30 August 2019, 22:30 – 01:00 BST
Much better transparency tonight – ideal for photographing my primary target for the autumn: M33. And the previous sessions had given me enough confidence in the imaging and autoguiding rig to leave it alone while it captured two hours’ worth of data. (With no bright stars nearby, the hardest part was getting the galaxy centred in the camera’s field of view.)
After idly touring the Milky Way while my eyes fully adapted to the dark, it seemed only right that I open the session with a closer look at the object I was imaging:
M33, Triangulum Galaxy
Viewed at both 50x and 133x; challenging as always. The northern spiral arm was easier to see than the southern one. The nucleus was star-like, with a faint star close to it (in line with NGC 604). Some of the other HII regions were suspected with averted vision, but not to the point where I could say I was confident of detecting them. I used a finder chart to pinpoint the location of the globular cluster C39 but, not surprisingly, it was below the threshold of visibility.
NGC 7331, spiral galaxy, Pegasus
Viewed at 133x and 240x. At the higher magnification there was perhaps a hint of one of the companion galaxies, but it was extremely subtle. Likewise, there was a very vague suggestion of a misty glow in the region where Stephan’s Quintet is supposed to be, but not convincing enough for me to call it.
NGC 7009, Saturn Nebula, Aquarius
Bright ellipse at 133x. At 240x with the OIII filter it became very bright, albeit devoid of detail. I couldn’t see the ansae directly, but with averted vision I could tell there was something “Saturn-like” about its shape. The nickname is well-deserved; at first glance it does look a lot like a ghost image of the ringed planet.
M2, globular cluster, Aquarius
Best view yet of this globular. Large, slightly elongated, well resolved, particularly with averted vision. The brightest member is just to the east-northeast of the core (though this may be a foreground star).
M15, globular cluster, Pegasus
Viewing one globular straight after another really allows you to appreciate the differences. M15 is brighter than M2 and clearly more condensed. Easier to resolve too (more stars visible in direct vision).
NGC 7293, Helix Nebula, Aquarius
With a declination of -21 degrees and a reputation for having a low surface brightness, I wasn’t sure if I was going to be able to see this planetary nebula, but a sweep of the area at 133x with the OIII filter quickly brought it into view. It showed up surprisingly well, looking not unlike its familiar photographic representation (albeit minus the colour). Even though I’d read about it before, I was still unprepared for just how big it appeared in the field of view. Overall it resembled a pair of large, ghostly overlapping smoke rings, with a darker cavity on the northwest edge and a hollowed-out interior. At 50x (still with the OIII filter) it was brighter still. The only other planetary nebula I can think of that vaguely resembles it is the Owl Nebula in Ursa Major, but the Helix is superior in every way (not just size). Easily the highlight of the evening. Afterwards, I removed the OIII filter to test if I could see it unaided, but it had left the field of view by the time I put the Panoptic back in and I couldn’t find it again. I’m pretty certain I was sweeping in the right area, so file that as another success for the OIII filter.
Nature note:
At least 10 frogs in the pond, including several of this year’s froglets and the large pale “telescope-hopper” from Monday night.
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