Merry Christmas!

I hope everyone had a wonderful Christmas. As is typical for the Pacific Northwest, it's wet and overcast, which unfortunately makes viewing the heavens difficult. It's especially hard when Santa brings lots of astronomical goodies that can't be used until the sun decides to return. Santa was very good to me this year, bringing everything I need to start doing long-exposure astrophotography, including a Celestron HD Pro wedge, a Nexguide autoguider, and a few other things. Here's hoping for clear skies soon!


By Beverly & Pack

Table Mountain Star Party 2010

Here are a few pictures from the 2010 Table Mountain Star Party:

From TMSP 2010 - Site Photos

Table Mountain

With a new moon and clear skies forecast for last weekend, Tony and I decided to head up to Table Mountain for an evening of observing and astrophotography. We loaded up my truck and headed out at 3:00 PM on Saturday. On arrival we discovered that the road was still blocked by snow about a mile from the summit, and in fact there was someone stuck in the snow that we helped tow out (I have a 4X4). I didn't think we'd make it to the top, so we set up in a big meadow right before the snow line.

After unloading the truck and setting up camp and the telescope, we cooked a fine dinner of cowboy beans and waited for the sun to set. As we waited, a few other observers arrived and set their gear up. Venus was the first to appear in the cloudless, dark sky.

Here's Tony relaxing and waiting for dark (click to enlarge):

We spent a couple of hours looking at various targets including M13, M31, M57, Saturn, Venus, Mars, and several others. Around midnight Tony got tired and crawled into his tent to sleep, and I broke out the Nikon to start taking pictures.

My first target was M57. I recently purchases a Bhatinov mask to help with focusing, and it REALLY helped. I was able to get pinpoint focus within just a couple of minutes. I started snapping 30-second shots of M57, and then realized I had left the focusing mask on :). After correcting that little problem, I proceeded to take about 30 exposures.

I then imaged M31, NGC6703, and NGC6946. After that I took the camera off the 'scope and tried taking a few wide-angle shots. I wrapped up at around 2:00 AM and went to bed.
The next morning we packed up and headed home, where I downloaded the data I had capture and started processing. Unfortunately the only shots that came out well were the ones of M57:

Here's M31. As I said, not very good:

Here's a shot of my telescope and camp site taken just after sunset (click to enlarge):

Overall it was a great trip. I really need to get a wedge and autoguiding setup to I can take longer exposures.

M13 - The Hercules Globular Cluster

Image of M13 I took last week. It took me forever to achieve decent focus, so I've since purchased a Bahtinov focusing mask.I did manage to get a good one-minute exposure despite using an alt-az mount. I also took some three-minute exposures, but there was some star-trailing so I didn't use those.

Adventures in Photoshop

I spent some time in Photoshop trying to bring out the colors:

M42...Again

Clear skies on Friday night made for a great opportunity to try out the new f/6.3 focal reducer. Again setting my sights on M42, I took 27 30-second sub-exposures at ISO 800. I stacked the images in DSS, and processed in Photoshop. Here's the result (click on image for larger version):

I think the reducer made quite a bit of difference. There's definitely a lot more faint detail in this image, and overall it's significantly less grainy. So far all of my shots have been done with in-camera noise reduction turned off, and I haven't been using dark frames. I think next time I will try turning noise reduction on and see well that works. Supposedly when shooting 30-second exposures and NR is on, the camera will automatically take and subtract a dark frame with each image.

First Imaging Attempt Part II

I spent some time processing the image I took of M42 with The Gimp (The Gimp is a freeware image processing tool similar to Photoshop). As you can see, a little processing goes a long way in bringing out details in the image. (click on the image for a larger version)

Here's the original, unprocessed image for comparison:

Some people say that it's not possible to take decent deep-sky images without long, guided exposures, but clearly the image above demonstrates the falsity of that claim. Granted this picture is far from magazine quality, but I don't think it's too bad given that I'm a complete newbie and this is the very first deep-sky image I've ever taken with a telescope I've only used for one full night!

I've ordered an f/6.3 focal reducer/corrector. This is a lens that screws onto the visual back of the telescope which turns the f/10 telescope into a "faster" f/6.3 optical system. The net result is that it reduces exposure times by a factor of three. So that means that a 30-second exposure at f/6.3 is equivalent to a 90-second exposure at f/10. This should help in capturing more detail at the exposure times I'm limited to since I currently can't take guided long exposures.

First Imaging Attempt

Last night was the first clear night we've had since I got my telescope nearly a month ago. Previously there had been only two occasions where a brief hole opened up in the clouds for about 20 minutes where I was able to view the moon. But last night was cloud-free and no moon. After putting my daughter to bed, I set up in the backyard. Aligning via All-Star align was a breeze. Mars was high in the sky so I slewed over to it and popped in a 2X barlow and a 23MM 2" eyepiece. I could immediately notice the polar cap, and as I stared at it for a few minutes began to notice a few details on the surface, despite the fact that the image was quite small. I think I need to get a shorter eyepiece for planetary viewing.

Given that this will be Mars' best apparition for the next four years, I wanted to try imaging it with my Nexstar camera. After spending a few minutes connecting the camera to my laptop and figuring our how to use wxAstroCapture, I centered Mars in the field and replaced the eyepiece and barlow with a 1.25" adapter and the camera. It took a bit of playing around to get it centered, but was finally able to get a bright blob in the center of the screen. I then spent several more minutes figuring out how to adjust the camera setting and focusing the image. Once it looked reasonable, I started capturing frames. I took three videos, two of 1000 frames and one of 2000 frames.

I then decided to try my hand at deep-sky imaging, and turned the 'scope towards M42 in Orion. It was beautiful through the eyepiece despite my light-polluted suburban Seattle skies. I then attached my Nikon D40x and spent several minutes trying to focus the image. I think I may invest in a Bhatinov focusing mask to help with this in the future. Once I got reasonably focused, I took a series of 30-second shots.

As it was now getting rather late, I packed everything up and went inside. Unable to resist the urge to see what my images looked like, I fired up the computer and transferred the pictures to it.

First I took a look at the .avi files of Mars. The raw video showed a fairly unimpressive blob, but after stacking with Registax I was got this:

This was a stack of 407 frames out of 2010. No processing was done beyond simply stacking and wavelet processing. The polar cap is visible, and some surface detail as well. I'm not sure if the light patch on the Western limb is clouds.

Next I used DeepSkyStacker to process the M42 images. I had eight good 30-second frames. This is what I got:

I realize that this isn't magazine-quality, but I was pleased at the result given that I'm an utter novice at this, and this was the first picture I have ever taken. Keep in mind that this is also an unguided image taken with an alt-azimuth mount in light-polluted skies with no processing beyond stacking. This is also a .jpg image that is greatly compressed from the original high-resolution RAW image (that one looks much better).

Now I need to start learning how to process the images in order to bring out the details. Overall I was quite impressed by the performance of the scope and the fact that I was able to actually capture something. Now I just hope we get a few more clear nights so I can practice.

First Light!

After waiting over a month, my new Celestron CPC 800 telescope arrived yesterday morning. Since we've had solid overcast for the past few weeks, and it is very nearly a law of nature that you will have cloudy skies whenever you get a new telescope, I had little optimism that I would get a chance to do any observing any time soon. But lo and behold, as I was driving home from work a hole opened up in the sky, and the waxing crescent moon hung high above in the blue sky. I raced home, quickly unpacked the scope, and set it up in the living room.

The telescope appeared to be in great condition, and so I quickly moved it out to the driveway to see what I could see. With little time left before the clouds came back, I didn't even bother powering the scope up. I manually pointed it at the moon, inserted a 40MM 2" eyepiece and had a look. WOW! The moon filled the eyepiece, and gorgeous detail was visible along the terminator. I popped in a 29MM eyepiece with a 2X barlow and was floored with the view. Stark shadows stretched out from the mountains and fine details could be seen along the crater walls. It was like flying across the moon. I only had a few minutes to admire the view, as the clouds came back and covered the sky.

I moved everything back in the house, and concluded that the 8" scope was definitely the way to go. I was surprised at how large the thing is, as the telescope alone weighs 42 lb.s. The tripod comes in at another 27 lbs. so all up the beast weighs nearly 70 lbs. The 9.25" or 11" scopes would have been pushing the boundaries of convenience. I think anything heavier than the 8" would have resulted in diminished enthusiasm for lugging it outside and setting it up.

Since there were no stars visible, I wasn't able to check the collimation precisely via a star test, though judging by the crisp details I saw on the moon, I think it's probably in pretty good alignment. I did pop a laser collimator into the diagonal, and was puzzled to see the beam bypass the secondary be a good half-inch! I'm thinking that the collimator itself may be out of collimation.

I'm hoping we get at least one good clear night within the next couple of weeks. Mars is in opposition on Jan. 29th, and while it's not a great apparition, it's the best we'll have for the next four years. It will be a good opportunity to do some imaging.

Now I just have to figure out where to store this thing.

Orion Nebula (M42)

Shot of the Orion nebula I took this evening with the wide field 90mm f/5.56 Apochromatic Refractor at the SLOOH observatory in La Dehesa, Chile. Five minute exposure.