AstroKev
Random Musings of an Amateur Astronomer
NGC 891
Aug 29th
This image is actually from data gathered on Aug 17. Heavily speckled from duddy darks (note the red, blue, green hot pixels), but this image still turned out alright. This stack was done on the NP101is, but with the 1.5 imaging extender on. No filters were used; 3 minute exposures autoguided with PHD and a new Orion autoguider (and not planetary imager!) This could certainly benefit from some additional aperture but I was still pretty pleased with how well it came out. Nice spiral edge-on galaxy. Enjoy.
NGC 891, 3 min subs, TV NP101is with 1.5 extender
Televue 1.5x Imaging Extender
Aug 16th
New toys! Always fun! After the 2x Barlow, 4x Powermate Test, I thought I would branch out a little with the 1.5x extender (for NPis scopes only!!)
Mirfak in NP101is Prime Focus and 1.5x Extender
The first thing that I noticed was that this thing is huge. It is almost as long as my Stellarvue 10×60mm Finderscope and a healthy slug wider diameter. Indeed – this monster fits into my NP101is with no special adapters needed as it’s built on the NPis 2.4 inch diameter specification. Since I use an APS sized sensor most of the time (on my Orion StarShoot Pro), I generally don’t need the extra big of space, but nonetheless it certainly does the job. It’s just a lot larger than you’d expect from a typical barlow or powermate type of accessory.
While I probably should have continued on with M2, the real comparison here is for field of view. I also gave the Orion SkyGlow a moment for extra comparison, although it was pretty dark and these were short exposures.
M33 on NP101is with 1.5x Imaging Extender
In this case, each image here is of Mirfak, a bright star in Perseus. Of course, I was looking that way for the Perseids meteor shower, so this turned out to be a fun target in hopes of catching some extra meteors. In this case, each image in the composite is 5x 15s exposures; nothing fancy here. While the fields are rotated (I didn’t put the camera back on the same), and the 1.5x is rotated more still, the interesting thing to observe here is the image scale. You can also see that the SkyGlow didn’t do much for me – but this wasn’t a long enough exposure with lots of light pollution to test with.
A slightly more interesting comparison is M33. I previously imaged M33 at F/10 on the CPC1100 and f/5.4 on the TV NP101is. This provides a pretty nice contrast to the field of view – with 20x 60s exposures.
NGC 6960 – The Veil Nebula
Aug 13th
Two days ago, some ‘late night clouds’ rolled in giving me only a tiny window to the sky. Like any good observer, I quickly scoured the skies for anything that might be interesting — when I came upon the Veil Nebula. Holy moley this thing is both gorgeous and easy to find!
For whatever reason I find that Cygnus the Swan is easy to find. Well, the Veil Nebula is near a ’sort of visible’ star off to the side of the main stars making it up. This ends up being about a fist and a half “lower” than Sadr, the ‘middle’ star – which is ‘not as bright’ as Deneb, one of the three stars making up the Summer Triangle. (The summer triangle is fabulous for aligning scopes, too — the other two stars being super bright Vega and ‘pretty bright’ Altair)
Nonetheless, I spend a good slug of time imaging NGC 6960. I was so excited with the results that I spent another day imaging it more. All together I ended up with several hours of imaging over two days. This created some interesting challenges. First, from day to day the image ‘centering’ varied. This is pretty easy to deal with. However, the second is trickier — rotation. Not because of an alt-az mount (I was on the CGEM), but rather because the camera actually was rotated from day to day! Of course, both DeepSkyStacker and MaximDL dont have much probelm with rotation and recentering, so software took care of most of the problems and a healthy dose of cropping makes it look like it was all planned!
NGC 6960, The Veil Nebula
For processing, I played with a few concepts. All the subs here were either 30 or 60 seconds each. In MaximDL, I chose the ‘Sum’ method for every five minutes of image time. This turned out to be tricker than it sounds since some images were rejected during the ‘Combine from disk’ phase. Nonetheless, I eventually ended up with 12 subs, which were summed up to 5+ minute exposures. Rather than combine these in MaximDL, I bounced over to DeepSkyStacker. Here I did a normal combine (Kappa Sigma, 10 iterations) and of course spent countless hours trying to get the color balance to some point where it was both colorful and contrasty. While this final image does appear a bit inflated in Greenness, I really can’t complain much about the final product here.
If it weren’t for Oceanside Photo and Telescope sending me the 1.5x extender and some new guidescope rings, I probably would be imaging it more today to add even more subs! Nonetheless, I hope you enjoy this particular image as much as I do. Even though the filaments on the left side don’t completely jump out, they are there. Maybe after a few more days …
Exoplanets, Aliens, and Where Are They?
Jul 27th
Today during lunch, one of my colleagues mentioned there was recent turmoil presented at the TEDGlobal conference. Normally, I’d not be thinking about it except that the enjoyable readings of Alan Boyle reminded me with an article: Millions of Earths Talk Causes a Stir. Ironically, I just the other day finished the book by the same author referenced at the bottom of the article, The Case For Pluto. Then the discussion quickly turned into the “have we ever seen an exo planet, or do we just see the transits affect the stars brightness” discussion. Enter the 2008 image from the Hubble Space Telescope, providing the first visual image of an exoplanet.
Exoplanet in Fomalhaut
Recent history has shown extremophiles expand the ranges where astrobiologists can hope to find life in other worlds. And, if Kepler and new technologies are showing us tons of planets out there — more than we originally expected — then why is it we haven’t found the aliens? Or even been contacted by them? SETI has been looking for communications for decades and hasn’t found anything. What gives?
In the 1960’s, Frank Drake formulated a thought experiment to calculate the probability of finding life out there. The Drake Equation is pretty simple:
N = R * fp * ne * fl * fi * fc * L
where:
N = the number of civilizations in our galaxy with which communication might be possible;
and
R = the average rate of star formation per year in our galaxy
fp = the fraction of those stars that have planets
ne = the average number of planets that can potentially support life per star that has planets
fl = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent life
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time such civilizations release detectable signals into space.
A few months back, Astronomy Magazine had an article highlighting some of the recent findings and how they may be affecting the estimates of these variables. To me, the universe seems so huge that the chances of life being out there are pretty good. Yet, the distances are so retardedly far apart that unless that have super special warp drives or wormhole teleportation, it’s not likely they’re going to be visiting us anytime soon. And, all this ’scale of the universe’ talk brings up a fun way to really appreciate and visualize the true distances involved. Check out this flash scale of the universe flash to help get acquainted…
M27, The Dumbbell Nebula
Jul 26th
I generally welcome a sunny day — if it’s going to lead to a clear night. However, clear nights this part of the lunar cycle are not quite as exciting. No, a full disc moon is not really something that makes for great ‘dark skies’. However, it does allow one to hit double stars, globular clusters, and of course, the ever exciting planetary nebula. Last night’s target was M27, the Dumbbell Nebula. Lumicon’s UHC filter probably would have been best, but I still ended up using the Orion Skyglow. The Skyglow is kind of like a bad UHC filter — it passes a lot of light through outside the OIII and H-beta lines. Nonetheless, it’s still a pleasant effect.
M27, The Dumbell Nebula
Last night was mega problems as far as guiding. I did a rough alignment to start with Mizar and Arcturus and added my favorite two calibration stars, Vega and Altair (love the summer triangle stars!) However, it was apparent from my goto’s that the calibration was way off. Usually I would use a collimated finder or illuminated crosshair reticle (Orions 20mm is nice!), except I didnt want to take the camera off and muddle with focus just for alignment. So I took pictures and centered them based on the image I took. This process was almost certainly slower than just refocusing later, so I’ll probably do it ‘the normal way’ next time.
Because I had some recent successes autoguiding with PHD Guiding, I tried to give that a whirl many times over and continually had problems. The two weird behaviors I couldn’t explain were the “frame rate” accelerating much faster than the 1s exposures I had it configured for and what appeared to be a “freeze frame” while trying the calibration steps. Unfortunately this always would result in the failure of calibration — and therefore no autoguiding. By this time I was so frustrated I ended up realigning all over again, and dropping in a 2x barlow for some extra fun.
Rules for next time: spend more time properly aligning and calibrating the scope!
The Dumbell Nebula itself is a pretty fun target because you can see it visually as we did nearly a week ago in the 11 inch. The central white-dwarf star is very hard to see visually, but in these images (from the Televue NP 101is — a four inch refractor), it’s obvious. The right side also shows some nice cloudy disturbances. Given that these exposures are only 30s each (40 of them), this image seemed to turn out alright…
M82, M33 – AltAz Imaging at f/10!
Jul 16th
The past few nights here in Woodinville have been really quite nice. And I’m not just saying that because our week of summer is going to end soon, but rather the air has been clean, calm, warm, and most important: dark. Very dark. Now, it’s really quite odd that some of the best times to do astronomy here you get the fewest number of hours to do it — it’s not “dark enough” until around 11pm, and there is an eerie brightness that begins to creep up to the east around 3.30am. But that’s still a few hours you can hit some nice targets.
The other day a co-worker came over and we hit up a lot of the usual “ooooh” targets, but then I remembered Epsilon Lyra. I’d ony set up the CPC 1100, and this famous double double was easily resolved with an Ethos 21mm. Some separation was even visible with a 28mm meade cheapie. A few months ago I had some issues with secondaries, corrector plates, etc — so it was nice to see my optics are still working at least for 2.5 arc-second resolution. And here are some nice photos to prove it!
M82, The Cigar Galaxy
Both these images were done in full Alt-Az configuration with the Celestron CPC 1100. I used the Pyxis rotator to derotate the field so I could experiment with some longer exposures that usual — although of course tracking related issues still make themselves known in some of the subs. These are also taken at prime focus with no reducer and no corrector — full f/10 optics (probably more like f/11 with all the stuff hanging off the end of the scope.) For those curious, the imaging train goes as follows:
- CPC Back
- Televue SCT short back #1
- Pyxis camera field rotator (2″ nose adapter and SCT back adapter)
- Televue SCT short back #2
- Orion Skyglow imaging filter
- Orion StarShoot Pro V2.0 Color CCD
Normally one could insert a f/6.3 reducer in there as well if you really wanted but I wanted to really stress this system out a bit more. This first image is a stack of 24x (of 40 taken) 60 second exposures of M82 with 4 darks.
M33, Triangulum Galaxy, CPC 1100
The second image here is pushing the limits even further of the ability of the CPC 1100 to track things in AltAz — full 2 minute exposures. This M33 image is a stack of 11 (of 19 taken) 2 minute exposures with 5 darks. Unfortunately it looks like my centering is a bit off — which seems to be a problem here since the image barely fits in the field of view. For comparison, I have a cropped version of M33 from the Televue NP101is. The image scale and detail here are pretty fun to compare side-by-side.
M33 in Televue NP101is
M31, Andromeda in the Televue NP101is
Jul 13th
M31, Andromeda Galaxy
So we were lucky and got a good stint of good weather last week and I hit up one of my favorite targets, Andromeda. The sheer size of this galaxy across the sky still amazes me. Nearly six times the size of the moon in apparently size (viewed from Earth) and 2,700,000 light years away, this is the most distant thing you can see with your naked eye. Sadly, it’s coming towards us and eventually will merge with the Milky Way.
This was about 20x 30s frames stacked. It turned out a bit monochrome-looking, so there’s more work to do to help the colors stand out, but I’ll probably grab new raw images before I do that. Anyway, enjoy.
Nice galaxy clusters: NGC 5982, 6946 and more!
Jul 9th
A few nights back we had some nice weather. A friend came over, we set up a super quick mini-star party and were off to the races. We had both scopes set up and did a lot of visual viewing on the CPC1100. Obvious targets – M13, M17, M27, M81, M82 were all offering brilliant views in the 21mm Ethos and 31mm Nagler. We fiddles around with some of the “super sale Meade 5k 20mm’s” in binoviewers as well. After viewing, lasering, drinking and all those other good things that go with astronomy, my friend headed home for the night and I began imaging on the Televue NP101is on CGEM. I am still amazed how incredibly awesome that telescope is, especially on the CGEM. It is such a pleasure to use!
NGC 5981, 5982, 5985, 5976, 5989
I really enjoy challenging the Televue NP101is on super dark “feint fuzzies” — and it works so well that every time I see the subs I am amazed how well it seems to be collecting up the light. In this image, we have a nice arc of three galaxies – not quite as large as Markarian’s Chain, but a little more dynamic: an ‘on edge’ spiral, an elliptical, and a spiral ‘on face’. As an added bonus, a few others pop into this image, although the real focus are the three of 5981, 5982 and 5985. This image was processed in MaximDL, 20x 30s exposures using the Orion StarShoot Pro v2.0 camera. As an added adventure, this was my first time using the Orion ‘SkyGlow’ imaging filter.
The first time I tried using this filter was a bit of a problem because the addition of the filter on the nosepiece of the camera added to the focal length also made it more challenging to attach to the NP101is. However, this time I used the new extension tubes and this made it extremely easy since I could just use the compression ring to clamp things down instead of screwing everything together. For some reason, I really like the compression rings much more than screwing thing in (where threading and sizes become issues), and really dislike the screws (which mar equipment and always feel a bit wobbly, especially as equipment moves around.)
The second fun target of the night was NGC 6946. This beautiful spiral galaxy has the added bonus of also being near NGC 6939, a nice globular cluster. I didn’t see this cluster in Stellarium when I first decided to make this a target for the night, so you can imagine my delight when it popped into view!
NGC 6939, NGC 6946
Both these images were taken simply at prime focus and probably would benefit from either a 2x barlow or simple imaged off the larger CPC 1100, and I’m definitely going to make a few more, longer exposure attempts at them both.
As usual, processing was done in MaximDL. I really had to work these a bit in order to get the contrast to show enough detail; fiddling with the screen stretch and gamma scaling was pretty intense guess work! I’ll have a few more images to come in the next few days!
4x Powermate, 2x Barlow, f/6.3 Reducer Comparison of M2
Jul 5th
Again with data from June 26th 2010, I diligently put some effort into determining exactly what the impact of barlowing would be on M2. Sort of like the M13 comparison, I thought this would be an interesting way to really see the difference.
In this comparison, the constants were a big, bright full moon, haze, the CPC 1100, Orion StarShoot Pro v2.0, and the f/6.3 reducer. Processing was done in MaximDL and I left the reducer on even with the barlows – generally a weird thing to do – simply for the flatness effect. In retrospect, this probably was a bad idea since I would have cropped things down so much anyway. Then I scaled each image to be approximately the same size, simply so the overall effects would be visible. I also tried to scale exposure times to be a bit more in line equally. I also used the Orion SkyGlow Imaging filter, just to help weed out any extra light – with the bright moon, I could use all the help I could get!
M2 Comparison
The upper left image is with a 4x Televue Powermate. The camera was set in monochrome mode using 2×2 binning and the result is built from 12x 30s exposures. This mostly looks like a b/w image and the center, while not very clear, does show some contrast – just not very much.
The lower left image is with a 2x “BIG” Barlow, 12x 15s exposures. The 2x Powermate is supposedly nearly parfocal with the 4x, so it’s a bit sad that I had to go through refocusing here, but nonetheless, this is clearly the worst overall. Partly because it’s moldy green looking (poor processing) and partly because the subs were “cloud challenged”. However, I felt it was important to include it alongside the others.
Lastly, the one which I’d have to say looks best, the upper right image is just the f/6.3 reducer – no barlows – and 12x 10s exposures. Arguably this is a little bit more exposure time than the others, but this image is much more vibrant. The “fuzz factor” looms wonderfully around the core. The obvious take away from this is that the reducer is certainly nice on DSOs, and the focal length increasers probably should be left to the planets on the CPC.
M64, The Black Eye Galaxy
Jul 5th
For whatever reason, hitting some of the famous DSO’s proves to be more challenging than I expect. This is 165 seconds of exposure time on the CPC 1100 with f/6.3 reducer up, from data gathered on June 26th. Each raw image here barely looked like much; I had to use a fairly aggressive Unsharpen to bring out some contrast, followed by Gaussian Blur to kill off the pixelation. Again, given the overall poor conditions of the night I was pretty pleased with how this ended up.
M64, The Black Eye Galaxy
