M51, Whirlpool Galaxy 04-15-17

This object is not a new one to me, or to any visitors to this site. If you have a telescope then you have probably looked at this galaxy colliding with another creating a spectacular view in images. This galaxy and it’s dance partner are roughly 23.16 million light years away in the constellation Canes Venatici. The larger galaxy is Messier 51, also known as the Whirlpool Galaxy, while the smaller galaxy it is colliding with is cataloged as NGC 5195. Discovered on October 13, 1773 by Charles Messier.

I recently purchased a used Celestron 8″ Schmitt-Cassegrain Telescope (SCT). This is a whole new beast to me in the world of astronomy since I’ve only ever used Newtonian Reflectors as my viewing and imaging source in the past. This, however, was my very first time imaging with this telescope although I’ve had it for over a month at this point.

This telescope has a focal length of 2300mm (Newtonian was 750mm), so I get a more magnified view of objects. The downside of this telescope is that it’s a bit “slower” than the Newtonian. The Newtonian had an aperture of F/5, meaning it allowed more light making objects appear brighter in a shorter amount of exposure time. The Celestron SCT I purchased has an aperture of F/10, so images need a much longer exposure to collect photons from deep space images. This telescope is typically used for planetary and lunar imaging as the magnification allows a much better view of these objects for visual and imaging purposes.

Considering all that, and the fact that I am using a low magnification guidescope, and that I attempted 5 minute images with a magnification of 86x compared to the 28x magnification I was getting with the DSLR and the Newtonian. I would have to say I am quite pleased with the final results of my first imaging session with the new-to-me telescope. Maybe a bit more tweaking needed for the polar alignment and I will have rounder stars, as you can see with the 5 minute exposures they are a little oblong.

M51, Whirlpool Galaxy in Ursa Major

M51, Whirlpool Galaxy in Canes Venatici (Schmitt-Cassegrain) April 2017

For a comparison, here is the image taken a few years back with the same camera, but connected to the faster, less magnified, Newtonian.

M51, Whirlpool Galaxy in Ursa Major (Newtonian)

M51, Whirlpool Galaxy in Canes Venatici (Newtonian) March 2014

Quite the reduction in field of view with the SCT, but the object being imaged is much larger. Both images were taken with a full spectrum modified Canon 350D, both were a combination of 5 minute images. The SCT was a combination of 10 images at 5 minutes a piece, and the Newtonian was 21 images at 5 minutes a piece. Both shot at ISO 800. Both images contained a set of dark images, but the Newtonian also made use of flat frames, which I did not do for the SCT image.

All in all, I’m extremely happy with the results of this new-to-me telescope, and I really look forward to more clear nights for imaging some of those small objects I never really attempted with my Newtonian telescope. I did purchase a focal reducer for the SCT which would essential turn my F/10 SCT into an F/6.3, but with that aperture reduction comes a reduction in magnification. If I remember correctly, adding the focal reducer would essential drop the 2300mm focal length to somewhere around 1200mm, which is still more magnification than I was getting with the Newtonian, and roughly the same aperture.

Equipment:
Celestron Celestar 8″ Schmitt-Cassegrain Telescope
CG-5 Mount
Canon 350D Full Spectrum Modification
Lin_Guider on Linux Ubuntu for autoguiding
Deep Sky Stacker for image stacking
Photoshop for post processing the stacked image

M51 – Whirlpool Galaxy

I have posted about M51 in the past, but not like I have it now. I have previously posted about some new astronomy gear. I got a CG-5 Advanced Series mount, it is computerized and I’m able to — after properly aligning — type in an object and the mount points directly to it. It also does a pretty good job of framing it in just about the same position over multiple nights. This mount really makes it easy to find the faint targets that you can’t see from dark skies, and definitely not in the light polluted skies I’m shooting from.

Not only did I get the CG-5 mount, but I also got an autoguider setup, the Orion Starshoot Autoguider and the Orion 50mm guidescope. This allows me to lock onto a star and track it to make up for some correction in alignment to keep the object in view allowing for longer exposures. I was previously limited to about 2 minute exposures per image. With the autoguider and the CG-5 mount I’m am shooting at 5 minutes. I haven’t pushed it further yet due to the light pollution from my yard, but once it gets warmer I’ll be experimenting a bit with exposure times.

This is my first round of imaging with the new setup. I got M51 because who doesn’t like two galaxies colliding? On February 28, 2014 I got out for the first clear night in what feels like forever. This was in the least light polluted direction and in a great spot for me to image it.

M51 – The Whirlpool Galaxy 02-28-14

This image is 21 light frames at 5 minutes with ISO800. Also included was 25 dark frames, and 25 flat frames. Image stacked in deep sky stacker and post processing done in Photoshop.

I have to say the combination of the mount and the autoguider is going to be a major improvement on what I can image. I have another image in store that I am currently working on processing which will hopefully be up with the week.

Visiting Some Old Objects

This post is a bit like one of your favorite childhood movies or tv shows being redone, but only better. It’s better because these remakes came out much better than their original versions. Below I have setup a side by side comparison of old and new, and then the new version below it for a comparison, with a click-through link of the original post in the titles.

All of these remakes were all made from the same stacks as the originals; the only thing different is my steps in post processing of the image in Photoshop. The links back to the original pictures have the information on the stacks if you’re curious about how many lights, and dark frames I did.

I did a bit more than just adjusting levels and curves. I took the steps a bit further by adjusting highlights and mid-tones, applying an artificial flat, and adjusted vibrance and hue.

M16 – The Eagle Nebula

M16 – The Eagle Nebula. Before on the Left, After on the Right

M16 – The Eagle Nebula

M20 and M21 – The Trifid Nebula, and Open Cluster

M20 and M21 – Trifid Nebula and Open Cluster. Before on the Left, After on the Right.

M20 and M21 – The Trifid Nebula and Open Cluster

M27 – The Dumbbell Nebula

M27 – The Dumbbell Nebula. Before on the Left, After on the Right

M27 – The Dumbbell Nebula

M33 – Triangulum Galaxy

M33 – The Triangulum Galaxy. Before on the Left, After on the Right.

M33 – The Triangulum Galaxy

M51 – The Whirlpool Galaxy

M51 – The Whirlpool Galaxy. Before on the Left, After on the Right.

M51 – The Whirlpool Galaxy

Look at all the faint galaxies I was able to pop out in view in M51. A few months of editing has come a long way.

M51 – The Whirlpool Galaxy

M51 is two galaxies colliding together at a distance of 23 +/- 4 million light-years away from our own Milky Way Galaxy, and a radius of 43,000 light years. This galaxy although it lies close to the constellation of Ursa Major, it’s actually within the constellation boarder of Canes Venatici. These are easily spotted in the average amateur astronomers backyard telescopes, and may even be visible through a pair of binoculars.

‘X’ marks the spot where M51 is located. Screen shot from astronomy freeware Stellarium.
M51 through my telescope with plenty of light pollution in the skies looks like a hazy circle with a bright central core… actually, two bright central cores. One from each galaxy as they’re colliding together. M51 shines at a magnitude of 8.4 so it’s quite easily visible from light polluted skies and will probably show even more detail through an eyepiece from a dark sky location. Previously I had drawn a sketch of M51 through the eyepiece. Amazing the difference between what you can see, and what your camera can capture with multiple long exposures stacked.
M51 – The Whirlpool Galaxy taken on March 26, 2012.

M51 – Whirlpool Galaxy. This is a re-edit of the same images used to create the image above.

This image is 16 images at 30 seconds a piece, 10 dark frames, and 20 bias frames stacked in Deep Sky Stacker and processed in Gimp. Photos taken on March 26, 2012 with an Omni XLT 150 and Canon 350D prime focus.

February 18, 2012 Viewing Session – Galaxies

I went on a bit of a galaxy hunt. I felt the need to take advantage of the crystal clear skies and the fact that there was no moon visible in the sky. I didn’t get out until around 10pm at which point I checked the astronomical seeing by magnifying Mars. I had no luck and couldn’t even make out a polar cap. At that point I decided it was going to be a night of deep sky observing. Without having a motor to track with I decided it would be a good night for sketching. It wasn’t unbearably cold out tonight, around 26°F, quite a treat after last weekends real feel in the negatives. My favorite thing about sketching is that it is exactly what I’m seeing through the telescope, no long exposure to get more detail out of it.

My first target of the night was a Messier object in the constellation Canes Venatici which in my location is only two stars visible; Alpha and Beta Canes Venatici. The object I located was the Whirlpool Galaxy, M51a&b. These two spiral galaxies are in the middle of a collision 23 million light years away, and M51 has a diameter of 38,000 light-years. The cores of both the galaxies are noticeable through the telescope, and you can just make out the connection between the two. Although I am unable to make out any spiral features from my light polluted skies this was still a great object to view.

M51a&b sketch with quick notes. Click to enlarge.

Even though there are quite a few other galaxies to view within Canes Venatici I moved on to another constellation after the galaxy M63 gave me a hard time – more like I couldn’t find it. So I moved on to a completely different area of the sky.

Ever since I got my first scope I have wanted to see the Leo Triplet in the constellation of, well I’m sure you can guess, Leo. I have not been able to see these until tonight. The Leo Triplet, also known as the M66 group, contains the three Galaxies; M65, M66, and NGC 3628 which are aroung 35 million light-years away. These three galaxies are below the 3.3 magnitude star Theta Leonis, and also happen to be above the planet Mars, so there are some easy ways to find this grouping. M65 and M66 are both intermediate spiral galaxies, while NGC 3628 is an unbarred spiral galaxy, which is almost directly edge on with our view. Having the three of these in my view immediately made me think of a smiley face with the two Messier galaxies as the eyes and NGC 3628 as the mouth.

The Leo Triplet from left to right: M65, M66, NGC 3628. Click to enlarge
As I got done with sketching this I looked up to see where I could point to do another sketch, I was on a roll. When I looked up I noticed that the majority of the sky was covered in clouds. Unfortunately I had to end my night there. I wanted to keep going, especially since the galaxy cluster between Leo and Virgo were just coming out from behind a tree. I’m sure I’ll get another chance.