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Category: Photography and Video

  • Working with a broken astronomy camera

    Last year, I had some really bad luck with astrophotography.

    I replaced my old laptop (Dell, Windows XP) and installed a new suite of tools to replace the somewhat ancient and unsupported camera software. At one point during my first “shakeout” evening (October 2014), the new software started spinning my telescope around the declination axis. It made at least two full loops (720°), wrapping the cables around the mount and stressing the camera case.

    Afterward, the shutter was not working, or making noise. In my attempts to solve that problem in the dark, I dislodged a small optical window.

    Back at home, I disassembled the camera, and found that I could move the optical window back into position, but it wasn’t held there firmly. Everything else seemed fine though. The shutter worked well, and the electronics all worked.

    All of the equipment has been put away since then, over a year.

    The time was coming to get back into the game. I knew I’d have several hours of work to update the software suite, not to mention Windows 10. The most delicate update was for the firmware in the keypad of my Mach1GTO telescope mount. I spent an hour and a half on that one update, following all of the procedures carefully. The rest took another few hours: TheSkyX, CCDStack, SbigControl, PEMPro, Skytools3, MaxIm DL6, ASCOM drivers, all the manuals. I hooked up all the cabling, the USB-to-serial adapter for the mount, and the camera itself. All of the software components worked — I could control the mount and the camera and take pictures.

    I also had to consider the condition of my camera. Had I damaged it beyond use? Beyond repair? I called SBIG technical support and described what had happened.

    The support rep, Tim, was audibly chagrined. “Oh nooo! How did that happen? Are you sure?” I learned that the optical window is supposed to be firmly sealed, maintaining a bone dry chamber that keeps out dust, and prevents condensation and frost from forming on the sensor chip. (During a session, the chip is cooled to well below freezing to reduce the amount of thermal noise in the images.)

    Next I exchanged some email with Bill in Santa Barbara who repairs SBIG cameras. He said I should send in the camera at my convenience. In the shop, he’ll affix the window, dry the camera severely in a chamber, and seal it all back up. He also suggested that I could probably use it this weekend, but with the seal broken it would “likely frost up, but then that usually dissipates after a while.”

    With expectations of little or no success, Jane and I headed off to Amboy Crater on Saturday (April 2). The forecast was for ideal conditions. I’d never seen a Clear Sky Chart that black; little or no wind, severe clear skies, near perfect seeing, a low temperature forecast of 56°F. My plan was to experiment with all of the unfamiliar software and learn how to do this again.

    With the mount polar aligned and all hooked up, I went to an old favorite as a test photo: the “Leo Trio,” M65, M66, and NGC 3628. At the site, the raw data looked really promising. Back home the next day, it was obvious that the image was marred by frost or condensation or both.

    M65, M66, NGC 3628
    The “Leo Trio,” NGC 3628 at the top, M65 and M66 below. Also a likely satellite streak in the upper left, and haze from frost or condensation on the imaging sensor. (Click for full resolution.)

    Afterward, I spent 90 minutes or so learning to use PEMPro, and ended up with a polar alignment within one arcminute of the pole. It’s an excellent program, and I’ll be much quicker at it on the next go-around.

    Meanwhile, there was some excitement among my fellow observers who were seeing the famous and very southerly Omega Centauri globular cluster. This object never rises more than a few degrees above the southern horizon. It’s known for being the largest globular cluster in our sky — probably the largest of all the globulars in the Milky Way’s halo. I couldn’t resist giving it a try.

    Omega Centauri
    Omega Centauri, 15 minute exposure (one exposure, not stacked). Astro-Physics Traveler 105mm f/6 refractor. SBIG ST-4000XCM one-shot color camera. (Click to embiggen.)

    With that in the bag, I had to get Centaurus A, the famous “Hamburger” galaxy, just barely north of Omega Centaurus.

    Centaurus A
    Centaurus A, active galaxy. (Click to biggify.)

    Then before crawling into the van for a nap, I shot a random field in the Virgo galaxy cluster, around M87.

    M87 and Virgo cluster galaxies. (Click to embiggenate.)
    M87 and several nearby galaxies from the Virgo cluster

    After a nap, I did something I haven’t yet been able to do successfully in astrophotography: I shot some flat frames.

    A “flat” is created by evenly illuminating the sensor to pick up imperfections in the optical train. It’s used to correct things like vignetting and dust spots, and produce a calibrated image.

    With the new software for capture, SbigControl, and data reduction, CCDStack, making flats turned out to be quick and easy. I used my iPad with a grey image on the screen as a light source. I pointed the telescope to the zenith, and rested the iPad on top of the dew shield.

    Here is my master flat, made by combining several raw images:

    Flat image with dust specks and vignetting.
    Master “flat” image taken in the morning after the previous shots, and used to calibrate the images. Notice all the dust specks! (Click for … god, why?)

    Oh gracious, that seems like a lot of dust to me! I’m sure I (un)sealed my fate by opening the dry chamber of the camera, allowing a few specks to settle on the sensor cover glass.

    All-in-all it was one of my most satisfying astrophotography expeditions. I’m really looking forward to getting the camera back from SBIG. I’m not expecting anything magic — it’s not going to take better pictures than these. But I do expect fewer images marred by frost haze. I imagine I’ll be able to shoot earlier in the evening and have the images be usable. With the modern software in place, I might be able to try some more ambitious projects.

  • April Observing: Supernova and a Comet

    The weather forecast for our favorite spot, Amboy Crater, called for decent conditions but high winds. (Why do we care about the wind? Here are four reasons I can think of: simple comfort, blowing charts and equipment, maintaining a target in a telescope, and blowing dust.)

    The best forecast in the area was at our old favorite spot in the Colorado Desert south of Joshua Tree National Park, an area of BLM land below Chuckwalla Mountain called Chuckwalla Bench. We had mostly abandoned Chuckwalla Bench because the unmaintained dirt road (Red Cloud Mine Rd.) was getting a bit treacherous. Someone suggested a different road, following a nearby train track, that got us to the same observing spot a lot more reliably.

    Conditions seemed near perfect, with calm to light winds, clear skies, comfortable temperatures, and pretty good seeing. The nighttime temperatures may have dipped a bit below 60 degrees F, but not a lot.

    Jane had our 14.5-inch dob, and reported that visual observing conditions were quite excellent. Her report is fabulous, and I wish I’d tried for those low southern objects! The Chuckwalla Bench location does have a light dome to the south, but nothing ventured …. [Read Jane’s report here.]

    I started with a galaxy in Leo that I shot last month, M65. Since shooting it last month, a supernova was discovered in the galaxy. I did one 15-minute exposure, and had fun today making a “blink comparitor” animation. Can you see the supernova?

    m65-sn2013am
    Two images of M65, one shot on 3/9/13, one shot on 4/6/13.

    At the end of the post, I’ll mark where it is. 🙂

    Being spring, I wanted to collect some galaxies. I started with a string of galaxies in the nearby Virgo cluster, called Markarian’s Chain. The chain extends from the middle-right of the image, to the left and upward. In the lower left corner is giant elliptical galaxy M87.

    markarians-chain
    A portion of Markarian’s Chain in Virgo, with giant M87 in the lower left

    Then I wanted to try for something a little more distant, and did 45 minutes on a remote galaxy cluster with the catalog number of Abell 2151, found in the constellation of Hercules. This is a group of about 200 galaxies some 500 million light years distant.

    Abell 2151
    Galaxy cluster in Hercules known as Abell 2151. This compact view doesn’t show them well, but click on the image for full resolution, and pan around to see if you can find some distant spirals.

    Finally comet C/2011 L4 (PANSTARRS) has been moving toward the north celestial pole, and right now it’s easier to catch before dawn than after sunset. After napping for a while, we found the comet at about 4:00 a.m. Here’s my first five-minute exposure.

    Comet C/2011 L4 (PANSTARRS)
    Comet C/2011 L4 (PANSTARRS) shot before dawn on 4/7/13, five-minute exposure

    I did a series of several 5-minute exposures, and stitched them into a GIF animation. If you look carefully, you can see the motion of the comet against the background stars. The other rather obvious feature is the coming dawn light as the sky turns brighter and very blue. 🙂

    Comet PANSTARRS animation
    Comet PANSTARRS moves slightly against the background stars, as dawn arrives at Chuckwalla Bench.

    And finally, if you didn’t find the supernova in my “blink” animation above, it’s marked for you here.

    SN2013am
    M65 with supernova 2013am taken 4/6/13

    If you follow us on Twitter or Facebook, you know that we finally replaced our intrepid green 1998 Dodge Grand Caravan with a new-to-us 2012 Grand Caravan. We purchased it from Carmax with 5,200 miles on the odometer, and this was its first official astronomy outing. Carmax disclosed that the previous owner used it in “fleet” operations.

    Of course the van was pristine when we took possession, but the molecular residue of some adhesives may never vanish, though invisible on ordinary glass. After two miles of dusty dirt road in Chuckwalla Bench, I said to Jane, “I know who the van’s first owner was!” This is what I saw on the back window of Earl the Grey Caravan.

    Dust pattern in car window.
    Earl, our grey Caravan, reveals his previous owner in the dust pattern on the rear window.
  • Finally some observing weather

    See Jane’s observing report from the same evening — some great binocular observing with Kemble’s Cascade.

    IMG_0890
    The 20D mounted piggyback on the Traveler and Mach One GTO mount, hoping to catch comet PANSTARRS on its first opportunity.

    Several months ago, David Green of the Santa Clarita Valley Photographers Association invited me to give a talk on astrophotography in March.

    I thought, “No problem! We’ll have several dark sky weekends between now and then for me to get some photos and screen captures, and I’ll have a fine talk.”

    Famous last words! I must have jinxed the weather. But my luck turned just in time to get out with Jane on March 9 for some dark sky observing and astrophotography at Amboy Crater.

    This trip would be the last remote observing session for our not-so-trusty Dodge Grand Caravan. It had been plagued with electrical troubles for the past several months, and on this trip it started behaving erratically on the climb up the Cajon pass on I-15. We opted to brave the possibility of being stranded, and carried on to Amboy Crater. Luckily everyone survived the trip!

    IMG_6204
    Getting everything staged to load into the van.
    IMG_6207
    Astro-pack


    Our first hope was for a shot of comet PANSTARRS in its first opportunity on the northern portion of its pass through the system.

    Those clouds you see in the set-up pictures hung around the western horizon just enough to keep the comet out of view.

    IMG_0875
    Astrophotography on the left, visual astronomy on the right. Those clouds kept PANSTARRS hidden, but cleared nicely later in the evening.

    My first target was going to be an easy favorite visual target, but one of which I didn’t have a good astrophoto. M64, M65, and NGC3628 are three galaxies in Leo that form a striking group. There are other galaxy groups in Leo, but I believe this one is the set known as the Leo Trio.

    Three galaxies in Leo
    The Leo Trio, M65, M66, and NGC3628. 45 minute exposure (3×15 min.) SBIG ST-4000XCM, Astro-Physics Traveler, 105mm f/6

    I went for a couple of other interesting easy targets that should be fun. The Whirlpool and NGC5907 “Splinter” are best with longer focal length telescopes, for a narrower field, but I enjoy these wide field shots too.

    The Whirlpool galaxy
    M51 the Whirlpool Galaxy in Ursa Major, Astro-Physic Traveler 105mm f/6, SBIG ST-4000XCM camera

    The “Splinter” in Draco is a lovely edge-on spiral.

    NGC5907
    “The Splinter” galaxy NGC5907, edge-on spiral in Draco. Astro-Physics Traveler 105mm f/6, SBIG ST-4000XCM

    Finally I went for a redo of a classic winter-sky object, one for which my Traveler with its wide field-of-view should be ideal, the Rosette nebula in the winter Milky Way.

    Here is my earlier shot of the Rosette, and the full size image of it here. On that night my focus wasn’t especially good. Since then my skill with focusing and processing has improved quite a bit, such that now I’m proud to show you my new Rosette image.

    Rosette
    The Rosette nebula region in Monoceros, 45 minutes exposure (3×15 minutes) Astro-Physics Traveler 105mm f/6, SBIG ST-4000XCM

    So I certainly had enough to make a fair astrophotography presentation for a camera club. My talk was the following Tuesday evening at Santa Clarita Camera, for the Santa Clarita Valley Photographers Association.

    Camera Club
    I had about 30 camera club members for my presentation on deep-sky astrophotography.
    Mojo with astrophotography gear
    I brought my A-P Traveler, mount, tripod, and camera for show-and-tell along with the talk. Not the usual gear found at a typical camera store.
  • Hot, dry astronomy

    Constellation Scorpius
    My piggy back shot of Scorpius taken in the early evening. Note the Pipe Nebula near the center left, a dark dusty pipe in silhouette against the Milky Way. Click for the full-resolution image.

    Observing report for June 16, 2012, Amboy, CA

    The forecast for Amboy had a high temperature of 104°F and a low of 72°F. Winds would be light to calm, and the sky would be severely clear and steady all night! Sunset at 7:58 p.m. and sunrise at 5:30 a.m.

    My European and metric system friends might enjoy converting those temperatures into Celsius for a jaw-dropping chuckle.

    Amboy Crater National Natural Landmark is on BLM (Bureau of Land Management) land near the tiny railroad town of Amboy, on National Trails Highway — a right-of-way that used to be marked as U.S. highway 66. Amboy, California, has also been noted as the inspiration for the town of Radiator Springs from the Disney-Pixar movies Cars and Cars 2.

    We’ve written much about Amboy Crater in the past. It has become our new favorite observing location, featuring a paved parking area, picnic tables, and pit toilets. There’s a lovely one-mile trail that leads into the volcano crater known as Amboy Crater, which juts up from a large black-rocked lava field.

    Amboy Crater
    Amboy Crater National Natural Landmark
    Train near Amboy
    One of the many long trains passing through Amboy, CA, that keep us company rumbling through the night

    When we arrived at the location, it was probably about 95°F. Our full dispenser of ice water and chilled Gatorades came in very handy! With sunset the temperature quickly dropped, and an hour after it was very pleasant short-sleeved observing under a perfect sky.

    We napped for a couple of hours at 2:30 or so, and woke to this stunning array of morning planets rising in the east.

    Jupiter, Moon, Venus
    Jupiter, the Moon, and Venus, lined up in the eastern pre-dawn sky Sunday morning. By all means click for the full-res image, and notice the prominent earthshine on the very old moon.

    I was looking forward to capturing some summer-sky Milky Way favorites this evening. I stumbled onto a nearly perfect polar alignment. It was one of those nights when I had no battles to fight, no problems to solve, I could just collect photons.

    I spent my few summer hours on three targets I hadn’t imaged, all rising in the very dark eastern sky.

    Click each of these for the full-resolution 2048×2048 image. They turned out particularly well!

    M16 the  Eagle
    M16, the Eagle Nebula and cluster

    I had previously shot M16, with one 15-minute exposure, and had an airplane fly through the shot. I didn’t want to photoshop the airplane away, and decided to collect more data for this stack. This one is three 15-minute exposures.

    M20 the Trifid
    M20 the Trifid Nebula, with M21, an open cluster, in the upper left corner.

    My Trifid is also three 15-minute exposures. I love seeing the lanes of dark Milky Way dust making inky lakes and tendrils among the stars surrounding the nebula.

    Veil Nebula
    The eastern side of the Veil Nebula, this half is cataloged as NGC6992.

    My small refractor is the perfect telescope to capture this half of the Veil Nebula, the eastern half, NGC6992. I hadn’t expected the mix of red and blue tendrils in this supernova remnant bow shock. This is four 15-minute exposures, stacked in Photoshop.

    Equipment and software list:

    • Astro-Physics Traveler 105mm objective, f/6
    • Astro-Physics Mach-1 GTO mount on wooden tripod
    • SBIG ST-4000XCM one-shot-color CCD imager
    • CCDSoft, CCDOps, Photoshop CS3
    • Skytools 3, The Sky 6

    The Scorpius constellation image was taken piggyback on the Traveler with my Canon 20D DSLR camera, one three-minute exposure.

  • Galaxy season

    Mojo at Amboy Crater
    Jane snapped Mojo waiting for darkness at the Amboy Crater visitor area.

    Observing report, April 21, 2012, Amboy, CA

    We’ve had a string of bad luck with new moon weekends for the past six months, so when this new moon Saturday showed nearly perfect conditions, Jane and I were quick to pack the van and get out to Amboy Crater.

    My only agenda for the session was to relearn my rusty imaging skills, and perhaps bag some Spring galaxies from Virgo and Ursa Major. Jane had plans to mostly eschew optical equipment and spend the morning counting meteors from the Lyrid meteor shower. (She’ll have a report on that elsewhere.)

    Conditions all night were as delightful as advertised. There was no wind, not a sign of a cloud. The temperature dropped quickly from 98°F on arrival to 62°F close to sunrise, calling for a light jacket. Humidity stayed well below 20% all night. We were prepared for the heat with lots of ice and Propel sports drinks.

    We were the only ones taking advantage of the smooth blacktop and hospitable visitor station at Amboy Crater. The great conditions kept both of us going without a nap all night. It made for a struggle returning home on little sleep, but we both managed to grab naps during the day.

    I imaged comet C2009/P1 Garradd to start the evening. I took four 5-minute exposures, allowing me to make two versions of the image.

    The first version stacks the images so the stars all match. The motion of the comet against the background stars blurs the head of the comet in the line of its travel.

    Comet Garradd moves against fixed stars
    Comet Garradd moves against fixed stars

    The second image aligns each exposure on the head of the comet, so the perspective moves with the comet over 20 minutes, making a trail of stars in the background.

    Comet Garradd fixed against a moving background
    Comet Garradd fixed against a moving background

    The rest of the evening focused on distant galaxies. For this session I added a barlow lens ahead of the camera to get a slightly narrower field of view.

    Each of the 400×400 thumbnails below links to the full-size image, which is 2048 x 2048 pixels.

    M104
    M104 the Sombrero galaxy in Virgo
    M109
    M109 in Ursa Major, a faint barred spiral. Note a few distant spirals in the full-size image.
    NGC5907
    NGC5907, an edge-on spiral galaxy in Draco
    M51
    M51 the Whirlpool galaxy pair in Ursa Major, one of the most photographed and observed objects in the sky.
  • Double your pleasure …

    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 - M32 - M110, the Great Galaxy in Andromeda
    M31 from 22 Oct. 2011, 4×15 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
    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
    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.

    NGC7479
    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
    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"
    NGC2359 "Thor's Helmet," 4×15 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.

    Abell 426 Galaxy Cluster
    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 - M82
    M81 the spiral (a.k.a. "Bode's Nebula"), and M82 a peculiar active galaxy, in Ursa Major

     

  • Observing at Amboy Crater

    Observing report, October 22, 2011

    Full photo album with site pictures here.

    Amboy Crater National Natural Landmark
    It's very easy to miss this sign from National Trails Highway, the delightful old U.S. Highway 66.

    This month is blessed with two very good dark sky observing weekends, and we opted to take the first one at a spot we’ve been thinking about for a couple of years now.

    Amboy Crater National Natural Landmark is a volcano crater in California south of I-40, near the town of Amboy, CA. We first visited the site in the spring of 2010. The hike to the crater was fabulous, and the wildflowers were stunning.

    Our regular site at Chuckwalla Bench is also a Bureau of Land Management (BLM) site, but unlike Chuckwalla Bench, Amboy Crater features a paved road, pit toilets, parking spots, and picnic tables. Here’s a Google Maps link to the landmark and its facilities.

    The downside is that the drive is about 25 miles longer than the trip to Chuckwalla Bench. It makes for about three-and-a-half hours driving each way.

    Astronomically, Amboy Crater is one of the darkest locations in the state, with frequently clear skies and sometimes overly hot conditions.

    Mojo with Amboy Crater
    Mojo set up for astrophotography with Amboy Crater in the background.

    This past Saturday evening had a nearly perfect forecast. We arrived on a hot dry afternoon, and enjoyed shirt-sleeve or light jacket conditions all evening with a crystal clear sky. We were joined by one other astrophotographer (Robin), and two seasoned visual observers (Cliff and Steve).

    My astrophotography is extremely casual. Living in the midst of Los Angeles county, I have no desire, nor is there much reason to, have a permanent observatory of any kind. We’ve both become adept at hauling our portable observatory to locations that offer good dark skies.

    Actually we have quite an advantage over astronomers in the eastern half of the U.S. The California deserts offer excellent astronomy, and are within a few hours drive of home.

    My telescope is an Astro-Physics Traveler, 105mm aperture (about 4 inches) with a short f/6 focal length. The mount is an Astro-Physics Mach-One GTO “go to” mount, and my camera is an SBIG ST-4000XCM, the perfect camera for my style of casual astrophotography. It’s a “one-shot color” camera, meaning I can shoot and process color images in a relatively short time, with extra processing to extract the data from the Bayer matrix. It wouldn’t be the best sensor for doing astrometrics or narrow-band imaging with specialty filters, but it’s great for playing around and taking pretty pictures (or trying to!).

    I had shot M31, the Great Galaxy in Andromeda, before, probably with my Canon 20D DSLR, but I wanted to take advantage of my wide field and gather an hour or so of data and see what I could get.

    I enjoyed watching twilight fade and set up with a very good polar alignment. By now I’ve managed to learn the quirks of Software Bisque’s CCDSoft, and was able to calibrate the autoguiding with great success.

    After returning home, I discovered that my first 15-minute exposure was not useable! The brighter stars in the image were fogged, probably by condensation on the CCD sensor glass. I have this mental image of bringing a telescope full of relatively moist L.A. basin air out to the desert, cooling the chip down to -5° C, and having every drop of moisture in that air condense on the chip.

    After the first exposure, the combination of the imager fan and the dessicant plug mounted next to the chip managed to pull out all that moisture and leave me with a dry and clear chip. The dry desert air kept me clear for the rest of the evening.

    Here is a luminance-only (monochrome) rendition of my M31 the Great Galaxy in Andromeda

    M31 the Andromeda Galaxy
    The Great Galaxy in Andromeda, M31, with M32 and M110 nearby. 3×15 minute exposures, luminance only. (Click for full 2048×2048 resolution).)

    Now after going to all the trouble of having a one-shot color camera, why am I presenting a monochrome rendition of M31?

    I have a processing problem with the color version that I haven’t resolved yet. This galaxy has an enormous dynamic range, and this monochrome image is compressed down from a 16-bit master luminance image.

    I’m only able to process the color information with 8-bit dynamic range. And my processing skill isn’t yet strong enough to preserve the color data when compressing it down to computer range. Here is the color version of this image. Note that the galaxy core is completely clipped to white in the color data, and I’m left with an ugly yellow ring around the core.

    It’s an interesting problem, and I’m sure that I can find a way to do some “high dynamic range” (HDR) techniques to recover that color data near the core.

    At that point, Jane called me over to see an interesting emission nebula she was observing visually in her 17.5-inch dob. The nebulosity was just detectable visually, and I really wanted an image to compare. Fun object, full of Milky Way stars, the nebula, and even some dark nebulosity in the upper right.

    NGC7380
    NGC7380 emission nebula and cluster, 3×15 minute exposures

    Jane hunted down comet C/2010 G2 (Hill), a magnitude 10 interloper. It was a very difficult visual observation, but she nailed it, and I saw it as well.

    C/2010 G2 (Hill)
    10th magnitude comet C/2010 G2 (Hill)

    Meanwhile Jane was also tracking down interesting galaxy groups, and had fun searching the fairly distant Pegasus 1 galaxy cluster in her 17.5-inch. I couldn’t resist imaging this as well.

    My own misfires only left me with one usable 15-minute exposure of this fascinating galaxy group. Even with just one 15-minute exposure and lots of noise, it’s fun to see how many galaxies you can find in the full-resolution image. The two brightest members are magnitude 12.

    Here we go from a relatively nearby solar system object, comet Hill, to a 200-million light-year distant galaxy cluster!

    Pegasus 1 galaxy cluster
    The Pegasus 1 galaxy cluster, one 15-minute exposure. Click for the full-resolution version, and see how many galaxies you can find in the somewhat noisy image.

    Now I was just playing around. As it turns out, the Pelican Nebula was well placed, and The Sky 6 told me it would just fit in my field of view. This emission nebula is most famous for being “that thing next to the North America Nebula.”

    The Pelican Nebula
    The Pelican Nebula, one 15-minute exposure

    One of my favorite visual targets is the enormous nearby open cluster M35 in Gemini in the winter Milky Way. Part of its appeal as a visual target is seeing the ten-times more distant open cluster NGC2158 which is about the same actual size as M35. The image didn’t disappoint.

    M35 with NGC2158
    Open cluster M35 in Gemini with distant sister cluster NGC2158. 2×15-minute exposures.

    Finally, even though it’s almost cliché, I had to see what I could do with M42 the great Orion Nebula. It actually turned out to be a delightfully pleasing image. Sure the trapezium area is blown out to white, and maybe I can work out a way to recover that, but it sure is a fun picture. B^)

    M42 the great Orion Nebula
    M42 the great Orion Nebula, 2×15-minute exposures

     

  • January observing, a Monoceros evening

    Click here for the full photo album with lots more pictures.

    Mt. San Jacinto
    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
    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.

    Milky Way stars with a faint comet
    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!

    Comet 103P/Hartley
    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.

    Rosette nebula
    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.

    Cone nebula
    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.

    NGC2655 and supernova
    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.

    M97 and M108
    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
    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.

  • Sky full of planets and lightning

    Distant cumulus clouds catch sunset rays
    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.

    Lightning in the desert
    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.

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

    And here is a late-night shot of Cassiopeia.

    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
    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:

    M57
    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).

    M57
    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.

    NGC7789
    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 …

  • Short summer night

    Mojo in the desert
    Jane snapped this shot of me shortly after sunset, squinting into the bit of wind we had.

    Happy Independence Day!

    This weekend wasn’t our usual dark sky new moon weekend; there would be a third-quarter moon rising just at midnight. With summer sunset at 8:00, and no real dark sky until about 9:00, we were looking at a really short (for us) desert observing session of about three hours. Next week is when all the big June star parties are being held.

    The weather was fair, not too awfully hot, or too awfully windy, just a little of both. The sky was brilliantly clear, and seeing was not particularly good. Sometimes we just say WTF. 🙂

    This was one occasion when I was glad to be living “in the future.” I somehow managed to completely wedge the ASCOM driver that lets my laptop communicate with the telescope mount. That’s the kind of thing that really eats up the clock when the moon is about to chase away your dark sky!

    Right there in the middle of the desert, I was connected to the net by USB tether to my Motorola Droid. (Thank you PDANet!) I posted a plea for help on the Astro-Physics User Group mailing list. The author of the driver responded to my post and helped me set it right within an hour.

    I had time for maybe two short exposures of a couple of objects, and Jane badly wanted a piggyback shot of Scorpius. That would be my first priority, and I had fun shooting it. I used a fixed-focus 35mm f/2.0 lens on my Canon 20D, and the big constellation just barely fit in the frame. We have a fairly strong light dome to the south from the Inland Empire. I cropped the shot just below the constellation where the light is strongest.

    Scorpius
    The fishhook of Scorpius fills the frame, with lots of Milky Way and dark nebulae throughout. Some light glow to the south.

    Jane had the “Bug Nebula” NGC6302 on her observing list, and I tried a shot of it myself. It’s a tiny thing relatively speaking, so there’s not much to see in the full field. There’s one interesting object in the lower left corner which could be another planetary, or possibly an artifact of my own creation. It only shows up well in one of my two sub-exposures.

    NGC6302 region
    That little red blob in the middle is the "Bug Nebula." There might be another planetary in the lower left corner, that or an imaging artifact.

    Here’s a cropped version at full resolution of the bug itself. Jane’s view in her big dob was actually very nice.

    Cropped detail of the Bug Nebula
    Not very impressive, but it somewhat resembles the visual view we had through Jane's big dob, minus the red color

    With only a little time left before moonrise, I wanted to see what I could get of the nebula around Rho Ophiuchus. It’s only one ten-minute exposure, and you’ll find lots of impressive images of this region out there on the net. I’m still tickled with what I was able to capture.

    Rho Ophiuchus nebula
    One ten-minute exposure of the Rho Ophiuchus region

    Finally the moon put an end to the dark sky observing, but moonrise itself was quite an event. The moon was joined quickly by Jupiter to the south. Jane has a great afocal shot taken through the eyepiece of her Televue Ranger. You’ll have to see that one on her observing report!

    Moonrise over Chuckwalla Mountain
    Moonrise with Jupiter over Chuckwalla Mountain. There's a light from the microwave station on Chuckwalla Mountain just below Jupiter to the right of the moon.