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

This weekend worked out great for my Linux and guiding test

Successfully got Lin_Guider to work under Ubuntu 15.04 which I could never get to work under Mint with my Orion StarShoot Autoguider. Not only is guiding working, but so is image downloading from my camera to my computer. Image below is Lin_Guider guiding on a star near M27.

I also just ordered the Celestron RS232 cable and RS232-USB so I can us Cartes du Ciel for Goto controls of my CG5 mount.

Just about all the pieces of the puzzle are finally together. Only thing left on the big astronomy list is an observatory, but that is still a ways away from happening.

#linux #ubuntu #astronomy #astrophotography #autoguiding 

Linux and Astronomy Frustration

Anyone that follows me knows that I have been relentlessly (bashing my head against the wall) trying to get Linux as my main astrophotography setup. I can successfully plug in my Canon 350D and download images instantly onto my computer with just a USB cable and the software Entangle: http://entangle-photo.org/ I do not use it as my means of controlling the shutter since I have an intervalometer that controls the shutter for imaging.

I use an Orion StarshootAutoguider (SSAG) as my guiding camera and a CG-5 mount, which I am attempting to control using Lin_Guider: http://sourceforge.net/projects/linguider/ I have successfully gotten the SSAG working to show me the stars it is imaging, but I still can't get the program to talk to the mount and send pulses. I can't calibrate or guide with it yet. This is the last thing I need to get working before I can be completely up and running in Linux, and finally be able to ditch Windows all-together.

I have been trying like crazy to get the computer to talk to the guide camera and mount, but I just can't get them to work yet. I'm probably missing something extremely simple.

#Linux   #Astrophotography    #Autoguiding   #Astronomy   #Lin_Guider  

Last week I broke down and bought PixInsight

Since my 45 day free trial ran out before I ever got around to really using it I decided to buy it for good reasons. One, it is a beast for astrophotography! Two, it runs natively in Linux which is a major plus for me since I mainly run Linux. I maintain Windows on my laptop for now only because I'm working out some kinks on getting autoguiding to work on Linux on my laptop.

This is my first attempt at PixInsight, and I can say I'm quite please, and proud of the final results. The comparison of these two images is quite a difference. I still have a ways to go to get better in PixInsight, but for a first attempt I couldn't be happier with the results.

These two images were created from the same exact data. I had a bit of an issue getting rid of the red blemish in the upper left corner of the PixInsight image. I think a bit of light bled through when I was shooting my dark frames which may have caused this since I forgot to cover the camera with a shirt like I usually do, which allowed light from my back porch to bleed through on the dark frames.

I'd also like to thank +Stuart Forman for helping me get started in PixInsight.

#astronomy   #astrophotography   #linux   #PixInsight   #space  

In album 2015-01-24

M33 – The Triangulum Galaxy

This face on spiral galaxy can be found just to the east of Andromeda in the constellation, Triangulum. M33 is a spiral galaxy around 3 million light-years from Earth. Sometimes referred to as the Pinwheel Galaxy, and often getting confused with M101 which shares the same nickname. Triangulum Galaxy is within the Local Group of galaxies along with our Milky Way, Andromeda, and 30 other smaller galaxies. It is thought that M33 is a satellite galaxy with M31, Andromeda. Within this galaxy there have been many discoveries of globular clusters or diffused nebulae; that along with the shape it is believed to be a lot like the Milky Way.

‘X’ Marks the spot of M33

My Observation: M33 is a very faint hard to see object through a 25mm eyepiece, but bumping up the magnification drowns out the faint galaxy. In the light polluted skies of Plattsburgh I’m unable to pull out any detail of the galaxy, maybe some of the brightest star clusters within it, but unable to make out the loosely wound spiral arms. The central core is the brightest part of the galaxy through the eyepiece. Can make out about 20 bright stars upon first glance, but longer viewing shows many more very dim stars in the field of view.

M33 – Triangulum Galaxy Sketch

M33 – Triangulum Galaxy

M33 – Triangulum Galaxy. This is a re-edit of the same images used above.

For this set of images I took 36 light frames, but Deep Sky Stacker only used the best frames leaving me with 29 60 second images stacked at ISO 800. Final editing done in Photoshop, no artificial flat frame used because they kept leaving a ring around the galaxy throughout the whole image. Subtle, but still a distraction from the main image. Instead I used a duplicate layer and the option of “Overlay” to reduce the light pollution in this image.

Equipment:
Omni XLT 150 with CG-4 mount
Canon 350D
T-ring
T-ring adapter
Intervalometer
DIY Reticle eyepiece for drift alignment