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.

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.

M63 – Sunflower Galaxy

Discovered first by Pierre Mechain on June 14, 1779, and then included into Charles Messier’s catalog the same day. This was the first Deep Space Object that Messier’s friend, Pierre, had discovered. M63 was one of the first early recognized spiral galaxies. This galaxy is joined in a group of several small galaxies about 6° north of it in the M51 group.

The box marks the location of M63

The box marks the location of M63

Although this galaxy has a visual brightness of 8.6 magnitude I found it a little tricky to pinpoint. I used stars from Ursa Major and Canes Venatici to estimate where to aim the scope and then I had to do a bit of sweeping around with the scope to find it. Visually from where I am it wasn’t much more than a round fuzzy which was mainly the core and a little bit of the spiral disk. This picture brings out a lot more detail than I would have thought this galaxy had.

M63 – The Sunflower Galaxy. 05-05-13

32 images at 2 minutes a piece, ISO 800, and 24 dark frames. Stacked in deep sky stacker and post processing done in Photoshop.

Omni XLT 150 with CG-4 mount
Modded Canon 350D
T-ring and adapter
Polar Scope for alignment

M3 – Globular Cluster


Messier 3 is a globular cluster in the constellation Canes Venatici at a distance of 33,900 light-years away from Earth with a magnitude of 6.2. It is one of the largest and brightest globular clusters visible in the northern hemisphere, and consists of around 500,000 stars. Globular clusters are groups of old stars with this cluster being estimated at 8 billion years old. Within this cluster are a known 274 variable stars – the most found within any globular cluster.
‘X’ marks the location of M3.
I happened to be out viewing this cluster as the moon was already beyond 50% so it was washing out a lot of the stars, galaxies, and nebula in the sky. I decided on M3 as it is one of the brightest globulars, and it was one of the few that was above my tree line from the backyard. Considering the moon brightness paired with light pollution I was very impressed with the view of it through the telescope, and of course couldn’t resist getting a few images of it to stack and show off.
Given it’s location along the border of 3 constellations; Canes Venatici, Bootes, and Coma Berenices it wasn’t the easiest to find due to it’s location in the sky and it’s lack of many stars visible to guide from. This was the first time I actually used my RA and DEC dials on my EQ mount. Using the star Arcturus as my setting star I tried it a few times with success on each attempt making M3 land within the view each time.
M3 Globular Cluster in Canes Venatici. April 2, 2012. Also above the cluster is Galaxy NGC 5263 at magnitude 14.
This consists of 14 images at 30 seconds a piece, 10 dark frames and 20 bias frames taken on April 2, 2012. Since the temperature at night has been the same during the last few sessions I’m able to reuse the same darks, and bias frames each time. I planned on getting a few more dark frames while I was out, but I had some difficulties with my polar alignment and tracking that I was getting a lot of star trails. By the time I finally got everything the way I needed it to be I was almost out of battery on my camera.

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.