Saturday, December 28, 2013


The weather the past few days has been frustrating here at my observatory...very clear skies day and night, with winds gusting on and off to 20 mph.  I am off work this week, and with lots of dark time I have been looking forward to spending some serious observing time with my new (to me) C 11 Edge HD (News Flash!!).  Even though I have already first lighted the telescope, the winds have been driving me crazy!
The winds died down, finally, very early this morning and when I went outside to check on conditions for Solar observing saw that high cirrus were beginning to form as a predicted front moves in.  As many observers know, sometimes a very thin layer of cirrus clouds can provide favorable observing conditions for bright targets such as the Sun (or Jupiter)-  I set up my Stellarvue 90mm triplet with Lunt Herschel Prism and sure enough the views of the Sun were quite stable.  While there is virtually no activity in the northern hemisphere, the southern hemisphere had numerous spots stretching in a band within 15 degrees of the equator.  At left is a white light image from the Solar Dynamics Observatory taken this morning.  Clicking on the image will bring it up full size and includes the NOAA active region numbers within which the current sunspots exist.  In addition, there is a scale at lower right to provide a sense of the size of spots relative to the Earth and Jupiter.

Below, is an image I took this morning using my ASI120MC camera.  It is a stack of about 600 individual frames from an avi of 1200.  Considering this was taken through a layer of cirrus, the results are quite nice and compare favorably to the SDO image.  North is up, and west is to the right.  Click the image to enlarge.

Wednesday, December 25, 2013

KPNO Sunset timelapse

Inspired by several time lapse videos that I have seen of astronomical events, (including this one by Dean Ketelsen made last week) I pieced together my version of the sunset which silhouetted Kitt Peak National Observatory yesterday evening.  See my previous post for more details...and it will look better if you watch it on YouTube and change the setting to 1080 HD...

Post-solstice KPNO sunset

The previous post detailed an annual trip to photograph the Sun setting behind Kitt Peak National Observatory as seen from the Catalina Highway.  As this alignment occurs 3 days prior to the Winter solstice (while the Sun is trekking southward), there is a second opportunity to observe the alignment approximately 3 days following solstice as the Sun is once again passing the same point on the horizon (while trekking northward).

Approximately 10 folks came out yesterday to take pictures of the Kitt Peak ridge line and observatories silhouetted by the Sun. Once again, I was taking pictures of the Sun using my Canon T2i through my Stellarvue 90mm triplet refractor with a Lunt Solar Systems Herschel Prism and a 2x Barlow lens.  This results in a focal ratio of approximately f/14.  Overall, the atmosphere was far less stable than the attempt last week which made focusing quite difficult.  At left is an image of the Sun about 20 minutes prior to sunset.  You can see there are some very nice spots on the disc and compared to the later images below how quickly the seeing (atmospheric stability) would continue to deteriorate.

As last time, here are two images of the Sun as it set behind the National Observatory.  The building that is on the left of the ridge line that appears as a "7" on its side, is the McMath-Pierce Solar Telescope.  At far right on the summit is the Mayall 4-meter Telescope.  Click the images to enlarge them to full size.

In addition to the generally poor seeing there was a thick inversion layer that was forming in the valley as temperatures quickly dropped around sunset.  It was easy to see this layer from our vantage point as it developed.  This resulted in a large amount of atmospheric dispersion and some amazing colors of the final bits of the setting Sun.  Below is an image of the nearly set Sun which shows the green rim as well as some blue-

Finally, here is an image at full resolution of the camera of the last fraction of a second of sunset-  The atmospheric dispersion shows colors from orange/yellow at the bottom to blue at the top!  None of this was visible to the eye, as expected, but I was surprised to see this amount of color in the image-  It is not much to look at due to the lack of context in the picture, however, knowing this is the Sun makes it impressive (to me anyway!)

Happy holidays!

Tuesday, December 17, 2013

Sunset behind Kitt Peak National Observatory

Click to enlarge
This marks year two that I have participated in a small winter tradition among a few local amateur astronomers-  That is taking pictures of the Sun setting behind Kitt Peak National Observatory, as seen from the Mount Lemmon highway.  I posted a few pictures from last year, exactly one year ago today.  Dean Ketelsen is the originator and organizer of this annual tradition and he is also the inspiration for the start of this blog!  You can see him at left, in the image at left, as we prepared for the sunset.  Also in the image are Dean's colleague Roger, his wife Melinda, and my good friend Jon.  It is due in small part to Dean that I am posting this report within a couple hours of our trip...he threw down the gauntlet as his parting words this evening were that he was looking forward to a blog post- so Dean, here you are!

I had planned to take an image every ten seconds and then make a time lapse-  I set up a tracking mount along with my Stellarvue 90mm triplet refractor, a Lunt Herschel Prism, and my Canon T2i with a 2x Barlow lens.  As the Sun dipped toward the horizon I made sure everything was set-  and sadly, I forgot to turn off the tracking!  So instead of the telescope remaining fixed on the summit observatories, it continued to track on the sun as the observatories slowly drifted up out of the field of view!  Regardless I ended up with a few nice images which I present here.  As you can see we had a large number of clouds drifting through and it made for some very photogenic moments.

First up, are two images of the Sun as it was descending behind Kitt Peak.  As always, click them to enlarge to full size and if your browse automatically resizes images, you may need to click them again.

Next, I was delighted to discover when going through my pictures that I captured the Green Rim!  Many have heard of the elusive "Green Flash" which is actually a distortion of the Sun's green rim.  The short explanation for this is that our atmosphere acts similarly to a prism as the Sunlight moves through it toward us, and the suns light is refracted and spreads out much like in a rainbow.   While you may expect the rim to be blue, similar to the rainbow, our atmosphere scatters much of the blue light and we are left with the upper limb of the Sun appearing greenish.  When most of the Sun is below the horizon and it is no longer overwhelmingly bright, we can often see this green rim with the magnification supplied by binoculars or a telescope.

Finally, once I pulled the camera from the telescope, I put a 24-105 zoom lens on with a polarizing filter and took the image below at the 105mm setting.  It was 1/500 of a second at f/4.

This was so fun, I may try again on the 24th.  In case you are wondering how we could have a second opportunity to find the Sun setting in the same place on the horizon within a week...we are approaching the winter solstice in approximately 3 days.  At solstice, the Sun reaches its most southerly point in our sky and then begins its trek about 3 days after solstice it will again be setting behind KPNO.

Monday, December 16, 2013

ISS Transits the Sun

Earlier this week I received an email alert from (a wonderful site for the amateur astronomer!) that the International Space Station (ISS) would transit the face of the Sun as seen from my observatory at 3:29 PM today. Once before, in October of 2011, I observed an ISS transit (see this post) and it was quite a thrill.  I was hoping to do it again and this time I was equipped with a camera that would allow me to video the event.

I invited my friend Jon Shallop to accompany me on my misadventure and as the day approached the predicted ground track of the ISS had been refined and shifted about 2-3 miles to the west.  This is due to the fact the ISS is continuously dropping in its orbit (they boost it back up occasionally) and also the solar flux can affect it's orbital path.  Looking at the map this morning it appeared that the center-line of the transit would run right over the southeast corner of Himmel Park, very close to the University in mid-town at precisely 3:29:29 PM.  As the day wore on, heavy cirrus clouds built in the southern sky and as the time approached we were worried about seeing anything at all.

I had set up both a hydrogen alpha and white light telescope and given the thick clouds decided I would scrap the video plan and visually observe the transit. Fortunately, about 10 minutes before the transit the cirrus thinned and I decided to mount the camera to the HA telescope and see if I could record anything.  Sure enough, despite the thick cirrus, I was able to capture it!  The transit occurred exactly at the predicted time, indicating we were right on the center-line.  Below is a single frame from the video, processed a bit to sharpen the details.

The ISS is just above left of center in the image.  Of course, I was in a hurry and did not notice that I had the camera binning the resolution is somewhat limited...although with the very poor seeing conditions, it may have been better this way.  The uneven illumination is due to passing cloud, and for my first attempt, I am happy with the results.

Saturday, December 14, 2013

Images of the Sun

It has been a few weeks since I had a window of opportunity to image the Sun.  I have had a few visual moments the last few weeks but just enough time to take a look and marvel.  This morning the Sun was ready for me, sporting several nice active regions which included several photogenic spots.  If the atmosphere steadies a bit tomorrow, I may try and take a picture of the individual spots using a barlow lens as they are quite detailed.  Below are the white light (top) and hydrogen alpha (bottom) images of the Sun, taken between 11:00 and 11:20 (18:00 and 18:20 UT)  this morning.  As always, click the images to enlarge them.

Venus Transit re-processed

Over Thanksgiving week I was leading a public observing program at the Mount Lemmon SkyCenter and one of the guests asked me what were my most memorable observations.  It was a question that motivated me to think about all of the wonderful times I have spent with friends and colleagues enjoying time at the eyepiece.  I hope to actually write up a blog post where I attempt to answer that question, and included in the answer will be observing the 2012 Transit of Venus.

Guest observing sunset - note the sun projecting on his eye
I observed the transit from the summit of Mount Lemmon with my colleague Adam Block and somewhere in the neighborhood of 100 guests that attended our special Transit of Venus program.  We had multiple telescopes set up, including some brought by visitors themselves, through which we observed the event.  I had purchased my first DSLR (ever!) the week of the Transit in the hopes that I would be able to take some pictures through my telescope.  I posted those images on the blog shortly after the transit, and to say I was lucky is an understatement.  I had very little understanding of how the camera worked, and practiced with the camera and telescope for just a couple days leading up to the Transit.  You can read about the adventure and see the original images on this post from June of 2012. About a month after the Transit I made an attempt to process my best raw image of second contact and was fairly satisfied with the results at the time. That post and image can be found here.

As I have been playing around with solar imaging a little bit this year, I have gained more experience in processing the images that I take.  While I was previously using the freeware program GIMP, I am now using using Adobe Photoshop and have been able to identify a few techniques to improve my images.  Below, is my latest attempt to bring out the best of my image of second contact-  I am quite happy with the result!  Click on it to enlarge.

Thursday, December 5, 2013

The UA Science: Sky School

One of the most satisfying parts of my job as Director of the Mount Lemmon Sky Center has been working to develop the UA Science: Sky School, housed at the SkyCenter campus.  It has been transformational for me, having the opportunity to work alongside some amazing graduate students as we create a truly unique and immersive science school.  Each time we have a public school visit I am reminded why I work in higher education, at a public university.

This week, Arizona Public Media produced a piece for the TV show 'Arizona Illustrated Science', which I have embedded below.  The spot does a nice job capturing the experience from the perspective of the students, their science teacher, and our graduate student staff.  I have been receiving a lot of personal accolades since this aired, and the truth is that our success results primarily from the remarkable core team of individuals who are giving of their time, energy and hearts to our program.  Ben Blonder, Rebecca Lipson, Pacifica Sommers...all are amazing, creative and visionary.

Clicking on Pacifica or Ben's names above will take you to their blogs, which are well worth a visit.  On her blog, Pacifica provided some insight into her role in the Arizona Illustrated piece, stating "I find it easy to talk about the UA Sky School with the media because it is important and powerful. That power comes from reality and rigor. This is not nature camp or space camp. The instructors are prepared with knowledge about unique opportunities to emphasize important scientific standards and the resources to investigate them, but our activities are not simulated and our lessons are not canned. Students on the four day stays especially interact with actual scientists, using actual mountains and plants and telescopes, to do actual original research. The potential to have an epic experience in scientific discovery or outdoor adventure is tangible."

Watch the video- it speaks for itself.  (You can read the accompanying web story here.)