Tuesday, June 30, 2015

Summer Projects

We have been busy this month at Little Piney Observatory. Summer brings a lot of things, some good, and some bad. Part of the good is the beautiful large nebula in the night sky. It was time to put the RC away and get out the Star71 for some widefield imaging. Since the RC telescope was going to be out of service a while, I decided it was time to give the primary mirror a long overdue bath.

The bad that comes with summer is the awful heat and humidity. Last summer was a constant battle to keep the observatory under 100 degrees. We often lost that battle, and it was such a hassle and a constant worry, that we decided to do something about it this year. Little Piney Observatory received a new roof this month, along with some one inch insulating foam with a reflective backing. The super thin sheetmetal on the roof was removed and replaced with some quality metal and a substantial overhang was added to keep things dry inside.

Lets start with cleaning the mirror. There are several of these GSO RC scopes being used, and I thought someone might like to see just how easy it is to remove these primary mirrors. The GSO scopes come with various names including Astro Tech, TPO, Levenhuk, Teleskop Service, and others. I have owned this scope almost two years. It has seen a lot of use in that time, and with the pollen, dust, and the spiders that found their way into the optical tube assembly (OTA), it was time for a cleaning.

The first thing to do is take the top and bottom dovetail screws out. Then there are two other screws on the side of the OTA that need to be removed. After this the entire rear cell with primary mirror can be removed.

Secondary mirror with primary mirror removed

Carbon fiber tube


Rear cell with primary mirror and baffle tube. Seen here after cleaning.
I chose to remove the mirror from the cell before cleaning. To remove the mirror the baffle tube needs to come off. The entire baffle came off for me in one piece. Others have said the small piece at the bottom of the tube remained attached and they needed some small allen wrenches to remove the rest of the baffle tube assembly. Once this is removed the mirror can be lifted right out of the rear cell. For more info on the baffle tube, please see this thread on cloudy nights that goes into more detail on removing this piece.

After removing the mirror, I ran some warm water in the kitchen sink along with just a drop or two of dish soap. I placed the mirror on a towel and let it soak for about half an hour.


I put about half a dozen cotton balls on the mirror and moved them from center of the mirror out to the edge without putting any pressure on the mirror. Discard these cotton balls and repeat. I used my fingers to get off any stubborn pieces and rinsed the mirror with distilled water. After rinsing I used a micro fiber cloth to remove puddles of water and dried it quickly with a blow drier.

Install the mirror back into the cell and reverse procedure to put the scope back together. I am sure the collimation will need a couple of tweaks to get the mirrors lined up again, but I have not checked it yet. It is sitting on the shelf now awaiting that next galaxy or globular. I plan to check and align the optics soon.

RC ready to be collimated

The new roof that I mentioned required a little bit of money and a lot more work. It also significantly increased the weight of the roof and made it a little harder to open and close by hand. However, with the drop in temps inside the observatory during the daytime, it was very much worth the time and effort that went into it. I plan to eventually add a gate opener to the roof, but it's nothing that needs to be done right away.

Removed old sheetmetal from the roof and removed aluminum flashing from the sides

Added new gable ends and solid boards in place of old flashing
Added new 2X4 laths for attaching new sheetmetal
Installed new foam insulation
Installed new sheetmetal and ridge cap

New roof with added overhang = Much improved!!
I still have to find something (lightweight) to cap off the ends of the newly added overhang, but I am very happy with the new roof. Temps inside now get to only 1-2 degrees above outside air temps, and the inside remained dry after a substantial rainfall dropped by a passing thunderstorm.

I'd like to end this month's post by showing off a few of the wonderful summer nebulae that require a short focal length scope to capture (without having to do mosaics). For these I used the William Optics Star71 telescope, a very small f/4.9 apo with a focal length of just 348mm.


My first Image of the Day on Astrobin!!!




For full size views of these and other images, please see my gallery on Astrobin. I just started a couple more projects, including a widefield Sh2-101, the Tulip Nebula in Cygnus. Cygnus is a treasure trove of fascinating targets that will keep me busy for many summer's to come.

Have a safe and happy summer everyone! :)

Friday, May 22, 2015

Motorized Focusers

In my last post, I told you I was dusting off the RC telescope to get ready for galaxy season. I managed a few galaxy shots, but had finally had my fill of the scopes stock focuser. The focuser is by far the weak point of the GSO RC's. I also like to rotate through the RGB filters when getting my color data. This is difficult to do when the focus points of each filter are not the same. I decided to go with the Moonlite CSL 2.5" Large Format focuser with High Resolution Stepper Motor. What a fine piece of equipment this thing is! It is really a work of art.



I chose the M68 threaded drawtube version. It came with 2" and 1.25" threaded ends with compression ring and thumbscrews. I may eventually purchase the M68 to M48 adapter to make the entire image train threaded. It seems to be working just fine like it is though.

The grey piece hanging off the motor is an adapter I got from Rigel Systems for $10. This adapter lets me use my Rigel controller that I purchased a while back along with a stepper motor for my TS 107mm triplet.


This is my second Moonlite focuser that I have bought and I really like them a lot. The Teleskop Service 107mm scope came with a nice 3" rack and pinion focuser so I decided to keep the focuser and just order the Rigel Systems kit for it. Here are a few shots of the Rigel setup on the TS107.



Rigel usb-nStep controller
Both of these work great with Sequence Generator Pro. Once focused you can save the focus position and it will automatically go to this preset position when the filter is changed. It also allows for autofocus, which can be programmed by temperature if you wish. You can also set it to run autofocus upon a filter change, once an hour, or a number of other options. Once autofocus is ran there is a box that can be checked to adjust the focus points of the other filters by the same amount.




The guys at The Astro Imaging Channel have a really good video that goes into this much more than I can here. If anyone is interested it can be found here.

Galaxy season was just getting started when I last posted in March. I have several more since then, all taken with the RC, along with the Globular Cluster M13, and the interesting planetary nebula Jones-Emberson 1. These can all be seen in my Astrobin gallery.

The motorized focusers are really very nice and I'd hate to be without them now. I was reminded of this last night when I got out my William Optics Star71. This scope has a nice 2.5" rack and pinion focuser and it will be receiving a Rigel motor very soon!!! I was able to get in a couple hours of luminance data with it before the clouds moved in. I am very excited about this image and am hoping to get some good skies to finish it soon. This is just 6 subs of 1200 seconds each on NGC 7023, the Iris Nebula, and the surrounding dust in the region. I'll leave you this month with this work in progress. I hope to share the finished image soon! :)


Tuesday, March 31, 2015

Galaxy Season in Full Swing

This is the time of year is when our night skies are packed full of beautiful galaxies. Some relatively near, some far, beautiful grand design face-on spirals and barred spirals, edge-on spirals, giant elliptical and lenticular galaxies, and the irregular galaxies. Each beautiful and amazing in its own special way.

While I love to image everything from Open and Globular star clusters to the planetary and large HII regions of nebula, it seems I am always in most awe when imaging galaxies. It is just amazing to me to see the HII nebula regions and even globular star clusters in galaxies that are light years away from us. I always like to research my target a little just to see how far away it is. To think the light that is running through my telescope and hitting my camera sensor left these galaxies millions of years ago never ceases to amaze me.

Before bringing in the William Optics Star71 and my Teleskop Service (APM) 107mm triplet, I wanted to finish a project I had started around mid-February. I'm very happy to say that the project did not go un-noticed, and was selected as the Weekly Image Spotlight a couple of weeks ago on The Astro Imaging Channel.  Adam and the guys there really do a great service to those of us in the hobby. If you havent checked them out yet then please do so. Every week they have a special guest on and talk about anything and everything imaginable in the hobby of astro imaging. Each weekly session is also posted to YouTube.

My Levenhuk (GSO) 8" carbon fiber RC is my weapon of choice for most galaxies. The Star71 and TS107 are relatively new scopes, so the RC had been collecting dust instead of photons the last few months. I am very happy to say that it still does a wonderful job on the galaxies. I'd like to share here my first three galaxies to kick off the new season.

Two of them were done last year unfiltered before I bought my Astrodon Gen2 E-series LRGB filters, so I wanted to shoot these again and add some color. The first one I shot though is a relative unknown and doesn't get much attention. I really cant figure out why this galaxy goes un-noticed by most people, and cant help but think that if Messier had discovered it, it would be famous. NGC 3344 is a beautiful face-on barred spiral that is relatively isolated between the constellations Leo and Leo Minor. It is fairly small at about 7 X 7.5 arcminutes, shines at magnitude 10.5, and is about 22.5 million light years away.

In this image shot with the SBIG STF-8300M and RC scope I collected 25 luminance subs of 900 seconds each, along with 11 subs of 600 seconds for each colored filter controlled with the Starlight Xpress (SX) electronic filter wheel. Guiding was done with the SX off-axis guider and the QHY5L-II. All processing was done with PixInsight and Photoshop CS4, and Sequence Generator Pro was used for automated image acquisition.


Next up was NGC 4631 (also known as the Whale Galaxy, or Caldwell 32) in the constellation Canes Venatici, an edge-on spiral with a slightly distorted wedge shape that gives it the appearance of a whale. The apparent dimensions are 15.5 X 2.7 arcminutes and the apparent magnitude is 9.8. The nearby companion galaxy (the Pup) is the dwarf elliptical NGC 4627. The estimated distance of the Whale galaxy ranges between 25 and 30 million light years.

Integration on this image was 24 X 600 seconds for luminance and 9 X 600 seconds for each colored filter.


The final image for this month is one that really touches on some of points that I opened with about imaging these galaxies. NGC 3718, also called Arp 214, is a fascinating galaxy that astronomers argued over for some time. Some thought it was a lenticular galaxy while others said it was a spiral. It is now generally accepted that this is a warped spiral galaxy. Its spiral arms look twisted and extended with young blue star clusters at each tip. It is no doubt twisted due to interacting with another large spiral, NGC 3729, seen just to its right. NGC 3729 is a mere 150 thousand light years away from NGC 3718. While these galaxies in the constellation Ursa Major are at an astonishing distance of about 52 million light years away, there's even some more remarkable subjects in this image. Just above NGC 3718 is Hickson Group 56, a grouping of five interacting galaxies that lie over 400 million light years away. For perspective on this, the dinosaurs went extinct 65 million years ago after living on the Earth for about 165 million years. So the light I collected left those galaxies roughly 200 million years before the dinosaurs even came into existence.

The image was captured with all the previously mentioned equipment. I used 36 luminance subs of 600 seconds each and the RGB was 12 X 600 seconds for each colored filter.


I hope that everyone gets a chance this Spring to get out and see some of these amazing galaxies that are in our night sky this time of year. Whether I'm seeing these on my computer screen while processing the images or looking through an eyepiece, I am always amazed by the beauty and the wonder of these galaxies.

Have a nice Spring and clear skies from Little Piney Observatory!

Saturday, February 28, 2015

Improving Over Time and Acquiring Flats

Some things just get better with age. Fine wines, vintage bourbons, cheese, cast iron skillets, books - who doesnt like the smell of an old book? The same can be said for we humans in the form of experience. I still consider myself to be in the beginner to intermediate phase in my journey into astrophotography, but I have seen myself improve by leaps and bounds.

I was looking back at some older images of mine and thought I would share them here for some other beginners. With patience, practice, and lots of reading and experimentation from the bevy of tutorials available on the web today, it is possible to improve rapidly with the wealth of information that is available to us. I am still nowhere near where I want to be, but it is still nice to look back and see the improvement I have made.

This picture of the Leo Triplet was taken in May 2012 with my Canon T3 and Astro Tech AT8IN. When I first started out I was using the camera more like video assisted observing. I think this is a 2 minute single exposure.



Here is another one of my first images. M81 & M82 from August 1st, 2012



Towards the end of 2012/Beginning of 2013 I started trying to take a lot of single exposures and tried stacking them in an attempt to increase the signal and drive down the noise. I had a ton to learn but was immediately hooked.

On March 2nd, 2013 I tried M81/82 again and produced this image with the same AT8IN telescope and Canon T3 camera. This image is just shy of 3 hours total with 34 subs of 5 minutes each. It required the purchase of an autoguider and a coma corrector to clear up the awful coma inherent with f/4 newtonian telescopes.


For a comparison of the Leo Triplet image, this one was done later that month on March 31st, 2013. It is 2 1/2 hours of integration with 30 subs of 5 minutes each.


Obvious issues with these images include tracking/guiding issues with elongated stars as well as other problems, but still quite a dramatic improvement from the previous attempts.

After going through the Summer of 2013 with my DSLR, I told myself I would not deal with that again. The noise caused from 30+ degrees C of the cameras sensor rendered several images as trash. I had to get a cooled CCD camera and began saving my money to do just that. About a year after taking these images, in March 2014, I got my SBIG STF-8300M camera and Starlight Xpress 7 position filter wheel. Shortly after that I got the Astrodon 5nm hydrogen alpha filter and the Astrodon Gen 2 E-series LRGB filters. This began another learning phase.

In January this year I attempted the Leo Triplet again with the CCD camera and my new Teleskop Service 107mm f/6.5 triplet apo refractor. I think the image came out much better and careful processing revealed several smaller galaxies in the background. The full size image can be seen here.


The newest M81-M82 image reveals dust in the area called the Integrated Flux Nebula or IFN for short, as well as the satellite galaxy to M81 called Holmberg IX. It is the small blue patch just below M81. This one was done over the nights of Feb 7th, 8th, 9th, and 10th of this year. Full size image can be seen here.


These newest ones are certainly far from perfect and have issues of their own, but it is gratifying to see the improvement. In fact, sometimes seeing this improvement is needed to keep me going forward. Astrophotography is certainly not the easiest hobby to become good at. With so many things needed to come together to produce a good image it can become frustrating at times. The good thing is there are a lot of tutorials available to help us continue improving. The main thing in any hobby is it is supposed to be fun. When frustration sets in, look back at some of your first images and see how much you have improved.

Acquiring Flats

Flat fields is a calibration frame used to clean up any dust motes you might have on your sensor or filters, and eliminate vignetting. When I was using the DSLR is was easy getting flats just after the Sun set by using the camera set in A/V mode and pointing the scope/camera at the sky. In A/V mode the camera would self adjust the exposure to get the histogram in the correct place or proper flats. It has been a bit more difficult since getting my CCD camera. I have been covering the end of the scope with a white trash bag or t-shirt and placing a light blub around the front of the scope with the scope pointing toward the observatory roof. The light doesnt always provide even illumination and it has been a hassle getting the trash bag or t-shirt flat over the end of the scope. I finally broke down and purchased the Spike-a Flat Fielder. This has been a wonderful addition.


At $250 shipped I thought it was expensive, but it is quite nice. The light box is big enough for scopes up to 12" (light box is 14"X14") and comes with both AC and DC power supplies, as well as a pair of wireless dimmer switches.

 

Its very easy to use and together with Sequence Generator Pro's Flats Calibration Wizard, obtaining proper flat frames is now quick and easy. I would recommend this to anyone looking for an easy way to take their flat frames.


Happy imaging from LPO!  

Saturday, January 31, 2015

Narrowband Fun

There are some things, like most all reflection nebula, and most galaxies, that must be shot in wideband luminance. This requires good dark skies to get the most of LRGB imaging. I'm sure this is not the case, but sometimes it just seems like we have cloud cover and rain around New Moon, then it gets clear with a big bright Moon in the sky. This is when its nice to have narrowband filters.

Narrowband filters cut through the natural light pollution of the Moon, as well as man made lighting common in big cities and large towns. Even here in the country, we have neighbors on all sides with bright night lights in their yard that can be a pain to deal with. I have had my Astrodon 5nm hydrogen alpha filter for a good while, but have recently purchased the Astrodon oxygen (OIII), and sulfer (SII) filters. The first time I used these three filters I got a very bad SII signal because I shot with it very close to the full moon. Using these filters are perfectly fine to use with a full moon but I would suggest choosing a target at least 30 degrees away from the Moon when it is this big and bright. Because the SII signal was bad, and the fact that I also added RGB to my Tadpoles (IC 410), I consider my recent Rosette nebula to be my first true Hubble Palette image.

The classic Hubble Palette image, or SHO, maps the colors as Red=SII, Green=H-alpha, and Blue=OIII. First lets take a look at the different components that each filter yielded.

Here is the Hydrogen Alpha image.


Here is the SII.


And here is the OIII.


As you can see, each filter highlights a different component of the nebula. By mapping these images into the color channels as descibed above, I came up with my first true Hubble Palette image.


These were all shot with my new William Optics Star71, a 71mm 5 element apochromatic refractor operating at the native focal ratio of f/4.9 and 348mm focal length.

You can also map these colors in HSO for a more red tone which is considered more natural looking. I tried it in this palette but the colors came out very purple to my eye instead of red. So I decided to try a blend of the different components to see what I could come up with. For this next image I used a blend of 65% SII and 35% H-alpha for my Red channel, for Green I used OIII, and for blue I used a blend of 65% OIII and 35% H-alpha. Since I did not use H-alpha as a dominant channel, I lost some of the fainter outer regions but came up with a color theme that I felt was very pleasing to look at.


November and December was just awful this winter for imaging, but January was very kind. I'd like to share my images from this month here.

First up, and shot over the nights of Jan 6th and 7th, was "First Light" for my WO Star71. This is commonly called The Ghost of Cassiopeia. It is a combination of H-alpha and RGB. The dominant star in the image is gamma Cas.


On the night of January 8th I decided to take aim at a solar system target, Comet Lovejoy C/2014 Q2.


On the nights of January 9th and the 13th, I shot one of the all time favorites, the Horsehead and Flame nebula. This one is also a combination of H-alpha and RGB and was shot with the Star71.


January 16th and 17th was spent shooting the Witch Head nebula, a reflection nebula just off from the bright star Rigel in the constellation Orion. This one is LRGB with the Star71. You can certainly see where this one gets its name. The bright flare in the upper right was caused by Rigel.


Early on the morning of January 17th, after the Witch Head was too low in the west to image, I slewed to the constellation Virgo and gave this great cluster a go. I was able to capture about 3.3 hours of luminance data on this target before the Sun started coming up. The dominant group of galaxies is called Markarian's Chain, but there are MANY galaxies scattered throught the image. I hope to add some color to this one in the coming months.


After then spending a few nights gathering the narrowband data on the Rosette I changed out scopes from the Star71 to the TS 107mm triplet and captured M78 the nights of the 20th and 23rd. M78 is mostly a reflection nebula and was shot in LRGB.


On the nights of the 20th and 24th, I was able to capture this wonderful trio of galaxies in Leo, appropriately called the Leo Triplet. M65 in the top one on the right with M66 below it. On the left is NGC 3628. I was able to get some of its faint tidal tail that stretches down to the bottom of the image.


The nights of the 24th and the 26th were clear enough to get my final image of the month, the Cone nebula. This nebula is also known as the Christmas Tree Cluster and NGC 2264. The Cone nebula is a huge HII region located very near the Rosette nebula between the constellations Orion and Gemini. This one was shot in H-alpha and RGB.


As you can see, January was a great month here for imaging the stars. After just one image in November, and one in December, this was a welcome change. So 2015 is certainly off to a great start. If the coming months yield half as much imaging time it will be a great year at Little Piney Observatory.

For a closer look at these images you can click on the pictures. Or to get an even bigger and better view of these and many more images, please see my gallery on Astrobin.  http://www.astrobin.com/users/rflinn68/

Clear skies everyone!