michael.h.f.wilkinson

Exactly a quarter of a century ago I stood on a parking place along the road near the town of Sarreguemines in the Alsace region, and through a four-minute break in the clouds could observe  and image my first total eclipse, using my C8 on its Great Polaris mount.

The same mount is still going strong, and with the more modest aperture of the APM 80mm F/6 triplet got me yet another batch of solar disks, and a detail shot with the 2.5x PowerMate inserted.

White light:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

Detail shot in white light, this time with dust bunnies removed using flats:

25 years ago I was using the C8 with Contax RTS-II camera and Fujichrome slide film. The image below is a scan of a print of the slide, so not that good, but the original slide got water damage when moving house.

Not the best of images, but I was chuffed to bits with it

Yet another gloriously sunny day, so here are some more disks in WL and Ca-K.

White light:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

I also made a detail shot using the 2.5x PowerMate, but had to crop out quite heavily due to dust bunnies.

Still, not bad detail for just 80 mm aperture.

And indeed, the weather is nice again once more in the Provence, so after my standard morning bike ride of 12.5 km (not much for a Dutchie) and 198 m total climb (unheard of in the Netherlands) to get my breakfast croissants, I set the gear up again, and got another set of disks. If this continues, I am hoping to get a near complete transit of the big AR. Fingers crossed.

White light:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

Sunny here again, so Ca-K and white light solar images are on the menu yet again.

White light:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

I do seem to get out more prom detail by stacking far more frames

Nice crisp detail. Maybe try MS-ICE (image composite editor). Not officially supported any, but the installation files can still be found online.

Four days in a row, although hazy clouds affected the capture of Ca-K somewhat. Still, I am not complaining about the results

Wight light:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

Fingers crossed for some more good days so I can make a bit of an animation

Three days in a row, what luxury! Another set of WL and Ca-K disks. This time I took the usual 1000 frames for WL, but upped the frame count for Ca-K to 10,000, in the hope of being able to push the processing a bit to enhance the proms a bit more in the part inverted images.

WL:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

I think the trick does work, and it certainly allows a bit more aggressive sharpening in ImPPG. I am puzzled that my ASI178MM seems to want to run at 18.3 FPS in FireCapture, whereas I know I had it running at much faster rates before. Can't seem to find the USB traffic settings I used to tweak in the past. 18 FPS is what my ASI183MC manages at full 22 Mpixel, so this is odd.

Had the telescope out again in the Provencal sunshine. The sunspot on the edge of the disc spotted yesterday has turned into a large, complex AR.

White light:

Ca-K, grey scale

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

I love the ghostly prominences visible in the part inverted images

Currently situated in the Provence, so sunshine is a bit more abundant. Rather stupidly forgot to pack the H-alpha filter, so will have to make do with white light and Ca-K.

WL:

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour:

Love proms showing in Ca-K

Just spotted and imaged it. Will post the ersults shortly

Had another go with the Helios LightQuest 16x80 mm binoculars, and under these conditions the nova was easily visible. That's nova number 6 under my belt.

Just got it with my Celestron C8, from a dark site in southern France. Tried before from home with the 16x80 binoculars, but couldn't definitely be sure I spotted it. Now it was easy, especially with the photos supplied in this thread 

Thanks for the heads up. I will certainly give this one a go in my big binoculars if the skies clear

Finally managed to make another full-disc, 16-pane, H-alpha mosaic this morning. I used my usual APM 80mm F/6 triplet with Beloptik tri-band ERF, Baader TZ-4 4x telecentric, Solar Spectrum 0.3 Å H-alpha filter and ZWO ASI174MM camera. I captured 16 1000 frame SER files, stacked the best 35% with AS!3, sharpened the result with ImPPG, stitched in MS-ICE, and final tweaks in GIMP.

Grey scale:

Pseudo colour:

Part inverted:

Part inverted + pseudo colour:

Clicking for the full resolution version highly recommended.

I took a separate 4000 frame SER file of the most active area, stacked as before.

Grey scale:

Pseudo colour:

Really happy with the results

Finally found time and sunshine to set up the APM 80mm F/6, and take some images with the ASI178MM. First with the Herschel wedge and Solar Continuum filter, best 500 out of 1000 stacked (yet, the seeing was pretty stable), postprocessed in ImPPG for sharpening, flipped vertically in GIMP:

I then inserted the Lunt Ca-K module and processed in much the same way, except for my usual play with curnes in GIMP

Ca-K, grey scale:

Ca-K, pseudo colour:

Ca-K, part inverted:

Ca-K, part inverted + pseudo colour

Pretty pleased with the results. Lost of activity to enjoy. I am still stacking the batch of H-alpha data I grabbed.

On 26/07/2024 at 09:34, Nik271 said:

Thank you for alerting me to this comet! I managed to see it last nigth (25 July) at 11pm just at the start ot nautical darkness. I was using my 100mm refractor at x40. It took me some trial and error star hopping to get to the right spot. Luckliy the comet was very close to the 7-th magnitude star HD93521 so once I was in the neghbourhood it was immediately obvious pretending to be  a globular cluster. It is going to fade rapidly from now on. I'm glad I managed to see it this time!

Glad you got to see it!

After a couple of abortive attempts (clouds rushing in, looking in the wrong spot, finally turning to the right spot, just for clouds to rush in), I managed to spot the comet with my Celestron C8. The previous attempts had all been with binoculars (Zeiss Victory 10x42, Helios LightQuest 16x80), but to no avail. This evening started clear, then some clouds came in, then it cleared again, but with some clouds threatening on the horizon, I drove to Aduarderzijl, where there is a good northern horizon, and city lights don't add to the perpetual twilight of these summer nights. When I arrived at about 22:50, it was still a bit too light, but I did have a go with binoculars. When that didn't work, I set up the Vixen Great Polaris mount, did a quick polar align, attached the C8 OTA, inserted the star diagonal and Nagler 31mm T5, aligned the 9x50 RACI finder, and star-hopped to the location in Leo Minor given by the maps from https://cometchasing.skyhound.com/ . After a short search near 38 LMi, I suddenly  spotted a very distinct fuzzy blob on the righthand side of the FOV. I centred it, and it showed up as a bright blob, very comet-like. I checked the star atlas, and there is a galaxy near 38 LMi but that should show up to the left and below in my star diagonal view. Besides, it is magnitude 12 or so, and this fuzzy was definitely closer to the magnitude 7 listed for 13P/Olbers.

Just out of curiosity, I tried the binoculars, and could just spot the comet in the Helios LightQuest 16x80s, but not in the Zeiss 10x42s.

Very happy at bagging comet number 39.

An external stacking program (I use Astro Pixel Processor for deep sky) allows you to combine images from multiple nights (or even multiple cameras/telescopes). I am not sure Seestar can do that. Combining multiple nights worth of data gives much better results, I find. For planetary, lunar and solar imaging you need very high frame rates, and stacking programs like AutoStakkert (free), and perhaps PIPP to preprocess before stacking.

I haven't any experience with the PST, but I did notice a similar issue with the Lunt LS35THa I used to have. I could just reach focus with the ASI130MM I had at the time but it was very tight. Using a tele-centric Barlow (Meade TeleXtender 2x or PowerMate 2.5x) sorted it 

I have always used an equatorial mount with my C8 (a Vixen Great Polaris, mainly). Makes life much easier for imaging, even when imaging planets and the moon, which is the greatest strength of a C8. For DSOs I tend to use either my 80 mm F/6 triplet with 0.8x focal reducer, or my 6" F/5 Schmidt-Newton (or even just the Samyang 135 F/2 telephoto). Polar alignment without direct line of sight to Polaris is possible now, and for planetary photography polar alignment need not be super accurate anyway. 

Just my tuppence

Sad news. I only have the one Meade scope (the SN-6 6" F/5 Schmidt-Newton), which has been both a great comet chaser and an outstanding deep-sky imaging scope. Slightly odd design, only really comparable to Maksutov-Newton scopes currently available. I also have a Coronado SolarMax-II 60 mm with double-stack unit. Good visual solar scope that is permanently based in my office and has given me lots of nice H-alpha breaks over the years.

I have the Zeiss Victory Pocket 8x25 and cannot fault them (except for the fact they do not come with lens caps). Not cheap but excellent in terms of quality.

The lens cap problem can be fixed with some Opticron ones at the front

and some Vixen ones on the EPs

They do come with a little carrying pouch, but I prefer the lens caps

I once had something similar when a USB 3.0 cable had some failure and was detected as a USB 2.0. Switching cables sorted it.

28 minutes ago, TiffsAndAstro said:

i believe you. i've just really really unsaturated it across the board and it might look better. thanks for this, i don't have app but i will try something (maybe) similar in siril 

People tend to increase saturation in many cases (I do it too), but you have to be careful not to explode colour noise. Here is an example of the same shot, without star colour calibration

and with star colour calibration and some gentle enhancement of saturation

This is about 3.5 hours of data from a Bortle 4-5 site, modded Canon EOS 550D, using an APM 80mm F/6 triplet with Tele-Vue TRF-2008 0.8x reducer. Yes, it needs (much) more data.

Sometimes this is a matter of colour balance. In Astro Pixel Processor there is a tool to calibrate the star colours so their colour distribution follows some expected distribution. That often sorts this out.