From last Monday night I had a good clear sky where I was able to get out for a few hours. I was capturing 400 second exposures for a total of 1 hour 40 minutes of integrated time. Using dithering between shots and just flat frames and bias frames for stack calibration, I spent some time in Photoshop to get this final image. Nothing too spectacular, but I like these kind of targets with my setup while I am trying to use longer exposures. Seems all the clear skies have a big fat moon in the sky lately…. Guess I will have to just look at the moon!
I have not posted in a while being too busy during good seeing conditions for late nights in August, and poor weather in September. The several times I did get out I was not able to capture enough data for good images but if I get time one day I should go back and see what I can do with a few of them.
I was able to find a good steady night on the 15th with a crescent moon that set early enough to provide very good dark sky conditions. Tracking was going very well and the Pacman Nebula was high in the sky for some great imaging. This represents a somewhat longer run for me with even longer exposures. About 23 frames at 400 seconds each or around 2 1/2 hours total.
The Pacman, also known as NGC281 is a bright emission nebula in the northern constellation of Cassiopeia and is part of the Milky Way. This image is cropped a bit but represents the relatively distortion free field of view with my current setup. I am using the Orion 6″ astrograph reflector at 600mm focal length and my Canon T1i which is still unmodified. This means I don’t get as much of the fainter red nebulosity. Since I am doing very simple processing with Photoshop, my stars are more prominent than would show in a sophisticated process separating the nebula from the star field. This would be a good base image to learn some more processing techniques when I can find the time!
From the 9th. I took a while looking for a target and settled on this one low to the North East. We had some breeze and the air was a bit unstable. Along with the warm summer air the stacked image was dissapointing with hardly any visible nebula and significant noise. So after a lot of noise reduction this is what I could pull out. At my imaging scale it did not all fit in the frame, but enough to give the namesake appearance!
The Heart Nebula is located in the constellation Cassiopeia. It was discovered by William Herschel in 1787 This is an emission nebula showing glowing ionized hydrogen gas and darker dust lanes.
The nebula’s intense red output and its configuration are driven by the radiation emanating from a small group of stars near the nebula’s center. This open cluster of stars known as Melotte 15 contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun’s mass.
Low in the southern sky, this is my first run at imaging the popular Trifid Nebula. Almost two hours of 400 second subs brought this image to life. The seeing so low in the sky is generally not so good, but last night the sky was rather clear. This has been cropped by about half of my full imaging scale.
From http://www.messier-objects.com/messier-20-trifid-nebula/ :
The name Trifid refers to its three-lobed appearance. Messier 20 consists of several different objects: an emission nebula, a reflection nebula, a dark nebula and an open star cluster.
The dark nebula, catalogued as Barnard 85, consists of dust clouds that absorb and block light from the bright objects behind them. It is responsible for the apparent gaps in the larger emission nebula that give M20 its trifurcated look.
The other two types of nebulae – emission and reflection – make M20 glow in different colours in images.
Emission nebulae are energised by the ultraviolet light of nearby stars and usually appear red in photographs. These nebulae are clouds of extremely hot hydrogen gas and usually regions where new stars are being formed. The light of the stars illuminates the surrounding clouds, ionizing photons in large portions of the clouds.
Messier 20 is a popular target for amateur astronomers as it is quite bright, even when seen through a small telescope. It has an apparent magnitude of 6.3 and lies at an approximate distance of 5,200 light years, or 1,600 parsecs, from Earth. M20 has a linear diameter of over 40 light years and is only 300,000 years old.
I was able to capture well over two hours of 5 minute subs to compile this region. Using an unmodified DSLR, I do not pick up much of the hydrogen alpha emissions found in this type of nebula, but it is a dramatic and beautiful target. The processing was complicated for me by the profusion of small stars which are brought up in brightness along with the faint nebulosity. I am starting to look forward to the day I can afford better software to process data like this. Also I would like to try incorporating narrow band data even if it is captured with my stock DSLR. Most serious imagers would scoff at this technique, but us shoestring astronomers have to be willing to be non conformists. The data can be captured in large part, just not efficiently.
The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus, a large but relatively faint supernova remnant. The source supernova exploded circa 3,000 BC to 6,000 BC, and the remnants have since expanded to cover an area roughly 3 degrees in diameter (about 6 times the diameter, or 36 times the area, of the full Moon). The distance to the nebula is about 1,470 light-years. This is also one of the largest, brightest features in the x-ray sky.
Last night the sky was perfect around midnight and I was imaging very well. I thought I could go for a long time, but by 1:30 the moon was up and before long my subs were starting to get washed out. I could have kept going but the magic dark hour was gone so I called it a night. My second sub and several others had satellites crossing the five minute exposures, but the stacking program nixed that data I hope. After tossing a few low scoring frames I put together one hour twenty minutes integrated time for this result. For my setup and Photoshop skill level I am happy with the final cropped result.
This is known as the Cocoon Nebula, which combines a star cluster, an emission nebula, a reflection nebula, and the vertical “tail” of a dark nebula. Surprising how short the dark time was last night before the moonrise started to dilute the imaging. One hour twenty minutes total image time.
I have not been out a lot due to cloudy weather, and on this night (the 14th) I thought it had cleared to a wonderful dark clear evening only to have the clouds come in all too soon. in all this left me with just four sub frames of 300 seconds each for only 20 minutes of data. Still, I processed what I had and here are the results! This region will give me more to do for sure as soon as the weather cooperates.
The East Veil Nebula is a hot plasma emission nebula producing beautiful colors from ionized hydrogen, sulfur and oxygen. The remnants of a supernova though to have occurred five to eight thousand years ago. The image here is just a fraction of the whole system which lies some 1,500 light years away, yet spans a portion of the sky 6 times the diameter of the moon!
The Pelican Nebula is seen near the top of this image from last night along with more of the American Nebula it is a part of. I managed 1 hour 33 minutes of integration time with 200 second subs. As usual I am not so sure of the post processing but I pushed it to make it interesting. The vertical band through a minor star in the Pelican was obvious in the subs as I was imaging but I think this is an artifact. I actually processed out vertical banding to minimize this. There is often something which puzzles the shot that can be more trouble than it is worth to track down. It does not seem to be real, as I don’t see this in other peoples images on the web. I have had some vertical anomalies before, so I think it is my camera doing something crazy! After all it is just a normal DSLR so it is not exactly designed for Astrophotography.
I was just looking for a target in the dark area of my sky for the short time between dusk and moon rise. I cam across this region searching in Stellarium, and was surprised it had no common designation. Captured around 1.5 hr of data to produce this image from the depths of the milky way, A myriad of colorful stars stand out from the thousands in this image. Astrometry found 4686 stars to work with identifying the center position as:
RA 19hr 59m 48sec
Dec +35deg 24m 46sec
The brightest star is the crook of the neck of Cygnus designated “n” or the abreviated “n Cyg”. It can also be described as the southern star of the “northern cross” which makes the body of the Swan. At the northern end of the cross is the better known star, Deneb. The Crescent Nebula lies just north of this region.
The Iris Nebula is a reflection nebula in the constellation Cepheus that I was able to image on the 24th. The moon was bright so I was looking for targets in the North East for the darkest skies. I got 22 subs at 240 seconds with ISO 800 but the tracking was only fair. Transparency was not the best and a bit of breeze caused some shifting I think. That and or “chasing seeing” where the guide scope image is wavering around. It still just amazes me what can be pulled from the data I start with. Never give up on washed out subs!
I need to try adding a little more distance to my Coma Corrector as it still shows under-correction toward the corners, but some of that is tracking. Some images I adjust a bit using the lens distort effect in Photoshop but not on this one. You can tell because it will distort the angle of the diffraction spikes across the field when software corrected.