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Astrophotography: Markarian’s Chain in Virgo Cluster

|Galaxies|2 Comments

Markarian’s Chain is an impressive photography subject for those with a camera and telescope to capture it.  This string of 7 distinct galaxies is a member of the Virgo Cluster and epitomizes the types of astrophotography subjects available during galaxy season.

On Friday Night (Good Friday), I was spoiled with a second consecutive clear night sky.  The moon would rise above the horizon by 11:30 pm, so I had a few hours of moonless imaging time to squeeze in.

Markarian’s Chain is a prominent feature within the impressive Virgo Cluster of galaxies.  M87 is the brightest member of the group, a very large elliptical galaxy. 

My final image of Markarian’s Chain included 2 hours and 10 minutes of total integrated exposure time.  To see a larger version of the image with complete photography details, continue down this post.

For a run-down of the processing steps used, have a look at my tutorial on deep-sky image processing in photoshop.

Astrophotography during a Waning Gibbous Moon

With a nearly full moon traveling across the ecliptic, deep-sky astrophotography becomes a lot more challenging.  Couple this with my lack of any filters for the ASI071, and you’ve got a difficult imaging session ahead.

basic astrophotography setup

View my updated list of equipment for deep-sky imaging

Luckily, the Virgo Cluster of galaxies including Markarian’s chain showcases many interesting, yet mostly featureless objects.  A forgiving target for imaging conditions such as this.




Usually, when the moon is out, I’ll capture H-Alpha data using my Canon T3i and Astronomik 12 Ha filter.  However, my previous attempts at capturing Ha on a small galaxy (The Pinwheel Galaxy) proved to be of limited value.

I think I’ll save the Ha capturing for some of the Nebulae that will be gracing our night sky in the coming months.  For now, I’ll focus on collecting RGB frames using the OSC (One shot color) ASI071 camera when moonlight is limited.

I can only hope that the clear skies continue as we near closer to the weeks on either side of the new moon.

Using the CMOS sensor Cooled camera

The ZWO ASI071MC-Cool remains in my procession for the time being, and I couldn’t be happier.  Spending time with this camera has allowed me to further familiarize myself with the CCD imaging process and software such as Sequence Generator Pro.

CCD Camera for astrophotography

If you are transitioning from a DSLR camera, I think you’ll find that the AS071 is a big improvement.  I’ve been cooling the camera to -40 degrees when shooting targets in my backyard, and the images produced are virtually noise-free.

The camera has some pretty neat features including a built in anti-dew heater window heater, that can be turned on and off.  I haven’t had to use the feature yet, but I have a feeling it will come in handy during the summer months.

This camera is available at Ontario Telescope & Accessories.

Markarian’s Chain: String of Galaxies in the Virgo Cluster

This area is considered to be the core of the Virgo Supercluster, and is a truly spectacular sight.

The Virgo cluster contains some serious astronomy eye-candy.  The sheer number of galaxies in this area of the sky is staggering.  If you are looking for a deep-sky view at the Universe, you’ve found it.

Markarian’ Chain – April 14-15, 2017

Markarian's Chain in Virgo Cluster

Markarian’s Chain – Wide Field ViIew through the ES ED102

Photo Details:

Total Exposure: 2 Hours, 10 Minutes
Image Frames: 26 x 300″
Support Files: 15 Darks, 15 Flats

Camera: ASI071MC-Cool (Color)
Telescope: Explore Scientific ED102 CF
Mount: Sky-Watcher HEQ5 Pro SynScan
Guide Scope: Starwave 50mm
Guide Camera: Altair Astro GPCAM2 AR0130

Image Aquisition in Sequence Generator Pro
Registering and Stacking in DeepSkyStacker
Post Processing in Adobe Photoshop CC

The Virgo Cluster is the closest cluster of galaxies to our own Milky Way. Markarian’s Chain appears to form an arc pattern, with 7 or more galaxies making up the formation.

M84, M86, and M87 are the largest galaxies of the group, cataloged by Charles Messier.  The galaxies may appear small, but each of them contains more than 400 billion stars or more.

Go ahead and explore this amazing area in detail.  Click here for a large version of the image.

Where is the Virgo Cluster?

Below you will find a wide-field image of the constellation Virgo and the surrounding area.  Jupiter is seen at the bottom right and Arcturus on the left.

Star Chart - Virgo Constellation

Markarian’s Chain is not observable visually but will become evident in short exposures at the right focal length.  Using the 2-second refresh rate on SharpCap, I am able to spot the 3 brightest galaxies in Markarian’s Chain.

I am quite proud of my framing on this one.  My goal was to center Markarian’s chain in the field of view while capturing as many additional distant galaxies as possible.

Image Processing Tips

As I mentioned, I could really benefit by using filters with the ASI071 while imaging in my light-polluted backyard.  Specifically, a UV IR Cut filter would reduce star bloat, and correct much of the color balance issues I had to tackle in post processing.


Thankfully, I received some useful information about stacking images with this camera’s color profile and Bayer pattern in DeepSkyStacker.  Because of the RGGB pattern used in the sensor of the camera, the default stacks were coming out with an odd color cast (mostly green).

I corrected this by a large degree by using the following parameters for RAW/FITS files in DeepSkyStacker.

DeepSkyStacker settings for ASI071

Adjusting DSS for better color balance using the RGGB Bayer pattern

As you can see, I bumped up the red and blue scales to create a more balanced final image.




Once this was corrected, my standard deep-sky processing techniques were effective in boosting contrast, removing gradients, and reducing star size.  The curves adjustment applied was much more subtle than it would be on a nebula.

Because of the visual characteristics of the galaxies in Markarian’s chain, you do not need an aggressive stretch to bring the objects forward.  I could have brought the “glow” from these galaxies out further, but not without degrading the quality of the background sky.

Much more exposure time would be required for the best of both worlds.

For the Love of Astrophotography

Telescope setup for deep-sky photography

I forgot how nice it was to spend the majority of the night outdoors while the camera was running, rather than monitoring TeamViewer in the house!  The milder nights have been hovering around 1 or 2 degrees, which is just enough to keep my hands from freezing.

I’ve mentioned this before, but I can’t stress enough the importance I give to the overall experience.  I believe that it is easy to get sucked into the fine details of your equipment and obsessing over the automation of your gear.  For me, I never want to lose the feeling I get when I look up on a clear April night.

Where’s your DSLR?

In case you are wondering, I’ve still got my hands on the ASI071MC-Cool from Ontario Telescope and Accessories.  They have graciously given me an extended period to use this imaging camera.  For now, my Canon DSLR remains stored in the garage.

Until next time, clear skies.

 

Related Posts:

Deep-Sky Astrophotography During a Full Moon

8 Galaxy Season Targets for your Camera and Telescope

CCD vs. DSLR Astrophotography – A New Learning Curve

Resources:

The Constellation Virgo – EarthSky

The Virgo Cluster of Galaxies – APOD

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CCD Camera Target: The Leo Triplet

|Galaxies|2 Comments

My testing of the ASI071MC-Cool Astrophotography Camera continues.  This time, on the Leo Triplet of Galaxies. This CCD-style camera (One-shot color CMOS sensor) has taken the place of my Canon T3i DSLR for now.  After some early struggles, I have enjoyed learning the new photography techniques involved with CCD imaging.

By now, many of you have transitioned from deep sky targets that were available during the Winter months into the springtime galaxies (myself included).  Even though each night kicks off with Orion, the constellation quickly fades into the glow of the city as the night progresses.

I have been pointing my telescope towards Leo the lion for a few years now, usually starting in the month of April.  The Leo Triplet occupies the “sweet spot” in the night sky where I have an opportunity to capture a respectable amount of data throughout the night, with a meridian flip intermission in between.

View my latest image of the Leo Triplet (April 3, 2017)




 

Target Acquired: The Leo Triplet

M66 Galaxy

If you read my post on 8 deep sky targets for galaxy season, you’ll already know that the Leo Triplet is one of my favorite subjects to photograph at this time of year.  Most galaxies are quite small when photographed through my 102mm refractor, but this trio of galaxies fits nicely within the frame.

The constellation Leo is present for the majority of the night during the months of March through May, which is where you’ll find the Leo Triplet. The diversity in galaxy types makes the Leo Triplet a satisfying astrophotography target for night sky photographers, both amateur and professional.

If you want to try it for yourself, set your goto mount to M65.  You’ll discover M66 and NGC 3628 nearby even in short exposures.

You can view my most recent image of the Leo Triplet further down the post. It is a good example of what to expect using a small refractor.

To me, the Leo constellation is most easily recognized by the sickle or “reverse question mark”, as I like to call it.  The sickle starts with the bright star Regulus and works up through the lion’s mane including another bright star, Algeiba.   I will often use Regulus as a target for my star alignment process, as its magnitude and location are familiar to me.

Leo Constellation Map

Camera: ASI071MC-Cool (Color)

I’ll continue my deep sky astrophotography work using the ASI071MC-Cool (one shot color) CCD camera for the next 2 weeks.  If you missed any of my latest experiences using this cooled astronomy camera, have a look at the video below.  I begin to understand some of the basics of CCD astrophotography and end up with a much better version of the M81 and M82 galaxies.

A night of deep-sky imaging in the backyard

Like anything else, my enjoyment of the process becomes greater as I achieve better results.  I feel like I have a system that works now, so it is exciting to keep using the new camera.  I will likely capture one more deep-sky target with the ASI071 before returning it to OTA.

I photographed the Leo Triplet the night I shot the video below.  It was the second target after spending time on Bodes’ Galaxy and the Cigar Galaxy.

 

New AstroBackyard videos are posted on Facebook too

Dew heater strap

I hope experienced Sequence Generator Pro users will excuse my lack of knowledge.  I was delighted to be able to capture successful light, dark and flat frames using the ASI071 with SGP.  The flats were a little different than I was used to, but I eventually had success using the methods outlined on the AstroBackyard Facebook Page.

The team over at ZWO graciously included my video on the product page for the ASI071MC-Cool.  I can only hope that sharing my experiences using the camera early on will be useful to future owners of the ASI071.  It may give another perspective to the realities of switching to a CCD camera by current DSLR owners.

I can see how SGP would do an amazing job automating almost the entire imaging session. I haven’t even scratched the surface of this software yet. The plate-solving, autofocus, and target sequencing features have opened my eyes to a new world of automation possibilities. These will come in handy when I eventually build a backyard observatory.

I also want to test out (APT) Astro Photography Tool before I have to send the camera back.  On the surface, it looks to be a slightly more user-friendly option than SGP.

Switching from DSLR to CCD?

I have been asked this question a number of times, and the answer is not yet.  For starters, the Canon 600D continues to be my only primary imaging camera.  I have been given an amazing opportunity to test products (Including the ASI071MC-Cool) thanks to my partnership with Ontario Telescope and Accessories.  I will be sending the CCD camera back in about 2 weeks from now.

CCD camera attached to telescopeThe costs involved in upgrading to a dedicated CCD camera are not in my budget for this year.  The equipment I currently use should paint a picture of the amount of money I am able to invest in astrophotography at the moment.

I have been very impressed with the results I have been getting with the CCD camera thus far.  The final stacked images are probably the highest quality data I have ever brought into Photoshop. The 4 and 5-minute exposures captured using the ASI071 have been incredibly smooth, with very little noise.  The color balance is little different than I was accustomed to with the 600D, but there are ways to correct this in post-processing.

Goodbye Thermal Noise

My regular processing workflow with the DSLR included a lot of time spent correcting noise and gradients.  With the frames being captured at -30 degrees and below, removing noise is an afterthought.  I still run one noise reduction filter near the end of the workflow, but that’s it.




It’s too bad that I am reviewing the ASI071 in the early Spring when the temperature regularly drops to zero at night.  Those hot imaging sessions in July could really benefit from a cooled sensor!

My latest image: The Leo Triplet

The Leo Triplet

Click the image for a larger version

The image above was captured on March 17th from my backyard.  I did not use any filters with the ASI071 including the recommended IR-UV CUT filter for better color balance and to prevent star-bloat.  The camera was cooled to -30 degrees Celcius before taking each frame.

Astrophotography Details:

Equipment:

Mount: Sky-Watcher HEQ5
Telescope: Explore Scientific ED102 CF
Camera: ZWO ASI071MC-Cool (Color)
Guide Scope: Altair Astro Starwave 50mm
Guide Camera: Altair Astro GPCAM2

 

Photo Acquisition Details:

Total Integrated Exposure Time: 3 Hours, 30 Minutes
March 23: 21 x 300 Seconds
April 1: 20 x 300 Seconds

Camera at Unity Gain
Support Files: 15 Darks, 15 Flats for Each Night

Processing: DeepSkyStacker and Adobe Photoshop

Astrophotography telescope

No filters, from a red-zone, light polluted sky!  I was shocked at the quality of the frames I was taking in the city with this camera.  I think that astrophotographers shooting in heavily light-polluted areas could benefit a great deal using a cooled CCD.

The photo above was under 2 hours worth of total integrated exposure time.  The potential for the ASI071 is remarkable.

If you would like to stay up to date with my latest images and equipment updates, please follow AstroBackyard on Facebook or Twitter.  You can also subscribe to the AstroBackyard newsletter here: AstroBackyard Newsletter

Until next time, clear skies!

Related Posts:

A photogenic group of galaxies – The Leo Triplet

Altair Astro GPCAM2 and Starwave 50mm for Autoguiding

Deep Sky Processing in Photoshop

Resources:

An incredible photo by one of my biggest inspirations, Scott Rosen: The Leo Triplet

Leo? Here’s your constellation – EarthSky

APOD – August 2011 – The Leo Triplet

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