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.