astrophotography

Whoever told you that you need a telescope for astrophotography was wrong. If no one told you such a thing, nevermind. My point is: check out what I photographed under the light polluted skies of the outskirts of Amsterdam, using nothing but a dslr and a tripod:

Spiral galaxies M81 and M82 in Ursa Major

This image was from the second night I tried to photograph deep sky objects near Amsterdam. My images from the first night weren’t focussed well enough, so I didn’t really get any good results from that. The second night however, I paid plenty of attention to focussing and the results were singificantly better. I used an old 35-80mm Canon zoom lens at 80mm to image my most distant target ever.

A while ago I mentioned the Andromeda galaxy being very far away right? Well, these galaxies reside at 12 million light years distance from us and 130.000 light years apart. In fact, the galaxies are so close to each other that M81’s gravitational forces are believed to trigger an enormous amount of star formation in M82 by pulling gas clouds into the galaxy’s core. M81 appears as an oval galaxy while our ‘edge on’ view of M82 causes it to appear as a bright bar. Hence its nickname ‘Cigar Galaxy’.

The M39 open cluster in Cygnus

M39 is a group of stars that all originated from the same gas cloud near the Cygnus constellation. You may have noticed that this photo contains way more stars than the first image. This has 2 reasons.

Reason 1: The first image was taken near where the sun had just set, so the sky was much brighter and less stars are brighter than the background glow.

Reason 2: The Cygnus constellation lies within one of the spiral arms of our galaxy and therefore, there simply are more stars to see.

The M13 globular cluster in Hercules

My last image is one of the great cluster in Hercules, which is a globular cluster. Globular clusters are groups of then thousand to a million stars very densely and spherically packed, so that look like fuzzy balls to my camera. On a clear night under dark skies, M13 will appear to your eyes about the same as in this image. When observed through telescopes, globular clusters start to show their distinct stars and look like brilliant clusters of shiny pearls. Open clusters may be even more breathtaking to view through a telescope, as more and more stars just keep appearing the longer you look.

Soon I will try to image some cool double stars, open (or globular) clusters and maybe shoot a good Andromeda image through my telescope. Also, a bunch of cool terrestrial photos is on its way 😉

Sometimes astrophoto processing can be quite time consuming. The last couple of days I spend quite some time behind my laptop to get the best results out of my raw astrophotos. First of all a Saturn photo from Tuesday the 1st of July.

I still haven’t figured out how to remotely make video recordings with my dslr attached to a telescope. Instead I shot about 120 photos, which is not a lot of frames, but I got bored of clicking the shutter button soon. The image below is the result of a 65 image stack. Whenever I find out how to make videos with the DSLR attached to a telescope, I will be able to push the enhancement sliders a lot more and hopefully to resolve some more detail. Until then, I’m very happy with my best Saturn so far:

Saturn through a 90mm reflector with fairly good seeing

The evening of the 2nd I got my full gear out again and went searching for some cool deep sky objects. One of the easiest to find is the Ring Nebula (Messier 57). Just like the Dumbbell Nebula from earlier, this is a planetary nebula. It is an illuminated bright shell of gas enclosing the center star. Why it appears as a ring instead of a ball hopefully becomes clear from the image below:

Why spherical planetary nebula appears as a ring

The upper line contains much more light from the nebula compared to the lower line, which only crosses through a thin layer of gas.

That said, I present to you, my first image of the Ring Nebula:

The Ring Nebula (M57) through a 130mm telescope with light pollution filter

On the upper right the double star Sheliak shows some cool diffraction spikes. A double star? Yes. The two are simply too close to be distinguishable. I will try to show you a cool double star soon.

Up next: the Andromeda galaxy (Messier 31). I promised to try and capture a good shot of the Andromeda galaxy through my telescope. Well, it turned out to be a difficult target. Someday when it is a little higher above the horizon, I will make a ton of photos and stack them to be able to resolve some detail. A stack of 32 frames just doesn’t have enough information and this is the best I could get out of it:

[I really didn’t like this picture so I tried some more. I stacked the result of the 800ms and 1300ms images together and stretched levels in nebulosity and processed further in Adobe Camera Raw. Still not perfect, but I like it a lot more (Note that this is just the core, the outer dust lanes of the galaxy are too faint to be captured in such a short exposure time) :

Bright core of the Andromeda Galaxy

I hope you don’t mind that I deleted the previous image 🙂 ]

And last but not least: Another Dumbbell Nebula. This time shot through a light pollution filter. I used a very questionable adapter built from paper and duct tape to attach the light pollution filter while still being able to focus at infinity. Questionable or not, this way I avoid spending 200 euros on a dedicated filter.

The Dumbbell Nebula (M27) through a 130mm telescope with light pollution filter

The image below is a combination of the frames from the previous session and the frames from the image above.

Best 41 frames of all the photos I got of M57 stacked together.

Also, another terrestrial photo post is coming up somewhere this week. Not as large as last time, but I definately got some cool images, so stay tuned!