweeping. Very pretty in the Ethos (if a little subdued by the poor transparency). Looked like a spiral galaxy without a core.

NGC 381, open cluster, Cassiopeia
Faint, boxy little spray of stars with bright tail of stars to north.

NGC 637, open cluster, Cassiopeia
Small, condensed haze – resolves with averted vision. Four bright stars at corners (double on eastern corner). Brighter field stars to west.

NGC 225, open cluster, Cassiopeia
Loose, sparse group comprised of equally bright stars. Online images show a reflection nebula (vdB 4) associated with this cluster (not sure if it's bright enough to see visually - even on a good night). NGC 225 is also nicknamed the “sailboat cluster”; I think I’d have to look at it again to see that, but I did get a sense of some kind of shape: the stars were arranged in angled lines, like a folded piece of cardboard seen from the side. I guess the “cardboard cluster” doesn’t have quite the same ring about it, but the sailboat shape didn’t jump out at me, certainly not as much as it does in NGC 1502.

Stock 24, open cluster, Cassiopeia
Spotted while sweeping area around NGC 225. Tight little fuzz with double star at eastern apex.

NGC 129, open cluster, Cassiopeia
Narrow “v” formation of stars pointing at bright star to south. Rich cluster.

NGC 136, open cluster, Cassiopeia
Small starfish or whirligig-shaped fuzz of stars. Resolved with averted vision.

Comet C/2018 N2 (ASASSN)
Small, very faint patch of light close to prominent asterism in Andromeda. Would be easy to overlook if I didn’t have the finder chart. Prolonged averted vision showed a condensed core and the suggestion of an extended coma.

At this point heavy condensation was setting in – even affecting the Ethos eyepiece – so I switched to the Nagler 9mm (133x) for the remainder of the session. I also noticed a featureless band of cloud rising slowly from the southeast.

NGC 1245, open cluster, Perseus
Rich spray of faint stars.

NGC 1023, galaxy, Perseus
Bright (relatively speaking) little galaxy, aligned east-west. Condensed core. Faint extension to east?

M76, planetary nebula, Perseus
Faintly visible unfiltered, but the poor transparency meant that I needed the OIII filter to do it any kind of justice. The familiar bi-lobed structure was apparent, with the south-western lobe clearly brighter – particularly with averted vision. On this viewing it was vaguely reminiscent of the famous Hubble image of the Homunculus (Eta Carinae).

Other notes
One tadpole in the pond (!); other frogs nowhere to be seen.
Also, the characteristic “tseep” of a migrating redwing.

Cepheus and Beyond

2 October 2019, 21:30 – 00:15 BST

Cold, breezy; patchy cloud moving from west.

NGC 7510, open cluster, Cepheus
Viewed at 92x (Ethos 13mm) – rich, condensed little cluster. Brightest stars form outline of fang or dagger, with fainter spray of stars alongside. This cluster resides in a particularly rich part of the Milky Way. While sweeping the area I stumbled across a small, crescent-shaped cluster roughly southeast of 7510, later confirmed as Markarian 50. It stood out despite the richness of the surrounding star-fields, so I’m surprised it didn’t make the NGC catalogue.

NGC 7762, open cluster, Cepheus
Faint, misty patch of stars north of bright star, shaped like an hourglass or bow tie.

Delta Cephei
Beautiful wide double. White primary, blue secondary to south. The prototype Cepheid variable.

NGC 7380, open cluster, Cepheus
Triangular cluster of stars, no obvious nebulosity.

Trumpler 37, open cluster, Cepheus
Cluster surrounded by IC 1396 emission nebula (not visible). Large sprawling star field; prominent triple star near centre, double star nearby (roughly between triple star and Mu Cephei).

NGC 752, open cluster, Andromeda
Large, rich cluster with lots of bright stars. Fills field of view of Ethos.

M33, Triangulum Galaxy
Well framed in the Ethos, and quite a good view despite average transparency. Could almost describe it as “bright”, particularly the core region. NGC 604 was obvious even at 92x. Spiral arms seemed mottled with averted vision. Suggestion of dark patches immediately S and SE of nucleus.

NGC 1528, open cluster, Perseus
Very rich cluster, about 0.5 degree across. Stars arranged in loose arms spiralling out from centre.

NGC 1513, open cluster, Perseus 
Smaller, fainter cluster with winding line of stars in reverse s-shape or shape of number “2”.

I then crossed over into Camelopardalis to look for galaxy IC 342, but I couldn’t see it even though I was pretty sure I was looking in the right place. This didn’t come as a complete surprise. I think with higher elevation and better transparency I should at least be able to spot it. Failing that, it’s in a good place for imaging.

NGC 7331, spiral galaxy, Pegasus
I probably wasted too much time trying to find IC 342, so by the time I got to this galaxy it had already slipped past the meridian. At 240x the core region showed up well, with a sharp cut-off corresponding to the dust lane. Even with the close-up finder chart I couldn’t be sure of seeing the neighbouring galaxies (the “fleas”).

Stephan’s Quintet, galaxy grouping in Pegasus
Using the finder chart I carefully navigated SW from 7331 to the correct area (still at 240x). With averted vision I could just about see 2 small galaxies right on the threshold of visibility, apparently corresponding to NGC 7318 A/B and NGC 7320. Very difficult – I need to try this again on a better night to be sure of what I was seeing.

Uranus 
Tough to find without any naked-eye stars nearby, but eventually tracked it down in the Ethos. Presented as a bright little green-grey disc, clearly non-stellar. Well resolved at 240x and 333x, and when the seeing occasionally “snapped” into place it looked quite eerie: a tiny little globe suspended in the depths of space. No additional detail seen other than perhaps some limb-darkening.

M45, Pleiades, Taurus
Attractive sight at 92x, but obviously still too large for the field of view. The reflection nebula is especially prominent at this magnification – it almost looks like condensation has fogged up the optics. Nebulosity brightest around Merope, but couldn’t see any structure to it.

Other notes
1 slow meteor some time around midnight, travelling from the zenith towards the western horizon. A possible early Orionid?