“Since when can weathermen predict the weather, let alone the future?” I found my mind dwelling on this exchange between Marty Mcfly and Dr Emmett Brown as they prepare the time-travelling Delorian while I looked up at a wonderfully clear, star filled Saturday evening sky at the AstroCamp in Cwmdu in the Brecon Beacons.
The forecasts in the week leading up to the Spring AstroCamp were not indicating much prospect of any stargazing over the long weekend, but perhaps the opportunity for some swimming lessons. A couple of astronomers cancelled their pitches and few others decided not to bring any kit with them. I certainly scaled back my observing arsenal to one of my smaller LZOS triplets as the effort to transport something larger did not seem likely to be rewarded. Early-arriving attendees were battered by Storm Hannah which delivered 80mph gusts to parts of Wales on Friday. Driving on to campsite, I expected to find a scene of devastation, of broken tent poles and upended scopes, but found an eerily quiet observing field, some patches of blue sky overhead, and whispers that the first evening would benefit from cloudless-skies. The ClearSkies App, a preferred forecasting tool of many amateur astronomers, certainly indicated some good potential. If anything, it underplayed the skies on that first night.
I often find myself on the observing field at AstroCamp somewhat earlier than most of the astronomers, who are probably in the Farmers Arms having a bite to eat. Perhaps it is the anticipation of clear skies that gets the better of me. It did mean I had the alignment tree (very pleased Hannah did not uproot it) all to myself while I set my 115mm f/7 APM LZOS triplet refractor on a simple manual Alt-Az mount. Keeping equipment to a minimum I only brought three eyepieces with me, the TeleVue 35mm Panoptic (23x / 2.8o), a 14mm TeleVue Delos (58x / 1.2o), and the TeleVue 3-6mm Nagler Zoom (134x-268x / 0.36o-0.19o).
As darkness began to fall, the first star I noticed was Arcturus, blazing lustrously in the east, before some of the brighter, familiar stars of the winter constellations emerged in the twilight sky of the west including Procyon and Capella. Though only subtending a 4.2” disc, I could not resist a quick peak at Mars in Taurus in a still bright sky. Sadly, a boiling atmosphere dashed any hopes of glimpsing surface detail on red planet. Before removing the zoom eyepiece, I swept up to Castor in Gemini for quick look at the famous double star. Though Castor bears the Bayer designation of Alpha, Castor is in fact the second brightest star in Gemini behind Pollux, indicating one of the two have changed luminosity since Bayer named them four centuries ago. The two components were easily separated using the 6mm setting, both showing bright white discs which is quite a contrast to Pollux, the other twin which is a deep orange.
Then it was time to show a small amount of patience. With astronomic dusk not until 10:40pm, a good 30 minutes needed to be killed before true darkness arrived and all the DSOs on my hit list would start showing their best. That didn’t stop my sweeping around the sky taking in some brighter objects, but I did not stay with any for more than a few seconds.
First up on the hit list was the second closest Messier object, M44, known as the Beehive Cluster. Though there are no bright stars nearby to act as an easy hoping point, under skies this dark, M44 was actually quite obvious to the naked eye making it easy to locate in the finder. Using the 35mm, the boxy cluster was nicely framed in the central half of the field. The view was spectacular with hundreds of stars appearing to swarm and radiate around the central “cube” of stars which I always see as the hive.
Sticking with open clusters, I switched eyepieces to the 14mm Delos and headed west to Auriga to take in the three fabulous Messier clusters before they before were lost behind the hill. Using Elnath as a starting point, I placed the star halfway to the edge of the finder field, and then panned up 7o straight to M37. Though the brightest of the three OCs in Auriga, it was somehow missed by Le Gentil who discovered M36 and M38 in 1749, and so was an actual discovery of the famous comet hunter. I was immediately struck by the Topaz jewel near the centre of the cluster, surrounded by an oval shaped arrangement of stars, almost sprinkled like diamond dust around the vibrant central stone. A rather prominent dark lane to one side which bisected the cluster from north to south also caught the eye.
Placing M37 just outside the field of 14mm, I then panned several degrees west and hit the Pinwheel Cluster (M36). Appearing about 2/3 the size of M37, a dozen or so stars shone brightly against the feeble glow of the many more fainter stars that make up the 60 or so members of this open cluster. While an impressive sight, it does not match the majesty of many OCs including the Pleiades. However, at more than 4,000 light years distant, it is 10x further away than M45, and would easily outshine the Seven Sisters were the location the same with more than three times the absolute luminosity of 8,000 suns. A short hop away was my final target in Auriga, M38. Similar in size to M37, but less impressive due to lower brightness, an elongated cross asterism was an obvious feature at the centre of the cluster. Using an undriven mount, as the cluster slowly drifted towards the field stop, small open cluster NGC1907 came into view. It took on the appearance of a smoky cloud with some granulation, hinting at the 30 or so stars that make up this cluster.
My tour of open clusters was not quite done yet. Next up was one of my favourite DSOs found anywhere in the night sky. NGC884 and NGC869 are better known as The Double Cluster (Caldwell 14). The 1-degree object was perfectly framed in the 14mm. Located in Perseus (pub quiz question on the Sunday in the Spiral Arms), but easily found by following a straight line from Navi and Ruchbah in neighbouring Cassiopeia, the cluster is visible to the naked eye under dark skies as a condensation in the Milky Way. The field comes alive the moment the eyepiece pans across this wonderful DSO. My eye is always immediately drawn to a horseshoe of tiny stars that wrap tightly around a ruby coloured star in the heart of NGC884. However, there are numerous subtle hues splashed across the two clusters with yellow topaz, blue sapphires, rubies and white diamonds all vying for attention. I do not think it an exaggeration to write that this is one of the most spectacular one-degree fields to be found, and it is even more so when considering that a thick cloud of interstellar dust sits along our line of sight, robbing us of the true splendour of the twin clusters. Without this cloud, they would appear four times brighter.
Heading back to Ruchbah, my next target, was as it turned out, also a Sunday pub picture quiz question. A couple of degrees south lies NGC457 (C13), the Owl Cluster, or as I call it, the E.T Cluster, such is its resemblance to one of Spielberg’s famous characters. The two blazingly bright eyes are the immediate draw, but very quickly the entire head, arms and body of the alien who wants to go home come into view. The two eyes, a 5th and 7th magnitude stars may not actually be cluster members, but it certainly does not diminish the sight of a very attractive open cluster. I decided to spend a bit of time just sweeping around the ancient queen given how busy that region of the sky is with open clusters before moving on.
Having had my fill of some of the youngest DSOs in the heavens, I decided to move on to the some of the oldest structures in the universe, globular clusters. First up was M3 in Canes Venatici. At magnitude +6.2, the cluster is just about visible to the naked eye from a dark site, though I was having trouble spotting it. However, it was very obvious in the finder as I swept west from Rho Bootis. Staying with the 14mm, the cluster had a densely bright core, approximately 2’ in diameter, with surrounding grainy mottling across a symmetrical face, which was peppered with dozens of resolved stars, before uniformly fading into interstellar space.
Easily a match for the Great Globular in Hercules, M5 in Serpens was my next target. Easy to find, by slewing west from Unukalhai (Alpha Sepentis), I switched to the 6mm setting of my zoom eyepiece. The central half of the field was awash with stars. The core was incredibly bright, giving the illusion that it was collapsing on itself, igniting more and more stars in the process. Away from the central core, several arms of stars seemed to spiral away almost like a face on galaxy. After spending some time with this wonderful globular, I moved on to the handler of the serpent, Ophiuchus, and took in several more Messier GCs including M10 and M12.
Next up was the ancient Greek hero of many labours, Hercules, which harbours two fine GCs, in M13 and M92. My first quarry was the great globular M13, which is easily located in the keystone asterism at the centre of the constellation. The dark propeller feature was obvious and cluster was resolving across the face with some brightening towards the core. Having recently viewed a rival for best GC of the northern hemisphere in M5, I did find myself asking which I preferred? While a close-run contest, M5 takes the title in my opinion.
In almost any other location in the sky, M92 would be more highly regarded, but it forever sits in the shadow of its brother in the keystone. Only a few thousand light years distance from earth separates these two clusters, so the perceived difference in size and brightness is a true reflection of their intrinsic qualities. While 1/3 smaller in apparent diameter, the cluster appeared far more compact to me thanks to an eye-drawing central core, which was surrounded by an asymmetrical halo which showed plenty of mottling and granulation with a number of brighter cluster members resolved across the face.
After indulging a desire for some globular clusters, I decided it was time to leave the confines of the Milky Way, engage the warp drive and head out into intergalactic space and take in some galaxies. The first target was a group of three galaxies that we have nicknamed the Leo Doublet from central London, home of the Baker Street Irregular Astronomers due to the stubbornness of one member to reveal itself under the light polluted skies of Regent’s Park. Of course, I am referring to the Leo Triplet of M65, M66 and NGC3628. All three galaxies were nicely framed in the field of the 14mm. M65 showed some strong elongation with a rhombus shaped core. Details in M66 proved slightly more elusive, though it did appear to have a bright, almost stellar like core. The bane of BSIA members in London, NGC3628 was more stubborn still, though with averted vision and patience, I was able to make out a thick dust lane which bisects the length of the galaxy. Taking the power higher using the zoom eyepiece, made this galaxy harder and harder to see.
Perhaps now one of the most famous galaxies in the heavens thanks to the recent spectacular image of the blackhole by the Event Horizon Telescope, M87 had to be next on my hit list. An easy sweep west from Vindemiatrix (Epsilon Virginis) brought the monster elliptical in to view. While elliptical galaxies are not as interesting visually as their more photogenic spiral cousins, knowing what lies at the centre of this behemoth certainly added to the spectacle. The galaxy itself appears like an unresolved globular cluster, highly symmetric with a slight condensation towards the core.
Less than a degree and half from M87 begins a sweeping arc of galaxies known as Markarain’s Chain. Named after the Armenian astronomer, Benjamin Markarian, who discovered that this group of galaxies shares a common motion through space. More recently M84 has been shown not to, but given it is so prominent in the chain, it is rather hard to ignore. M84 and M86 are the first two galaxies on this short arc, both giant ellipticals with intense nuclei, though otherwise featureless. However, M86 appeared more elongated than its neighbour. 20 arcminutes from M86 lie a pair of galaxies known as the “Eyes.” NGC4435 presented a small symmetrical oval with a bright core, while NGC4438 was almost three times the size and show hints if distortion in the disc, the result of a gravitational battle with its neighbour. A further set of “mini-eyes” is next on the arc, with both appearing far smaller. NGC4461 showed a distinctly elongated shape with a stellar core while dimmer NGC4458 was more symmetrical though had a similarly bright core.
Just across the border from Virgo in Coma Berenices, but very much part of the chain, are the final two galaxies, NGC4473 and NGC4477. Both appeared quite similar to me, with bright, stellar cores, though the former probably just edged it for intensity across the disc. After wondering up the chain, I spent a few minutes just sweeping around the area. With more than 2,000 galaxies in the Virgo cluster, there are more than 100 in the range of a 4” class scope in a roughly 10-degree square, it was hard to go more than a few seconds without another galaxy entering the field, even if almost all of them went unidentified.
After a good spell exploring the Virgo Super-Cluster, I headed back to the Milky Way and the jewels of the Summer Triangle which were now well placed in the east. The Ring Nebula in Lyra, the remnant of a long-dead sun-like star is easy to find located between Sulafat and Sheliak at the bottom of the celestial harp. Using the 6mm setting of the zoom, the delicate little smoke ring looked like it was about to disperse into nothingness. The dark “streamers” of material that I have noticed before, seem to criss-cross the torus of ionised gas, were once again on show, but never seem to show up in astro-photos, probably indicating it is variations in brightness rather than obscuring material.
Not many DSOs really match up to the poetic names given to them by discovers, but NGC7000 in Cygnus certainly does. The North American Nebula (C20) really takes on shape of the continent which gave its name. Using the 35mm Panoptic, the bright region in the Gulf of Mexico region was immediately obvious, but I was able to trace out almost all of nebula with some patience, though I did wish I had taken along a UHC filter to camp to help boost the contrast.
Last on my list for the night was an object that was born from a far more violent death than the puff of stellar mass progenitor of M57. The Veil Nebula is a supernova remnant located a short hop from Glienah (Epsilon Cygni), one arm of the Northern Cross. Placing that star on the edge of the finder field brings into view 52 Cygni which sits atop the western arc of the Veil. The very delicate thin ribbon of gas would certainly have benefited from a UHC filter, but with averted vision an ethereal vapour was glimpsed. The brighter eastern arcs were far easier, showing an apparent ripple in their structure.
Having arrived at camp with a touch of the man-flu, I decided to call it quits just after 1:30am, but before I had started to pack down my scope, I was approached by a scope-less young woman asking what I was looking at. She mentioned the half dozen or so objects she had seen that night which I suggested were far too few, and spent the next 10 minutes giving her a whistle-stop tour of some of the night’s highlights including M57, the Double Cluster, M13 and M3 as well as a final quick glimpse of Albireo. While now known to be a chance line-of-sight alignment thanks to Gaia data, it does not diminish the beauty of this wonderfully colour contrasted double star. Satisfied with a successful night of stargazing, I headed to bed anticipating the quizzes and dark matter presentation on Sunday in the Spiral Arms.