wimvb

53 minutes ago, vlaiv said:

48mm

It is 48 mm (haven't measured it, though). The removed back makes it look shorter than it is. The front measures 42×42 mm, and it's slightly longer than that. 0.85A/phase is also plausible, the mount draws about 2.5 A while slewing. But I also have to make sure that the shaft is long enough. The aluminium block in the background (right side) sits between the motor and the belt. I ordered the replacement because I need something fast. I don't want to miss galaxy season.

... and combine that with temperature changes, you have a recipe for metal fatigue.

A few days ago, my AZ-EQ6 started tracking erratically, and guiding was all over the place. I narrowed the cause down to the RA motor (it made a strange noise when slewing with the hand controller).

Today I removed the motor and opened it up ...

I've ordered a replacement motor from Pierro Astro, but these are quite expensive (140 €). As a backup, I'll see if a standard NEMA17 0.5 Nm stepper will do.

Btw, does anyone know if this is a 0.9 or a 1.8 degrees/step motor?

18 minutes ago, AstroGS said:

Im still experimenting a combination of GHS and Histogram stretching.

I've never had much luck with GHS on galaxy images. I use a combination of Histogram stretch, Curve Transformation and HDR Multiscale Transform to control the core

Great image. Definitely better than the bin2 version.

Nice!!

The tidal stream of ngc 3628 is just visible.

2 hours ago, gorann said:

I assume this one also has an Arp number.

Thanks, Göran. Of course it has; nr 215.

According to Wikipedia:

"NGC 2782 is a peculiar spiral galaxy that formed after a galaxy merger in the constellation Lynx.
The galaxy lies 75 million light years away from Earth, which means, given its apparent dimensions, that NGC 2782 is approximately 100,000 light years across.
NGC 2782 has an active galactic nucleus and it is a starburst and a type 1 Seyfert galaxy.
NGC 2782 is mentioned in the Atlas of Peculiar Galaxies in the category galaxies with adjacent loops."

This image was taken during a gap in the clouds on March 11.

Despite the fact that the sky was clear during the entire night, I could only collect 4 hours of data. After the meridian flip, my mount broke down, and now I'm waiting for a replacement RA motor.

Nonetheless, the data was collected with my SW 190MN and ASI294MM camera

RGB: 1.5, 1.5, and 1 hour

Processed in PixInsight

2 hours ago, tomato said:

Fabulous image, glad to see it entered into the Deep Sky Survey competition. It’s inspired me to change cameras and have a go at something similar, assuming I can get a clear night and and the dome operational.

Thanks! I am, as sailors say, dead in the water. Yesterday I started on a new project, but after the meridian flip, my mount started misbehaving. At first I thought a cable pulled the mount and the clutch had come lose. Today the problem persisted. I connected the hand control and noticed a strange sound from the RA axis. It seems that the RA stepper motor has a mechanical failure. I just ordered a replacement from Pierro-Astro in France. Hopefully, I will be able to fix the mount before the season ends. If not, this is going to be my final image until after the summer.

This is the large scale and wide field version of Abell 1185 which I previously published in the Deep Sky Imaging section (judges, if it is not allowed to enter an image previously posted on this forum, please remove this entry from the competition).

16.5 hours with my MN190 and ASI294MM

Capture dates: March 6 and 7 of this year

Click on the image to show the full size version

You can find the annotated version here:

https://stargazerslounge.com/topic/419923-galaxies-galore-below-the-paws-of-the-great-bear/?do=findComment&comment=4468655

Full size annotated version with QSO's, galaxies, galaxy clusters, brightest galaxies in a cluster, LEDA, NGC, plus a few unidentified objects

4 hours ago, Roy Foreman said:

My god its full of galaxies, to sort of quote a famous movie line. Excellent result, nice work.

Thanks, Roy. I guess you could call it the 'Holland Hill deep field'. (Since I'm dutch and live on a hill/ridge near the swedish village Lindholmen, I named my observatory Holland Hill Observatory.)

What movie was that, btw?

1 hour ago, gorann said:

I only tried drizzling a few times and remember that I got really big files that slowed processing down. At least for my RASA data with a pixel scale near 2" I do not think it would help it I got the theory right.

you've got colour cameras, so all images have three channels. That makes them three times as large as my mono images. As I wrote, I stacked the RGB data without drizzle, and only L at drizzle x2. I also have a smaller sensor than you, my fits files are 23.4 MB out of the camera. The camera resolution is half that: 11.7 Mpixels.

Normally I don't drizzle either. With this image I just experimented with it, and I think it paid off. For nebula images, where the level of detail isn't that critical, drizzle isn't necessary in my opinion.

14 minutes ago, gorann said:

Just amazing and very zoomable! Do you think drizzling made any difference?

Thanks, Göran. I think drizzle in combination with BXT made a difference. Guiding during the night that I collected the luminance for this image was about 0.8", so not that great. With a pixelscale of 0.955" and the atmosphere as it is, I wasn't undersampled. Drizzle shouldn't have done much, but since BXT seems to like oversampled data, I think the combination improved the final image. Btw, the colour data wasn't drizzled, I just upsampled it to match the luminance pixel scale.

Thank you, Steve, for your kind words.

53 minutes ago, bomberbaz said:

I envy the skies you must have to image such tight data

I had the good fortune to be able to move away from the Stockholm suburbs, to the countryside. It's not very dark, but at least there are no street lights, and only one neighbour whose house is behind ours.

Just now, WolfieGlos said:

Wow, what a fascinating image and looks great zoomed in too - so many galaxies!

That tail almost looks like a guitar....the guitar galaxy maybe?

Thank you. That's why I drizzled the luminance data. The "guitar galaxy" are ngc 3561, ngc 3561 N and ngc 3561 Irregular (from bottom to top).

9 minutes ago, ONIKKINEN said:

One can only assume those 2 galaxies recently (cosmic timescales speaking) had a collision and one was torn apart.

Three galaxies, actually. There is an irregular galaxy in the plume at the end of the tidal structure.

10 minutes ago, ONIKKINEN said:

Great image.

 

Thank you.

Or plain and simple: Abell 1185 in Ursa Major

I spent two nights gathering data for this one. Two nights ago gave me 10.5 hours of RGB, and I completed the data collection yesterday night with 6 hours of Luminance.

Abell 1185 is a group of galaxies, some 400 - 450 million light years distant in the constellation Ursa Major. One of the more interesting members in this field of view is ngc 3561, which actually consists of several galaxies, ngc 3561, ngc 3561 N, and ngc 3561 Irregular. Equally interesting is that there are more galaxies in this images than there are stars. Most of the background "gnats" are distant galaxies and quasars, up to 6 billion light years distant.

As always, I used my trusted 190MN and ASI294MM with Optolong LRGB filters

Processed in PixInsight. I drizzled the Luminance master, so even this crop is quite a large size.

And by the way; that isn't Saturn in the lower right corner. It's ngc 3536, 500 million light years distant. It has a very nice double ring structure.

@engstrom try clearing the mount settings. You can do that in the mount/telescope section of ekos. "Clear mount model"

29 minutes ago, engstrom said:

I’m just taking my first steps into using an Astroberry pi 4. It’s accessing the home WiFi and I’m connecting to it via a MacBook.

This evening I managed a few hours to figure things out live before the clouds rolled in. Managed to get the indi server running and connecting to the heq5 and asi585. Tried solving to no avail initially. I hadn’t entered the focal length and aperture 🙂 but when I did it complained of too few stars a few times before suddenly working. I solved a few times and got the error down.
Emboldened I tried to Polar Align and it worked first time and I was only a few minutes out. I tried to correct but racing ahead and not thinking I accidentally slewed the mount instead of fiddling with the knobs. Tried to PA again but when it came to the first Image it captured and received but just seemed ti hang there. Stopped it after a few attempts and tried simply plate solving and it did the same thing; captured and received and the activity indicator just spun and spun. I killed the instances and the server but it just did the same thing. By this time the clouds were rolling in so I guess I’ll see what happens next time.

Make sure you have all the essential and optional index files installed. I have ekos on a 64 GB card, and have installed index files down to less than 10% of the fov. Also, there is a smallest fov, below which plate solving for PA becomes unreliable.

1 hour ago, tomato said:

Back to the SN, what a show for astronomers  living in a (not too) nearby spiral arm of NGC 4216.

Earlier this evening, as I was driving, a meeting car didn’t dim their headlight. I guess that’s how those living in ngc 4216 must feel. 😁

4 hours ago, tomato said:

Yes @wimvb's image of this trio of galaxies doesn't show it either. My money would be on a geostationary satellite, but it would have to be a pretty darn big one, it's approx 23" in diameter, that's roughly twice the apparent diameter of the ISS.  Do planetarium packages like Stellarium show these? 

Nope, no chromosomes, no supernova and no satellites in my image. I'd thought of imaging the SN in ngc 4216, but my mount doesn't reach past the cloud cover. Maybe wednesday night ...

With most skywatcher mounts, you can put the mount head turned 180 degrees. The counterweight bar will then fit between two tripod legs, rather than be above one leg. To clear the tripod legs, you may also need a pier extender. One trick that people living living on high latitudes use is to not extend the tripod legs completely. This has the effect of not placing the mount head exactly horizontal. Even then, reaching 4 degrees will be tricky. You might consider investing in a harmonic drive mount that doesn't need counterweights.

7 hours ago, Tomatobro said:

as NGC2460 is known as the little whirlpool I did a comparison size wise using my ED72 portable rig between it and M51.

NGC2460 is the tiny Fuzz right in the middle of the image. Smaller than the core of M51

Nice! Ngc 2460 looks smaller. But if you take into account the faint spirals, not that much smaller. I combined my ngc 2460 with an older image of M51. Stretched both about the same (but had to adjust the dark level of M51 somewhat), and added HDR transformations to both images equally to get this. (Same scope, same imaging scale)

(M51 2 hrs 24 min, ngc 2460 16 hrs 21 min)

If you also take into account that ngc 2460 is about three times further away, then they compare like this

(Btw, ngc 2460 is upside down)

7 hours ago, tomato said:

There might be traces of IFN there, or more likely my uneven background.

Let’s call it IFN, otherwise we both have an uneven background.

8 hours ago, gorann said:

So you are using cameras without cooling. Interesting. It seems to work quite well for you.

According to an old entry on the zwo website, the ASI178 had the worst amp glow of all their models. The ASI174, which I used, was the second worst. With the new amp glow free models, maybe cooling isn’t necessary any more.

1 hour ago, gorann said:

By the way In your original post I think you invented a new ASI camera model.

And since @tomato has edited the original post, now we'll never know what that invention was. 😉