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Showing results for tags 'globulars'.
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Difficult globular clusters.
Xilman posted a topic in Imaging - Deep SkyGlobular clusters are popular subjects for deep sky imagers, and rightly so. However, some are very popular because they are easy. Omega Centauri and M13 are perhaps the outstanding examples. Anyone with a smart phone or better can image those. I have started imaging less popular ones because, in the words of JFK sixty years ago, we do these things not because they are easy but because they are hard. This one is Segue 3, which is quite likely the smallest and faintest globular cluster in the entire galaxy. It has 32 known members and a total brightness of only a few hundred times that of the Sun. The brightest member is just 17th magnitude and the next half dozen or so are 19-20. This image goes almost to 21.0 and shows about half of the cluster members. A similar image, which goes slightly fainter, can be found at https://aladin.u-strasbg.fr/AladinLite/ where you should set the co-ordinates to 21:21:31.0 +19:07:02 and zoom in to a FOV of 5-10 arc minutes. Technical details: 3150 second unfiltered exposure in 53 subs. 0.4m aperture Dilworth scope and a SX 814 CCD camera. Other imagers who are up to a challenge are urged to post their own efforts. If you wish for some easier targets on which to cut your teeth, you could do worse than start with the Palomar clusters. Beware: Segue 3, Balbinot 1 and AM 4 are hard. Go for it!
Aside from picking up globular cluster M80 from the park last weekend, my Messier tally has languished in the upper 80s for some time. Ticking off all my forecasting elements as Friday afternoon wore on I was pretty excited about the prospects for last night's session: Weather, warmish, light wind. Met office cloud forecast, clear. Jetstream forecast, kinking away from the southern UK from later afternoon, CO Clear to 3 am. No moon until 4 am. At this time of year, what we give up in terms of astronomical darkness, we gain in family sociability. I was able to enjoy the evening meal with the kids and then catch up on a couple of episodes with the lovely Kathy as dark fell. (The latest series of Bosch is great btw and the soundtrack left me with a hankering for cool jazz, so my observing session last night was accompanied by John Coltrane, Dexter Gordon, Lee Morgan and the gang - as a soundtrack to the stars it works surprisingly well. Nice...) I pulled into my normal layby up on the downs at just after 11 to find I was not alone, a couple had stopped off to relax on their evening drive, & presumably enjoy the stars... Unpacking and swiftly moving on I checked out the sky, transparency was quite good although not as perfect as hoped, some big bands of thin haze were taking the edge off to the West and worse to the South. Very clear overhead and through Lyra and Cygnus however. The Milky Way well seen and 10+ stars visible in Ursa Minor, so can't complain. Hit a snag, had left my diagonal in the Clarkson 3", so had a bit of faffing around to get the tripod at the right height to be able to see into the 9x50 finder and not have to roll around on the floor to execute straight-through viewing. Alignment was a pain - first go was rubbish, but readjusted and aligned on Spica and Altair which then set me up well for accuracy in the Southern sky. My forgotten diagonal had the effect of committing me to low angle objects. I'd made a vague time plan and knew that if I was to get M83, The Southern Pinwheel, before it set this would need to be the first target. Spent a while hunting for that first GoTo then an expanding search pattern but, nope, couldn't pull anything out of the LP over Southampton. Similar result in the search for M68, glob in Hydra. Switched to other targets on the list and the fun began.... M4 Nice, slight sparkling. Wide extent, diffuse. The best I've seen this and one to revisit with the big Dob another time. M9, Smudge in finder, well seen. Similar extent to M3, less bright. Denser core in AV. M19 - shining through the murk at 10 degrees. Compact. M80 - small & quite bright. Nice star field. M10 for comparison. Much brighter, many tiny points on edge of vision. M14, Fainter, slightly uneven. Triangle of stars to W. M107 - Sparser quite wide, unstructured. M4-like diffuseness. M17 - Swan Nebula lovely in 40mm - green tinged. Central dust lane.. M16 - Eagle Nebula. Mainly the star cluster. O111 revealed a blob of nebulosity but seen it better. Best seen in 40mm Plossl (37.5x) M20 - Triffid nebula, hints of the dark lanes in AV, exciting object but not the best view I've had. M21 - Webbs Cross open cluster, bright & nice view. M8 - Lagoon nebula, slightly in the haze but still a fabulous object, greenish glowing nebulosity punctuated with bright white blue stars. M6! Offset square with outliers. Maybe 20 stars with more in AV. Well seen at 6 degrees above the horizon. Filled the field (1.04 degree) M7! Sparse, fairly bright to penetrate the murk at 3 1/2 degrees. Twinkling away above Fareham! Main group about .75 degree across. Both M6 & M7 improved with the Baader 18mm which darkened the bright background sky and pulled out more resolved stars. Pretty loose clusters both and chuffed to catch these most southerly of Messiers, let out a "yes!" on each. M54 - dim glob but seen. Tapping to confirm. Unsure with 40mm, definitely there in 18mm. + Baader Neodymium filter. M62 - a bit higher in elevation that M54 and correspondingly better view, compact globular, easily seen. Not resolved. After the first crop of objects in & around Ophiuchus I gave my back some time off and had a nice binocular tour lying on a camp mat on a grassy bank whilst waiting for Saggitarius to. get up. Milky way through Cygnus was fab and followed the tracks of a few satellites. M13 good in the 10x50s plumb overhead at that point and could just make out the tiny circular smudge of the Ring Nebula, M57, in Lyra. The Sagittarius Messiers looked great in bino-sweeps too. Surprise performer of the night was the 40mm Celestron Plossl which worked well in straight-through mode in the Mak 127 at low magnification, nice flat, bright views and easier to get my eye around the whole field at the odd angles compared to the Hyperion 24, whose immersive 68 degree field required closer eye placement than the Plossl's immense eye-relief, & entailed consequently more gymnastics to view the whole field. A good night all round and the Messier tally up to 95.
ISS, Starlink and M5
Pixies posted a topic in Observing - with BinocularsI was out just now, hoping for a view of the nova in Cassiopeia, but clouds to the north. The only clear part of the sky was around Bootes and Arcturus. I thought I'd try and find M5 in my 10x50 bins. I've never seen it with binoculars before. As I was scanning the sky, an ISS pass caught my eye. VERY bright. But then I noticed a train of Starlink satellites following it. About 10 degrees behind it and a little further south. The train was 10 degrees long and the satellites appeared to be in pairs when I viewed them in the bins. Then I saw another train following on behind, in the same configuration as the first train. I followed them in the bins, right past M5!