All Things Astronomical

Long standing issue resolved: caveat emptor

2008-03-29T09:14:00.000-07:00

Let me compress a long, eight months old story about the image above into a short one.

In July 2007 I ordered a Tak 180E and a SBIG 2000XCM to go with it from OPT. The Tak to SBIG adapter that OPT sent was, as my first trial run revealed, perfectly suited to any SBIG with a filter wheel. But not to the one shot color XCM. Focus was impossible to achieve. As any imager knows, when you run into problems like this, you’ll soon discover that you’re about to burn up some major time. I was less than pleased. :(

After several conversations with OPT staff, I contacted the owner, Craig Weatherwax. Craig made things happen – albeit with another cash ante from moi. OPT contacted Texas Nautical, the Tak dealer. Texas Nautical ultimately came up with the appropriate SBIG adapter. (Of course I now have a nearly $200 "extra" adapter that OPT is not interested in accepting.)

A clear night finally arrived (March 11), albeit one with an early rising, nearly full moon. After a quick and, as it turns out, imperfect focus run, I zipped over to M42 and ran a sequence of roughly 75 by 20 second unguided images of M42. The results were not picture perfect, given the soft focus and the marginal framing. But I can see the light at the end of the tunnel.

One conclusion: the Tak is amazingly fast!

Max

re: November update

2007-11-23T11:59:00.000-08:00

November has been a wash for collecting photons in these parts. The first snow is on the ground. The clear nights without a moon were few. And Father Time has been kickin' my hind end. I had loads of fun wearing out my joints over 60-some years. But the arthritis in my hips has...uh...put a damper on moving around very much. This too will pass, as modern medicine offers a variety of fixes: most likely hip resurfacing.
Meanwhile I have dabbled in some small terrestrial shots, using a Canon 10-22mm zoom. I like the lens, and it will come to focus in the macro mode at about 8". The image at the top was shot at 16mm, processed, cropped, and saved for the web in Photshop CS2. It's a particularly appropriate subject-matter, as both the flower and Ol Max are pansies!

M-33 comparison image

2007-10-15T12:31:00.001-07:00

This image partially illustrates how important additional "subs" (light exposures) are in helping to define an image. The M-33 on the left integrates the image on the right (15x3min exposures, collected on September 13) with an additional 60 minutes of subs (20x3min, collected on October 11, 2007).
The differences are subtle but nonetheless discernible. I note four:
First, the extent or sweep of the spiral arms has been clarified. The diffuse nature of M-33 leads to a very low surface brightness.
Second, there is more "texture" or overall detail to the image. The 45 minute exposure required smoothing via a Gaussian blur. The 105 minute combined stack has been smoothed, but only by a small amount.
Third, the hydrogen alpha regions (with the reddish tinge) stand out more clearly, not only in the named regions, but also as H-alpha is intermixed with the arms.
And finally, the overall coloration of the image is, to my eye, more pleasing, moving from a muddier-greenish tinge in the smaller stack to a "ruddier" and somewhat bluer coloration in the larger stack.

Acquisition and Processing
Acquisition and processing per usual. Stacks combined with IP. Composite image created with PS CS2.

IC-405, The Flaming Star Nebula

2007-10-15T07:51:00.001-07:00

Astrophysical data on the Flaming Star Nebula is easy to find online. Click here for the NASA overview. After a couple of quick and dirty processing attempts that yielded a drab image, it suddently occurred to me that the goal for my processing should be "flame-like."

The star AE Auriga is powering the "flame," so to speak. There's an interesting astrophysical history here, since "AE Aurigae's story is inextricably linked to another star called Mu Columbae. Around 2.7 million years ago these two stars were formed and had a close encounter with one another in the Great Orion Nebula. The encounter was so close (another star was certainly involved) that each of them was ejected from the Orion complex never to return again. Currently these stars are 66 degrees away from one another in the sky. Astronomer's discovered these two runaway stars by measuring their apparent (fast) motion and noting that if you work backwards in time - the origin is in the same place at the same time! But AE Auriga is certainly the more glamorous of the two stars since it just happens to be moving through a region of gas that makes it look like a 'Flaming Star.' " Source

Acquisition and Processing
SV115 at f/5.6 on the CGE, SBIG ST2000XCM, 22 subs at 3 minutes, acquired using CCDSOFT v.5, processed in ImagesPlus 3, beta9 and PhotoShop CS2.

M-31 - The Andromeda Galaxy

2007-10-14T08:09:00.000-07:00

There's no need to go on about M-31 -- clearly one of the most beautiful and photographed DSOs. Rob Gendler's M-31 just about takes your breathe away (click here). Note how Gendler captures multiple colors. He emphasizes that his processing, which is truly spectacular, is done to suit his aesthetic taste. I've processed more than one version from these subs, but this one is my favorite. Why? Because the "rifts" or dust lanes are so plainly obvious. As Eric Jacob notes, someone ought to sweep this "dirty" galaxy up.

In any case, here are a few quick points about the Great Galaxy in Andromeda. First, M-31 is a naked eye object from a reasonably dark site. Interestingly, the photons that we see or collect have been on their way for about 2.2 million years. In other words, long before there was a sentient, cosmically aware species on Earth those photons were making their way here. M-31 is one of if not the most distant naked eye DSO.

Second, M-31 is a so-called sister galaxy, part of the local cluster. The local cluster has two giants -- M-31 and the MWG -- some fair sized sisters such as the SMC and LMC, and M-33 -- and a slew of little elliptical galaxies. (There's an interesting visual of the local cluster here.)

And finally, gravity is bringing our own Milky Way Galaxy and the Andromeda Galaxy together. They are approaching each other at an incredibly fast rate of speed. There's a good chance that they will merge when the rendezvous is finally complete.

Acquisition and Processing
SV115 at f/5.6 on the CGE, SBIG ST2000XCM, 17 subs at 3 minutes, acquired using CCDSOFT v.5, processed in ImagesPlus 3, beta9 and PhotoShop CS2.

The Bubble Nebula (NGC 7635)

2007-09-20T05:22:00.001-07:00

Here's a "sub-starved" (only 7x3 minutes) composite of the often photographed Bubble Nebula in Cassiopeia. Why only 21 minutes total? I started collecting the subs "too late" for a full run: the camera and scope were about to "run into" the mount. So it goes. In any case, there are dozens if not hundreds of superlative images of the Bubble Nebula online.

The image is still "under construction," as more subs are required. The slight red cast to the image is apparently due to the extensive nebulosity in the region. Aesthetically considered, I don't like the red cast, and have tried to mute it. However, the red cast may be inevitable. This link connects with a close-up of the Bubble Nebula made with a 20" RC and an SBIG ST-11000. The detail is wonderful. Notice the pervasive red nebulosity, which is especially evident in the 11 o'clock direction.

This link connects with an early shot by Jerry Lodriguss (a most accomplished astroimager and author), using gas-hypersensitized Fujicolor Super G 800 film. The shot offers an interesting comparison between what was (film) and what is (digital photon collection). Jerry offers a few astrophysical details concerning NGC 7635, including the fact that it's one of only two such objects.

Astrophysical data

The bright star (at 12 o'clock) is SAO 20562 with an integrated visual magnitude of 6.94. The Bubble Nebula itself (15'x15') surrounds SAO 20575, an 8.53 VM star about 20x as massive as Sol. The complex is estimated to be 11300 LY distant.

Equipment

SV 115 + TV .8 focal reducer + CGE + SBIG ST-2000XCM

Processing

ImagesPlus v3.0 beta 7 primarily + resized and saved for the Web in PS CS2

Max

Driveway Observatory

2007-09-18T09:05:00.000-07:00

Here are four quick jpgs of the "Driveway Observatory" setup, taken on September 14, shortly before dark.

Top photo: Mission Control Center

Given all the various pieces of equipment and software, I've found that three laptops makes life a lot simpler...basically one laptop to control each of the three imaging setups.
Photo two:

The StellarVue (908mm focal length at f/7) with eyepiece, ready for aligning the mount, and the Borg (300mm focal length at f/4) with a Hap Griffin modified Canon XT (350) in place.

Photo three:

The Takahashi Epsilon 180 (500mm focal length at f/2.8) with the SBIG ST2000XCM. The Celestron 102 is used for aligning the mount and/or as a guide scope when using the XT with the Tak for an extra-large field of view.

Photo four:
The entire suite of equipment for the driveway observatory. Obviously, a "real" observatory with piers and such would be ideal. Unfortunately, there is no site on my property suited to the placement of such a structure. Thus the Driveway Observatory. The ScopeBuggies make wheeling the mounts into place a snap....about one minute each, setting over permanent "true north" markers. Placing the vibration pads and levelling the mounts takes about two minutes each. The CGE 2 star alignment + 4 star calibration plus polar align (followed by repeating the 2 + 4 routine) requires about 10 minutes per mount. The payoff is spot on go to and virtually perfect polar alignment.

Max

M-39 from September 13

2007-09-17T15:42:00.000-07:00

Another image from September 13 -- M-39. This is a young and "loose" (open) cluster with about 30 members total, roughly 800 LY distant. The lucida is mag 6.83 -- clearly not an eye-ball popper, especially given it's location in the summer-time MW.

More information at: http://seds.org/messier/m/m039.html and http://seds.org/messier/more/m039_more.html.

Technical details: 4 subs at 180 seconds, SBIG ST200XCM, SV115 at f/5.6, processing in IP plus AstroTools increase star color and diffraction spikes.

Max

re: ImagesPlus 3.0 beta 7 curves image

2007-09-17T14:41:00.001-07:00

This screen shot is possibly interesting to those who are familiar with ImagesPlus v3.0, PhotoShop CS2, and Scott Ireland's fine book, PhotoShop Astronomy. On page 60 he presents the "ultimate PS curves tweak," the "S" curve, which looks nothing at all like the curve that I've found useful so far in the newest version of IP.

Max

Hi-Rez version of M-33, the Pinwheel Galaxy

2007-09-17T13:53:00.001-07:00

Here's a slightly higher resolution image of the one posted immediately below.

Max

Finally, Photons Are Collected!

2007-09-17T13:11:00.000-07:00

After nearly three months of unrelenting cloudy nights, interrupted only by a clear night on the eve of a full moon, the new moon came with a clear night time sky. I collected several sets of subs, while also running into some unexpected snafus. Digital astrophotography always presents its challenges.

The image above is M-33, the famous galaxy in Triangulum, visible naked-eye from my high mountain site (at least for young folks). While M-33 comes alive for telescopic obsevers only through large apertures (due to its low surface brightness), its face-on appearance makes it an astrophoto show stopper. M-33 is a member of the local group, the third largest after M-31 (tilted at a fifteen degree angle from our perspective) and our own Milky Way (a barred spiral, not nearly as asthetically pleasing, in my opinion, as M-33).

The technical details, briefly, are 15 total subs at 180 seconds, acquired through the StellarVue 115 at f/5.6 using the SBIG ST2000XCM. Initial processing, alignment, combining plus digital development, standard smoothing, star size reduction, sharpening, and curves adjustment in ImagesPlus v7Beta with image size reduction and saving for Web in PhotoShop CS2.

This image is likely the best of the evening, although I collected the subs 1 by 1 with CCDOPs while I fiddled around with CCDSOFT. By about three a.m. I figured out the arcane nuances of CCDSOFT, and finally collected an automated set of subs for M76 using that program.

Max

Additional Tak Epsilon 180ED images

2007-07-27T07:29:00.000-07:00

Since the night sky is absolutely miserable and the rain seemingly relentless (not all bad, as New Mexico is the only interior Western state not suffering the ravages of forest fire), my only recent images have been of the new imaging instrument.

The first image shows the beefy Tak focuser. I have the 10.8:1 Tak microfocuser on order (not pictured here). The rack and pinion knob is at the bottom and the focus lock at the top. The "frame locks," which allow the imager to rotate the camera, are the shafts protruding from the aluminum ring around the focuser.

The second image shows the 180mm mirror and the offset secondary, designed to offer the maximum image circle.

The final image shows the hyperbolic ED corrector (designed as all correctors are to optimize the flat field).

Max

Who says that reasonably priced mounts won't deliver?

2007-07-22T13:07:00.001-07:00

This beautiful image of M-31 is compliments of my friend, Eric Jacob. Click on the image for a full frame version. Eric purchased my CG-5 just a short while back. The image is a stack of 32 unguided 2 minute subs using the CG-5, an unmodded Canon Xti attached to a Celestron 102 widefield (500 mm focal length), processed using Nebulosity with final touches in PhotoShop.

Eric opines this is his best M-31 to date. He's promised to put together a 3-panel image of his previous M-31's: one from the film era, one from the Canon 10D and EQ mount era, and the most recent.

You can find out how to get started in relatively low cost astro-imaging by visiting Eric's website. Click here.

And Eric is always available for free consultation with folks just gettin' started. Heck, he even talks to me. :)

Cheers.
Max

The July Tale of Photon Starvation

2007-07-20T15:14:00.000-07:00

The July report can be brief so far as photons go: none, zero, nada. Not only was New Mexico slammed with relentless cloudy skies, but much of the nation was (as noted on various Cloudy Nights threads). However, my old photon collecting pal Eric Jacob did well this month. You can see his work on his CheapSkate Astrophotography webpage.

My report consists primarily of an equipment update. The main events (skipping over ancillary purchases) are:
(1) the CG5 has found a welcome home in Eric’s hands. He’s running up to two minute unguided exposures with about a 50 percent usable rate.
(2) I replaced the CG5 with a second CGE (used). That’s a long story that I won’t go into.
And (3) I purchased a new Takahashi astrograph. That’s a long story that I will go into.

Making the transition from visual astronomy to astroimaging means – at least for me – a continual shaking out and revaluation of the equipment. Astroimaging equipment reminds me of the time when I first became passionate about fire arms, particularly shotguns and center-fire rifles. I must have owned and sold at least twenty different guns before I finally wound up with the keepers.

I started the month with a long standing order for a TMB 130SS APO f/7 at about 900mm focal length. No doubt this is a fine telescope. It’s received nothing but rave reviews. But after repeated queries to the vendor yielded nothing more than "we’re trying to fill orders as fast as possible," I began to rethink the entire issue. "Why duplicate the SV115APO?" became the question of the month. "After all, Max, you’d only gain about a half inch of aperture. Why not try something else?" The something else, as it turns out, is a Takahashi Epsilon 180ED – 500mm focal length at f/2.8. More on that instrument below.

Dean Rowe, a fine and very experienced astrophotographer, and owner of a Tak 180, helped me think the decision through. His advice was reassuring. One of the great things about the astroimaging community is the willingness of almost all its members to share their insights generously. Thanks to Dean. You can view his outstanding work on his website.

The Tak weighs in at 22 pounds, just about the same as the TMB130 would have. The Takahashi Company has a fine reputation, and from what I can see without actually using the new instrument, it’s well deserved. "Built like a Mercedes" is the phrase that comes to mind. Flawless paint and fit everywhere. Five year guarantee. And state of the art technology. Or so this old man is led to believe.

So what are the innovations? To simplify, Tak took the basic premise behind a Schmidt Camera – combining a convex mirror with a concave surface yields a flat field – and improved upon the design. According to Wikipedia, "The Schmidt camera was invented by Bernhard Schmidt in 1930. Its optical components are an easy to make spherical primary mirror, and an aspherical correcting lens, known as a corrector plate, located at the center of curvature of the primary mirror. The film or other detector is placed inside the camera, at the prime focus. The design is noted for allowing very fast focal ratios, while controlling coma and astigmatism." (Source)

Takahashi designers, aided by computers and contemporary glass, created a hyperbolic ED (extra-low dispersion) glass corrector (the concave surface) combined with a precisely ground mirror (the convex surface) to yield a 44mm image circle. The user’s manual notes: "Since the stars in the field of the E-180ED are only 10 microns [in diameter], very precise focus is needed to keep the stars pinpoint on the image." Yah, I bet so. The manual notes that the instrument was specifically designed for the new generation of large frame CCD cameras. Gee whiz, I might just have to get one.

Max

re: low resolution images

2007-06-23T13:47:00.001-07:00

re: M101, more on the SV115 + SBIG

2007-06-22T03:58:00.000-07:00

This is far, far from the best Pinwheel Galaxy image that you can find online. The image here is a stack of seven x 120 seconds subs, and thus a total exposure of fourteen minutes. I would estimate that at least an hour's worth of exposures are required to really bring out the finer details and beautiful structure of M101.
All the image processing details are as with the previous image. Here's some of the technical data on the scope and camera from June 19.
The camera was thermoeletrically cooled to 20d Celsius below ambient (which was about 60% of the total cooling capacity available). I used the CCDOPS (SBIG camera control software) autodark feature. Apparently the initial dark frame is subsequently used for calibration of the light frames. That's a huge time saving feature.
The image scale using the StellarVue115 with the .8 TeleVue focal reducer is 2.37 arcseconds/pixel with a 47x63 arcminutes field of view. (I've cropped the M101 image.)
I also tried the CCDOPS track and accumulate feature on two different objects. Unfortunately this feature did not produce usable images, as the "accumulated" stack lacked precise alignment. Over an hour worth of imaging time was wasted on this dead end. After consulting the manual (on the following day), I discovered that track and accumulate is recommended only for relatively short exposures.
Max

re: the Trifid Nebula

2007-06-21T15:38:00.001-07:00

So here's the first decent image made with the SV115 + the SBIG ST2000-XCM + the CGE + CCDOPS (SBIGs proprietary camera control software) + ImagesPlus + PhotoShop CS2 + lots of trial and error. :)

Let me make a long story very short. New equipment means plenty of trial and error testing. After setting up, calibrating, polar aligning, recalibrating, and enrolling in the school of hard knocks, I finally had some usable subs. Of course, the first thing I discovered is that I did not have enough back focus for the SV115 at f/7. The TeleVue .8 focal reducer saved the night. The image that you see is the famous and fabulous M20, the so-called Trifid Nebula, located in that most wonderful of all constellations, Sagittarius!

The composite image is a stack of 15 two minute subs, converted, aligned, and combined and digitally developed in Mike Unsold's ImagesPlus. FYI, for my money, this is absolutely the best investment any imager can make in software. Can't afford PhotoShop? Fine. In fact, why bother with PS? IP will give you everything you need and more in a powerful image processing and camera control program that is, frankly, awesome. Here's a link to the IP page. Mike also participates on a frequent basis in the Yahoo ImagesPlus group.

I'll fill in all the wonky processing data at a later time. But I'm pleased with the results. I've seen better Trifids, of course. But hey, I'm just foolin' around, havin' some fun!
Max

re: new cameras!

2007-06-21T15:08:00.000-07:00

The first day of Summer and shortest night of the year has arrived! How I hate nights that have clouds! And I hate nights where it's still light at 9:30 ! Tonight is a double whammy! :) So it goes.

My part of New Mexico has had a long and incredibly cloudy spell...nearly two months. By all indications the monsoon season came very early this year. So I've had lots of time to anguish. And spend money on new gear. A simple fact: at my age, I'm not inclined to wait years before I try to peek at what's over the next mountain. Thus my desire to test modified DSLRs and dedicated CCD imagers.

The upgrades are two. A Hap Griffin modified Canon 350D. More on that camera later, after I have a chance to acquire some photons. And an SBIG ST-2000XCM single shot color camera. A full run down on the SBIG ST-2000XCM can be viewed here.

Believe it or not, I finally caught a night to test the camera! Results will follow in subsequent posts. My initial impressions are: the single shot XCM is one fabulous camera. The self-guide feature alone makes the camera worth the $! (One disappointment: the camera came to me with a big finger print smack in the middle of the optical window. SBIG has not seen fit to offer so much as an apology.)

Two facts convinced me to buy this particular camera. Fact one: I'm not ready to shell out $8K or 9K for the high end, 35mm frame SBIG camera.

Fact two: the image at the top of the page indicates that the single shot XCM performs at a qualitative level across the RGB spectrum to satisfy all but the fussiest of imagers. Maybe a monochrome multi-filter camera awaits me in the future. But for now I'm a "one shot kinda guy!"

Max

re: data from Mike Reid's pages

2007-06-10T06:13:00.001-07:00

Here's an interesting link showing differences in the internal noise (so-called amp glow) between the Canon 350D eight meta-pixel camera and the QHY8 dedicated six mega-pixel camera. Mike is a very accomplished astroimager who has posted a large number of quality images captured with his 350D. You can view his astrophotos here.
The QHY8 is a "storied" camera. There area various threads on Cloudy Nights and elsewhere discussing the camera.

re: 1 more 10 min ISO 1600 Xti dark

2007-06-02T05:45:00.001-07:00

Here is a third dark, Xti, ISO 1600, 10 minute exposure, provided by Phil from the Yahoo Canon_400 Yahoo group. Click on the photo for a high resolution version. Canon raw opened without manipulation in PS, resized, and saved for the web. I will send the raw file on request.

re: comparison of Canon 350D to Canon 400/Xti

2007-06-02T04:58:00.000-07:00

At the bottom of the page you will find links to a page that compares the Canon 350D and the Canon Xti (with occasional data points from the Canon 5D). Please consider the following remarks before proceeding.

Keep in mind that the page is translated by a machine from French into English. There are obviously some substantive issues with translation.

The author (authors?) conclude that the 350 is a better performer for astroimaging than the Xti. Is that true? Well, maybe. And maybe it all depends. I'm the proverbial "man from Missouri" -- so to speak. I'll run my own set of tests over the next few months using my Griffin modified 350 and my unmodified Xti on actual objects. Obviously, the Xti cannot compete with a modified 350 on objects such as M8 and M20. Accordingly I will chose objects for the tests that negate the advantage of a camera with the standard IR filter removed and replacement with a Baader UV/IR block filter. Information on this modification can be found at: http://www.hapg.org/camera%20mods.htm

An issue of some concern to me is the validity of comparative testing based on a single camera of each type. So-called single subject designs can be valid. The 10-minute ISO exposures from last month (see May posts) suggest that despite Canon's quality control and uniformity of production techniques there appears to be variance in performance from chip to chip.

Enough said. Here are the links:
Tiny URL: http://tinyurl.com/y8ws6t
Full URL: http://translate.google.com/translate?u=http%3A%2F%2Fwww.astrosurf.org%2Fbuil%2F400d%2F400d.htm&langpair=fr%7Cen&hl=en&safe=off&ie=UTF-8&oe=UTF-8&prev=%2Flanguage_tools

Max

re: more 10 minute darks

2007-05-19T15:54:00.001-07:00

Top image by Eric Jacob, Xti, 10minutes at 1600 ISO, temperature 55degrees F.

Second image by Eric Jacob, 10D, 10minutes at 1600 ISO, temperature 55degrees F.

These images speak for themselves. Worthy of notice is the reduced noise in the Xti as compared to the one in the previous post. Why? I think the difference can be explained by the reduced temperature (55d compared to 70d). The previous two and these two can be viewed in sequence on my Picasa page.

re: 10 minute darks

2007-05-19T13:47:00.000-07:00

10minute Xti ISO 1600, temperature 70d F, on top.

10 minutes XT ISO 1600, temperature 70d F, on bottom.

These two images are for testing purposes only. Interesting debates about amp noise in the various Canon models frequently pop up on various sites. The most informative one that I've run across can be found here. This thread contains many links to additional sources of information. To make a long story short, there's apparently no way that photons can be converted into electrons and stored without some of those electrons creating what is called "amp noise." So it goes. If you'd like a really wonky explanation, check this link out.

Max

re: new equipment update

2007-05-16T12:35:00.000-07:00

Clear night skies have been hard to come by during the May cycle of the moon. Why? Never fails, does it? New equipment guarantees cloudy nights. I’ve decided that refractors are the instrument of choice for astroimaging. I traded my trusty Celestron 14 OTA and associated goodies for a beautiful StellarVue SV115 f/7 instrument with the associated goodies, including a Televue .8 Focal Reducer (making the SV115 an f/5.6 instrument) and a FeatherTouch Digital Focuser. See the top photograph for these details.

The second photograph shows the SV115 as well as a Celestron-102 guidescope sitting in ScopeStuff 3-point rings and attached to the SV115 tube rings via a ScopeStuff piggyback adapter. The total payload load including the camera is less than half of the rated capacity of the CGE mount (65 pounds). Thus, carrying a much smaller load than formerly, the CGE should prove adequate for imaging. At least that is my working hypothesis. The jury is still out of course.

I’ve discovered that digital photon collecting is a lot like farming: you better harvest when the field is dry – or in this case, when the night sky is dark. Accordingly I’ve decided to add a third mount and scope. The scope is on order – a TMB130SS f/7. TMB is the name for Thomas M. Back telescopes. There’s a long story here which I won’t go into, but this instrument carries the best price of any TMB scope that has ever been manufactured.

I’m still deliberating on the mount selection. A second CGE might be a possibility, or a Takahashi-EM-200 Temma II (high end), and a Losmandy-GM8-Gemini (lower end). There’s no doubt, of course, that the TAK is the most accurate of these three. It’s also the most expensive.

I’ve also ordered two additional imaging cameras. A Hap Griffin modified Canon-350 and the SBIG ST-2000XCM. More details on all of the equipment when I finally get to use it.

Cheers.

Max

re: Messier 44, aka, The Beehive

2007-04-23T13:37:00.000-07:00

M-44 is the final image from the night of April 19. It's hard to believe that Messier could have mistaken M-44 for a comet, since it's a huge (nearly 1.5 degrees in diameter) naked-eye object (3.7 visual magnitude) better suited to binocular than telescopic viewing. (Click on the image for a larger view.)

I previously noted that the Borg field of view is nearly 4 degrees across the long dimension. Thus the enormous size of M-44 is readily apparent. Professional astronomers believe that both the Hyades and the Beehive originated in an enormous nebular cloud, much like M-42, some 750 million years ago. M-44 is nearly 670 LY distant from the solar system.

Clear skies.
Max

Image Acquisition and Processing Data
Camera control with ImagesPlus 2.82 using the Xti and Borg f/4 astrograph on the CG5 mount
Autoguiding with C102, PHD and Meade DSI

5 subs at 1 min/ISO1600(5 total minutes)

Eight darks at 1 min/ISO 1600

No bias or flats

Converted, calibrated, aligned, stacked, digitally developed in IP

Resized in PS CS2

Astronomy Tools star reduction action and increase star color action

Converted for the web in PS CS2

re: The Leo Trio (more results from April 19)

2007-04-21T08:31:00.000-07:00

The Leo Trio is an often imaged object, and thus offers abundant opportunity for comparisons with the work of others. I'd like a tighter shot to show more detail in the galaxies, but that goal will have to wait for "new equipment." (Click on the photo for a larger image.)

The Trio (in the middle of the image) is comprised of NGC3628 at the upper right, M65 on the bottom right, and M66 on the left. One additional galaxy is visible at the bottom of the image near the middle. With additional "new equipment" (like a dedicated astroimaging camera) and longer exposures additional galaxies would be visible -- there are literally dozens in the FOV.

The subs were acquired before those of Markarian's Chain. I was still "tweaking" the autoguiding, so there is some trailing visible. But given that the majority of the subs were 3 minute exposures, I'm not disappointed. Live and learn, eh? Likely I need to reprocess the subs, and eliminate a few frames, but that will have to wait another day of processing.

Clear skies.

Max

Image Acquisition and Processing Data

Camera control with ImagesPlus 2.82 using the Xti and Borg f/4 astrograph on the CG5 mount
Autoguiding with C102, PHD and Meade DSI
14 subs at 1 min/ISO1600
15 subs at 3 min/ISO1600
(59 total minutes)
Eight darks at 1 min/ISO 1600
No bias or flats
Converted, calibrated, aligned, stacked, digitally developed (settings 0, 1.04, 4500, soft sharpen), auto stretch, saturation-brightness adjustment 1.2 in IP
Resized in PS CS2
Astronomy Tools star reduction action, increase star color action
Small levels and curves adjustment in PS CS2
Rotate 180d
Converted for the web in PS CS2

re: Markarian's Chain and Autoguiding

2007-04-21T08:02:00.000-07:00

Will miracles never cease? After a long run of cloudy and blustery nights, including a 9" snow and several rainshowers, April 19 offered a calm and clear night.

Several "advances" (relatively speaking) were made. For one, I was finally able to field test the autoguiding setup (PHD Guiding + Meade DSI). With a minimal amount of tweaking the CG5 mount was tracking like never before! My compliments to Craig Stark, who distributes PHD Guiding as freeware. (Click on the photo for a larger image.)

The second step ahead was tweaking the focus using ImagesPlus rather than my own eye. Eric Jacob and Mike Reid had noted that the focus was soft in the previous images. And finally I increased the exposure from 60 seconds to 180 seconds. (Acquisition and processing details below.)

The photo has a good bit but not all of Markarian's chain included. The two bright galaxies near the middle of the photo are M84 (on the right) and M86. M87 is in the lower left. Altogether I can count 22 galaxies in the image -- all part of the Virgo Supercluster. If the opportunity presents itself I plan on capturing the missing Messier objects (M88-M91, M99, and M58) and then taking a shot at my first mosaic image.

Abundant information on Markarian's chain can be found online. Here's a link to a fabulous astroimage by Karel Teuwen of Markarian's Chain.

Clear skies.

Max

Image Acquisition and Processing Data

Camera control with ImagesPlus 2.82 using the Xti and Borg f/4 astrograph on the CG5 mount

Autoguiding with C102, PHD and Meade DSI
18 subs at 3 min/ISO1600
(54 total minutes)
Eight darks at 1 min/ISO 1600
No bias or flats
Converted, calibrated, aligned, stacked, digitally developed (settings 0, 1.05, 4500, soft sharpen) in IP
Resized in PS CS2
Astronomy Tools star reduction action, enhance deep sky object action, and increase star color action
Converted for the web in PS CS2

re: M-81, M-82, Coddington Complex

2007-03-23T09:05:00.000-07:00

The M-81, M-82, Coddington complex is part of the Local Group of galaxies, which includes M-31 and our own Milky Way Galaxy. As Galaxies go, they’re practically next door at a mere 12 MLY.

I enjoy the widefield image, but two points stand out. Visual observation of M-81 and M-82 through the C-14 and a 12mm TeleVue eyepiece provides details that cannot be seen in the image. (See the technical specifications below: at 4.28 arc secs per pixel you lose fine detail.) And I’ve viewed some prime focus amateur photographs of these galaxies that absolutely knocked my socks off – most recently at: http://infiniti-eng.com/astrophotos/displayimage.php?pos=-53

As previously noted, "prime focus" imaging is on my list of things to do! But I’ve a lot more dues to pay.

Cheers.

Max

Addenda

On the M81-82 group see: http://www.seds.org/messier/more/m081gr.html
On the Local Group see: http://www.seds.org/messier/g-group.html

M-81, also called Bode’s Nebula

Magnitude: 7.0
Size: 24.9 x 11.5

http://www.seds.org/messier/m/m081.html

M-82, also called the Cigar Nebula, also called the Exploding Galaxy
Magnitude: 8.6
Size: 11.2 x 4.3
http://www.seds.org/messier/m/m082.html

Coddington’s Nebula (NGC 3077)

Magnitude: 10.6
Size: 4.8 x 4.2
http://astro.neutral.org/imagehtml/20060225_ic2574.html

Data acquisition and processing details

Camera control with ImagesPlus 2.82 using the Xti and Borg f/4 astrograph
16 subs at 1 min/ISO1600, unguided on March 16
8 darks at 1 min/ISO 1600
No bias or flats
Converted, calibrated, aligned, stacked and stretched in ImagesPlus 2.82
Resized and cropped in PS CS2
Astronomy Tools reduce star size, enhance DSO contrast, reduce space noise, diffraction spikes on medium stars

Adjust levels, curves, hue and saturation in PS CS2

Converted for the web in PS CS2

Equipment for widefield DSLR
Borg 77mmED f/4 (using super reducer)
Canon Xti (unmodified)

Hap Griffin astrocable
CG5-Go To GEM
Telrad
Dual saddle by Ken’s Rings
Celestron 102 guide scope
Meade DSI camera for guiding

Technical specifications for widefield DSLR
Borg/Xti Field of View: 167'x251' Field of View (2.78E x 4.18E)
2394x3520 pixel array
4.28 arc seconds/pixel

Incidental notes
Dell Inspiron camera control
Dell Dimension Intel duocore processing

re: M-41 and more on dim bulbs

2007-03-22T08:30:00.000-07:00

I've added a second image featuring M-41. As with the M-35 image, what really intrigues me in the image are the dim bulbs.

Having lived in Flagstaff for nearly a decade, I got to know several of the local professional astronomers . While Lowell’s new "Discovery telescope" will be dedicated to the search for NEO’s, a significant part of the USNO’s research program involves measuring the parallax of the "dim bulbs" – otherwise known as red dwarfs. It's a treat to view some through the 155m (61") astrometric reflector. Link: http://www.nofs.navy.mil/

The bright stars and the Milky Way itself tend to mesmerize the lovers of the night sky. Of course! The visual threshold, as all amateurs known, is mag 6.0 (and for people with really sharp "peepers" slightly beyond that). From a dark site on a moonless night, then, about 3000 stars can be viewed without optical aid on any one evening. As it turns out, however, those stars are just the tip of the galactic iceberg. The dim bulbs constitute the overwhelming majority of stars, perhaps as high of 90 percent of the total number.

One of my favorite astronomical writers is Chet Raymo. "For every yellow star like our sun in the middle of the main sequence," he writes, "there may be ten times as many red dwarfs" (p. 66, 365 Starry Nights).

Raymo’s on solid ground. James Kater’s excellent The Hundred Greatest Stars (a must have, in my opinion) writes that "by the far the most numerous kinds of stars are the faint M, L, and T dwarfs, which constitute at least 80 percent of the whole tally. As one climbs the main sequence, the numbers quickly drop; fewer than one star in a million is class O" (p. xx, Kater).

The Rigel’s, in other words, are the stellar freaks! It’s the dim bulbs that are the average Joe’s. All of these stars are, of course, invisible to the naked eye. In fact, most of them are beyond the reach of smaller aperture amateur telescopes. Which is why, when I first "stretched" the image of M35/NGC2158 and saw all those dim bulbs the experience was an immediate "Shazam, Holy cow, unreal, dude!" astronomical surprise.

Color me a rookie, eh? ;-) I was preoccupied with the techniques of astroimaging and conceptually disengaged – i.e., smacked with a stupid stick. The contemporary era of charge-coupled-collecting devices, computers and such has revolutionized stellar study, including the study of the dim bulbs. And the results have tended to upset the accepted picture of star formation and distribution. The accepted hypothesis has been that stars were born in stellar nurseries like the M42 complex, formed clusters like M35, and eventually wandered off as "single stars" – for example, Sol.

To make a long story short: "[I]n the last 15 years or so, astronomers have used more sensitive telescopes to survey smaller, dimmer stars called red dwarfs, which are between 10% and 50% the mass of the Sun. ‘The faint stars are harder to see, but they make up 85% of all stars in the galaxy, and three quarters of those are single,’ [according to astrophysicist Charles] Lada.... ‘I think the result strongly favors the idea that most stars form initially as single objects, not in multiple systems.’ "
"That goes against current models, which explain the existence of single stars by arguing they are born with siblings and are then separated after a gravitational interaction with another star. ‘You can certainly form a lot of stars that way, but with so many single red dwarfs, there's no simple way’ to explain them all, says Lada."
Source: http://space.newscientist.com/article/dn8640.html

Let me direct your attention back to the image of M35 from yesterday.Whoa, Nelly, that’s a whole lot of single stars, eh! And wow, are they dim. Makes me wonder just how low can we go in that image? Meaning, how faint are those dim bulbs? The starfield through my C14, which has a limiting magnitude around 15.3 (according to the manual: in use maybe mag 12 or so), is nowhere as rich as the image.

Let me use one of my planetarium programs to grope for answer. In my normal settings for The Sky no stars dimmer than mag 14 appear. With that setting the star field is clearly not as rich as the star field in the image. Left-clicking on the smallest stars gives data such as:
Object name: GSC 1868:2661
Magnitude: 13.7
Object name: GSC 1868:1857
Magnitude: 13.4

If I tweak "The Sky" (>"View"> "Stellar Options">"more stars" (move the slider for "more stars" all the way to the left) I can repopulate the "stellar field" with some really faint stars like these:
Object name: GSC 1881:232
Magnitude: 14.6
Object name: GSC 1881:744
Magnitude: 15.6

GSC1881:774 is the faintest star I can find. There may be some fainter ones. And by adding additional catalogues I might be able to tweak The Sky stellar field in the vicinity of M35 to approximate that of the image. But as a close comparison of the image and The Sky’s stellar field makes clear, there’s a bunch of dim bulbs in the image not on The Sky. For example, study the field at about 7 o’clock very near to M35.

Thus, a provisional answer to the question of "how low can you go with 5 minutes worth of subs?" Pretty low. Mag 16? Mag 17? I’m not sure.

In any case: Sagan was right. Billions and billions of stars. Most of them dim bulbs.
Cheers.
Max

More technical details concerning red dwarfs can be found online.
1. A short defintion and discussion at:
http://www.astro.umd.edu/educationalresources/astro/stev/rdwarf.html
2. Red dwarfs within 10 parsecs of Sol (a must see):
http://www.solstation.com/stars/pc10rds.htm
3. Short discussion with links:
http://jumk.de/astronomie/about-stars/red-dwarfs.shtml

re: Caveat emptor: wonky details below

2007-03-21T05:04:00.000-07:00

Unless you enjoy astroimaging, there's not a snowball's chance in Hell that you'll find anything of interest in this post. And even if you are an "insider," you may be bored beyond belief.

The photograph shows my basic setup in the "driveway observatory" and the longer-term "vision." I'm starting in the "easy mode," meaning widefield DSLR astroimaging. And in the next year I want to add prime focus imaging at f/6.3 through the Celestron 14" using a dedicated astroimaging camera. (Click for large view.)

The widefield set-up is as follows: CG5-Go To mount, which has been a pleasant surprise in both go to accuracy and tracking, given its relatively low cost. Borg 77mm astrograph at f/4 with the Borg super reducer: no surprise here. An excellent instrument free of chromatic aberrations with flat-fields edge to edge. Celestron 102 guide scope: again, a pleasant surprise given the very low cost of this instrument. Meade DSI camera for guiding only. (I would not recommend this device for imaging.) Canon Xti DSLR for imaging.

The Borg/Xti combination yields a 167'x251' Field of View with a 2394x3520 pixel array at 4.28 arc seconds/pixel. The M-35 image posted immediately prior to this post shows both the "costs and benefits" of such a setup. Very wide FOV (2.78dx4.18d) showing a few hundred of the dim bulbs that make up Sagan's "billions and billions of stars." But at 4.28 arc seconds per pixel the exquisite nature of "cosmic jewel boxes" like NGC-2158 is simply not apparent, becoming little more than a smudge. M-35, on the other hand, is nicely resolved.

The data acquisition and processing details are:

Camera control with ImagesPlus 2.82 using the Xti and Borg f/4 astrograph

Five subs at 1 min/ISO1600, unguided on March 16

Eight darks at 1 min/ISO 1600

No bias or flats

Converted, calibrated, aligned, stacked and stretched in ImagesPlus 2.82

Resized in PS CS2

Astronomy Tools star color action

Converted for the web in PS CS2

Incidental notes: "in the field" PC control via a Dell Inspiron. All processing done on a Dell Dimension 2 gig memory Intel duocore. I highly recommend Mike Unseld's ImagesPlus and Noel Carboni's Astronomy Tools.

There are multiple examples online of expert-level widefield DSLR astroimaging. I'll leave you to your own devices in that regard. Special thanks to Eric Jacob who's been a constant conversational partner and source of advice and encouragement.

There are only a few who are achieving expert-level imaging with the C-14. The most inspiring and generous with his advice is Lyndon Thompson. http://www.lyndonthompson.co.uk/

Cheers.

Max

re: M-35/NGC-2158 astroimage

2007-03-21T04:48:00.000-07:00

In the last month I've been "gearing up" (almost literally) for having a go at astroimaging. As the British like to say, "There's many a slip between cup and lip." So I've learned.

I'm about ten percent down the road towards the destination: actually winding up with some astroimages of decent quality. The image here is M-35. Click on the image for a full screen view.

To me the most interesting features of this image are (a) the star colors, (b) the "3-D illusion" of the M-35 cluster, and (c) the myriad "dim bulbs" - meaning faint stars that cannot be seen with the naked eye. The hundreds of them that appear on the image remind me of Carl Sagan's "billions and billions and billions of stars!" Indeed. And most of those billions and billions of stars in the Milky Way are dim bulbs. We're very lucky, by the way, that Old Sol is not one of them.

I won't reveal my limited astrophysical knowledge by discussing the importance of star colors. Simply think of a star's color as indicating its temperature. For example, red stars are relatively cool, aging stars like Betelgeuse and Aldebaran. Blue-white stars are often younger, intensely hot, super-giants like Rigel (estimated 55,000x more luminous than Sol, 910LY distant from us). Sirius outshines Rigel, but only because it is so close to us, at 8.65 LY, the fifth closest star (approximately 22x more luminous than Sol).

The flaws in the image of M-35/NGC-2158 are many, not the least of which is a modest amount of star trailing (that is readily apparent at the pixel level). Autoguiding during image acquisition is the obvious solution, but that "next step" has provided several complications to date.

The wonky details "behind" this photo are boring to anyone except fellow astroimagers, so I'll place them in subsequent posts.

Cheers.

Max

re: getting started in astronomy

2007-02-15T08:00:00.000-08:00

Blog visitors interested in All Things Astronomical sweep across a spectrum from beginners to advanced amateurs. My focus today is providing information for folks who are interested in getting started -- but are uncertain as step one.

Here's a fact that anyone considering "getting into astronomy" should know. Most telescopes wind up in a dark closet or corner of the garage, seldom if ever used. Why? Generally because people have "leaped" before "looking." For example, too many folks believe that they'll see images through their telescope that look like Hubble Space Telescope photographs. Uh...not! Or they believe that a super duper K-Mart special 500x magnification scope is just what they need, rather than a little bitty 100 power magnification. Uh...not! Or they go out at night and are immediately lost in the night sky. (See the previous post for a solution to that issue.)

When it comes to astronomy caveat emptor (buyer beware) rules! So an informational "jump start" that's not the purchase plunge is the place to begin.

Two websites come immediately mind, both constructed by friends of mine. While the two sites are different, they offer sound advice.

Let me begin with Bill Ferris's "Cosmic Voyage" pages. http://members.aol.com/billferris/beginners.html
Bill is a highly accomplished life-time observer who's actually worked in astronomy in a professional capacity. Be sure to check out his "Telescope Buyers' Guide" as a first step.
(Note: Bill's pages are on AOL Hometown, and are thus slow to load. Be patient.)

The second featured site is Eric Jacob's "Cheapskate Astrophotography." http://www.cheapskate-astro.net/index.html
Eric's webpages will introduce you to the next step in astronomy beyond eyepiece views: making your own astrophotos using equipment that will not break the bank.

So, enjoy your visits to Bill and Eric's pages. And make sure to surf the links that they provide. By the time you finish you'll be in a place to make a reasonably informed decision about your own prospective purchases.
Cheers.

re: the web and astronomy, part 2

2007-02-12T08:13:00.000-08:00

Picking up where I left off, the web is literally a treasure trove of astronomically relevant free software! Here's the sample du jour: Cartes du Ciel.

Every heavenly observer needs a star atlas. And the information revolution has brought us the digitized star atlas. A really nice one is Cartes du Ciel at: http://www.stargazing.net/astropc/

Rod Mollise -- an "astro-guru" who's answered many a question for me -- notes in his review that "I reviewed the previous major release for this program in these pages about a year ago (v2.61), but for those who’ve not yet heard of CdC, the bottom line is that Cartes is a FREEWARE planetarium/deep sky program of surprising power. It’ll do what most other astronomy programs will do—present an onscreen "planetarium" sky for the date and time of your choosing. But what’s amazing is how it combines this basic planetarium functionality with the features of a real, computerized and star atlas." Source: http://skywatch.brainiac.com/sw0102.pdf

Rod, btw, is the author of many useful astronomically relevant books. You can find out more about Rod on his home page. http://members.aol.com/rmollise/

Must go for today.
Cheers.

re: the web and astronomy

2007-02-10T12:29:00.000-08:00

The Web has changed everything, hasn't it? And it has certainly democratized access to the knowledge of all things astronomical. I've bookmarked hundreds of sites. And I regularly visit about a half dozen of them.

Rather than provide a list of links without explanation, let me discuss four of my favorites, beginning with Cloudy Nights. http://www.cloudynights.com/ubbthreads/index.php?Cat=0

If you're not a member, and you love astronomy, CN is a goldmine of information. The articles and reviews are useful. And the forums are the best! There's a forum to suit every interest you have.

A second must see is Astromart. http://www.astromart.com/

Do you want to buy or sell used astronomy equipment of virtually any sort. Astromart is the place! High quality astronomy goods typically retain 70 to 75% of their original value. If a deal is too good to be true, it likely is!

A third "you gotta see this to believe it" is Yahoo Groups. http://groups.yahoo.com/

Type a useful search string into the "Find a Yahoo Group" box and you'll be amazed. For example "astrophotgraphy" yields 97 hits. Too many, for sure. But a generic category is often the place to begin.

Last but not least is Google. http://www.google.com/

Of course I don't need to tell you this, eh? But Google will put you on the fast track to the information you want.

Enough again already.

Cheers.

Source for the image above: http://www.irtc.org/ftp/pub/old-competition/competition-Mar-95/sjg-internet.jpg

re: links of the day

2007-02-09T05:50:00.000-08:00

"Eyeball observers" know all too well the frustrations of the urban life: light pollution kills the dim fuzzies that lie at the heart of our passion. The image at right (source: Light Pollution Science and Technology Institute) illustrates the problem.

So how much light pollution do you suffer from? There are any number of useful sites on the web. Here's a link to the main page for the Light Pollution Science and Technology Institute:

http://www.rei.com/?cm_mmc=ps_google_reibrand-_-REI_Brand-_-REI-_-r.e.i.

And here's a link to the global map. Scroll down the page to find your continent. If you download the large maps (100 mb plus), you can pretty much see your own neighborhood. http://www.lightpollution.it/worldatlas/pages/fig1.htm

What can you do about the problem of ever increasing light pollution? How about joining the IDSA? http://www.darksky.org/ The IDSA site contains a wealth of information.

As it turns out, local groups (cities, like Flagstaff, AZ) and regional have made strides in fighting light pollution. Here's a link to the Flagstaff Dark Skies Coalition: http://www.flagstaffdarkskies.org/

FYI, the IDSA has a slide show that you can use for a presentation to the "poobahs" who run your city or county. http://www.darksky.org/resources/protecting-our-night-environment

Enough already. But check out the web on light pollution.

Cheers.

2007-02-08T11:45:00.000-08:00

Why a blog? I guess cuz it's been way too cloudy and/or snowy to pursue my passion at night. We've had close to 90" of the white stuff to date. Great for snowshoeing. Bad for observing. The snapshot is yours truly (aka, Nanook) at work.

My home is at 7254', give or take a few inches. I have dark skies to the south and east, with the glare of Albuquerque on the other side of the Sandias to the west. As a "refugee from the city" and a dark skies advocate, my location is...well...heavenly. You can find more information about the IDSA at: http://www.darksky.org/

Today is the first day (Feb. 8, 2007) of the blog. I'll add posts and photos over the next few weeks. Right now "all things astronomical" is just a speck in the ocean of blogs. In other words, pretty much like the solar system in relation to the Milky Way Galaxy or the Milky Way in relation to the cosmos. More on all that later.

Reader responses and posts are quite welcome, within the guidelines of all things astronomical.

Cheers.