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Moon Zoo: Crater Survey from The Zooniverse on Vimeo.

And if you think that’s all, check out There are many projects you can become a part of. Sure beats playin’ Solitaire!

You decide; the above picture of M3 was taken with Teide 2 at, under excellent weather conditions in the Canary Islands in Spain, virtually free from light pollution. I reserved a slot on Sunday, April 10, 2011 to get this image of M3 and compare it with my own. The specs of the telescope are:

Dome 2
Primary Instrument: 0.35 meter f/11 Schmidt-Cassegrain
Field of View: 13.1 × 8.8 arc-minutes
Camera Resolution: 2,184 × 1,472 pixels

Compare this to my picture with a modest NexStar 5SE in my light polluted backyard.

Messier 3 - another shot at ccd imaging this globular cluster

This is my latest picture of Messier 3. I took a few hundred images of 6 seconds each using Nebulosity with my Macbook Pro in the garden. On top of my Celestron NexStar 5SE telescope was a dew cap, which does make a lot of difference it turns out. The Lumicon deep sky filter was also in place (just before the zenith prism). All images were taken with the Meade DSI II pro ccd camera. From time to time I hand adjusted the NexStar to center the globular cluster M3 in the ccd. I don’t autoguide (yet). The NexStar 5SE isn’t equipped to use an autoguider, though I’m sure it would be possible to hack together some sort of autoguiding system. In fact, I wouldn’t be surprised if the electronics are identical to the NexStar 6SE which does have an autoguider port. But enough about that.

Inside, I handpicked the best pictures, which left me with 266 frames to stack in Nebulosity. I subtracted with a bad pixel map and aligned all the pictures using Translation + Rotation + Scale while saving each file instead of a stack. I love this technique, because I can then preview all the aligned pictures and toss out the ones that are slightly mis-aligned, or blurry. I find it easier to decide when I see all the pictures aligned. I then stacked the remaining frames using None (fixed) and did some post processing with curves and levels. I sharpened the image using Sharpen. I find Sharpen and Laplacian sharpen filter nicer for globular clusters than Tighten star edges.

Of course it took me at least 6 hours in total (imaging and post processing) to create the above picture. Which brings me to the limits of image quality. I created a similar photo of M3 months ago, and that photo was of much less quality. There is of course a sharp limit in terms of image resolution, based on the diameter of the main mirror of the NexStar 5SE, which is five inches. Maybe the above picture is hitting that limit. But the light pollution and the camera quality – which could easily be blamed for lesser quality pictures by a novice – certainly aren’t the true limits of taking beautiful pictures. By taking enough pictures and taking the time to read the manual of Nebulosity (and trying out several techniques), it seems to me that the picture quality to a certain degree is a function of the amount of time spent. Or should we say, the lack of boredom 🙂

Sunspots on March 15, 2011

Imaging the Sun is very dangerous without the proper filter. In this case I used AstroSolar (from Stichting De Koepel in Utrecht, the Netherlands) in front of my NexStar 5SE. In order to Solar System Align with the Sun, you will have to allow it in the menu of the NexStar. You will find this in the Utilities menu under Sun Menu. Once enabled, Solar System Align will let you align with the Sun. I held a bit of AstroSolar filter in front of the viewfinder to center on the Sun. Then I took a whole bunch of photos with Nebuolisty and stacked the best ones to this image. With the enormous amounts of light from the Sun, a short exposure time (like 0.002 seconds) will be enough, so it was easy to get a lot of pictures in a short amount of time. But the fuzziness of the Sun spots makes it hard to align them.

M42, yet another processing run

I would never have dreamed that I would’ve been able to capture the above image when I just got the Meade DSI II pro ccd camera. This is actually my first ever color image with the monochrome camera, and also the first time I’ve imaged M42. Still in my backyard in light polluted Zeist. So what’s the difference? Well, I read the entire manual of the amazing astronomy software called Nebulosity! I also created flat frames and bias frames, bought a dew cap for my Celestron NexStar 5SE and really took the time to capture 100 red, 100 blue, 100 green, 100 luminance and 100 dark frames. And the results could be better the next time! Because I have yet to start with EQ mounting and wedge aligning my telescope. It’s like with just about everything else in life: if you put in the extra hours, eventually it will pay off.


For those of you with a Canon point and shoot camera and who love to take pictures of constellations and such, there’s a really cool firmware hack called CHDK. This particular (non permanent) adjustment to your Canon camera will let it shoot in raw and – more importantly – use much longer exposure times, up to something like 30 minutes! Yes that’s true, 30 minutes!! All you need to do is download the right CHDK for your camera and copy it to a bootable SD card. Then make sure the card is locked (don’t worry, you can still take pictures with it with the lock enabled) and it will boot up with CHDK options. My little Canon Powershot SX 200 IS now has the above menu (and a lot more). Tons of fun, but you gotta be somewhat adventurous to get it all working.

Comet Hartley 2 on October 9, 2010

I took this photo on the night of October 9, 2010, in my garden in Zeist, the Netherlands. I had been trying to see this not-so-bright comet for a while now, but finally succeeded. How? Of course! I used precise goto on my Celestron NexStar 5SE. I first found its exact coordinates using Voyager, my favorite OSX planetarium by Carinasoft. A comet moves pretty fast, so you may want to get the coordinates of the exact minute you are trying to hunt it down. At that moment, comet Hartley 2 was at R.A. 02h 44m 37.18s and Dec +56° 12′ 37.9″. My NexStar was of course already linked to GPS satellites and auto two star aligned to Polaris and Albireo. The NexStar computer suggested Mirfak (α Persei), which I centered in the eyepiece. It then instantly slewed to Hartley 2 which was dead center in the eyepiece. I had to use averted vision at first to see it, but quickly got used enough to the dark to see it. I did use the light pollution filter, but it just shows it is possible to find such a faint object in terrible light polluted surroundings with a magnificent instrument like the Celestron NexStar computer.

A few notes about astronomy metadata:

– I have my photo of Comet Hartley 2 in my FlickR photostream. Simply by posting it in the flickr group will add notes and tags to it with the exact coordinates, some of the bright stars, etc. It is also called the “Blind astronomy solver” and it’s a wonderful free service for your FlickR astronomy photos.

– Adding FlickR tags will make your photos easier to find at any rate.

– But if you are really serious about your astronomy metadata: there’s a standard for it called AVM. I won’t even begin to explain it, because there’s a cool site with everything you could dream for, including white papers and a plugin for Adobe products. It works fine with Adobe Bridge on my Macbook Pro running OSX. It’s the future of information. Learn about it now. Metadata is uber cool. A good place to start is XMP panels in Adobe Bridge.

Here’s my mosaic of the Moon on the International Observe the Moon Night, september 18, 2010.

Mosaic of about a dozen FITS frames.
Meade DSI II pro ccd camera.
Celestron NexStar 5SE telescope.
Moon contrast filter.
Post processing in Adobe Photoshop Elements.


I took this photo of Jupiter (currently with only one of its prominent atmospherical bands visible) on Sunday, September 19, 2010 from my backyard in Zeist, the Netherlands. At magnitude -2.9, Jupiter is really very VERY bright. Actually, it is even too bright for my Meade DSI II pro ccd camera. How can that be, you may wonder, and what can I do about it?

Well, according to Meade, the Monochrome Sony EXview HADT CCD Sensor (ICX429ALL) that’s at the heart of the DSI II pro ccd camera supposedly has a shutter speed from 1/10,000th of a second onwards. But in my experience, the image starts to distort seriously at such fast shutter speeds. When I crank up the shutter speed, the image however starts to over expose. So in the above case, I added the red filter #24 and this brought out much more detail because I could use the longer exposure times (something like 0.6 seconds if I recall correctly). Shutter speed is really something to experiment with, it appears. For deep sky objects, I expose between 10 and 20 seconds (beyond that, most images become blurry), but things like the Moon and planets require much faster exposure times if you want to avoid over exposure.

It’s amazing how many people I’ve met who own a telescope with a GOTO mount and don’t actually use it! The reason given is usually that “it is too complicated”. I do admit it takes some getting used to, but once you know how to do it, it’s dead easy and super for finding things. Back in the old days at age 12, I used to have a 60mm self-built refractor, which of course wasn’t computer powered at all. So I used most of my time outside to actually find objects. Now with my Celestron NexStar, it’s a mere matter of two star aligning and off I go, finding things I never would be able to find as quickly on my own.

I did start out using Sky Align at first, but soon discovered I was having more success with Auto Two Star Align. For one thing, Sky Align does err on occasion or isn’t able to match the objects. Finding three objects takes more time and there’s something conceptually weird about finding three random bright objects when you know most of the bright stars.

Auto Two Star Align is an easy procedure.

1) Make sure the telescope is positioned fairly level and will not move easily (this can be tricky when you position your telescope on grass or dirt).

2) The NexStar should know its position and time accurately. You need the GPS option for this.

3) In the region of the sky you want to observe, get to know the bright stars. This is fun to do and very useful knowledge, now and in the future. For instance, if you’re gonna look at Gemini, know which stars are Castor, Pollux and Procyon. Go get yourself some software that will tell you what you’re looking for. This too is essential for your stargazing fun.

4) Follow the procedure for Auto Two Star Align with those bright stars from step 3. Easy! You will notice that the NexStar already suggests stars you’re currently seeing. It will also “guess” a very reasonable second star that won’t take forever to slew to. It has never failed on me.

Once you feel comfortable using Auto Two Star Align, be sure to also check out Precise GOTO, because that’ll make you find things you thought were impossible to find.

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