Kitt Peak Kraziness!

Late May and early June in the Southwestern Desert... Hot and clear! Again, I apologize in not posting for nearly 2 months! I continue to lack inspiration! But the clear dark skies here in AZ truly inspire! I had a couple friends visit that had never been under a dark sky - so the need for outings descended!


My friend Karen from Chicago was down and didn't know what all the astronomy fuss was about, so I scheduled a trip to Kitt Peak National Observatory for one of their "Nightly Observing Programs" (NOPs). It is a pretty cool program (literally, a temperature relief with nearly 20 degree cooler temperatures than Tucson), that allows you to be among the research telescopes at the National Observatory 40 miles SW of Tucson. One drives their own car to the site after it normally closes to the public. After checking in the program, it starts about 90 minutes before sunset with an orientation and a box dinner. Then we head out to watch the always-enjoyable sunset. We had Charles leading the group, who gave a fantastic tour of all we could see, both locally on the mountain, and phenomena in the sky to watch for. That is him at the left with the setting sun in the background. A few moments later, we all watched spellbound for an appearance of the "Green Flash" as the last rays of the sun set below distant mountains. I'm pretty sure I saw it, but was a second or two early with the photo at right for a pure green!



Shortly after sunset, a glance to the east reveals one of the "often seen, but rarely noted" phenomena - the shadow of the earth rising into the sky! In the image at left with the McMath-Pierce Solar Telescope (now closed due to defunding), the dark line above it is the rising shadow of the earth, topped by the pink sunset line of the "Belt of Venus", where the still-shining sunset is tinted pink by sunlight going through massive amounts of atmosphere - just like how our viewed sunset colors are seen. Charles continued his monolog of post-sunset items of interest, then descended back to the Visitor Center. There our group was split into 3 groups - the "Dark Sky Discovery Program" went off to their own 16" telescope for the evening. The remaining 45 folks in the NOP was divided in half, one group to the 20" scope, the other for their orientation to observing with planispheres and binoculars. That is our leader Robert at right, the lights in the VC now using red lights to preserve dark adaptation...


Even though taking night-time photos was discouraged, I did not get permission, but rather, turned down the screen brightness, and the Canon 6D does NOT have a built-in flash, so the effect on nearby large telescopes was nil... I set up on the Visitor Center patio with an old Nikon 16mm fisheye taking in a large swath of the VC and sky, as well as the people out using their planispheres. At left is a single exposure, 15 seconds long at ISO 3200 with the fisheye at F/2.8.  I took these a good portion of the evening, perhaps to someday make a time-lapse, but not today! At the left of the VC is the dome of the fine 20" telescope that we used for our observing a little later. Be sure to click the image and see if you can make out the major constellations in the northern sky in June. For your convenience, I've done the work and labeled the same photo at left...


I let the camera run unattended while we went to the telescope to observe. With the large group of people (23) and only an hour to observe, we only had time for 4 objects. It's always an issue in a dark dome with big crowd as queuing up is always an issue without clearly defined pathways... And with a big telescope and fully-dark skies, I had issues with some of those 4 objects - a double star? Really? And the Beehive open star cluster? With a 20"? Both Karen and I LOVED the view of the M13 Globular Cluster and rising Jupiter (disks of moons could be resolved, even at its low altitude!), but the decision not to show ANY of the spectacular galaxies in the springtime sky is unconscionable! Oh well... Some may remember I used to help run this program a few years back, so I've got stronger opinions than most...

With the large amount of time we had sitting in the dark dome, I got permission to step downstairs to relocate my camera to the elevated catwalk of the dome and took few shots showing the rising Milky way over the mountaintop - shown at left. Still with the Fisheye, this is a 25 second exposure, still at ISO 3200.  A piece of the 20" dome at upper left, and along the mountain profile is the 2.1 meter, the 50", the WIYN 36" and the WIYN 3.5 meter. The red streaks are from folks walking back to the VC from the rest rooms... Jupiter is the bright object leading the Milky Way across the sky.


With the end of observing, we moved back downstairs. I sent Karen in for final instructions from the NOP crew. I knew there were shopping opportunities, so I had a few minutes to continue some projects on the patio. One of my thoughts was to try to shoot the rising Milky Way in the "new" sundial (likely now 20 years old!). Shown at left in daytime, the "crystal ball" effect provides a wide field visible in the polished sphere. Unfortunately, it isn't optimum for my application as the projection screen normally receiving a spot of the sun for telling the time, blocks a good chunk of the sphere and the image it transfers. My best effort is shown at right... Still, I liked the sharp little image contained therein, and also loved the out-of-focus stars that reveals their colors more intensely than when in focus! I might have to make my own ball for a repeat!


Thusly inspired by the colors of out-of-focus stars, I purposely took a set of exposures both in-focus, then intentionally out. The rising constellation Scorpius seemed a suitable target, and these are both 2-frame vertical mosaics with a 50mm lens, each frame a combination of several exposures (stacked), 15 seconds each at F/2 to minimize trailing (no tracking device this night!). I love the details seen in such short exposures - the dark nebulae against clouds of Milky Way stars especially!

And while I love the exposure at left of sharp stars, I also love the defocused star images at right that more intently shows the star colors! When in focus, the star colors turn to white as they are mostly saturated in brightness. Defocused, they retain the true star colors. And of course, you know what you can derive from their colors - anyone??? Yes, you in the back - YES, you can tell their temperatures! Well, at least the blue ones are hotter than the yellow or white ones!



The last image taken was just barely seen, but looks much more impressive in the photo as levels adjustments can be made! The Milky Way was rising behind the solar telescope, partially diminished by the lights of Green Valley and Nogales. Pretty amazing what the 6D and 50mm lens can do in 15 seconds!

With that, the crowd was leaving, so packed up the tripod and camera and headed down the mountain, the first mile with headlights covered. Were back home by 12:30 with what I can now confirm were pretty nice images!




BUT! While tripod shots can be fun, Tracked shots are even more fun with the depth, details and colors they can record. I was looking for another opportunity to go photograph with a tracking mount. I've had an AstroTrac for a few years now (may no longer be available). While it seems fine with a 200mm and 300mm lenses, I've not really found the upper limit, so wanted to try the 500mm F/4 camera and lens on it. So 4 days after the above Kitt Peak trip, I returned to the Mountain, this time to a pullout to set up my own gear with friend Susan who claims to have never been under a dark sky. Well she got an eyeful as the Milky Way made an appearance. The 500mm seems to work well with the mount, though I think polar alignment is a bit dodgy! There was slight trailing, but acceptable if the sub-exposures were kept to 90 seconds or so. This required an ISO of 4,000 and shooting at F/5. My target with the 500 was a 3-frame mosaic of the dark cloud commonly called the Pipe Nebula. From a wide-field image, it looks like a smoking pipe with curling smoke rising to form the "Prancing Horse". Shown at left is the mosaic with about 2 hours of exposures with the 3 frames, flat fields and darks subtracted with Sequator and mosaic assembled in Photoshop.


Similarly, with the night winding down on a "school night", I pointed it to a popular field of Messier 8 and 20, the Lagoon and Triffid Nebula (bottom to top). Only 7 minutes of exposure, it is a nice field to shoot quickly before closing down for the night. Susan was impressed with the sky, and I found a new tracking mount easier to set up than the AP1200 that can handle the 500mm lens! So a useful night. Well, any night under clear, dark skies is worthwhile unless Mr. Murphy makes an appearance!

Post-Thanksgiving Outing

I hope you all had a great Thanksgiving! I spent a quiet day with a friend up in Phoenix, but was home later in the evening much to my cats' relief!

But Friday dawned pretty darned nice, though still some thin clouds in the sky. But I had visualized a photo op of the nearly full moon rising over the Tucson valley. Where is the best place to observe such a thing? My immediate thought was to shoot it from Kitt Peak, the moon rising over the profile of the Catalina Mountains and the city lights.

That is about the way it worked out - an uneventful ride to arrive at sunset, and set up 2 tripods for 2 lenses (500mm and 200mm) and 2 cameras (Canon 6D and XSi). Pretty much as soon as it got dark enough to take some exposures of the city lights with each lens, the glow identifying the moonrise position came into view! In making these images, I combined the long-ish exposures of the city lights with a shorter exposure properly exposed for the moon. So it is sort of an High Dynamic Range (HDR) exposure to record details much different in brightness. At left is the slightly wider view with the 200mm lens, and at right the 500mm, taken a few seconds later.

It was amazing how fast the moon rose above the profile of the Catalinas, but the clouds really add to the images. In the end, it pretty much turned out like I had envisioned... And with that image the only one on the program, with packing up of gear, I was back in town before 8pm! An early night!

A Fine Winter Night!

Those of you who know me knows it doesn't take much to get me under a dark sky, so when buddy Laurie Larson expressed interest in coming down for a visit and a camera session under the stars, my answer was, of course, YES! So last weekend we headed west towards one of my favorite pieces of sky, that over Kitt Peak National Observatory. It was a job on that mountaintop that got me to Tucson, and after a stint as a full-time employee there in the '80s, another as a docent in the '90s, and another with their nightly observing programs in the '10s, it is still a favorite place to go, though one can't interfere with the night time activities there. I use one of the pull offs on the west side of the mountain for a sky that can't be beat! We made it to the Observatory well before they closed to the public and wandered around for a bit, finding I no longer know anyone working in the visitor center! The photo at left shows a view of the 4-meter telescope atop Kitt Peak from the road far below through a 500mm lens and a 6-frame mosaic assembled in Photoshop...

A bit later, after we finished atop the mountain, we went to the first pullout below the 4-meter telescope and set up my TEC 140 to do some real telephoto-lens imaging! With a focal length of 1,000mm, it works great if the seeing allows. Case in point is the shot at upper right. At right foreground is the San Xavier Mission, likely just under 40 miles distant. Above that is the Tucson International Airport, above that the Pima Air Museum and at top is the "Boneyard" of spare airplane parts at the Davis-Monthan Air Force Base!

Also, a couple months ago I documented the LBT shooting off the ARGOS laser from Mount Graham 120 miles distant! While easy at night, I've never spotted it during the day. While I couldn't see it in the viewfinder, I shot blind and sure enough, is also easy with a little Photoshop adjustment of brightness and contrast...

We moved down a few miles to my favorite pullout and set up a small tracking mount for wide-angle lenses, and the big AP1200 mount here to mount the 500mm lens, as well as another piggyback 300mm without breaking much of sweat! That is Laurie doing her best Vanna White impersonation...

The first object of the night was an unusual comet - 2016 R2 PanSTARRS. It has been putting on a good show in larger telescopes and digital detectors, with an unusual blue color due to an overabundance of CO. Not quite as impressive through the smallish 500mm lens (compared to some telescopes), but the color still comes shining through! This is 15 minutes of total exposure through the 500mm. The 10 exposures were stacked on the comet nucleus, so the star images are trailed due to the comet's motion.

Laurie was interested in chasing down some of her favorite sky objects through the 500mm telephoto, and took these of the Rosette Nebula at left, and the Horsehead Nebula at right. In both images, the colors are real - the red is mostly from ionized Hydrogen gas, the most common element in the universe! Also in both images, the gas is condensing to form new stars. In the Rosette Nebula at left, you can see there is a loose cluster of stars that have used up and/or blown out the gas from the center of the nebula accounting for its hollow appearance. The Horsehead nebula is similarly composed of dust and gas also forming new star systems. the cream-colored nebula at upper left is actually a "reflection nebula", reflecting starlight from nearby stars, compared to the red glow caused by the gas' fluorescence! The "horsehead" part of the nebula is a dark cloud blocking the glow from the hydrogen cloud behind it. The Rosette is 10 minute total exposure, the Horsehead is 22 minutes!


I was content with some wider-angle fields, so went with the small tracking device after the comet photo above. At left is the Winter Milky Way rising over the southern slopes of Kitt Peak. While we thought it was clear, the photos make it obvious that it was not, with thin clouds being lit up by distant city lights. Over looking towards the west was a different kind of light! While parts of the Milky Way is visible in both images, the searchlight-looking beam reaching nearly the zenith at the Pleiades is the Zodiacal Light - meteoritic dust in the plane of the solar system reflecting sunlight to us. It is bright this time of year in the evening sky, even outshining much of the Milky Way! Both of these frames are with the 16mm Fisheye, and are each 70 seconds long.

As the night wound down, I did a 2-frame mosaic of Orion with a "normal" 50mm lens. The effect of doing the mosaic is retaining a little more resolution, though blog limitations remove most all of those advantages! Visible through most of the Orion shot (at left), are a plethora of red hydrogen clouds, including the above Rosette Nebula in the upper right corner, and the Horsehead under the left-most star of the belt of Orion...

I took another Fisheye shot to close out the night as the night's attendees also departed the mountain, illuminating the roadway with their headlights. Just above the southern horizon near the "blip" of Baboquivari is the bright star Canopus. I never saw this star growing up in the Midwest as it never clears the horizon there. The "light domes" of a couple towns are visible - I think the glow just to the left of Canopus is the border town of Sasabe about 30 miles to the south. And on the right hand edge of the horizon, the largish town of Caborca about 90 miles away illuminated the cloud deck.

Even given the clouds it was a great, mild night for January. They just don't come often enough for my taste!

A New View!

Long time readers know I'm justifiably proud of some of the Mirror Lab accomplishments, including the twin mirrors of the Large Binocular Telescope, each 8.4 meters (about 27.5 feet) in diameter. In particular, I've been on a quest of sorts of imaging the telescope while it does interesting things. It seems to have culminated last Spring when I caught the ARGOS laser propagating into the sky from a distance of 12 miles. From the town of Safford, through a small telescope, I almost had a front-row view of the instrument, visible at left, which is used to project a constellation of artificial stars in the field of view of the telescope to partially correct atmospheric turbulence. Several hundred similar frames were combined to make a short video seen here.


Well, without permission from the powers that be to get any closer (made more difficult by the recent severe fire this last spring that approached within 50 meters!), my most recent query was - from how far away can you see it?! From a post a few years back, I knew that LBT was line-of-sight from Kitt Peak National Observatory, very close to 120 miles away! The image at left is from that post and demonstrates that if you can see KPNO from LBT (flat-topped mountain in center), you can see LBT from KPNO!




So last night after work (working evenings this week at the Mirror Lab), I found my way driving westward - this after confirming with the LBT telescope operator that indeed ARGOS was operating properly. Being that it was dark-of-the-moon, I parked on the last pullout before turning towards the Observatory so that my lights would have no effect on operations there. It was an interesting night - totally clear, but obviously above an inversion layer. I watched the thermometer climb as the van ascended. It was 60F at the base of the mountain, 70F on top! The wind seemed a little blustery, alternately blowing out of the south or the north - weird! But fortunately, I was very comfortable in shorts and a long-sleeved t-shirt.

I had several optics to try - the first was easiest to set up - the 500mm F/4 "big bertha" telephoto. I had it up, pointed and focused on the lights of Tucson in a few minutes. It took me a couple shots to find where the LBT would appear - I'd never seen it from Kitt Peak, as it is quite small. But I knew it would be left of the red-lit radio transmission towers atop Mount Lemmon, so used that as my guide. About my 3rd shot - there it was! The green laser standing out from the occasional star and headlight visible on the Mount Lemmon Highway. At left is shown a 6-frame panorama of part of Tucson. with the green spot of the 18 watt ARGOS laser visible. At right is a single frame at a little larger scale better showing the laser beam.


I then broke out the big gun - the TEC 140 - a 5.5" diameter telescope with 1,000mm of focal length. Again, because of the large magnification, it took a couple practice frames to get it pointed properly. Note that at NO TIME was the ARGOS laser visible to the naked eye or even visible in the camera viewfinder. It was only the power of a 20 to 30 second exposure that revealed it was there. I had started an exposure sequence for a possible time-lapse, and interestingly, the inversion layer is visible just under LBT. In a couple minutes of exposure, it slowly dropped and became a little brighter in the less-affected air. Also visible in the exposure is the south slope of the mountain, brightly illuminated by the lights from Ft Grant prison at its base.


Most of my outings, I usually finish with a practice shot or mini-project that can be completed while putting away gear. This night, approaching 1:30 in the morning, I mounted the 16mm fisheye on the Canon 6D and took a couple frames of the sky from Andromeda to the rising Winter Milky Way. What is most interesting, besides the reddish airglow that looks like clouds to the west (right), is the oval glow just below center. This is called the Gegenshein, or counter-glow - a spot defined by being opposite to the sun in the sky. An optical effect allows sunlight to reflect from meteoritic dust back to us. This may be my best photo of it, and from only 2 stacked exposures shown here. Each of the 2 exposures were 2.5 minutes with the fisheye working at F/4.

Always great fun to be under a clear dark sky, and while chasing an ARGOS viewing might be only an excuse, it doesn't take much to get me out looking up!

Deja Vu, And Then Some!

My friend Donna had a hair appointment in Tucson this last weekend and suggested a road adventure, and another buddy Bernie was impressed with my photos from the weekend before on the Baboquivari 4WD trip. What could I do but suggest another trip to the most sacred site of the Tohono O'odham? Neither had been to the area, so by noon we were again winding down the Sasabe Road! As on the previous trip, my new riders were impressed with the view of Kitt Peak from 12 miles away. At left, Bernie shoots the observatory - the flat peak seen on the horizon.


We didn't waste a lot of time on the drive down - turned off the paved road just beyond milepost 16 and followed the road back NW towards the impressive profile of Baboquivari. With our little later start, we found a nice spot for our lunch with a view of both the peak and vistas to the east as well. The 5-frame mosaic here from our lunch spot with the 300mm lens well-captures the peak and surrounding area. Unfortunately, with the 1600 pixel-wide limit of pictures much of the impact of these panoramas is lost. At right what I've done is crop out the peak area of the panorama, keeping it at full resolution to give an idea of how powerful the full resolution panorama is! The crop at right is the same image, just cropped, not downsized from the panorama...


The previous trip I had seen a lot of huge grasshoppers, though didn't stalk one down on that trip. This time one came walking by at our lunch, so was able to molest it and take it's photo. It is a colorful fellow, flightless, though with underdeveloped wings seen here with black spots. It didn't take long to identify it on the Google as a Plains Lubber Grasshopper, Brachystola magma. Interestingly, in that link, they find that the Plains Lubber has a 2-year life cycle. I really love the subtle but strong earth-tone colors!

A little later we did some hiking when we hit the locked gate mentioned in last week's post. We turned a corner and I discovered the Praying Mantis shown at right at eye level on a plant. It was quite patient while I twisted the plant to bring it into the sunlight to get one or two good shots...


About 1km above the locked gate, we saw a ranch house that looked a lot better-kept than I remember hiking past back in the 80s! It appeared to have newer double-pane windows and a metal roof, even as the road leading up to it seemed long-unused. I ventured a little past the "private property" sign, but only to get the photo at left. Following the trail around the house and the corral, I took the mosaic at right. It looks like an idyllic place to spend some time! Back 30 years ago when last here hiking the peak, we parked much nearer the ranch house, but was pretty run down. In my reading, about that time it was known as Riggs Ranch. I'm not sure who operates in the area now. On our trip last weekend, we saw a big truck going in, but didn't stop to talk. Did not see any cattle either trip, though saw some white-tail deer (about a half dozen, including fawns) this trip.


We pointed the Jeep downhill about 4pm, making good time back to pavement without incident. Returning north on the Sasabe Road (the way we went out) we were rewarded with more nice views of Kitt Peak. Shown at left is an odd-looking view when 99% of the time you only see the profile from Ajo Way on the way to the Observatory from Tucson. Here, looking from the SSE, the 4-meter telescope appears between the solar and 2.1 meter scopes! This was taken with the 500mm lens...

Thankfully, one of us was thinking and we used Donna's phone to take a selfie of the three of us, shown at right. It was another beautiful, if not warm (temps still in 90s) Fall day that will remain memorable!

Another Jeep Adventure!

Well, it is October in Arizona, which means that the temperature has dropped below 100F - barely! After being back to Tucson (from Illinois) for over a week, it was time to get out of town for a drive. I still have Melinda's Jeep, so since it has been parked the last couple months, I thought it should get out on a day trip. I decided to redo a trip that Melinda and I had done almost 9 years ago shortly after she moved to Arizona - a drive out to a unique mountain, Baboquivari! Since the car was her daily driver, she got nervous when the road got a little rocky, and we turned around WAY early. Less chance of that happening today!

Anaglyph image - 3D pair of Kitt Peak from east

Anaglyph image- 3D pair of Kitt Peak from the SSE

The route from Tucson takes us out Ajo Way towards the SW, then turns south on the Sasabe Road at Robles Junction (Sometimes called Three Points). I've often been on this route when photographing sky objects in the west, as the silhouette of Kitt Peak National Observatory 12 miles to the west makes a fine foreground! I used the opportunity on Saturday to take some stereo pairs of the Observatory, taking image sets a couple hundred meters apart to show 3D effects at the distance of the mountain. Use the usual anaglyph red/blue glasses to see the 3D effect! While the image at left shows the usual profile one sees heading west towards the Observatory, the 3D image reveals the topography you don't usually see! As the road continues south and curves towards the west, you get a completely new vantage point of the mountain, as shown at right. Kitt Peak's top is sort of shaped like a "T" with the broad side on the south, and you can see this topography with a couple hundred meters separation. These pairs were taken with a 500mm lens out the car window, pulling over when there was a clear shot to the horizon...

Anaglyph image - 3D of Baboquivari over foothills

A few more miles and Baboquivari, which had been visible miles away, comes to dominate the western horizon. It is a spectacular mountain - the remaining lava plug from an ancient volcano. The anaglyph at left shows the peak towering over some of the foothills that surround it. The diagonal slash of green just above the foothills is a natural ledge (called Lion's Ledge) that forms a route across the sheer east face of the mountain. A lifetime ago, a Kitt Peak programmer (an experienced climber) led another employee and me across Lion's Ledge to climb that left side profile, called the "Southeast Arete". Never having been rock climbing before, I chickened out and met them back at the saddle on the north side, after they successfully summited and descended again. I've never been comfortable in highly exposed situations, and while I've climbed to the peak three times since, it was always on the easier Forbes route on the north and west sides...

Peak nears, road becomes a little sketchy!

The turn towards Baboquivari was near milepost 16 on the Sasabe road. The dirt road was near perfect condition, except for occasional small gullies that would have slammed your head on the roof of the Jeep if you didn't slow and didn't have your seatbelts on! It was about 8 miles to a locked gate, the road getting progressively worse as the peak became more and more impressive as it grew nearer! Really, only the last mile required 4WD in climbing out of a wash and a steep rocky hill beyond. Shortly after crossing a wash with actual standing water and deciduous trees showing some Fall colors, we came to the locked gate, the weeds growing on the route beyond indicating it is not open very often! But that is MUCH farther than Melinda let me go with her baby back in 2008! I took a photo of the Jeep and the gate with the peak in the background in celebration!

I didn't feel like hiking much beyond the gate and other than take a few stereo pairs didn't stay long. I had spotted a striking seed pod while climbing through the desert vegetation, the crimson seeds standing out against the browns and tans of late Fall. I took a photo of it against some striking pink metamorphic rock that I collected in a wash crossing.

I also collected a set of photos of the peak with the 300mm lens, zooming considerably into the slab, taking 13 frames to cover it down to the lower elevations. While the mosaic loses considerable power when reduced to the 1600 pixel wide limit of the blog, it still reveals lots of details in the sheer walls.

The return down the route seemed to go faster and the Jeep enjoyed returning to pavement in less than an hour. Like the trip in '08, returned via Arivaca and Amado to return to Tucson via I-19, arriving by sunset, making for a long, but memorable drive to some difficult-to-forget wilderness!

Out And About!

After a month in the Midwest and a brief taste of dark skies on the CAC bus trip the weekend before, the draw of dark skies on the long Memorial Day holiday was enough to get me out to look at the stars! On Friday, after feeding the kitties, I headed out towards Kitt Peak and set up on a favorite pullout along the access road. Unfortunately it had been a windy day and the winds failed to drop like they were supposed to. I was way underdressed for the gale winds and cool temps at elevation - fortunately the snow mobile suit I keep in the van was still there and made the night's observing possible! The wind also limited the scopes I could use - I stayed with the 500mm Canon lens and the 70-200 zoom for some wider-field imaging.

The highlight of this time of year is always the rising Summer Milky Way! How can I avoid shooting my favorite area of the sky yet again - the area around the orange supergiant star Antares in Scorpius? At left is a spectacular 2-frame mosaic with the 500mm lens. Antares is the orange star very near the center - its light scattering off the dust cloud through the center of the frame. Right of Antares is the huge globular star cluster Messier 4, while between them and a little above is another globular - NGC 6144, located more than 4X the 7,200 light years of Messier 4. I love this field of view because of the complicated mix of dark, reflection and emission nebulae.

But I knew there would be another visitor as well! I recently saw a finder map for comet 71P/Clark. It is not particularly bright, but visible as a small greenish smudge not far from the left edge. The right image shows it a little better, complete with a little tail trailing off to the upper right! Comets that display any color usually show some green - caused by the sunlight breaking up carbon molecules that will glow green in the vacuum of space.


Another target on Friday was an emission nebula in Scorpius. I was shooting with 2 cameras - a recently-obtained T5i that has been modified for increasing red wavelengths to better record the red nebulosity of ionized hydrogen clouds. My other "new" camera (now over a year old) is the full 35mm format Canon 6D which also seems to excel at recording red nebulosity. I headed for what is called the "Cat's Paw Nebula", NGC 6334. At left is a wide field with the Canon T5i and 70-200 lens working at 175mm focal length. The two bright stars at lower left are the "stinger" stars of Scorpius, so this field is quite low in the sky. But right in the center is the "Cat's Paw" - looking like a red-ink print of the paw of a cat. The red coloration, of course, is caused by the ionization of hydrogen by ultraviolet light from hot stars in the cloud of gas. At right is the view with the 500mm and 6D, and again, has good red sensitivity for these hydrogen clouds. Both are relatively short exposures - the wide field at left is 12 minutes total exposure, the right is only 10 minutes! I've still got some exposures from Friday to look at, but these are gonna be my favorites!

On Saturday, I decided to head out to the Chiricahua Astronomy Complex (CAC) of the Tucson Amateur Astronomy Association (TAAA). Even though I had just been out the weekend before, with the 40" scope as a potential viewing instrument, and the dark skies there is a powerful draw making up for the 2 hour drive... I got there just before sunset and set up my mount and the same setup as the night before on Kitt Peak. However, this time there was no wind and it was much more pleasant! At left Carter Smith is at right with his trainee John Meade, getting the 40" telescope ready for the evening. While it looks like a shot taken about sunset, it was considerably darker, but thanks to the "magic" high speed of the 6D, 1/3 second at ISO 8000 makes it no problem! Returning to the pads where my gear was set up, the same shot reveals the hubbub of observers preparing for the night...

My main goal for the night was a "bright" comet - C/2015 V2 Johnson! When it comes to comets, most anything visible in a small telescope or binoculars is considered bright, and unfortunately, this one will not quite be visible to the naked eye. Some of you know that Melinda's maiden name was Johnson, and as far as I know, the discoverer of Comet Johnson is not a relative! He is Jess Johnson, and works for the Catalina Sky Survey right here in Tucson. This comet was discovered as a faint smudge in November of 2015, and is just now at its closest point to the sun and the earth. We'll be able to show it as part of the Grand Canyon Star Party this June, after which, it will slowly be leaving the solar system - its hyperbolic orbit means it will not return to our part of the solar system again. With the 500mm lens, I got 10 frames of 2 minutes each and used the "Nebulosity" program to stack the images on the slowly-moving comet image. The result is at left. The bright star at right is Epsilon Bootes, and the comet is slowly moving almost due south.
What is interesting about the comet is that when zooming in, a sun-ward pointing spike appears!  This usually indicates that the earth is passing through the orbital plane of the comet.  At right is a cropped, stretched version perhaps showing it more clearly.  These sunward spikes are illusions and are actually well beyond the comet.  The solar wind pushes released gas and dust away from the sun to make the tail, and as we pass the plane of its motion, long-ago releases material can appear to point towards the sun.

 

That was the highlight of my Saturday at CAC. I tried some similar low Milky Way objects, but ran into some of the light dome off of Douglas 20 miles south of the observing site. Best to stay higher in the sky! I'm spoiled by the black high-elevation skies of Kitt Peak... Oh, and I did get a glimpse thru the 40"! While my camera was shooting comet Johnson, I ambled up and was just in time to view the huge globular cluster Omega Centauri. With it so low, no stepstool was needed, so extremely comfortable to observe. The cluster looked for all the world like a swarm of fireflies as the long path thru the atmosphere made the stars dance wildly! It was a sight not easily forgotten!