Wednesday, May 31, 2017

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!

Sunday, May 21, 2017

CAC Dedication!

I don't set out to only post every 3 weeks or so - it just happens to work out that way! Last night the Tucson Amateur Astronomy Association (TAAA) threw a party! Over the last couple years the club has developed a relationship with a benefactor that funded a warm/meeting room along with a pair of ginormous telescopes! Last night was the dedication of the Reynolds-Mitchell Observatory at the TAAA's Chiricahua Astronomy Complex (CAC). Bob Reynolds has generously contributed to a large roll-off roof observatory, but the star of last night's show was dedication of a 40" telescope! The TAAA wanted to make sure that everyone who wanted to attend could make it, so went to the trouble of leasing a big tour bus for hauling members on the 90 mile drive from the TTT truck stop at I-10 and Craycroft. Who could turn down a free bus trip, box dinner included, highlighted with viewing with a 40" telescope?! Not me! At left, our travelling hostess Mae makes sure we all have what we need!

I can't recall riding a big tour bus since our Senior Class Trip to Washington DC 45 years ago, so it was a fun time. Our seats were higher than the truckers in the big semis that we passed, so was a nice view of the passing scenery. Of course, some might claim there isn't much scenery in Southern Arizona except brown-colored desert, but Texas Canyon, shown at left is always amazing, especially if you don' have to pay attention driving! And, of course, once you've made it to Texas Canyon, you've already passed about a million of the signs at right - "The Thing" is a tourist destination just east of Texas Canyon, and is actually kind of a cool-kitschy stop worth a visit - especially if you need a rest room or a Dairy Queen stop! As mentioned, the TAAA also sprang for meals - boxed dinners from a local deli, with 4 choices of sandwich - pretty high living!

The trip seemed to fly by, and we got there a bit before sunset. There was quite an agenda on the night's program and after a rush to the bathroom (twin flush toilets!), the facility tour started. First up, former TAAA president and site manager John Kalas gave a guided tour of the site from the ramada. That's him at left, taken in a 4-frame mosaic taking in the sweep of members present (nearly 100 I'd guess), ramada and the new scope/warm room at right.

As the sun dipped below the horizon, I skipped the treasurer's tour of further development plans, instead staying and documenting some of my friends that I recognize from my travels up and down the Sulphur Springs Valley. From CAC, as from down to not-to-distant Whitewater Draw to the south (sandhill crane site) views of "Cochise's Head" as well as the 60-mile-distant Mount Graham topped by the LBT telescope showed up as familiar friends!

A few minutes later and it was time for more speeches! Former TAAA president Tim Hunter and owner of the Grassland Observatory reviewed the club's search for a dark-sky observing site, culminating in CAC. In the photo at left, Tim is shown at left, and Carter Smith (Chief Telescope Operator) prepares the 40" for use as John Kalas introduces our benefactor. At right, Bob Reynolds says a few words before handing off the sissors to his wife to cut the ribbon opening the warm room and telescope!

All too slowly, it got dark and the scope operators did an alignment to get the giant 40" telescope pointing and tracking and finally ready for use. The first object - a stunning view of Globular Cluster Messier 13. This view is taken with the Canon 6D with Nikon 16mm fisheye lens wide open at F.2.8. The 20 second exposure (ISO 5,000) shows stars and objects much fainter than the naked eye can see, including Omega Centauri just upper left from light dome from Douglas at right. Messier 13 can be spotted at upper left if you can make out the keystone of Hercules. At the upper edge is Jupiter, and between it and Scorpio rising at bottom center, a faint section of the zodiacal band can be seen!

A bit later and the scope was turned to Messier 82 in Ursa Major. The edge-on galaxy, 12 million light years distant displayed very nice dust lanes crossing the luminous band. In the photo at right (exposure details same as above), besides the scope, dominating the sky is the bright glow of Zodiacal light in the west - the Beehive Cluster (Messier 44) can be spotted in the midst of it! While both photos seem to show the area was brightly lit, the exposures seem to amplify the amount of ambient red light about. It certainly didn't look brightly lit to eye!

Before we knew it, 9:30 had arrived and we needed to board the bus for the return trip to Tucson. By the time we disembarked, loaded up the small amount of gear into the van and dropped off passengers, we walked into the house right at Midnight. A very special night of observing "in the can"! All I can say is that an observing trip down to CAC with the 40" is a rare treat - about to become less rare!

Tuesday, May 2, 2017

Fishing Season!

I'm currently at "Ketelsen East" in the western suburbs of Chicago, enjoying some "real" Springtime weather! After already threatening to break 100F about the time I left Tucson 10 days ago, the cooler temperatures, rain, flowers and outbreak of green here is a welcome sight! And we've had it all - 4" of rain over last weekend, and tonight there are freeze warnings in the area, so Summer still seems a long way off!

But with the downpour this weekend, on Monday the Fox River jumped out of its bank and got within about 50 feet of the house here! The image at left shows the water as it came up the "canoe beach" at far left and filled a depression in the middle of the lawn as shown. As the water drops back down, usually carp, some of pretty good size (I've seen up to 20" long!) are trapped in the "yard pond"! Somewhere I've got pictures that Melinda took of me trying to catch them by hand (hard) or with a large fishing net (easier) to dump them back in the river. After I gave up that earlier time, the herons and egrets move in and they were gone in a day.

So I wasn't really surprised, but startled when I saw my first great blue heron appear just before sunset tonight. The only telephoto I have is a 500mm Nikon mirror lens of '70s vintage given to me by a friend, and I rushed to install the adaptor that lets me use it with my Canon camera. Unfortunately I missed his playing with a sizeable fish, but got a nice portrait at left in the "yard pond" before he moved back over to the main river channel for some fishing where only his head is visible.

It started raining pretty hard again, and my last view of him was standing on the bank looking across it, or perhaps looking downstream at a kayak that was bearing down on him as he took off a few seconds later as they passed going upstream. If there are still fish in the pond, they will be back, though other than the one I saw the heron play with, I've not spotted any...