Hughsie

The constellation Cassiopeia is named after the Ethiopian Queen Cassiopeia, mother to Andromeda who was saved from the whale, Cetus, by the Greek hero Perseus. You would have been forgiven for thinking that I had spent a short dark night taking a photograph of Cassiopeia but this is in fact the asterism, Kemble 2. Given its similar "W" shape, Kemble 2 is also known as 'The Little Queen' or 'Mini Cassiopeia' and can be found in the constellation Draco located RA 18h 35m 32.4s Dec +72° 22' 38.353" it is approximately one degree south east of chi Draconis.

This asterism was discovered by the Franciscan friar and amateur astronomer, Father Lucian Kemble in August 1994. Father Luc was a keen observer of the Saskatchewan skies in Canada building upon his first observations as a child from the dark prairies of Canada. Over the years he became an accomplished observer receiving the RASC Messier certificate, Astronomical League of America Herschel 400 certificate, RASC Amateur Astronomer of the year 1989 and the Webb Society award of excellence 1997. 

As the name would suggest there is a predecessor Kemble 1, also known as Kembles Cascade, a beautiful line of unconnected stars located in the constellation Camelopardalis and Kemble 3 (The Kite) which can be found in Cassiopeia. It is my aim to photograph these remaining two asterisms later in the year when they are higher in the night sky.

Being a man of faith some would assume there could be a contradiction between his religious belief and scientific interest. In fact in an interview he was once asked about the relationship between his interest in astronomy and his faith. He replied;

This is a question that often intrigues people. I know people who say, “Gee, if you’re interested in science, then how can you believe […] the Bible? Or if you’re a theologian, how can you believe in science?”

They see it as a contradiction, I see it as complementary.

I have no conflict at all. One bolsters the other.

My theology is made richer by learning the real cosmos in which we live […] and vice versa; my interest in astronomy just overwhelms me sometimes with the beauty and the order and the precision and the absolute awesome wonder of the universe.

So my prayer life is just as much at the telescope as it is in the chapel.

Father Luc passed away in Regina, Saskatchewan on 21st February 1999. His obituary can be found here:

https://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1999JRASC..93..151.&defaultprint=YES&page_ind=0&filetype=.pdf

Stand by your scopes.

Well done on your first mosaic.

There are lots of panoramic stitching software available that can bring the panes together. Personally, I use Affinity Photo and it’s Panorama tool, but that comes at a one off cost (currently £68) but they do from time to time offer great deals. Alternatively, you could try https://sisik.eu/pano which is free. A fellow astronomy club member uses it and has had good results with up to 7 panes so that might be worth a go.

Caught it on my All Sky Camera whilst sitting back and enjoying the view.

23 minutes ago, LukeTheNuke said:

Nice one! I'd better finish up my gin in case we're all doomed. Would be a shame for it to go to waste.

We drank our rum stash during Covid and have just built it back up again. If you are certain we are doomed it would be rude not to try some liquid sunshine.

An early start and some blind luck saw me pointing the scope at AR13664 this morning. Below are two images (RGB and Greyscale) of this region at 07:00:22 UTC.

X3.8 commenced at 06:27 UTC, peaked at 06:54 UTC and downed tools at 07:06 UTC. I do have earlier captures and will update this post later with them.

Top images and some lovely processing.

This is what I use when I’m having to make adjustments to the image train/flats/tuning the etalon. I find standing helps and you can place yourself up close to the mount with the Pulse stand.

The iCap hood unzips and stores flat, this is the mid size and easily holds a laptop. Slots run down each side so you can pass through cables.

Sadly, I had a failed mosaic of the solar disc this morning. Not enough alignment points between t'north and t'south so I ended up with two separate hemispheres. As all the action was down south I thought rather than bin the data I thought I would share it. 

Here is the southern solar hemisphere this morning in glorious technicolour and good old black and white. Inverted of course.

26 minutes ago, TiffsAndAstro said:

Plastic storage container turn on its side?

+1 for the storage container. Mine is grey so little light can come in through the sides plus I have cut out some slots on short sides to pass cables through. In addition, I have two large beach towel pegs and a black sheet. The sheet goes over the container and is pegged down on the table it sits on. I then put the sheet over my head and can see the screen fine. It’s all close enough to the scope so I can reach the scope and focus.

Active regions 13668 and 13664 continue to be the main feature on the solar disc this morning. Conveniently on the South West limb near these AR's is a massive prominence.

13668 & 13664 in RGB.

Same image inverted revealing the prominence nearby.

The prominence on the South West limb rotated to a more convenient angle to avoid any unnecessary neck and head movements.

On 07/05/2024 at 22:33, Dunc78 said:

Great sun images. Are they double stacked? 

Yes they are.

17 hours ago, Bugdozer said:

Great picture! Technical question though - since that appears to be a negative image, how come you still have a black background with bright flares and prominences? 

Windows based software ImPPG is free to download. Within it is a tone curve function that allows you to invert the image, amongst other adjustments. The Woodland Hills YouTube video goes through this.

Looking at the center of the Sun through a 2.5x Tele Vue Powermate we have (L-R) AR13667, AR13668, AR13664, AR13661 and AR13663.

Captured using the following equipment and software;

• Lunt LS60THa/B1200/CPT and Lunt 60mm front mount double stack H-alpha etalon.
• ZWO ASI174mm.
• Sky-Watcher EQ6R-Pro.
• 2.5x 1.25" Tele Vue Powermate.
• SharpCap Pro, Autostakkert4!, ImPPG and PixInsight.
• 200 from 2,000 frames stacked in AS4!. Exposure time 3 ms, FPS 130.

2 hours ago, Elp said:

Think you've got other problems...

They should have called me for the new Andrex advert.

Morning Rob. Having run the image through nova.astrometry.net the image scale comes in at 0.589”/pixel. With the sensor pixel size at 4.63um this equates to a f/l of 1621 mm whereas the advertised f/l is 1600 mm. Having read numerous user reports on RC’s this is not uncommon for these scopes and if I was going to sweat on this I would be looking for a Ronchi eyepiece to verify if this is correct, too short or too long a f/l. But I’m not going to tinker down this rocky road 🙂

As to the focal ratio, I read somewhere that the Primary Mirror on an RC is somewhere in the f2 to f3 range and the secondary has a magnification of 2.5x to 3.5x. May be the difference is down to the specs of the mirrors.

But the main issue here is you only live 5 mins from me and it should have been you on the ground with the Allen keys and me watching the laptop screen!

On 11/04/2024 at 20:09, Mark_C said:

Very nice!

Regarding flats, I also do the same, I use an A4 ring binder wallet that I've separated in to one single sheet then wrap it around the OTA dew shield with an elastic band. I then higher the exposure so that it's at around 60% in the histogram, then get SharpCap to take the flats, seems to work just fine and the results seem to be decent. I think this is the way DayStar advise to take solar flats, or use one of their dedicated flat screens (that do pretty much the same thing but more convenient.)

I use a crumpled up sandwich bag over the front of the scope held on with a lacky band. Beats paying what DayStar charge for their flat panel!

When I store my data for the future after using WBPP I generate the following folders;

• The original data from across one or more nights excluding flats, dark flats and darks.
• A folder called Final Images in which I keep an XISF and JPEG version of the final processed image and any annotated images.
• Lastly a folder called Master Lights & Calibration Frames in which I keep the post calibrated and integrated light frames pre-processing plus the Master Flat and Master Dark generated by WBPP.

Although I have a darks library which I update once a year, I keep the original master dark used in calibration for the current imaging session in case the camera sensor changes over time. Like Ouroboros, I will only delete the individual flats and dark flats subs once I am satisfied the Master Flat has calibrated the lights properly.

2 hours ago, Rallemikken said:

Very nice picture. I'm considering one of those for next season, most likely the StellaLyra 8" f/8. What camera did you use on this?

I used the ZWO ASI294MC camera with a UV/IR cut luminance filter. The camera sensor has a 4.63um pixel size which leads to a slight over-sampling. I have also used the ZWO ASI1600mm which has a smaller pixel size. When using this I will still use bin 1x1 and then resample the image to 2x2 when processing the data to see if there is an improvement or not.

The scope I used is the same one you are looking to purchase. Don’t be put off, the poor collimation was all my doing and a lack of understanding on my part on the mirror dynamics. Collimating these can be a challenge but it just requires a methodical approach and a star test. Worth researching online to see what method may best suit you. Having said that, once collimated they hold very well and probably need checking once a year.

The final thing I would add for you to consider is the stock focuser that comes with it. In summary it’s pants. Build into your budget the cost of a new focuser, the Baader Diamond Steeltrack is available through FLO along with the adapter to attach it to the RC8. I bought this and it’s a marked improvement. You pays your money and takes your choice when it comes to accessories but I would hold fire on things like flatteners, reducers and tilt adapters. This image was a bare bones camera/filter/native 1600mm image with the Baader DST. 
 

I hope this helps.

John

12 minutes ago, Vic L S said:

I actually use PixInsight, and WBPP to integrate my files, I should have mentioned that in my post. 

When doing multi-night projects I save all my data by night. In each folder will be the lights, flats and dark flats captured for that session. If the project has the same camera settings such as exposure time, gain and temp then there will only be a single master dark otherwise there will be different darks to reflect those camera settings as well.

In WBPP you can view a calibration diagram for each set of lights to ensure the correct flats and darks are being used. It helps to be methodical otherwise it can become confusing. If WBPP selects the wrong calibration files then you can override it. 

Another setting to be aware of is the exposure tolerance. This defaults to 2 seconds. WBPP will integrate all calibrated lights with the same exposure time but you may have used different exposure times during the project and still want the data integrated into a single master light. For instance, one night you may have collected subs at 300 s exposure and a second night at 180 s exposure. By default WBPP will produce two master lights one representing 300 s data and the other for 180 s. There may be good reason why you want this eg where you want data not blowing out cores on globular clusters. If you don’t need them to be separate then you can adjust the exposure tolerance from 2 to 120 s (300-180) and WBPP will combine the lights data post calibration for you.

Hope that helps.

John

26 minutes ago, RobertI said:

That looks excellent John, I think you might have finally nailed the collimation. 

Thank you Rob. Just have to check the secondary one last time then, fingers crossed, we get some clear nights.

I own an RC8 which has been a source of frustration for over 4 years. When I first bought the scope I tinkered with the collimation. What was I meant to do when a regular feature in the forum topics is the heading 'Ritchey-Chretien Collimation....', I thought everyone enjoyed collimating them. How wrong could I be.

So I tinkered so the collimation got bad, then tinkered some more until it was horrendous and finally when I thought I could tinker no more.....I tinkered again!

The RC8 was like a loveless marriage but we both needed each other. The RC8 needed me to be able to see again and I needed the RC8 for the challenge of getting the poor thing fixed. So, last week I stripped it down to its bare bones (no I didn't remove either mirror, I am not that stupid) and started again. Having gone backwards and forwards between aligning the primary mirror with the optical axis then adjusting the secondary and back again I reached the point where I was only making the tiniest of adjustments. Time for a star test!

Now, there is nothing I enjoy better than a dark night with two tiny Allen keys, a scope pointing at the Zenith, me laying under it figuring out which part of my varifocal lens glasses gives me the best focus and finding that I have just crushed two amorous snails. Seeing wasn't great and common sense said that I should wait for a better night but they are few and far between in the UK. I restricted myself to a loosening tweak here and a tightening tweak there. 

The out of focus star looked......good? Never a word I have used with the RC8. Anyway, I slew the scope to M51 as it was due to cross the Meridian to the South and rattled off 17 subs at 2 minutes each. I actually captured more calibration frames than lights so to be honest but I wasn't expecting much other than good looking flats.

Here is the result. As I say, it's just 34 minutes integration time and I was very surprised. Still, just a few more tweaks here and there and ..........