Hi,
I had another great
EAA session last night. The sky was clear, the wind had dropped, and the temperature had returned to a seasonal norm. As usual, I had the start of an observing list in AstroPlanner (4 objects) but then added more as the evening progressed.
As the temperature had dropped, I started the session by creating dark frames for 4s, 8s and 12s subs. In the end however, I decided to just use the power of SharpCap 4.1 and switched to using Hot and Cold Pixel Removal. This along with software dithering gave (to me) a good view of the objects being observed on my 4k monitor.
I aligned my Celestron CPC-800 using CPWI and focussed using SharpCap’s Multi Star
FWHM focussing tool. I usually limit the focussing to the central part of the view but tonight I selected a region half-way between the centre and edge of the
FOV. The CPC-800 with the F6.3 focal reducer does not give a flat field of view, but I hoped that by ‘averaging’ the focus it would give a more pleasing aesthetic view of extended targets.
The first target was the mighty globular cluster M13. The image of M13, just like all images in this report, is the snapshot at the end of visually observing it. As I want to ‘see’ as much as possible my settings are usually aimed at greatly stretching the image. This brings out more detail but also noise. The dithering and hot/cold pixel removal tool provide some noise dampening but manipulating SharpCap’s Histogram and using SharpCap’s Colour Noise Reduction and sharpening filters really helps my view of the objects.
The fine powder of faint stars surrounding that bright ball and ‘star arms’ makes M13 an amazing sight.
14 October 2023 20:29:13 (
UTC) - Subs: 60, Exp (s): 8.0 Total Exp (s): 480.0 Alt: 34.1° Az: 287.8° Airmass: 1.8
App Mag: 7.4
Next, I stayed in Hercules but slewed further North to view the comet 12P/Pons-Brooks. The comet is currently accelerating down our Sun’s gravity well towards
perihelion in April 2024. It is inclined at 70 degrees to our orbital plane around the Sun and if you view the orbit at JPL Horizons or in Starry Night then it appears to be plummeting downwards towards us. It has an orbital period of 71 years, so catch it while you can.
To the left of the ‘ghostly’ comet are a few smaller smudges from the light of distant galaxies.
14 October 2023 20:50:13 (
UTC) - Subs: 25, Exp (s): 12.0 Total Exp (s): 300.0 Alt: 26.2° Az: 309.1° Airmass: 2.2
App Mag: 10.2
Moving into the constellation of Lyra I viewed a small planetary Nebula,
NGC 6765. It was almost lost in the rich starfield and tiny in my F6.3 scope. The images below show the
PN in its rich setting and then a cropped view of this diminutive, green nebula.
14 October 2023 21:24:07 (
UTC) - Subs: 75, Exp (s): 8.0 Total Exp (s): 600.0 Alt: 44.9° Az: 265.2° Airmass: 1.4
App Mag: 13.2
Slewing into Cygnus, I had to view part of the Veil Nebula (
NGC 6960). A twisting vortex in space with its strands of greens and reds (at least in my image) winding past the star 52 Cygnus, an amazing sight. I sometimes find it hard to balance the colours in SharpCap. As an example, the colour of 52 Cygnus looks wrong to me.
14 October 2023 22:26:46 (
UTC) - Subs: 75, Exp (s): 12.0 Total Exp (s): 900.0 Alt: 50.0° Az: 258.4° Airmass: 1.3
App Mag: 7.3
Remaining in Cygnus, I headed over to the Crescent Nebula (
NGC 6888) with its massive, glowing central Wolf-Rayet star. I was trying to tease out the faint gas clouds to the left of the star but in my final snapshot I must have dialled back the stretch a little.
14 October 2023 23:28:23 (
UTC) - Subs: 88, Exp (s): 12.0 Total Exp (s): 1056.0 Alt: 40.0° Az: 284.7° Airmass: 1.6
App Mag: 10.4
Moving to the north of Cygnus I observed
NGC 6946 the Fireworks Galaxy. A face-on barred spiral 25 million light-years distant. The galaxies sweeping arms contained small bright condensations of gas and stars. I believe there is a distant globular cluster visible in one of the galaxies arms, but I could not find a designation or location. If anybody knows where it is, then I would love to know.
I really loved exploring the Fireworks Galaxy, but I couldn’t get SharpCap’s tools to really bring out the faint clouds and structure as well as I wanted. So, I opened the image in Microsoft’s Photo viewer and enhanced it a little! It only took a few seconds to do and improved my observation of the object no end. The image details are the same as the original but with a few ‘slider’ modifications.
14 October 2023 23:59:49 (
UTC) - Subs: 100, Exp (s): 12.0 Total Exp (s): 1200.0 Alt: 49.7° Az: 312.6° Airmass: 1.3
App Mag: 10.0
Staying with galaxies I slewed over to the Deer Lick Group (
NGC 7331, largest) in Andromeda. A large, structured galaxy with an entourage of smaller companions.
15 October 2023 00:40:02 (
UTC) - Subs: 75, Exp (s): 12.0 Total Exp (s): 900.0 Alt: 48.9° Az: 267.4° Airmass: 1.3
App Mag: 9.8
It was getting late by now and I realised I had been observing for over 6 hours! Where does the time go when you’re enjoying yourself!
Last object, I said and moved onto the Pleiades and the Maia Nebula (
NGC 1432). This amazing blue cloud reminded me of the wispy high cirrus clouds of Earth. As the image built-up and the noise fell away it was an awesome sight.
15 October 2023 01:37:46 (
UTC) - Subs: 101, Exp (s): 12.0 Total Exp (s): 1212.0 Alt: 62.5° Az: 160.0° Airmass: 1.1
Just as I finished with the blue wispy clouds of the Maia Nebula and was about to pack away the scope. I noticed in Stellarium that the Orion Nebula had cleared my neighbour’s house. I couldn’t resist as this was my first view of Orion this Autumn.
The Orion Nebula was low down and right where a light-dome from our county town drowns out most sky objects, but this is the Orion Nebula and it looked amazing as usual. A great way to finish off an
EAA session.
15 October 2023 01:57:56 (
UTC) - Subs: 93, Exp (s): 4.0 Total Exp (s): 372.0 Alt: 27.4° Az: 143.2° Airmass: 2.2
App Mag: 4.5
I apologize for the length of this
EAA report but as usual once you get into the swing of observing, the hours fade away as old and new favourites present themselves for observation.
Have fun.
Pete
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