A Moonshadow, and some deep-sky treats.

Had a good session on Saturday night with the 10” reflector on a dobsonian mount. One of the highlights was the unexpected Jovian shadow transit of Ganymede. From around 1am to 2am I watched the shadow of the moon travel across the disc from left to right, (left to right in eyepiece). I saw later the transit was discussed in the July Sky at Night magazine, but I missed reading it, so it was a nice surprise. There are more shadow transits later this month.

Deep sky stuff; I started off in Sagittarius with one of my favourites that never gets very high in the UK, M8 the Lagoon Nebula, which also has open cluster NGC 6530 in the same field of view. It took a few minutes for the nebulosity to ‘grow’, but I managed to make a sketch. This is one of the most distinctive deep sky objects.

A failure tonight was the globular cluster M4 in Scorpius. I’ve never seen it, and still haven’t, though I suspect I wasn’t looking in the right place. After checking my Glyn Jones Cambridge Messier book, I was looking too far to the left I think. I’m pretty sure the 10” mirror should have picked up this 6.4 mag cluster, despite its low altitude.

Back to Sagittarius, and near M8 are globular clusters M22 and M28, which were easily found, and both markedly different in size and contrast. M22 is smaller in the eyepiece, bright and compact, and M28 much larger and ghostly.

With Capricorn so high, I was able to make my first observation notes on Messier objects M72 and M73. M72 is a loose, quite open globular cluster, 62,000 LY away. Easy to find by star-hopping from Capricorn (though M72 and M73 are technically in Aquarius). M73 is a four star asterism, and a quirk of the Messier list, (like M40 in Ursa Major).

Because I was looking mostly towards the south, it was an evening for bright globular clusters. M13 (Hercules), M5 (Aquarius) , all really bright, contrasty and resolvable.

M11 – The Wild Duck cluster is one of the Summer’s jewels. When doing a 10×50 Opticrom bino tour of the Scutum area I noticed a bright patch below it, which I found was the cluster M26. Not often visited by me, and a little underwhelming in the scope. A better binocular object?

Galaxies are a challenge in nautical darkness, but I managed observations of M101 (the Pinwheel) and M94 in Canes Venatici, which was surprisingly bright.

Around 2.45 the Milky Way disappeared, almost within minutes! The Sun was making its way towards the horizon and I just managed some binocular observations of M31 and the rising Pleiades open cluster (M45) in an adjoining field, rising in the east.

Edit – I forgot the planetary nebulas M27 and M57. The latter (Dumbell) being very bright indeed.

And, Saturn, of course.

Between the mist and clouds

Observation report, Sat 10th July, Shropshire. Nr Craven Arms.
Spent 10.30pm-2.45am approx observing with the 10” reflector on its dobsonian mount, and my Opticrom 10×50 bins. The sky was not completely clear at all, and quite misty from 1am onwards. A true ‘hit and miss’ session. But there were a few clear spells, and at times the sky was so clear as to see the Milky Way. Particularly in Cygnus, and the Scutum Star Cloud.
I started off as it got dusk and found M13 (the great cluster in Hercules) and M57 (Ring Nebula in Lyra). M13 being very bright already at 5.5mag (O’Meara), and the Ring Nebula ghostly faint at 8.7.
I started on double stars before it clouded over for approx. 1hr, at 11pm. Alberio was lovely, and the stars around 02 Cygni (not a double, actually), which showed the colours of blue, gold and silver in three stars in the same field of view. One of my favourite new telescope sights.
As it got truly dark (albeit nautical darkness), around midnight, the sky cleared in the east and Cygnus, Lyra and Delphinus (etc) were seen. I looked at the Coathanger asterism (Brochii’s cluster) through 10×50 bins, and easily found M71 in the 10” mirror, in Sagitta. This cluster went unfound by me for years, yet recently I’ve been able to view it. Tonight though, perhaps due to the slight mist in the air, it looked more nebulous than mottled with stars.
Ursa Major we heading towards the west, and in a bright patch of sky where the sun wasn’t far below the horizon. I still managed to locate M51 and its companion (NGC 5195). I had hoped to sketch this, but its western aspect meant its spiral arms were lost in the bright, almost twilight sky. I tried for Bode’s galaxy and its companion, but didn’t see it, and didn’t spend much time looking.
I did find galaxy M101, (the ‘Pinwheel’), at mag 7.9 in Ursa Major. And this was a treat after so many years unable to find it (why?). Very large in the 32mm eyepiece, and pretty. Again, the summer western sky glow prohibited fainter detail. I can’t wait to re-visit this under inky black winter skies.
With Cygnus clear of clouds, I looked at the open cluster M29. The ‘anvil’ as I like to think of it. Its brightest stars were recognisable but I saw nothing like the 80 plus mentioned in O’Meara’s book.
M13 was stunningly bright as I re-visited it in the dark patch of sky to the south. What a treat in the 10” mirror! M92 also looked superb. I didn’t find this on my previous session, as I misjudged the memorised ‘triangle’ shape from the top of Hercules.
The faint electric light from the toilet block in the adjoining field was throwing out misty ‘streamers’ through the trees, so I knew there was much mist in the air, and my red torch was showing light-sabre like paths of swirling mist.
But even so, it was well worth scanning Perseus, now rising in the north.
I viewed the Perseus double-cluster through the 32mm eyepiece, and the Pegasus sat cloud through the 10×50 bins. Superb!
Between 1am and 2am the Square of Pegasus rose, and I was able to see M31 with the naked eye when the troublesome clouds allowed. Through the 10” mirror, with the 32mm eyepiece the galaxy appeared bright and well defined I thought. M32 was also easily observed (as a ‘fuzzy star) in the same field of view, technically making it the 5th galaxy of the evening.
M33 was lost to the skyglow in bins. In a few months it’ll become apparent from my dark sky site.
Taking advantage of another gap in the clouds, I spent some time viewing M11 – the Wild Duck cluster. Just to the right of the – now very naked eye visible – Scutum Star Cloud.
I first looked at M11 through the 32mm eyepiece, and the distinctly shaped, easily defined open cluster looked fantastic. More stars were resolved in the 9mm eyepiece, although the usual lack of contrast at high power meant the 32mm gave me a more pleasing view.
I wasn’t expecting to do any planetary observing , but through thin cloud in the east, the bright ‘star’ I initially thought might be the ISS at first glance, turned out to be Jupiter.
It was very misty by this time, and very little detail was seen on the disc. Just the Southern Equatorial Belt,. Three moons were visible, with Calllisto seeming the brightest. Ganymede may have been behind the planet according to Sky at Night mag July 20211 P49.
Saturn, (to the right of Jupiter), appeared noticeably different to observations in recent years, as the rings are now closing and the disc of the planet is now visible above and below the rings. I didn’t spend much time on Saturn because of the mist and low elevation. No ring-gap or planetary markings were seen.
Jupiter did, however, look very ‘large’ in the 32mm eyepiece, and the edges of the flattened disc looked pleasingly crisp and well defined.
Other objects; Mizar and Alcor, (the Horse and Rider), seen easily as a triple star system. And cor Caroli easy to split, a bright gold star with a similarly coloured fainter companion.
Around 2.45 it grew lighter, mistier and it was time to put the dob back in its telescope tent. Not a bad session seeing as the evening had only earned a 60% cloud cover rating earlier in the day.