Wednesday, December 28, 2016

The Orion Molecular Cloud

Flame and Horsehead
Last night was one of the best we have had all year--above freezing temps (just), decent seeing, high transparency, and little sky glow. I took out the 8 inch, f/4 Newt and the DS 16C. All these images were taken with no dark subtraction, no filters, and were stacks of 20 x 15-second integrations. Of course, there is noise in the images as a result of the "raw" stack, but the images are pretty decent.

The Orion Molecular cloud has many wonderful objects for imaging, and last night's conditions enabled me to capture some of them: the Running Man Nebula, the Flame and Horsehead Nebulas, and, of course, the mighty Great Nebula itself.

The Great Nebula

The Running Man and the Great Nebula


Wednesday, November 30, 2016

A Walk on the Moon

This is a set of lunar images I took with my 125mm MAK and the ASI 120MM imager. The ASI is a very good monochrome imager and matches the MAK pretty well. Images were captured with Firecapture and stacked and processed in Registax.

The first image is of the famous Alpine Valley area (click to see a larger image). The valley is a line extending into the Lunar Alps (Montes Alpes) just above and to the left of center in the image. It is 166 km long and about 10 km wide.


The second image is the crater Copernicus:


Copernicus is 93 km in diameter and has a prominent ray system (the lighter "splashes" around the crater). The terracing of the crater interior is clearly visible in this image. These terraces are the result of landslides as the walls of the crater collapsed. The sloping rampart around the crater is about 30 km across.


Gassendi can be found at the northern edge of Mare Humorum. As you can see, the crater has been filled with lava during the formation of the Mare. The gap at around the 3 o'clock position is as low as 200 meters high; the highest part of the crater rises 2.5 km above the surface.


Thursday, November 10, 2016

Large Stack Experiment--M33, M31, NGC6912

Despite a half moon, skies were steady and transparent last night, with still conditions, making it a good night to try some more stacking experiments. The setup was my ZEQ 25 mount, f/4 Newt, and DS16C imager; no filters were used. I upgraded to the latest version of the MallincamSky software, but I was unable to get the dark field capture to work. However, the DS16C is very low noise, so I decided to go ahead and do the experiments anyway. Given that there is no noise correction of any kind, the images are remarkably low noise with little amp glow visible.

Image capture parameters were: Gain: 18; Exposure: 19 seconds; auto white balance. Histogram upper end was 100, lower end varied between 10 and 15, depending on the image.

Stack sizes were:

M33: 2x99-image stacks combined in Nebulosity
M31: 99 images
NGC6912: 99 images

Noise stacking artifacts are visible on the M33 image; the M31 image shows very minor improvement over the smaller stack I captured last Friday (a little more dust lane detail is visible above the center of the image), suggesting about 25-35 images is the "sweet spot" for good S/N in skies with moderate skyglow.

Images:





Tuesday, November 8, 2016

My Best M31


I captured and processed this image on Saturday night with the remarkable Mallincam DS16C and my f/4 Mallincam Newt. I used integrative stacking plus some minor tweaking (color balance--Photoshop; Curves--Nebulosity) to produce this final image. This combination of imager and scope really delivers!

Tuesday, October 25, 2016

Averaged stacking experiments--Bubble Nebula and M31

Equipment: Mallincam f/4 Newt and Mallincam DS16C.

Here are 3 pix I took using averaged stacking with the DS16C. I used the f/4 Newt, so there is considerable coma distortion. The M31 pic is an averaged stack of 20 integrations. My research and conversations with people who know stacking suggests that averaged stacking reduces overall noise, but "redistributes" it so that fine details are obscured and contrast is reduced. Compare this averaged stack image (20 integrations) with my previously-posted image of M31. Compared to that image, the noise is lower, but the sky background is quite light even after histogram adjustment. My earlier M31 (posted yesterday), was a much smaller stack using additive stacking. As you can see, there's more detail and a darker sky background, but the overall noise is higher. Unfortunately, I did not capture a single pic, but I suspect it would have shown more detail with a little more noise.

I also captured an image made with a large, averaged stack of the Bubble Nebula. The larger image shows how tiny the nebula is in the very wide field of the scope/imager combo. This image was the result of 70(!) (30+20+20) averaged integrations (the 3 stacked images were combined in Nebulosity). The cropped image shows the faint "bubble" nebulosity. Although the noise is lower than a single image, the single image I used to adjust the integration settings showed the nebulosity with more contrast.

Interesting results.



Monday, October 24, 2016

M31 with DS16C

I'm still learning about the DS16C--but what I know, I really like. The cam combines high sensitivity with very low noise and no amp glow. With this cam, you can capture detail fast!

My goal here is not to spend hours producing an image, but to see how good an image can be with fast capture and minimal processing.  Below is an image of M31 captured with the DS16C and f/4 Newt. It is a stack of 3x10-second integration with some level adjustment in Photoshop to darken the background--less than 5 minutes of total work.


Tuesday, October 18, 2016

First Light, Mallincam SkyRaider DS16C


Last night was First Light with the MC SRDS16C--a remarkable, 16 megapixel CMOS color camera which eliminates the Bayer Matrix and combines high sensitivity with low noise.  

My first, out-of-the-box dark field tests showed virtually no noise on 30-second integrations at maximum gain. Lengthening the integration to 1 minute showed a speckling of color noise. The biggest difference between this camera and my others is that even on a 2-minute integration, there is no amp glow! This is remarkable and greatly simplifies long exposures and multiple-exposure stacks that tend to enhance amp glow, even when corrections like DFC are applied unless great care is taken with dark field capture settings.

The images below are significantly "down-rezzed" as the actual images captured are in the 30 to 40Mb range. These were captured with my MC f/4 Newt under almost full moon conditions last night with no filtration. This is a great combination of scope and camera! As you can see, the result is a wide field with minimum vignetting and superb imaging capabilities. I can't wait to try it on more challenging--and more colorful--objects!

The Double Cluster (stack of 3x20-second integrations)

M31 (stack of 2x20-second integrations)

Deneb--the Very First Light Image (1 x 250ms integration)



Thursday, October 6, 2016

A Cosmic Bubble

The Bubble Nebula (NGC 7635) is an H II emission region located in Cassiopeia. The bubble is created by the stellar winds from the nebula's central star. The whole is surrounded by a giant molecular cloud. Both the nebula and the cloud are visible in this image, taken 10.5.16 with the 8 inch f/4 newt and DS 2.3+.


The Saturn Nebula

Running the 14 inch at f/5 with the large DS2.3+ imaging chip results in a relatively wide fov.  This is not a good combination for imaging small, compact planetary nebulas.

This is especially true of the Saturn Nebula (NGC 7009). The nebula was a tiny object in the full image and this rather noisy image is a very small, cropped part of the full image. It's immediately obvious why the object is called the Saturn Nebula. The nebula is formed by the ejection of the outer layers of a low mass star. The characteristic blue/green color is obvious in this image. The internal structure of the object is complex, but unfortunately, that complexity cannot be seen in this image. The object was either invisible or "blown out" in every integration I tried. I am sure that a larger image scale (for example, the 14 without the focal reducer) would stand a better chance of showing this structure.


Glorious Globulars!

There's nothing quite like a globular cluster. In my 14 inch scope, many of the brighter globulars make me feel as if I am falling into the sky. While it's impossible to recreate that feeling with an image, these objects are still impressive.

Here are images of two of my favorite globulars: M15 and M2. M15 is in the constellation Pegasus. It is one of the densest globulars having undergone core collapse. It's central structure may be a shell of stars orbiting a black hole.

M15 through the 14 inch with the DS2.3+ imager
M2 is found in Pegasus. It is one of the largest globular clusters and shows an slightly elliptical shape with a dense center.

M2 


Wednesday, October 5, 2016

The Eagle Nebula (Messier 16)

The Eagle is an iconic object and home to the famous Hubble-imaged Pillars of Creation. Also an H II star forming region, the latest research suggests that the Pillars may have already been destroyed by a schockwave from a supernova explosion 8000 to 9000 years ago. We will probably have to wait another thousand years to find out if the relatively slow-moving shockwave from the supernova riped them to shreds.

The Lagoon Nebula (Messier 8)

As in the last two posts, the Lagoon is another star-forming region. An H II emission nebula, the Lagoon is a dramatic object. Approximately 110 x 50 light years in size, it is an extensive object. The open cluster NGC 6530 is in the foreground. This is another image taken with the !4 inch at f/5 with the DS 2.3+.


The Trifid Nebula (Messier 20)

Taken with the 14 inch and DS2.3+, the Trifid is a lovely sight. At f/5, the nebula fills the FOV of the imager. The Trifid is an H II region in Sagittarius. It is a combination emission, reflection, and dark nebulas, plus a star cluster. The dark lanes that define the lobes of the nebula are designated Barnard 85.


The Iris Nebula (Caldwell 4)

The Iris Nebula is a bright reflection nebula. The cluster within the nebula is NGC 7023.  This image was taken with my MC 2.3+ and 8 inch f/4 Newt.


The Wizard Nebula (NGC7380)

The Wizard Nebula is a tough object to image in the haze of Indiana skies and the light pollution of my small home town. However, the tell-tale red color of the nebula can sometimes to pulled out of the skyglow with a little processing.


The nebula surrounds a cluster of new, young stars. If you look closely below and right of center, you can just make out the shape of the wizard's face and hat which give the nebula its name.

Sunday, August 28, 2016

Three full-frame Dumbbells

The scope/imager combo is critical to capturing the objects you want to image. There has been a great deal written about pixel sizes, focal length, optimal sampling, etc. I'm not going into that here, but I thought it would be interesting to show two uncropped images captured with the same scope (f/4 Newtonian) and two different imagers. The first image is a full-frame capture from my Mallincam Universe. You can see some vignetting as the Universe has a large, 6 MP imager. 



The second pic was taken with my DS 2.3+, which is has a 2.3 MP imaging chip. Notice the smaller FOV, but also notice how much more detail in the nebula the DS captures due to the larger image scale. Zooming the Universe (built for stunning wide-field views) does not produce as much detail.

I think this demonstrates well why no one imager/scope combo will "do it all." Needless to say, neither of these combos would do a great job with planetary imaging. So, as with anything else, you have to choose the right tool for the job.  Just for interest, here's another pic of the Dumbbell taken with the 6 inch RC scope and the DS 2.3+ with a .5x focal reducer for an f/4.5 ratio . Yet again, the scale is a little different.




Sunday, August 14, 2016

Stacked Dumbbell

I took this image on the August 7. This is cropped image from a stack of 5 x 15-second integrations using the DS 2,3+ and the f/4 Newt. I turned the gain down to around 3 and the stacked image is a huge improvement over my earlier image (a couple of posts ago) where high gain resulted in prominent stacking artifacts.


The stacking produced some slightly misshapen stars, but overall, it's a much better pic.


Sunday, August 7, 2016

The Sun 8/6/2016

Solar activity is diminishing after a disappointing solar max. While white light images show just a couple of small sunspot groups (ARs 2571 and 2572), H-Alpha shows much more detail, including prominences, granularity, filaments and, in this case, minor flaring from AR 2571.  I've also added an inverted image from May, 2013, as a comparison.




Monday, July 11, 2016

Live stacking--and mixed results with the new Mallincam Sky Software.

The latest Mallincam software has a really valuable new addition--live stacking that auto-aligns the captured frames into a single image. This ability to stack exposures, especially short ones, allows the capture of pinpoint stars, even if the scope's tracking is less than perfect. For example, a single, 30-second integration might show some "smearing" of stars if the mount or alignment is "less-than-perfect." But 6 x 5 second stacked integrations will show virtually no tracking errors.

I tried the setup out for the first time last night with the Mallincam DS 2.3+ with 0.5x focal reducer and Orion Skyglow imaging filter. The scope was the VRC6 on the ZEQ 25 mount. The sky was less than perfect and conditions deteriorated through the evening. By 1 am, skyglow was quite intense.

The first thing I noticed is that 6 x 5 second integrations are not the same as a single, 30-second integration (the gain settings were the same and the software was set to stack DSOs). Imaging the Dumbbell, a single 30-second exposure showed significant detail, while 6 x 5 seconds stacked did not show the nebula at all.

There were also a couple of other problems I ran across. All stacked images showed linear colored noise artifacts. Here's an example from 10 x 15-second integrations of the Dumbbell. The image shows an odd vignetting feature in the top left, along with some star distortions that must be due to a non-orthagonal imaging path. This is unrelated to the stacking and might be solvable with less aggressive focal reduction. This unprocessed image shows the linear noise artifacts clearly (click for a larger image):


I also tried a long integration of the North American Nebula. The image below is 99 x 5 seconds integration (!). The processed image follows it. I'm not sure if I captured nebulosity or skyglow in this image. Note how well the software stacks-- this is an 8.25 minute exposure. Unguided, it would be a streaky mess. But here the stars are round (apart from the vignetting artifacts mentioned above) and the depth is outstanding:


Faint streaks of glow are visible in the right, central part of the image. Processing brings them out--again, I'm not sure if this is not just skyglow, which was quite intense last night:


Notice again, the linear artifacts.

I did also have a glitch where the software reported stacked images, but did not update the output image (either in the output image counter or the actual image itself). I rebooted the computer, but that did not help. In the end, disconnecting and reconnecting the camera solved the problem,

Overall, the addition of stacking to the Mallincam Sky software is a huge improvement in capability (thanks, Rock!). I'm hoping that with some expert advice and more practice, I'll be able to get it to work for me much more effectively.



Thursday, June 30, 2016

The Eagle Nebula

One more f/10 image from last night--the Eagle Nebula. This image is 9 x 30 second integrations with the Universe and the 14 inch ACF. The Universe was running 3x3 binning and again, I did a quick 5 minute post processing session in Nebulosity.


Wednesday, June 29, 2016

A night at the Lagoon

Tonight gave us cool and transparent skies here in Indiana.  Here's a quick processed image of the Lagoon Nebula, imaged about an hour ago. This is a composite of 10x30 second integrations. The camera was a Mallincam Universe (unfiltered) running at 3x3 binning attached to the 14 inch at native f/10. Images stacked in Nebulosity with quick curve adjustments. I'm pretty happy with this, considering it is 5 minutes of data with 5 minutes of post-processing.

In the center of the "pink" region, the Hourglass Nebula is clearly visible (click image for a bigger view). This is an area where the first Herbig-Haro objects (patches of nebulosity formed by jets of gas from newborn stars colliding with clouds of gas and dust) were detected.


Wednesday, June 22, 2016

Mars--Seeing is Everything...

Last night's imaging session also gave me the opportunity to compare my image of Mars taken 3 weeks ago from the Isle of Palms in SC (using the 6 inch RC scope) with one taken here in Indiana with the 14 inch. The expectation, of course, is that the 14 inch would produce a much superior image. The 14 is perfectly collimated (as is the VRC 6) and, operating at about the same f/ratio with a barlow, produces a much larger image on the DS 2.3+ imaging ship.

However, my previous experience indicates that is not the case. I have never been able to get as good an image of Saturn as that I achieved in Cape Cod 3 years or so ago with my ETX 125. The 14 inch was not even close.

Why?

The answer is seeing. In Indiana, we tend to have either hazy, steady seeing, or very transparent but very unsteady seeing conditions. Transparent and steady almost never happens (although around 3:30 in the morning seems to be the best bet!).

Last night was no exception. To me, it seemed I was looking at Mars though quickly rippling water. The image was almost impossible to focus as it quivered and danced. There's a reason Percy Lowell set up his observatory in Flagstaff, AZ...

For comparison, here's the best image of Mars I could achieve last night with the 14. Syrtis Major is very visible--but that's about it:


By comparison, here's the image I took with the 6 inch scope in SC. Although the image scale was much smaller than in the 14 and I had to crop and enlarge it considerably, the much better seeing conditions in SC resulted in a more detailed image of the area of Mars presented at that time (see my Mars Through the Palms post for more details).



Conclusion: size isn't everything!






The Eagle Nebula--6.22.16

Last night offered very transparent, but unsteady skies with a full moon. I decided to attempt to image the Eagle Nebula (M16). The Eagle is low in the sky from Indiana and last night was made more challenging with the moon quite close to the nebula. This image was taken with the 14 inch ACF and MC DS 2.3+. The scope is native f/10 and I used an MC MFR 5 II focal reducer (both elements) which reduces the scope to f/5, but which also produces very significant vignetting.  I also used a top-of-the-line nebula skyglow filter (Baader). The images below are a stack of 9x 20-second integrations with dark field correction. The first is a cropped and more processed image; the second shows a basic stacked image with levels adjustment and vignetting--essentially what you see "raw." Given the conditions, the result is not bad.

The Eagle Nebula--Cropped and Processed



Image showing Vignetting

Thursday, June 9, 2016

A Needle, a Cigar, a Spiral and a Globular Cluster--Experiments with the MC Universe

A couple of nights ago, I decided to try an experiment with the Mallincam Universe camera and my VRC 6 scope. As conditions were less than perfect (some intermittent cloud and haze), I decided to use 3x3 binning, short exposures (15 seconds) and stacking (20 images per stack). The results are interesting.

The Universe shows significant vignetting with my 8 inch f/4 newt; it is even more pronounced (as I expected) with the VRC 6 and .5x focal reducer (f/4.5 effective focal ratio). The sensitivity of the Universe with 3x3 binning is outstanding--although at the cost of reduced resolution, of course. And even with this binning, the FOV is still huge.

My targets for the night were the Needle Galaxy (NGC 4565), M81 and 82, and M3. I was only able to get 5 images of M3 as the clouds rolled in. I took no darks. I used max gain and no noise reduction. My goal was not to produce high quality, printable images, but to see just how well the Universe would work in a more "real time" mode with short exposures. I also wanted to get an idea of how well it would work in combo with the VRC 6.

My conclusions: the FOV is impressive, as always, but I think the Universe is really more suited to a larger aperture scope. I can't wait to try it with my 14 inch ACF. I still expect to get some vignetting with the MFR II focal reducer, but I suspect this combo will match much better with the outstanding capabilities of this imager.
NGC 4565

M3

M81 and M82


Cropped image of Needle

Thursday, June 2, 2016

Mars in the Palms!

Mars is a challenging target. At favorable oppositions, the planet is low in the sky for observers in the Northern Hemisphere. From my Indiana location, it will never rise above the treeline for this opposition. Indiana is 40 degrees north; the Isle of Palms 32 degrees north, which places Mars a little higher in the sky (there was a huge splash in the pond next to our house as I was writing the last sentence and a huge alligator reared up out of the water--I wonder if astronomer is on their favorite foods list...).

Mars is still low in the sky here, and I had to move the scope a few times to find a gap in the trees, but the VRC 6 pulled out a pretty nice image. Margaritifer Sinus and Aurorae Sinus are visible at the upper right of the disc, and the Niliacus Lacus area at the lower left. This image was created from a stack of the best 200 frames from a 700 frame avi, stacked in Registax with unsharp mask processing in Photoshop. I've included the cropped and uncropped images for comparison.





Imaging at the Isle of Palms--Jupiter & Mars are Alright Tonight!

The weather in Indiana has been consistently cloudy for weeks, so I was really looking forward to our vacation on the Isle of Palms, just off the coast of Charleston, SC. We arrived at precisely the same time as Tropical Storm Bonnie. The grey skies and relentless rain did not look promising. And while it was grey skies and warm rain with palm trees, it seemed an ominous sign of things to come. After two days of cloud and rain, conditions improved. But it seemed the weather was settling into a pattern familiar to me in Indiana--clear days and cloudy nights.

Last night was different. The clouds stayed away and the night sky was velvety black and transparent. One the the great things about the Isle of Palms is that sea turtles nest here, so lighting is very strictly controlled by ordinance. One of the less good things (astronomically speaking) is that the island is covered in dense, tropical foliage. Our house is no exception and I had to setup in the driveway to image. Good polar alignment is pretty much impossible as the house blocks the pole star. That put DSO imaging out. But at 32 degrees south, Mars was a brilliant object in the SE. Jupiter was also, of course, very prominent and that was my first target. I brought the VRC 6, which, although better suited to DSOs, did a great job with a barlow, giving an effective focal ratio of f/18. The DS 2.3+ gives a very wide field, even in this configuration, but its resolution enables aggressive zooming.

Seeing was very good (as it often is on the coast) and I was able to capture a pretty decent image of Jupiter, especially for a 6 inch scope. I captured a 700-frame avi and stacked and processed the best 150 frames in Registax. The first image is a cropped version of the original, the second is the original, stacked image which shows the wide field of the VRC 6 even at long focal ratios.