As promised, last weekend was the first of two excellent dark sky weekends this month. The weather turned out to be perfect for this one as well.

Jane and I went to our old favorite spot off I-10, Chuckwalla Bench, on BLM land south of Joshua Tree in the Colorado [...]]]> Chuckwalla Bench, Colorado Desert, California, 29 October 2011

As promised, last weekend was the first of two excellent dark sky weekends this month. The weather turned out to be perfect for this one as well.

Jane and I went to our old favorite spot off I-10, Chuckwalla Bench, on BLM land south of Joshua Tree in the Colorado Desert. We were joined by Dave Hasenauer and his dob.

Bad news about Red Cloud Rd., the dirt road we take to our favorite spot. The road is sadly in need of some maintenance. Portions of the road are very treacherous with deep ruts and deep sand. We didn’t encounter any problems this trip, but it will be a worry.

We had crystal clear skies all night, with temperatures around 85°F at sunset, dipping close to 50°F in the wee hours.

The evening twilight featured Venus in its new evening apparition setting in the west, Mercury just below, with Jupiter one day after opposition rising in the east.

Early in the evening while spotting satellites, we managed to catch a bright fireball meteor (7:22 p.m.) probably around magnitude -10. I saw a double terminal burst from the fireball, which traced from Cassiopeia through Triangulum. It left a persistent train that was visible for several minutes in binoculars and Dave’s telescope.

Jane even indulged in a little afocal astrophotography capturing some splendid crescent moon shots on her point-and-shoot camera.

I had a couple of “firsts” in my astrophotography accomplishments, doing my first successful drift alignment when my polar alignment was slightly off, and finally successfully capturing useful “flats” for image calibration in the morning twilight.

I also had a brainstorm about how to process the color data from bright targets without data being clipped in the bright areas. With that in mind, first let me revisit my M31-M32-M110 the Great Galaxy in Andromeda from last week, this time in full color.

M31 from 22 Oct. 2011, 4x15 minute exposures

(For all the images, click the image for the full-resolution version.)

And I promised to revisit the Pegasus 1 galaxy cluster, this time giving it an hour of exposure, which it fully deserved. Here’s the full field first.

Pegasus 1 Galaxy Cluster, click for full-resolution.

The one-hour exposure time cuts down the noise nicely, and calibrating it with a good flat field removes the vignetting. Check out this detail from the center of the cluster at full resolution:

Pegasus 1 galaxy cluster detail

Jane was observing this delightful face-on S-shaped spiral galaxy, NGC7479. It was such a small target that I didn’t think my short-focus 4-inch would do it much justice. It turned out to be a delightful crop with lots of detail.

Detail of NGC7479, click for the full field, 15-minute exposure

Another surprisingly good image came from NGC55, a fabulous extended galaxy, so far south in the sky that it’s rare to be seen by northern-hemisphere astronomers. Complicating matters is a light dome from Inland Empire cities that encroaches on our southern horizon. Nevertheless, my 15-minute exposure was worth passing on. The full-resolution shot is very nice with lots of detail.

NGC55, one 15-minute exposure, through a bit of "foreground" light pollution.

Jane also suggested one of her favorite difficult winter visual targets, NGC2359, known as “Thor’s Helmet.” I collected an hour’s worth of photons. Here’s the detail from the center of the field, click for the whole thing.

NGC2359 "Thor's Helmet," 4x15 minute exposures, detail from the center of the field.

I’ve long been fascinated with distant galaxy clusters, and they’re very difficult visual targets. Some find them to be uninteresting photography targets. I opted to try 30 minutes on Abell 426, a massive distant galaxy cluster in Perseus. Here is some detail from the center, but the full field is full of easter eggs.

Detail from the Abell 426 Galaxy Cluster in Perseus. Click for the full field.

My last target of the evening was to be an indulgent treat, the M81-M82 galaxy pair in Ursa Major. My mount battery finally quit just at the end of the second exposure, and morning twilight was about to arrive. A fabulous end to the evening.

M81 the spiral (a.k.a. "Bode's Nebula"), and M82 a peculiar active galaxy, in Ursa Major

The snow-capped peaks were beautiful from the Foothill Freeway

It had been several months since our schedule, the weather, and the moon phase all cooperated to give us a chance to get out to our favorite astronomy spot. Jane and I, joined by Dave Hasenauer, ventured [...]]]> Click here for the full photo album with lots more pictures.

The snow-capped peaks were beautiful from the Foothill Freeway

It had been several months since our schedule, the weather, and the moon phase all cooperated to give us a chance to get out to our favorite astronomy spot. Jane and I, joined by Dave Hasenauer, ventured out to the Colorado Desert with promises of a chilly evening but mostly clear skies. The snow-capped peaks of San Jacinto and Gorgonio mountains were calling to us from almost our first moment on the road.

Twilight on Chuckwalla Bench

During our twilight setup, some fellows from Arcadia stopped to check out the equipment. Dave was all set up and ready to show Jupiter if we could find it. While hunting in the twilight glow, we all exclaimed as a flock of probably 100 geese were approaching from the west. The geese turned out to be our guide to Jupiter! They flew right in front of the planet, and gave our eyes a convenient focus target. We all enjoyed the view through Dave’s big dobsonian.

Jane had plans to attack the faint periodic comet 103P/Hartley, famous for its huge outburst of a year ago. Jane and Dave both claim to have found the glow of the incredibly diffuse comet. I tried for an image of it myself, but was convinced I didn’t have anything. This is my shot, with the comet buried deep in the winter Milky Way in Monoceros.

Can you find the comet?

Can you find the comet? Here’s a full-resolution crop of the center of that field. Look right in the middle, and try to ignore that my focus wasn’t especially good for this picture!

Look for the faint cotton ball in the center.

I was delighted that most of my hard-won imaging skills hadn’t been completely lost during the time away from it. I didn’t get a perfect focus for my first couple of shots of the evening, the comet Hartley photo above being one.

Even with a less-than-perfect focus, this one of the Rosette Nebula in Monoceros turned out pretty well. This is only 30 minutes of exposure, and it’s pretty clear this object would benefit from a couple hours of exposure time.

The Rosette Nebula, click for the full frame

The Cone nebula is another one that could benefit from a lot more exposure time, but at least by now I’d corrected the focus. I love this beautiful field, with a vast mix of Milky Way stars, emission, reflection, and dark nebulae. The “cone” that gives the nebula its name is near the center of the image. This is also two 15-minute exposures stacked.

The Cone nebula in Monoceros, click for the full resolution image.

A bright supernova was discovered just a couple weeks ago in small distant galaxy NGC 2655 in Camelopardalis, very high in the northern sky. Jane and Dave both enjoyed hunting it down, and the nova is bright and easy, itself as bright or brighter than the rest of the galaxy. Of course I had to get an image, here’s my crop of the field with the supernova marked.

Supernova in NGC 2655, click to see the whole wide field image.

Finally Jane suggested this great pairing, “The Owl and the Cigar,” she called it, M97 the Owl Nebula paired with galaxy M108 in Ursa Major. I only got one 15-minute exposure of this field, as the clouds were starting to move in, but I loved the colors in the Owl nebula, and the detail in M108. It’s fun to contemplate the difference in their distances, with the Owl being the gasping exhalation of a single star in our galaxy, and M108 being billions of stars in a very distant galaxy.

The Owl and the Cigar, M97 (top) and M108, click for full resolution

The first half of the night was interrupted several times by loud flights of two or three helicopters passing nearby. We speculate that they may have been in service to the border patrol, using infrared or intensified imaging. Our little site must have been interesting to see from their vantage point.

Pre-dawn Chuckwalla Mountain with the moon and Venus

By the time the sky show was interrupted by clouds, we all were tired and cold and felt like we’d had a full evening. Amazingly it was only 11:00 p.m.! We all tucked ourselves into warm sleeping bags to catch a few hours of sleep. Meanwhile the sky cleared again for spectacular pre-dawn show of the moon and Venus. We all got up to enjoy the old crescent moon, Saturn, and watch for Mercury to rise over Chuckwalla mountain.

With the local star finally clearing the horizon, we packed and headed off to breakfast at Chiriaco Summit. By the time Jane and I arrived back home in Monrovia, it was raining!

P.S.: In the photo album linked here, I included some detail photos of my astrophotography equipment, with captions, for the benefit of some friends who’ve wondered how these things happen.

We hadn’t expected to be able to observe during this part of the summer from Chuckwalla Bench in the High Colorado desert south of Joshua Tree, but this August night’s forecast at Desert Center [...]]]>

These cumulus clouds were nearly stationary all evening, making quite the light show with an electrical storm

Observing report, August 7, 2010

Chuckwalla, CA

We hadn’t expected to be able to observe during this part of the summer from Chuckwalla Bench in the High Colorado desert south of Joshua Tree, but this August night’s forecast at Desert Center looked very inviting. The forecast high there was 101°F with a low of 74°F. I believe our actual location is at a higher altitude; it always seems at least a couple of degrees cooler.

It was forecast to be breezy though, and that can make it uncomfortable to observe as well as blow telescopes and tripods around. We did have some periods when the wind was a nuisance, but for the most part it was pleasant t-shirt and shorts weather all night long.

I caught this great lightning bolt from the distant electrical storm, with the camera on a small tripod and the bulb left open for a while.

We had crystal clear transparent skies overhead all night, with a great sugary Cygnus Milky Way transiting high overhead mid-evening, but there was an interesting weather phenomenon happening some number of miles north-northeast of us.

As the sun was setting, we had this great view of some towering cumulus clouds catching the sunset glow to the northeast. Over dinner I thought I saw a lightning flash in the clouds. As it turned out, throughout the evening all the way to 2:00 a.m. we were entertained by a sometimes massive electrical storm that seemed to be nearly stationary. I caught this one good lightning strike off in the distance. The full-res version is a crop from the center of a very large picture.

It was also to be a fun evening to see a planet grouping in the west, following the sun to the horizon. I caught this great shot of bright Venus, with Saturn to the upper right, and Mars to the left. To the far left is the bright star Spica. Click to see the great full-resolution picture. In binoculars, Mercury was also visible, but deep in the red sunset glow well out of the field of this picture. In a few days the crescent moon will join the trio for another good picture.

Bright Venus grouped with Mars (left above) and Saturn. Click for the full 4MB experience.

I did take a couple of interesting piggyback Milky Way pictures. My focus wasn’t perfect, and the white balance doesn’t seem quite right. They are mostly untouched except for some slight darkening of the blacks. They are both five-minute exposures on my stock Canon 20D. I think if this camera were modified to remove the deep red filter, the red hydrogen-alpha glow of the North America nebula would show more.

Cygnus Milky Way, north with bright Deneb to the lower left from center.

And here is a late-night shot of Cassiopeia.

Cassiopeia reclines in the summer Milky Way. The "double cluster" is visible near bottom center.

And of course I did some exposures through the Astro-Physics Traveler as well. Here is the Swan Nebula, M17, four ten-minute exposures, ST-4000XCM one-shot color camera. Click on each for the full-resolution image.

M17 also known as the Swan Nebula or Omega Nebula.

I knew that the Ring Nebula, M57, would be an almost silly target for a telescope with this wide field of view. It would appear as a tiny donut swimming in a field of Milky Way stars, just as it often does visually in a telescope. Of course that made it irresistable. Here is the full field:

There's the Ring Nebula, M57, just right of center.

And now as you can see in a crop at full resolution, it’s not a bad image at all. This is three ten-minute sub-exposures (30 minutes total).

Full-resolution crop from the wide field above, M57 the Ring Nebula.

Finally I wanted to get one of Jane’s (and my) favorite Cassiopeia star clusters, one discovered by Caroline Herschel, and known as the Magnificent Cluster, NGC7789. This scaled down version is not terribly impressive, but the full-res image is a treat to swim around in.

The Magnificent Cluster, NGC7789, in Cassiopeia

On a techy note, for the first time I started to have some issues with haze forming on the chip. Given the presence of those nearby cumulus, I guess I can’t always count on the desert air to be completely water-free.

Besides the great deep sky and planets, of course we also had lots of meteors from the forward edge of the Perseid meteor shower. Jane did some great counts, and I enjoyed some bright meteors while the shutters were open.

‘Til next time …

Update: Jane wound up using most of my astrophotos below in her July NASA What’s Up podcast. Check it out!

The forecast was for a very temperate desert evening, so six of the Old Town Sidewalk Astronomers headed off to the Colorado Desert to play outside all night. Seeing was [...]]]>

Mojo, Caroline, Jane, Catherine, Gary, and Todd

Update: Jane wound up using most of my astrophotos below in her July NASA What’s Up podcast. Check it out!

The forecast was for a very temperate desert evening, so six of the Old Town Sidewalk Astronomers headed off to the Colorado Desert to play outside all night. Seeing was forecast poor, but actual conditions seemed much better.

Jane packed her 17.5-inch dob, and I loaded the Astro-Physics Traveler 102mm f/6 refractor to do some astrophotography. The highlight of the evening promised to be comet McNaught 2009R1, but it wouldn’t be available until the pre-dawn hours. That left me with late spring galaxies and summer Milky Way targets. (Jane also had a great target which she’ll be writing about!)

I tried the M84-M86 region of Virgo last month with the AP180, but the field of view was too narrow. I knew it’d be a good warm-up for tonight. The grey scale version looks better to me than the color rendition.

M84-M86 region in Virgo, "the Nine Gals"

Jane and I both love piggyback pictures, taken at “naked eye” scale. This is one of “the teapot” and the Sagittarius Milky Way. The full-size image isn’t bad, but it looks better scaled back a bit. Click for the really big version. It’s fun looking through all the dark nebulae and bright clusters.

Looking towards the center of our galaxy.

Deep in the Milky Way just above the spout of the teapot is Barnard’s famous “Ink Spot” dark nebula, B86.

Barnard 86 "The Ink Spot"

I started out trying to fit M8 “The Lagoon Nebula” in the same field as the nearby Trifid Nebula, but they wouldn’t quite fit. So I did 15 minutes just on M8, and love the result.

M8 The Lagoon Nebula and cluster

I love hunting for the Pipe Nebula, a huge dark nebula best seen in binoculars. Seeing the Pipe is a portent of great transparency and dark skies. The detail photo here is centered on the Pipe, taken piggyback with the 20D. Click for the full field, see if you can find the Pipe there.

Do you see the pipe outlined here? Click for the full field.

Ever since I started doing astrophotography, I’ve been waiting for the opportunity to shoot M16 The Eagle Nebula. This nebula is famous for its Hubble Space Telescope image showing the embedded dark nebulae as stellar nurseries, the “Pillars of Creation.”

I only did one fifteen minute exposure. By then it was getting quite late, and I need to catch a couple hours of sleep before getting up to catch comet McNaught. Naturally that means I had an airplane fly through the image! Should I wipe it out with Photoshop? Naaaah.

M16 The Eagle Nebula and cluster. Plus United flight 2037. (Just kidding!)

Jane and I napped for a couple of hours, with alarms set to catch comet McNaught in the early hours

This image of McNaught is made from ten one-minute exposures. They’re stacked with the comet centered, so the background stars are streaked. It looks out of focus, but it’s actually just the motion of the comet you see.

Comet 2009R1 McNaught, ten one-minute exposures stacked and centered on the comet.

I also took my ten comet pictures and made a little animation that shows the motion of the comet against the background stars over the course of 15 minutes or so.

Comet McNaught moves against background stars over fifteen minutes. The sky is also brightening with dawn towards the end.

I was also taking piggyback images of the sky where McNaught was lurking. Can you find the little green dot near the center?

This is the "naked eye" view of the sky where Comet McNaught can be found. The horizon is tilted as an artifact of the way the mount holds the telescope and camera mounted piggyback. Click for the full scale version.

Here’s a little close up of the beautiful binocular cluster Collinder 39 in Perseus with the green dot of McNaught just to the right. The color was evident in binoculars even.

This is somewhat the view in a pair of binoculars of large open cluster Collinder 39. See the green dot of comet McNaught slightly up and right of center.

What a fabulous night of astronomy! Shirt sleeves or light jacket all evening.

Mojo setting up his "desert office" for some astrophotography

Equipment notes: The telescope shots were taken with an SBIG ST-4000XCM one-shot color CCD camera, at prime focus of an Astro-Physics Traveler 105mm f/6 refractor. The mount is an AP Mach 1 GTO on a wooden tripod. The piggyback photos were taken with an unmodified Canon 20D digital SLR camera.

Update: Be sure to see Jane’s A Ten Planet Night report from the same evening!

It was another perfect new moon Saturday for a trip to our favorite spot in the Colorado Desert out I-10.

Yes this is a very full Grand Caravan!

Jane and I happily took out all [...]]]> Full photo album of setting up and astrophotos here at the Whiteoaks Photo Album.

Update: Here’s Jane’s version of the same evening.

It was another perfect new moon Saturday for a trip to our favorite spot in the Colorado Desert out I-10.

Yes this is a very full Grand Caravan!

Jane and I happily took out all the seats of the old Grand Caravan and filled it with telescopes and gear. We brought her 17.5-inch Litebox dob, and our AP180EDT f/9 refractor.

Jane has been indulging my dabbling in astrophotography lately. I’ve been delighted that Jane is using some of my astrophotos for the What’s Up podcast, lucky that she wants imperfect images that are closer to what one might actually see in an amateur telescope.

This 180mm f/9 refractor should be an outstanding astrograph; it’s certainly an amazing visual astronomy instrument. I dabbled with it a little last year in Anza Borrego, knowing I needed to learn a lot of operating technique to get some good results. I solved a few mechanical problems then, and ran into autoguiding calibration later. Those lessons served me well, even though it’s almost a year later.

Early in the evening was Jupiter time, and we all spent some time soaking up the gorgeous views through a binoviewer in steady seeing. 300x on Jupiter showed lots of detail in the bands, including a nice red barge in the North Equatorial Belt, and nice little disks and color on the moons.

I’m going to take a few paragraphs to talk shop, gadgets, problems, and solutions.

Setting up the AP180, all ready to take flats, except there's no known focus position!

My camera is an SBIG ST-4000XCM single-shot color CCD camera which perfectly suits my recreational needs. The big AP180 is mounted on an older 900QMD mount, a simple but stable platform without GOTO electronics or servos.

The 900QMD mount comes with digital encoders on the R.A. and Dec axes, but having spent several years using this telescope for primarily lunar and planetary observing, those encoders went unused for the life of the mount.

The R.A. axis encoder is removable so you can use a polar alignment scope, and the encoder shaft has a slip fit into a metal sleeve when it’s in place. Last year I discovered that this mechanical connection slips very easily, rendering the encoder useless.

The trick I settled on, which worked again tonight, was to cut a little piece of rubber band and push it into the fitting to serve as a tightener.

Jane aligns the Telrad on her 17.5-inch Litebox

To use the digital encoders for pointing, I acquired a BBox from JMI, connected that to a USB-Serial adapter, and used Software Bisque’s TheSky 6 to serve as my controller. I’ve learned by experience (at Fremont Peak observatory) that the alignment doesn’t need to be 100% perfect. I’ve learned the trick of syncing the software and encoders to a bright star near my target, then doing an accurate short slew to my actual target.

(One problem I haven’t quite solved yet is play in the polar scope. I haven’t figured out how to tighten the polar scope in position, in the correct orientation, so it doesn’t wiggle.)

So with a not-quite-perfect polar alignment, autoguiding becomes my essential partner. CCDSoft can be tricky software to work with when calibrating the autoguiding. The error messages and manual don’t really help solve problems like “Illegal motion in X-axis, error 352.” I thought I might even be dealing with a problem in the mount mechanics. In retrospect, I think I also hadn’t learned the correct switch settings on the QMD controller. (“Guide” and “.5″ works much better than the 16x slew mode for visual!)

On perusing the Software Bisque support forum last week, I was able to learn that their autoguiding calibration depends entirely on there being only one bright star in a large region of the guide imager. While I could see the guide motions working perfectly and orthogonal, the software doesn’t do matching of the star field, only looking for the one significant guide star.

Having discovered that, I was finally able to successfully calibrate the autoguider. And with one successful calibration (remembering to set the current declination), I could autoguide on different targets successfully for a long time.

(The Software Bisque manuals hint that there’s a way to link to TheSky so CCDSoft knows the declination of its target, but I haven’t figured that out yet.)

M74 two 15-minute exposures, SBIG ST-4000XCM, 180mm f/9, October 17, 2009

Pisces was high overhead, and I love M74, so I decided as a first target to revisit that favorite. I settled on 15-minute exposures. The first one came out “double vision” when the autoguider momentarily lost track during the exposure, but that was the only time that happened during the evening.

NGC7541 in Pisces, 15 minutes

A visit to the Night Sky Observers Guide suggested NGC7541 as a Pisces “showpiece,” and I love galaxy groups. This one was gorgeous in Jane’s 17.5-inch, too.

NGC7640, 15-minute exposure

Jane showed me NGC7640 in her 17-inch, a really lovely look, and I thought it would be a great target. We’re starting to enjoy comparing visual and imaging views.

NGC253, 2x15minute exposures

I admit I get impatient when I’m imaging, and want to collect more targets rather than more exposures on the same target. As a result, I have a little more noise in my images, but I’m having fun anyway. That said, I couldn’t resist spending some time on NGC253, the Silver Coin galaxy. I had a tantalizing glimpse of this target last year at Anza Borrego when I hadn’t yet learned how to make the autoguiding work. This time I got two lovely 15-minute exposures. Well worth it.

Pre-dawn crepuscular rays at Chuckwalla Bench

After a few hours sleep, we were greeted with lovely pre-dawn crepuscular rays, Venus, and Saturn making its return after solar conjunction. Not to worry, the telescope was capped, and about to come down into its box, anyway. (You can see the box ready to be loaded with telescope.) Jane paused to take this lovely picture.

The Clear Sky Chart forecast for Desert Center, CA, was dark blue all night for our favorite observing site. The NOAA forecast called for a high of 99 and low of 77. Often a night like this can have uncomfortably hot [...]]]> Observing report, dark sky weekend, September, 2009, Chuckwalla Bench

The "Double Cluster" between Cassiopeia and Perseus

The Clear Sky Chart forecast for Desert Center, CA, was dark blue all night for our favorite observing site. The NOAA forecast called for a high of 99 and low of 77. Often a night like this can have uncomfortably hot weather. Chuckwalla Bench is a little higher than Desert Center, so I was hopeful that the night wouldn’t be miserable with heat. It turned out to be lovely shirt-sleeve weather all night.

Several of us were feeling dark-sky-deprived, so Jane and I were really looking forward to some quiet time with friends in our favorite desert location.

I took the Astro-Physics Traveler (pictured at the top of my blog in a photo taken at Chuckwalla Bench) to attempt a little low-power astrophotography.

As I mentioned, I was really rusty with the equipment and procedures, and am a beginner at astrophotography anyway, with a total of about four sessions under my belt. We were all out of practice; I think everyone on the trip left something at home or had some minor trouble.

After warming up with the Double Cluster as a good focusing target, my main goal of the evening was to make my first real asteroid trail or animation. With Juno very much in mind from Jane’s What’s Up podcast, I decided it would be my second target.

Animation of four Juno images taken over 50 minutes

Jane and Gary were hunting down Juno visually while I was imaging it. We had a great time using a combination of images and TheSky 6 to make a positive identification of Juno. I collected four ten-minute exposures, and made my first asteroid animation above.

The Helix planetary nebula, crop from full-frame image.

The Helix Nebula NGC 7293 is an irresistible target for a good wide-field telescope and a color camera. I combined three ten-minute exposures. The image above is a crop — click to see the full field image.

Crop of M1, "The Crab Nebula," click for the full frame.

My Crab Nebula is a combination of three ten-minute exposures. It’s not a great image, but still a treat to see the kind of detail that we don’t get to see visually. The full-frame image (click to see) shows this small target.

A crop from my M74 image, click for the full frame.

I love galaxies, and M74 is a favorite — for being small, hard to find visually, and a difficult “first target” of the Messier Marathons we do in March. I couldn’t resist trying to get an image of this little gem.

I know I need to put more exposure minutes into my images, especially of my favorite faint targets. My backgrounds are still very noisy; my focusing isn’t perfect. Since I don’t get to do this very often, I get impatient and want to grab several targets over an evening. Practice, practice!

Gary Spiers snapped pictures as we set up in the desert. Click the image for a link to his photo album from the night.

A night in the desert has to be followed by a great breakfast. After catching a couple hours of sleep, we all packed up the site in a gorgeous desert dawn and headed ten miles west to Chiriaco Summit, home of a great diner and the General Patton Memorial museum. Tanks and eggs, four stars! (Ratings and generals.)