It's been very cloudy for quite a while, but the past two nights have been nice and clear. I missed last night, but decided to get my act together this evening. I'm definitely in photon-deprivation mode these days, so I opened up the dome and spent several hours in there. I have been doing most of my observing for the past year or so with the wide-field scopes, but my CGE mount is still in the shop so I fired up the RCX again. I was pleasantly surprised to find that it had retained its alignment since the last time I used it, so it was just turn it on and go.
The RCX needs a lot more hand-holding when I image through it, and it is a work night, so I didn't stay out all night. My main target was M16, and here is a quick process of the first 10 subexposures. They were 300 second frames at -20C (I'm using the chiller that my wife used during her knee surgery recovery last year), and I also used the SBIG adaptive optics unit which really helps the guiding.
This is one of my favorite targets, I always love to see "The Pillars of Creation" show up on my screen when the frames download. I'm hoping for some more clear nights, if we get them I will try for additional data, including using the color and other narrowband filters.
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It's been real cloudy lately, the monsoons are arriving daily with plenty of rain, lightning, and wind. No damage around here yet but it's impossible to do any astronomical observing.
I did attend the monthly meeting of the Tucson Amateur Astronomy Association on Friday night. George Barber gave a great talk on solar observing for the Astronomy Essentials, and then we heard Dr. Tim Swindle of the U of A Planetary Sciences Department tell us about his adventures hunting for meteorites in Antarctica.
I've got plenty of "administrative" astronomy tasks to take care of. The CGE is in the shop for repairs; I need to bake my CCD dessicant plug; there are a few items I want to list on AstroMart; I've got some configuration work to do; I have a ton of image data to process; and of course the big one is completion of the roll-off roof shed. But it's hard to get motivated to do these things when I know I can't do any observing. So instead I've mostly been spending my play time on ham radio stuff. But I did spend some time this afternoon teaching the Astronomy Merit Badge to my son's Boy Scout Troop.
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Jupiter, the king of the solar system, is only about 2 days away from opposition. This means that it is basically 180 degrees away from the sun as viewed from Earth. When planets are at opposition, they are usually also roughly closest to the Earth and thus have a larger apparent size.
Here's a webcam image that I took on July 1st with the 14" RCX. I'm no expert at webcam imaging, and it was a work night so I was taking the images too early in the evening - Jupiter was only about 20 degrees up in the SouthEast when I shot it. I took several 2 to 3 minute .avi videos, then used Registax freeware to split it into frames and process them. I also didn't get a perfect focus. So the details are a bit rough, and I had to overprocess it to bring out the minimal details visible here. On nights of good seeing, it would not be unusual to see more detail using a high-power eyepiece than this image shows.
I may try to image it again soon, but that depends on the weather - we are in the midst of monsoon season so there is not much hope for clear skies most days.
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Here I am in Northern Arizona again. I'm in Sedona for a family reunion on my wife's side, and today we took a jeep tour. While seeing the sights we saw this house under construction. It's supposed to be 30,000 square feet, and the dome on top looks like a large Ash dome, or something similar. Wonder what type of scope is being housed inside, must be a nice big one. The skies here must be nice and dark, and although this is perhaps not the best way to build an observatory (too close to the mountain, on top of a house), I sure wouldn't mind having it at my disposal!
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Today was my second day at the Grand Canyon. During the day, we hiked up Mt. Humphreys. This is the highest peak in Arizona, at the top it is at 12,650 feet. It was about 10.8 miles and went up a steep and rocky route, so it took most of the day. The view from the top was quite dramatic, although haze and some far-off rain limited the view somewhat.
In the evening, I enjoyed the final day of the Grand Canyon Star Party. There were many scopes set up, and crowds of visitors gathered around each and every one. It is really an amazing sight to see so many people, who often have zero knowledge of the night sky, showing an interest in astronomical observing. I heard tonight that in the past 18 years the GCSP has literally had hundreds of thousands of visitors! Most are people who are simply on vacation at the canyon and happened to see the scopes, or read about it in the park newsletter. Tonight was almost the perfect summer observing night, with temperatures around 72 degrees Fahrenheit, and very clear skies. The transparency was not perfect, but many objects like M13 were plainly visible to the naked eye. The Milky Way is simply spectacular here, it is so bright that many visitors mistake it for clouds in the sky.
I'm sure I will be back for more GCSP in the future, although it is undergoing a change. My friend Dean Ketelson (the "other Dean") is passing the reigns after 18 years of coordinating the star party. Fortunately he will still be spending half his time in Tucson.
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I've finally made a visit to the Grand Canyon Star Party. It's been something I've wanted to do for years, but other commitments have always kept me away. This is the 18th year of this large event, which is a week long star party focused primarily on public outreach. The park rangers at the Canyon are very supportive as it allows them to encourage public visitors to experience the joy of the dark night skies, and perhaps learn to value the preservation of dark skies, which fits well into the National Parks program here in the U.S.
The party started last weekend and ends tomorrow night, so I will only be here for two nights. Dean Salman and I drove up today from Tucson, and this evening Dean gave a very nice presentation to about 200 park visitors. He showed many of his outstanding CCD images during twilight, and afterward everyone went down to the parking lots where about 60-70 telescopes were set up. The whole event takes place right on the South Rim of the Grand Canyon. Actually, there is a North Rim version of the party that runs simultaneously, but the South Rim event is the larger one.
The skies here are quite dark, with a dramatic Milky Way providing an awesome backdrop to the star-studded sky. This is really a great place to hold a star party!
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Someone asked me whether I've taken a break from astronomy since I don't seem to be blogging lately. I definitely am still stargazing at every opportunity, but life has kept me so busy that sometimes I wonder which way is up.
The past few months have been frustrating on many nights because my CGE mount was damaged and I can't seem to get it back in shape. We've enjoyed an incredible stretch of clear skies here in Tucson, for most of this year so far, but many nights I have been unable to work the CGE. There are other scopes available, but certainly the CGE has been the workhorse.
There are some exciting things coming, and I expect to be doing some serious astronomy in the fall, after monsoons (we're officially in monsoon season now, but the rains have not started yet).
Anyway I will try to post a little more often. Meanwhile here is a recent image, taken over the course of 4 nights at the end of last month. It's the Crescent Nebula, NGC 6888, and the image includes data taken with traditional narrowband filters (Ha, OIII, and SII), as well as some near-infrared filters (above 7000 Angstroms), This was my first attempt imaging with the NIR's. To see a the individual versions (i.e. Hubble Palette, CFHT Palette, and NIR) as well as an animation of the various versions, see my website at
http://www.xanaduobservatory.com/ngc6888.htm
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Today I visited Kitt Peak National Observatory with my oldest son's Boy Scout Troop 753. I'm teaching the kids the Astronomy Merit Badge and one of the requirements is to visit an observatory.
We had a chance to get an up-close tour of the McMath Pierce Solar Telescope as well as the 2.1 meter telescope. This picture shows me and two of my sons, the oldest a Life Scout and the youngest a Bear Cub Scout, with the 4-meter Mayall Observatory in the background.
There were about 20 people in the group and everyone seemed very interested in the tour. We're lucky to have such a well-known site nearby (it's about an hour and a half drive). The weather was perfect.
I'm imaging again tonight, lots of data being collected with little time to process it...but the first light image from the new Tak is coming soon.
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I attended the monthly meeting of the Tucson Amateur Astronomy Association this evening. Our speaker was Peter Smith, of the Lunar & Planetary Lab, who is the Principal Investigator for the Phoenix Mission to Mars.
Peter gave us an excellent overview of the mission, which is currently on its way to Mars after launching last August. It is expected to land in the North Polar region on May 25th of this year. The lander has a robotic arm with a shovel and will explore the surface ice next to the landing site.
While I was at the meeting, my imaging system was starting itself up for an observing run. My targets tonight will be M42, M51, and M101 (although I may intercept it and change M101 to something else later). We've had a nice week or so of clear skies and I've been imaging with the new Epsilon every night, so there is plenty of data to process. But since it's my busy season I have not had any time to process it much yet. I do know that the very fast focal length of this telescope results in more severe color gradients than I have experienced before, so I will need to develop some skills to handle that.
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No, I have not disappeared into a black hole...it's hard to believe how rapidly time can go by. Seems like only yesterday that I last posted a blog, and here it is March already.
I must admit, however, that I have not been as active with astronomy these past few months as I wish I had been. I've had a few imaging sessions, but the data sits unprocessed on the hard drive. Our local club has been pursuing acquisition of a new dark site, and since I'm on the Board, I've been somewhat involved with that. I've been getting ready to teach the Astronomy Merit Badge to my son's Boy Scout troop. And I've spent a lot of time working on the roll-off roof observatory that will eventually allow me to do even more astronomy from my back yard. But I've missed quite a few clear observing nights, and obviously I have been bad about posting to my blog.
There have been a few equipment plans in the works. One was an intended acquisition of a Paramount equatorial mount, but that was cancelled for a variety of reasons, primary among them that Software Bisque could not seem to deliver it. So now my name is on the waiting list for an AstroPhysics mount, which will take quite a while to get.
Meanwhile I made a deal with my friend Dean and ended up with his Takahashi Epsilon 180. He's imaged just about everything possible and needed to move to a longer focal length, so we worked out a trade and now I'm the proud owner of this scope. It's a lot for the CGE mount to handle, and I'll be interested to see whether I can get decent images out of it without a larger mount. I needed to add a second 25# counterweight because it is much heavier than the refractor. Tonight I got it all set up and balanced, and as I type this I'm running "V-Curves" in FocusMax to get a good profile for automated focussing. So far it's looking pretty good.
I know I won't be able to produce the quality of images that Dean has - many of them have been published in the magazines, including several pages worth in Sky & Telescope's "Beautiful Universe" book and the inside back page of numerous issues of Astronomy Magazine, including the latest issue. But hopefully I'll have some fun with it, that's what it's all about!
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This evening (12/23/07), there was a stunning pairing of a nearly full Moon and the fiery red planet Mars. We're just a couple of days past the Winter Solstice, and Mars will be at opposition tomorrow for a Christmas Eve present. I observed the conjunction of the Moon and Mars from what would normally be a horrible place to observe from - the shopping mall parking lot - as we were leaving a movie with some visiting family members. In fact it wasn't me who noticed it first, but my Siste-in-Law, who said, "Look, the Moon has a satellite"!
Seeing this motivated me to try to complete processing on some Mars images that I took last week using a Phillips Toucam webcam with a 2x Orion barlow, on my 14" Meade RCX. Capturing the data was the easy part; I simply took short (~2 min) .avi video frames using K3CCDTools software. However, since I don't do this type of image processing regularly, I found it very challenging to do the processing. I used Registax and Photoshop. This image is the result of my attempt, and while it's far from perfect I'm pleased to be able to discern various features on the surface of Mars. Click here to see a slightly larger version of this image.
I used the Sky & Telescope freeware program called "Mars Previewer II" to help identify the exotic-sounding names of the various markings, such as Sinus Meridiani, Sinus Sabaeus, Niliacus Lacus, and Mare Erythraeum. Far away places to be sure, but once again my telescope has allowed me to briefly be transported away for some exciting exploration of the universe (figuratively speaking of course)!
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Turns out amateur astronomers are good at having potlucks too. Tonight was the annual TAAA holiday party, held at the home of our President, Bill Lofquist. The sky was cloudy but no problem, we all had a great time socializing anyway. Pam came along for a change, and she actually won a raffle prize - which she gave to me. We won a nice Moon globe, with plenty of named features on it. The club also raffled off a C8 with Byers gears, an old but very classic telescope. I know one astronomer who says these are the best drives ever made - and he should know, he has discovered more asteroids than anybody else. I had picked up the C8 from a nearby neighbor, who was one day away from throwing the scope in the trash! Instead we had it cleaned up by Dean Koenig of Starizona, and the winner this evening was none other than my good friend Victor, who until tonight did not even own a telescope. So it all turned out very well for that old scope, as I know Victor will give it a fresh new outlook on life.
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Last night it finally cleared up after more than a week of bad weather. I knew it was going to be a wet one, but I set up anyway, hoping to get some imaging in before the dew hit.
Here is what I started with, Open Cluster M35 and it's old friend NGC 2158. The stars in M35 are mostly blue but NGC2158 is full of old red stars. They're a nice pair for observing (in fact they made the list in January 2008 Astronomy Magazine's article, "Observe Celestial Odd Couples". Click Here to see a larger version of this image and more details.
But unfortunately I pushed my luck a bit too far and by the time I went outside, a little after midnight, to check on the gear, it was a soggy mess. So I got the hair dryer and spent a while trying to dry things out, but it was rather hopeless. I wonder if any of my neighbors heard and wondered about the crazy guy next door drying his hair outside at 1:00 in the morning! In the end I just covered it up, set the camera to take darks for the rest of the night, and called it quits.
I'm imaging again tonight and everything seems to be fine, so I guess no damage was done by the water. I did hook up my Dew Heater, though, which is something that is almost never needed here in the arid desert.
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The cold weather is finally here, today I closed down the swamp cooler and fired up the heater for the first time this season. Along with the cold, we've been getting a few drops of rain and the clouds might be a real problem for the next week or so.
On Friday night, I drove down to Sierra Vista with Larry to attend the monthly Huachuca Astronomy Club meeting. As always it was worth the drive. The guest speaker was Steve Coe, who spoke about nebulae. Steve has written a couple of books, including "Nebula and How to Observe Them". He also writes articles and columns for Astronomy Magazine and Cloudy Nights Forum.
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I'm about a week late but my blog has now passed the two year mark! I sure enjoy using the internet this way, I do think it's enhanced my astronomy experience to write about my activities now and then. And I definitely enjoy reading the other blogs, each with its own personality. Thank you Astronomy Blogs!
So here is a picture of the two tadpoles, swimming in the sea of IC410. (They are tiny and near the center in this little image - to really see them well, click here for a larger version of the image). It's been a long swim for them and I think the current will eventually win in a few million years. But for the time being we are lucky enough to be able to observe the dramatic effects of radiative pressure from the stars in cluster NGC1893, which are struggling through their early Hydrogen-burning years inside the dusty cocoon of the IC410 nebula. The tadpoles are areas of cooler, denser gas that are resisting the flow, thereby producing the interesting stretched-out tails which are roughly 10 light-years long. The darker "holes" in the nebula are areas that have been carved out already by the strong stellar winds. I wouldn't want to live there, but it's a nice place to visit with the telescope.
The two concrete foundations are the pier foundations that we poured on Sunday. My friends Dean and Larry came over and worked hard helping me with the project. These are going to hold the two piers that will be in Xanadu West, which I hope to have in operation very soon.
As for the too much fun, well, as always I will maintain the focus of this blog on astronomy which means I can't complain about all the other trials and tribulations of daily life - but without a doubt, astronomy continues to be one area that can be guaranteed fun!
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This Comet is quite spectacular. In less than two weeks it has really grown fast, and although it has dimmed a little bit it's still shining brightly. I observed it tonight naked eye and could easily see that it was a fuzzy blob instead of a pinpoint star. I also checked it out in my 6.5 x 42 binoculars and was really impressed. 17P/Holmes was expected to be a minor league comet and would probably have escaped most of us, but the sudden brightening a couple of weeks ago made it a household name for amateur astronomers.
I took this image tonight using just 9 x 60 seconds in each of red, green, and blue filters. The challenge with comets is stacking them, but I think I got it pretty close. Click Here to see a larger version of this image. Compared to my image from less than 2 weeks ago, the comet is much larger. It seems that 17P has acted up before - in 1892, Barnard imaged it from Lick Observatory; it grew from 8 arcminutes to 25 arcminutes in diameter in just about a month! Here are some scans of the Lick plates:
-Nov 10 1892
-Nov 10 1892
-Nov 21 1892
-Dec 8 1892
By the way, I was supposed to go to a star party at the new dark site near the Chiricahua mountains tonight, but it was so cloudy late this afternoon that I decided not to go. It's cleared up nicely here in Tucson, but the satellite images seem to show quite a cloud cover down there so hopefully I'm not missing out. I was hoping to do a visual session with the dob, I need some eye photons! I did spend some time out back enjoying the sky tonight though. In addition to the comet, I've got the refractor plugging away on my California Nebula mosaic project tonight.
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Here's an image of the Double Cluster in Perseus. "The Double" is a well-known target for amateurs, and is visible to the naked eye. I have viewed this many times through the scope, but it needs a very wide field eyepiece to get it all in. A Nagler 31mm 'hand grenade' or something like it is usually needed for a long focal length telescope.
The red giants really stand out in this field as they contrast well with the other stars.
I took this image over two nights earlier this week, first the color channels and the following night the luminance. The subexposures were only 1 minute each, the stars are so bright that it doesn't need much. Click Here to see a larger version of this image. I did a PinPoint plate solve in MaximDL, and it tells me that there are 8,376 stars in this image! Sometimes the seemingly boundless size of our universe just leaves me awestruck.
Tonight is cloudy so it's looking like a catch-up-on-sleep night for me. I've been working hard lately and plan to do some more labor on the shed tomorrow so I'm ready for a good rest.
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When I was a teenager I loved to play Space Invaders at video arcades. We didn't have Playstations or XBoxes, but for a quarter you could experience some amazing graphics for the time. Another popular game, not one of my favorites but addictive nonetheless, was Pac-Man.
There's a very nice bright emission nebula in Cassiopeia, NGC 281, which has earned the name "The PacMan Nebula" because its shape has an uncanny resemblance to that little gobbling monster of PacMan fame. I doubt that NGC 281 is actually devouring everything in its path as it flies through outer space, but it's still a fun object to observe either visually or in the camera.
I took this image over 4 nights in mid-October. Click Here for a larger version of the image. I wound up discarding much of the data and used only the best subframes. I used the Hydrogren Alpha filter to obtain luminance data, and also combined it with the red, green, and blue channels in an 80%, 5%, and 10% mix accordingly. Since NGC 281 shines brightly in H-alpha, using it in this manner helped bring out some of the contrast.
There's been a lot going on lately in my "normal" life, but as always I'll try to keep this blog on the astronomy track. I've been working on the shed project for Xanadu West and hope to pour pier foundations this weekend. I've also been imaging a lot recently, with the help of CCDAutopilot which has been an awful lot of fun. The data is getting backed up...
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Here is an image I took from the JMSM Observatory, located in the mountains of New Mexico. It was an unexpected surprise for me when the observatory's owner, Mike, offered to let me control the observing plan for the night last Saturday while we were attending the AIC conference in San Jose. So there I was, an Arizonan visiting California, imaging in New Mexico!
This observatory has incredibly dark skies and also some very high-end amateur equipment. So I was pretty excited to be able to grab some data, even though the moon was nearly full. Dean and I set up CCD Commander to use a 6" refractor and an SBIG 6303 camera to image two objects all night long, the first being NGC896 and the second, NGC1893. Due to the moon we only used the Hydrogren Alpha filter. The image above is a mean combine of the best 10 images, each one 10 minutes long. I dark subtracted but didn't have a flat field. I'm hoping to get some color data, either from the JMSM or perhaps even with my 105mm here in Tucson, and I also need to process it a little more carefully, but for now this is still a decent result. Click here for a larger version of this image. There is some fascinating detail in this object, which Pam calls "The Cracked Egg Nebula".
It sure was fun using this setup. IP cameras at the site allowed us to watch the dome, mount, and scope in action. There are a large number of amateurs with observatories in the nearby hills (this site is right next to New Mexico Skies), and it's easy to see why they set these up - the seeing is sub-arcsecond, and darkness is better than just about anywhere.
I've been using CCDAutopilot lately to help in managing my imaging runs right here in my backyard. I've written before about the use of technology to enhance astronomy, as well as the risks of losing sight (forgive the pun!) of what attracted me to the hobby in the first place. There truly is no match to being outside under the stars on a cool evening and enjoying the quiet majesty of our universe. One reason I am using CCDAP is to allow me to spend less time staring at the red computer screen and more time staring up and contemplating the heavens above.
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This is an image that I took two nights ago with the William Optics 105mm refractor. It's a combination of 12 30-second luminance images, plus 12 each 60-second red, green, and blue images.
It was really a challenge to try to make the color combination "look" correct on this one. I'm not quite satisfied with this result but I'm weary of messing with it so I think I'll stop here. The neat thing is that you can see some detail, for example there appears to be an annulus around the coma (this is the result of the spherical arrangement of the shell, it's not really thicker on the outside. The multicolored streaks are stars, which elongated because the comet was moving as the images were taken. A larger version of this image can be seen by clicking here.
The comet has been generating a huge amount of interest among amateurs over the past week and a half. Today's APOD was of the comet and there are pictures flowing from telescopes everywhere. People are sketching it, and observing it through eyepieces and binoculars, as well as the naked eye. I checked it out again tonight naked eye and it's still a bright star-like beacon near Mirfak (Alpha Persei).
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Tonight was Members Night at the TAAA meeting. Plenty of interesting speakers on various topics. Not surprisingly there were several images of Comet 17P/Holmes as well as some excellent sketches. I gave a talk about the LHIRES III Spectrograph, and also showed my comet image from last night along with the spectrum from last week. I got a decent comet image last night and will probably post it tomorrow.
Gotta get some sleep as tomorrow is going to be a hard labor day while I work on Xanadu West.
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I'm back home after 3 fantastic days of Astro-Imaging seminars and fellowship. The AIC Conference is really a good one, with some extremely skilled, world-class astroimagers sharing their tips in the seminars. There's also a great exhibit area where the top manufacturers pitch their wares. One can't help but get totally pumped up for some serious imaging after attending AIC!
Speakers yesterday and today included Rob Gendler, Don Goldman, Neil Fleming, Steve Cannistra, Michael Barber (from SBIG), Stephen Bisque (of TheSky and Paramount fame), Brad Ehrhorn (RC Optical)
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I'm sitting here on Saturday morning awaiting the start of day two of the Adanced Imaging Conference in San Jose, CA. Yesterday was an excellent day with a workshop by Adam Block. The vendors are here in force with all kinds of wonderful toys.
More to come soon.
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The internet is abuzz with talk about Comet 17P/Holmes, which suddenly brightened by an astonishing 13 magnitudes over just 3 days!
Comets brighten but this is simply stunning. Apparently 17P has played like this before but not quite as dramatically. It's currently in Perseus and despite the full moon, is easily visible to the naked eye. I found it tonight in a little triangle pattern with Alpha and Delta Perseus.
I'm about to head off for the AIC and had planned to be well rested, but this event was too good to pass up. So I spent some time in the dome and captured some spectra of the Comet, as well as some stars (for flux calibration as well as general interest purposes). Then I decided it would be worth performing a quick processing on the Comet spectra, so here is the result.
The odd thing is that this spectra does not look like a comet spectra, but instead it looks like a Type K star. So, I must admit that there is a possibility that I messed up and got the wrong object. But I was quite careful, and the object in the guider field was clearly the Comet with a fuzzy glow around it. And the spectra were extended rather than thin strips like stars give. People are reporting that the Comet appears yellowish or even reddish, and this spectra seems to support that.
Anyway I guess I will find out soon. Meanwhile I need to try to get a few hours of sleep before the trip tomorrow.
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Last week I finally got serious about putting the camera back to work. I spent every night from Monday through Saturday collecting data. It was a lot of work, but I used CCDAutopilot to handle some of the load, which allowed me to continue to get sleep and get my work done at the office each day. There are other advantages from using CCDAP, such as a more efficient focussing process (I'm now able to refocus every 30 minutes).
So far it appears that the results have been good. This image is a narrowband (so it's false-color) look at IC405, the Flaming Star Nebula in Auriga. I've been playing around with various combinations of color mapping to enhance certain structural detail in nebula, and this one certainly has a lot to explore. Click here to see a larger version of this image. I imaged the same region almost exactly a year ago, with fairly similar results, but I think this one may be slightly better. I've got data for about 5 more objects from last week that still needs to be processed.
Tonight is very windy, and there's a very bright moon anyway, so I've just got the camera collecting dark frames for the library.
I can hardly wait until the weekend...stay tuned for the reports.
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Tonight I attended a star party at Steve's Vail View Observatory. The TAAA Astroimaging Special Interest Group meets there occasionally for a star party, and this weekend Steve invited us to spend both Friday and Saturday nights there.
I was not able to go last night, and today was an incredibly busy day with an early start for me, so I just didn't have energy to pack up my gear for an offsite session tonight. Instead, I set up a session in CCDAutopilot to run my scope all night, right here at Xanadu Observatory. But I did go out to Steve's, and logged in remotely from there to control my scope here. Things were running smoothly so it wasn't really necessary to log in, but it was kind of fun to play with it. Technology has become so advanced in amateur astronomy, and this was a good example - it's kind of strange to think about going to a star party and logging into the home observatory! Steve, Michael & Mary, and Dean were all there running their telescopes with CCD cameras, and Victor also was there.
I've been imaging every night for the past six nights, but have managed to get some sleep thanks to CCDAutopilot. I love astronomy, but I also really have fun making all the technology work properly.
Tonight was supposed to be the peak of the Orionid meteor shower, I saw a few but not too many. The skies at Steve's are certainly darker than mine so it was nice to get out in the warm night air and do some visual stargazing as well, although the moon was rather bright. It was dark enough to easily see M31, the Andromeda Galaxy, naked eye, even before the moon set.
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Telescope mounts can be finnicky things. Sometimes they work wonderfully, and other times they inexplicably misbehave (reminds me of one of my sons!).
Tonight I'm set up poolside and at first, everything seemed to click into place. I just plunked it down, using a neighbor's tall evergreen to point me approximately North; on my first alignment I was less than 7 arcminutes from the pole in Altitude, and only about 2' in Azimuth. "Ah", I thought, "tonight is going to be one of those nights when everything goes well, so I'll go ahead and refine it to get even closer." But the mount had other ideas. Two frustrating hours later it seemed that I was back where I started.
But once I finally got to imaging, the tracking seemed to be doing very well. Here's a screenshot, I enlarged the tracking graph to show it better. The graph shows guiding errors over about a 12-minute period, and it shows that the tracking was nearly dead-on. The errors are sub-pixel in size, in fact even the largest error was only about 1/3 of a pixel. This is especially good for a mid-range mount such as my CGE (although I have to admit that the wide-field produced by the refractor makes the graph flatter. Still, these errors are sub-arcsecond in size). When I have it on a pier, and refine my PEC curves, I may even be able to improve it further.
Tracking isn't just important for imaging, it also is crucial for a lengthy visual session. The eye can resolve much more detail during a long session when telescope tracking is good. A proper polar alignment goes a long way in helping a scope track targets.
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Here's a screen shot from CCDInspector, a powerful program that I sometimes use to evaluate my images. This software does a nice job of quantifying certain characteristics of a series of CCD images, such as FWHM and contrast ratio, which makes it easy to identify the bad ones. Since most processing jobs involve combining multiple images, CCDInspector is a powerful tool for culling the best ones.
This particular image is the software's attempt to measure the curvature in my imaging train, as well as the collimation. Basically this helps me to see whether the camera is perhaps not orthoganal to the telescope lens, or whether the telescope is out of collimation. Ideally, you would want a perfectly flat image, but that is virtually impossible to achieve. A system with a lot of curvature will exhibit noticeable distortion in the images. I'm very pleased that this particular system, my William Optics Zenithstar 105mm with a 0.8 focal reducer/field flattener, provides a reasonably flat result. For a relatively inexpensive system, it has done quite well for me. Of course I dream of something better and perhaps someday will upgrade, but it's nice to know that the current setup is not way out of whack.
I used my ZS105 on Sunday night at an observing session over at Dean's house. I spent some time fiddling with software configurations so don't have a lot of data, but I'm working on processing it and should be able to post it soon.
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Last Friday night was the October meeting of the Tucson Amateur Astronomy Association. The guest speaker was Dr. Steve Howell, an NOAO astrophysicist who was fortunate to get observing time on the Spitzer Space Telescope.
Dr. Howell is studying dust in the region around binary stars. He's a very animated speaker and did a great job bringing some high-level theory down to the layperson realm. Observing dust is generally done in infrared wavelengths and it was interesting to hear his comparisons to optical observing (for example measuring wavelength in microns instead of Angstroms). Although these dust clouds would be extremely cold by human standards, they can be "hot" from an physics perspective, if there is an energy source available to heat them up.
He has interpreted his data to indicate the presence of a large dust disk surrounding certain binary star systems; the image above shows Dr. Howell in front of his closing slide, which is an artist's rendition of the dust glowing red around a binary system.
I'll have to keep all this in mind next time I'm working on a double star. Of course, the dust would never be visible, but it's always fun to let the mind wander and consider what is going on with the objects in the eyepiece.
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A couple of years ago I purchased the book "Seeing in the Dark" by Timothy Ferris for a few dollars on eBay. I love to read books that are written with a poetic view towards astronomical endeavors and this one did not disappoint. Ferris has written numerous astronomy books as a 'popular science writer', and his style and prose is obviously influenced by his own personal passion for amateur astronomy.
So it was with excitement that I learned a few months ago that Ferris had produced a television show for PBS to accompany the book. The long wait was finally rewarded this evening with the show and in general I enjoyed it very much. It didn't really teach me anything new about astronomy, and certainly was not filled with scientific facts; rather, it affirmed my own enthusiasm for the hobby by presenting a fairly wide-ranging overview of various themes in astronomy, interspersed with Ferris' own poetic narrations.
I've been unable to get out for some time now, mostly due to weather but other obligations have kept me inside even on the few clear nights. Monsoon season's coming to an end - in fact it is quite clear tonight. I suppose it was worth staying in to watch "Seeing in the Dark" instead of sitting at the eyepiece, whereas normally I would not dream of putting television on equal par with the eyepiece. But now that Ferris has topped off my tank with fuel for some all-night sessions, I cannot wait to get back out. This weekend we're planning a couple of nights of star parties and I'm praying for the skies to be clear.
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