The sky was bruised . . .

Cepheus

2008-09-25T09:22:00.002-05:00

With a return to autumn, the temperatures have finally begun cooling in the southeast United States and the swarms of vampiric mosquitoes are thinning in numbers. After sleeping through this summer in my shed (and providing shelter to any number of spiders), the big dob I purchased last winter was ready to catch some photons. This past Monday on the night of the autumnal equinox, we shook off the webs, or in some cases beat them down with a stick, and rolled into the backyard to take on Cepheus, the Royal Father of Andromeda.

This constellation is generally much less bright than some of its late-summer/early fall counterparts. And from my backyard, still suffering slightly from the Alabama summer haze, it looks decidedly less regal and much more akin to a child's drawing of a house. Using my trusty Pocket Sky Atlas and the observing lists for the different Astronomical League clubs, I had already compiled a list of objects to observe. In originally sweeping over the constellation with my guide scope, the dearth of bright stars towards the constellation northern end (with a handful of exceptions) and the great number of stars at the base of the "throne" made it difficult for me to orient myself when switching between the guide scope and the eyepiece. A 12 inch scope can really fill the view up quick when skimming the edge of the Milky Way, which does not correspond to the view in the guide scope. Finally, I settled on a simple asterism located near the center of Cepheus as my home position for Star hopping. Just north and east of the open cluster NGC 7142 is a small collection of five stars that mimic the general shape of the larger constellation. This collection stood out in the finder scope easily due to its shape, and I could quickly return to it from one object to jump over to the next.

The first object I viewed is actually quite distant from the remaining objects, the planetary nebula NGC 40, which is located at the top (northern end) of the constellation, as viewed in the Pocket Star Atlas on page 71. For this objective, I started at the bright star Errai (Gamma Cepheus) and slowly followed a trail of magnitude 6 and 7 stars over to the nebula. My sketch, using a Hyperion 17 mm eyepiece with a 2x Barlow for a magnification of 176x shows a small compact halo around a visible, though faint central Star that seemed slightly off-center to West (Burnham's Celestial HandBook gives the magnitude of the central Star at 11.5). All of the remaining objects were viewed using the 17 mm Hyperion (88x) unless noted otherwise. Using the Orion ultrablock filter dimmed the surrounding field of faint stars but made the nebula appear more uniformly bright. I was pleased about this since I had been initially disappointed with the filter last winter.

Next, I jumped all the way across the constellation to one of the highlights of Cepheus, the open cluster/Galaxy duo of NGC 6939 and 6946. Like the planetary nebula I first viewed, actually used a different home position for Star hopping to these. The remainder of objects were observed jumping from the small collection of stars mentioned previously. For this pair, I centered on Alderamin, the brightest star in this constellation, and slid straight over to Eta Cepheus, from which it was a simple shift to NGC 6939 (PSA, page 73). This cluster appeared fairly compact at 88x, with a brighter Star immediately south and three similar stars outlining the other directions so that the cluster appears to be centered in a small cross. The brightest stars in this cluster appear on the western edge and fan out north and east and a progressively fainter pattern.

NGC 6946, also known as Caldwell 12, was just outside of the field of view Southwest of the cluster, on the opposite side of a bright star that centers the two. Initially, I could only detect the faintness brightening in this area to separate it from the sky glow, but after changing eyepieces to a 26 mm and 32 mm I could sketch a basic outline. I doublechecked my sketch against the photo in Burnham's later and had positioned correctly, but this was a difficult object for me. Galaxies between 10th and 11th magnitude (Burnham list this as 11th) generally give me trouble and take a bit of effort. In photographs this Galaxy shows nice spiral arms, but I would need much better conditions to be able to confirm those visually.

The next to objects I viewed are found back over on page 71 of the PSA, and both are fairly open clusters that did not contain a huge amount of stars. NGC 7160 was bright, and highlighted by two stars that stood out as a seemingly identical pair. The next cluster, NGC 7142, was just to the east of the small asterism I was using to Star hop from, but I was unable to confirm the nebula NGC 7129 nearby.

Moving over to what would be Cepheus' right foot, I located NGC 7380, and open cluster within a cloud of nebulosity. This object is found within a very rich star field, and my sketch reveals the general shape to be similar to a Chevron or arrow tip, with the nebulosity pointing Southwest. Again, the ultra block filter really helped to confirm the extent of the nebula.

From here, I shifted northwest to NGC 7510, another open cluster (enough with the open clusters already!) that turned out to be exceptionally small and concentrated in a wedge. The entire cluster is centered between three similar stars that form a roughly equilateral triangle. This completed all of the Herschel 400 items in this constellation (for those of you working on this monster list), but after having had my share of open clusters I decided to tackle some double stars as well. Delta Cepheus was easily split, and in a 26 mm with a Barlow appeared orange white with a somewhat fainter blue white companion. In my ignorance, I completely missed the significance of this system. Delta is a variable that was instrumental in determining that some "nebula" were actually Galaxies, and the predictability of Delta's change allowed astronomers to calculate (obviously I'm simplifying here, after all, math is not my strong suit) estimates that greatly enlarged our understanding of the size of the known universe. I just thought it was pretty.

Kurhah, a double in the center of the constellation, had much less separation than Delta, but when you're using a 12 inch telescope on a relatively clear night you can brute force that sucker apart. The difference in magnitude between the primary and secondary was also much greater.

The last double I viewed was Beta, also known as Alfirk, which had slightly more separation than the previous pair but an even greater difference in magnitude between the primary and secondary. The final object I viewed for the night was Herschel's Garnet Star, one of the most colorful (to a visual observer) stars in the sky. Its yellow orange appearance (Garnet maybe? Ha!) really stands out.

For a constellation I had never paid a lot of attention to, Cepheus held several interesting objects. And I'm now a handful of objects closer to completing the Herschel 400.

Second Attempt at Saturn with the WebCam

2008-04-17T08:52:00.000-05:00

After four weeks of miserable weather, the last two nights finally cleared up (though with a near full moon). With Saturn nearly at the Zenith just after dark, I decided to take a second try at imaging. This image is the result, and I rotated the final photos to match the alignment of my first attempt for comparison sake. Notice the well-defined shadow of the planet on the rings. Good to finally get out again!

First Impressions of the Orion UltraBlock Filter

2008-03-24T07:41:00.003-05:00

As I have discussed in my earlier posts, the acquisition of a 12 inch dobsonian has temporarily derailed my photography attempts and replaced them with a keen interest in visual observation. Lately, I've been working on the Herschel 400, a difficult list of fainter objects. Some of these require, at least for a visual beginner like me, as much help as possible to identify. After getting snagged on a couple of nebula, I decided to invest in a narrowband filter.

Narrowband filters work by transmitting only a small fraction of available light to the eye, and in doing so block out wavelengths common to light polluting sources such as streetlights while still allowing wavelengths common to most nebula to pass through. The idea is to darken the background sky (especially useful in areas with some degree of light pollution) to increase the contrast between nebula clouds and surrounding empty areas.

After a little investigating, I decided to go with the Orion Ultrablock because, while not as highly rated as the Lumicon Ultrahigh Contrast, it gets almost as good marks and for significantly less (I had a gift certificate to Orion). Orion service proved as good as always, though I feel like they really bleed you on shipping prices for small objects, but I have always received my products rapidly and reliably from them.

Depending on how the filter is turned into the light, it appears purple or sea green or mirror like. I decided to test it out last night before the just passed full moon could arise. My test instruments were the 12 inch dobsonian, and two identical 25 mm Orion plossl eyepieces. This way, only the filter would be different, but by using two eyepieces I could quickly shift from one view to the other. Unfortunately, the conditions outside did not seem favorable. A bank of clouds began moving in just as I targeted my first nebula, M. 42. I only had about 10 minutes of observation time before I had to pack it up. So, while I'll discuss my initial impressions, this review can only be introductory in nature, and I'll try to post a more thorough follow-up later.

In the pamphlet included with the filter, it specifically says to try the Orion nebula the first time you use it. Also included is a wavelengths scan report, and mine claimed all wavelengths below 473 nm and above about 505 nm would be blocked. With this in mind, I targeted the Orion nebula first with the unfiltered eyepiece. In a word, amazing, this scope continues to impress me and it never fails on this nebula. The view revealed an expansive brightness beyond the central trapezium area including sharply defined "wings" and intricate cloud detail. And all this without sufficient dark adaptation for a regular viewing session. Based on this, my expectations for the filtered eyepiece were high. Switching over, my first thought involved the deep green coloration of everything in eyepiece. Once passed this initial surprise, I noticed that the areas of the nebula shown closely matched the unfiltered view. This surprised me, so I slipped over to the very bright multiple star in front of the nebula. This area also has nebulosity, and recently I had had difficulty distinguishing it from the bright star. With the filter, the star was dimmed and the surrounding nebula apparent. Once spotted, however, I had little difficulty in the unfiltered eyepiece for the same area.

I tried to jump over to M. 78 and M. 45 to continue my test, but the clouds had already moved in enough to send me packing. With this short comparison, I did not see as large a difference between the filtered and unfiltered views. However, I suspect that under better conditions with longer dark adaptation, and with a larger variety of subjects, I might have a different experience.

The filter does help one negative, which all narrowband filters may share, so I'm not sure it is specific to this particular one. In changing from the unfiltered to the filtered eyepiece, I noticed what seemed to be extra light in areas not previously seen. Moving around different patches of the sky and switching between filtered and unfiltered, I realize that what I was seeing was a reflection off of the backside of the filter. Typically when deep sky observing I set up walls of tarp to block extraneous light, but in this case I did not. Stray light was being reflected from my eyeglasses through the eyepiece and bouncing back off of the filter. This was distracting. I doublechecked this by holding both eyepieces up to a light, and in the filtered eyepiece I could easily see my reflection coming back at me through the eyepiece. In the unfiltered one, this is not a problem.

With this limited run, I cannot see the filter as a huge improvement to my observing tools though. With the new moon approaching in a few weeks, I should have a couple of nights to try this out again soon.

Observing Lists For Amateur Astronomers: The Astronomical League Observing Clubs

2008-03-20T10:33:00.000-05:00

When I started (sporadically, at least) posting to this blog, my intent was to chronicle the steps necessary to build up skills and equipment for respectable astrophotography. During the course of this little project, I picked up my Orion 12 Inch XT, a visual only instrument, and since that time I have spent far more time observing with it than taking photographs. But as you may have noticed, space is a pretty large place, filled with more than a few things to look at, and being a complete OCD, I needed something to bring order to my observing chaos.

Thankfully, astronomy is full of OCD types. How else can you explain the willingness to dump tons of money into buckets of glass? Anyway, the good folks over at the Astronomical League have put together numerous programs to guide visual astronomers through the heavens. These range from the very simple to the very complex, with difficulty levels everywhere in between. Currently, I am working through the Messier lists (telescope and binocular), lunar list, solar system list, deep Sky binocular, and finally, the Herschel 400 list. That last one is a real dinger. Comprised of objects ranging from the marginally faint to the not really an object at all just put it in the list to screw with you it is so faint, this list has really made by observing sessions more interesting.

I strongly recommend anyone with binoculars or telescope to try some of these different lists. It is easy to get wrapped up in all of the new technology available for amateur astronomy, but these lists help to remind us of the joy of plain Jane visual observation. Give it a try! The link to many of the lists is:

http://www.astroleague.org/observing.html

First Saturn of the Year

2008-03-02T15:23:00.002-06:00

Finally had a chance to take a shot at Saturn. Transparency was good but seeing was only average to little above average site. Though not visible in the image, three moons were also easily visible at the eyepiece.

Observing and sketching log template

2008-02-12T09:57:00.000-06:00

A few folks have had difficulty printing out the image I posted for the observing log. I've created a new version with different dimensions, and tested it here. This one prints out fine for me without any modification to settings. Hope you guys find this useful! Be sure to click on the image to get the full-size version, then right-click and save as to your computer.

Book Review: Sky and Telescope's Pocket Sky Atlas

2008-02-08T15:19:00.000-06:00

Title: Sky and Telescope's Pocket Sky Atlas

Author: Roger W. Sinnott

ISBN: 1931559317

Publisher: Sky Publishing Corp.

Price: $19.95

One of the most immediate frustrations for someone only beginning in amateur astronomy involves finding something to look at, or, figuring out exactly what is seen in the eyepiece. Armed with a nice scope and a dark sky, inexperienced amateurs are faced with a thousand possibilities but little information on what a fuzzy actually is or how to look up more information about it. Thankfully, humans have marked the position of stars for centuries, and recently (in about the last 500 years or so) man has carefully plotted the positions and magnitudes of heavenly objects for later reference. These maps of the sky have long been collected into atlases. And while urbanites may forget it, the sky is filled with millions of stars (or at least several thousand easily visible ones), which makes creating a book of them large indeed. For this reason, many of the most complete atlases are large and not conducive to being held at the telescope. Yet the Sky and Telescope Pocket Sky Atlas seeks to remedy this by providing a compact, fully functional Atlas of the stars in an easily readable format.

In the Pocket Sky Atlas, readers find page after page of 5" x 7" sky charts, and little else. The charts are arranged in groups according to Right Ascension. Each group starts with a map at the celestial North Pole, and following maps work south until reaching the celestial South Pole. In all, there are eight groups, and each group contains 10 maps. There is quite a bit of overlap between maps which helps prevent any one area from ever being stuck on an edge of a page. The chart number is displayed prominently on the upper outside edge, and adjoining charts are marked in smaller numbers in the center of each side. This makes it very easy to quickly flip from one to another while at the telescope.

The charts themselves show stars as black dots on a white background, with the Milky Way shaded a variety of blue, depending on density. Constellations are drawn in by light green connecting lines and very light dotted boundaries. One handy feature for reading a map is that the front cover extends past the inside pages by about an inch, and in this inch space a star magnitude legend is printed along with an angular distance rule and telrad finder circle. Most items are labeled with their NGC designation, the items known by a more common name also have those included. The pages are heavier than average stock, and bound together by ringing, which allows flipping of the book in half so they can be held with one hand at the eyepiece.

Additional maps are included for the Pleiades, Orion sword area, Virgo Galaxy cluster, and large Magellanic Cloud.

Having had a chance to use this several times now, it is difficult to really find a drawback. Stars are only printed down to about magnitude 7 (with a symbol used to note fainter stars of interest occasionally) so occasionally I would find an area where I wish I could see the magnitudes of fainter surrounding stars. With this exception, the Pocket Sky Atlas has proved to be an excellent addition to my observing aides. I cannot recommend it enough to amateurs just starting out who have no need for a large, cumbersome, but more comprehensive Star Atlas. This is a good value and should prove useful for years to come.

Book Review: Celestial Sampler by Sue French

2008-02-07T12:59:00.002-06:00

Title: Celestial Sampler
Author: Sue French
ISBN: 1931559287
Publisher: Sky Publishing Corp.
Price: $24.95

Published in 2005, this is another entry in the Sky and Telescope Stargazing Series of titles. The author, Sue French, has for some time pened a monthly column in Sky and Telescope devoted to targets in the night sky for small aperture telescopes (this column is now changed to more of a general deep sky column). Because of this, she is well-prepared to live up to the book subtitle: 60 Small Scope Tours for Starlit Nights. The book's 169 pages are filled with finder charts, object tables, photographs, and eyepiece sketches. The format of the book follows the night sky through the course of a calendar year, offering five different starhopping tours for each month. Before jumping into the tours, an introduction explains some basics of visual astronomy, how to navigate the night sky using a star chart and finder scope, how to judge the conditions of the night sky (seeing, transparency, etc.), and a few visual observation tips. Following this, a general all sky map for each month is included. Readers of Sky and Telescope will recognize these as the monthly maps the magazine always includes, complete with when to use timetables. Yet the meat of the book is found in the tours themselves.

Each month's tour selection involves five different options, and each option covers two pages. Three to four columns guide the reader from object to object and include background information about the listed items and helpful tips from getting from one to the other. Each tour also features a small sky map for the specific area being discussed, as well as an object table that lists the size and magnitude and object type of each item in the tour. Finally, a selection of photographs highlight objects for each tour or help the reader in picking out difficult objects in a field of view. The text is well-written, and Mrs. French handles the material excellently.

The book is not without its drawbacks, however, and chief among them is its construction. In a couple of observing sessions, I have had this book out beside my telescope. While it seems well made, it is not easily held while observing and it is difficult to get the pages to remain open without placing something on them. Since the book subject is actually night sky tours, it would have been far more logical for this book to have been bound in a spiral ring, much like Sky and Telescope's Pocket Atlas. The glossy paper used in the book also seemed susceptible to moisture much more than the Pocket Atlas, which I had laying beside it. Basically, it isn't made as a field book.

With that said, I find the book a valuable addition to my library. Only recently returning to visual observation from the dark clutches of astrophotography, I have enjoyed using the book to learn my way around less traveled areas of the night sky. It has also revealed many objects that qualify as small scope targets, but that look dazzling in a larger aperture instrument. For this reason, I don't think the book is only useful to beginners. Experienced astronomers who may own large aperture telescopes will also enjoy working through these tours. And if you live in the soggy Southeast, reading through these pages will remind you of what the night sky looks like, since it has become all but invisible here!

Telescope Buggy for a Dobsonian

2008-01-31T14:00:00.000-06:00

As described in one of my earlier reviews, I recently purchased an Orion 12 inch XT dobsonian telescope. It did not take long for me to realize that moving such a large scope across my backyard, even just 15 feet, could be a real undertaking. Flipping through my issues of Sky and Telescope, a couple of options jumped out. These scope buggies (one of them is even called the Scope Buggy) have similar features: large tires, adjustable width, and a way to pull it. Unfortunately, I was looking for something a little cheaper and, being taller than average, I also wanted something to lift the telescope up about a foot. The commercial versions all rested low to the ground, to improve stability and prevent rocking. Most of the commercial versions ran between $250 and $300, but I had less than $100 available.

Living in an old house, I spend a lot of time at home repair stores. Browsing through the Garden section, I found a solution. Lowe's had a 24" x 48" garden buggy with 10 inch tires for about $90. Measuring the distance between the 3 feet of the dobsonian, I realized that the Scope would just fit on the buggy. Plus, this would raise the telescope to a comfortable position for me.

Now that I have had a couple of chances to test this out in observing sessions a couple of points become obvious:

n because the telescope is raised up about a foot off the ground, I placed a couple of cinder blocks on the front axle to add a little weight and stability.

n The Scope itself is placed on the very back, and when you position the Scope for observing, you point the front in the direction you are least likely observe. This allows you to stand beside the eyepiece in about 280° range.

n Pay careful attention when you lay the guide bar down. Speaking from experience, this thing can be a deathtrap in the dark!

Overall, this has been an awesome accessory for observing. Parked in a shed, the Scope is already mostly cool down, and I just wheel it out and check collimation, and I'm observing. Obviously this solution is good for dobsonian owners, but not tripod users. Also, if you are short one of the commercial options would probably be better suited for you. But for me, I keep the garden buggy.

Review: Orion 12 inch XT dobsonian

2008-01-28T14:53:00.000-06:00

After deliberating for several weeks on a scope upgrade, I chose to get an Orion 12 inch XT dobsonian. I selected this scope for a number of reasons: it was the most Aperture I could afford for the money, dobsonian mounts are quick and easy to set up, and I had previously had very good experiences with this vendor (Orion has good customer service). Also, it was on sale because it was from an open box floor model. Ultimately, it seemed the best match of price, performance, and quality that fit within my needs. I ordered it through Astronomics, and, as always, they were very helpful with my questions and the package arrived quicker than expected.

My first thoughts (and I guess I'm not alone in this) was "Wow that's a big box!" But in fact it comes in three boxes: one containing the tube, one containing the primary mirror, and one containing the base assembly. They are bulky but well within ability of an average adult. I feared putting the mirror into the tube because let's face it, if there's one thing to not screw up, it is the mirror. However, this turned out to be much simpler than expected. The base assembly took about 20 or 30 minutes, but might take longer, since in my case, all of the holes were already established because it had been assembled as a floor model. Total assembly took about an hour, with quite a bit of that dedicated to mount the mirror and collimating.

I had been warned that this size solid tube dobsonian could be a lot to handle. It is. I found it difficult to gently place the tube in the cradle of the base, and the jarring certainly didn't help my mirror alignment. In general, I found it difficult to maintain proper mirror alignment which resulted in constant recollimation, but part of this is due to my continued problems with my secondary mirror alignment. The included laser collimator greatly helped with this problem, so even if it got knocked around only a couple of minutes were required to get things back in order. As for carrying it inside and out, I have found a better solution for that. (I'll post pictures and a short write up later).

My impressions for the remainder of this write up are based on two nights of observation. The first night conditions were windy and cold, with a first-quarter moon blowing out most of the sky. The second night both seeing and transparency improved, and moon had moved to third quarter, which gave me four good hours of dark skies.

Mechanically, this scope is a snap to move around. On the first night the bolt holding the base together gave too much resistance when turning the scope, but I loosened it before the second night so that it became much easier to turn. The supplied finder scope is a large right angle version, and while it is much easier to use of the original straight through finders, I did struggle to get used to it. The focusor clearly improved over the old model, and is far more pleasurable to use.

On the first night of observations, I stuck mostly to bright objects. My initial impression set around the number of stars visible. The 12 inch definitely seems to go deeper for those faint stars than in my old model, an original 8 inch XT. Even with the moon out, things looked good. Because the wind continued to pick up, I decided to check out the moon and then called it a night. A word of warning: a telescope this size will produce a painfully (painfully!) Bright image of the moon if set at a lower power without any kind of filter. With a 10 mm plossl, the number of small craters and craterlets really stood out as being significantly more than I had noticed in the past.

With weather conditions much better, and my transportation issue solved with the scope, the second night involved a four-hour observation session focused on hunting down some of the Messier objects I needed for the Astronomical League Messier Observing List. I cruised through Cassiopeia, Perseus, Orion, Taurus, Canis major, Gemini, Hydra, and Monoceros before the moon came up and cold (32°F) sent me packing. I used the two Sirius eyepieces that came with the scope, a 25 mm and a 10 mm plossl , as well as a 2 inch Q70 32 mm eyepiece, and a three element 1.25 inch Barlow. I'll write more on the Q70 another day, in short I ended up using a 25 mm and the Barlow almost exclusively.

My targets included a few nebula, but mostly open clusters. On M1, The Crab Nebula , the view surprised me. With smaller scopes I had had trouble locating this object, even though at magnitude 8.4 it should be visible. With the 12 inch, not only was it easy to find, but it appeared significantly brighter than I would have expected. It actually made me wonder if an optimal observation site with a good weather would allow me to use the scope to pick the Pulsar in its center (although I'm pretty sure that it is far dimmer than the limiting magnitude of this scope) still, that is how pleased I was. Jumping over to the Orion nebula , M. 42 and M. 43, dust lanes seem to flow against the bright background and filamentary detail filled the field of view. For the first time, each of the six stars of the Trapezium stood out, although the F Star winked in and out with the atmosphere. And my last target in Orion also surprised me. M. 78, a reflection nebula north of the Alnitak region, proved difficult for me to find with the scope' s finder, but once there, the offset nebula stood out well as a pair of two tenth magnitude stars stared back at me. Sue French' s book definitely helped find this one. Several open clusters followed, with M. 35 revealing over a hundred stars (estimated) and the intervening NGC 2158 standing out , despite the fact that I did I know to look for it.

Rolling the 12 inch back to its shed, I cannot help but be extremely pleased with the scope. I cannot imagine how I could do better than this for visual observation for $700 (remember, mine was discounted). Even at the regular price, I would still consider a 12 inch dobsonian a great bargain for anyone who focuses on visual observation of deep sky objects. But remember, this is a Large Scope! Hopefully I can have pictures of a poor man's scope buggy up soon.

Downloadable observation and sketch amateur astronomer log

2008-01-24T13:21:00.000-06:00

I have put together a printable sheet to use as an observer's log. At the top, I have included the Seeing and Transparency Scales from the American Association of Amateur Astronomy. On the left-hand side, under the eyepiece column, just write the type and size of the eyepiece you are using. In the circles, use a pencil to sketch in what you see at the eyepiece. This can really help develop visual observer skills as well as increase your experience at the telescope. It can also be frustrating at first. I can only load images here, so I have saved it as one. Enjoy!

2008-01-15T15:37:00.000-06:00

RIP: George MacDonald Fraser, 1925-2008

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2008/01/03/db0304.xml

Cheap Man's Observatory

2008-01-14T07:42:00.000-06:00

While I live in a rural part of our county, and the skies are startling crisp at the Zenith, I am located near an intersection that features a safety light, store light, and neighbors on each side of my property. Up to this point, much of the glare from these sources has been avoided by setting the telescope up in the shadow of my storage building. But light is still slipping into some of my photos as a gradient and if I take one step the wrong direction I lose my dark adaptation. Since a permanent Observatory housing for my telescope is not feasible at the moment, I wanted to try a low cost solution to block out a lot of the stray light.

My plan is this: find something to act as 10 foot poles that would extend from each corner of my building. Between my building and these poles, I will hang tarpoleun to act as a temporary wall. This will hopefully block out extraneous light while having the advantage of being quick to assemble and disassemble as necessary.

Project Materials:

3 8x10 tarps (I could only find 10 mil thickness, colored gray on one side and Brown on another)

2 PVC 10 foot long pipes

2 cinder blocks

1 roll of duct tape

1 box of eye hooks

Project Materials Needed Later:

1 roll of twine

2 cans of matte black spray paint

4 camping tent stakes

First, I measured up the PVC 8 feet and screwed in two eye hooks at a 90 degree angle from each other. Next, on each corner of my building, I measured up the same height and screwed in an eye hook on each side. Now I can use the reinforced eye holes in each tarp to hang my temporary walls.

Now I only needed to secure the poles and I should be set. To do this, I liberally applied duct tape to the base of each pole and a cinder block. In hindsight, not the best idea I never had.

The PVC turned out to be too weak to really hold each tarp, so I had to break out the twine and tent stakes to string up some guide wires opposite the directions of tension created by each tarp.

This created my enclosure and after each session I could unhook the tarps and be done with it. Now to test it!

Once settled in after sundown, I noticed a significant reduction in glare. Two problems were obvious though. First, the caution light at the intersection was just high enough to slip over the edge and create some glare on the top foot off the glossy tarp. To fix this, I took some matte black spray paint and coated areas that were affected. Problem solved (mostly anyway). Second, because the tarp was not as thick as I would like, my neighbors safety light created a soft glow of against one side. Another application of spray paint should fix that!

In the end, I achieve the desired effect of greatly reducing the effect of my neighbors' lights. Is it the best solution? Definitely not. Is it much cheaper than a dedicated Observatory? Absolutely. Will my dog rip it down when my back is turned? Almost certainly.

Book Review: Digital SLR Astrophotography

2008-01-06T13:53:00.000-06:00

Book review: Digital SLR Astrophotography
ISBN number: 9780521700818
Price: $45 US
Author: Michael A. Covington
Publisher: Cambridge University Press

Astrophotography has always involved a skill set requiring precision, patience, and a lot of trial and error. The learning curve has been steep, to say the least, but with the advent of Digital photography a larger and larger number of amateurs face this learning curve. Unfortunately, Digital photography also demands a different set of skills not documented before. With the exception of the few books that have tackled the subject in one way or another, amateur astronomy using DSLRs still lacks one good all-around, comprehensive introductory text for beginners. A few books have concentrated on the processing aspects of Digital imaging, and a few older books have updated sections on film photography with mention of Digital cameras, but Covington's work here is one of the first to approach DSLR astrophotography as its primary focus. Digital SLR Astrophotography does a good job of introducing the interested amateur to the subject while providing enough information to allow a beginner to advance in the hobby.

Astrophotography's 217 pages are divided into 14 chapters. In the first part of the book, Basics, Covington spends four chapters discussing DSLR options, technical issues unique to this format, problems associated with using electronic sensors in the cameras, and a few simple projects to introduce the reader to some immediate success using the camera. Throughout this section Covington mostly refers to Canon or Nikon cameras, which are the two main brands currently on the market, but he pays little attention to other options aside from a brief mention. His treatment of software is similar, however, he does mention freeware options which any beginner is well advised to try before investing in an expensive processing package. Most examples used in the book refer to Adobe Photoshop or MaxDSLR.

In part two, Cameras, lenses, and telescopes, Covington uses a chapters to explain how to couple the camera to the telescope and how different configurations how different effects on the final image, modifying the light path with focal reducers (Meade or Celestron), the pros and cons of using camera lenses piggybacking to a telescope, issues and solutions to focusing Digital cameras, the necessity of tracking the sky and how to go about it, keeping power to the camera and finally, different types of Digital sensors in the cameras and their response to various wavelengths with and without filters. Throughout this part of the book Covington references Meade and Celestron products but with one or two exceptions, ignores what has come to be the third major supplier of telescope products, Orion Telescopes. Covington does a good job of providing illustrations that clarify some of the technical issues he discusses in the text. These are generally excellent, and go a long way towards clarifying the various lenses and focusing options. Covington also does a good job for presenting the reader with the various choices and amateur astronomer has to make, including guiding options and focusing aides. Unfortunately, in the case of the latter, Covington mentions that it is easy to create a Hartmann mask but fails to deal instructions, instead referring the reader to his earlier book Astrophotography for the Amateur.

Part three, Digital image processing, covers a topic that can be most confusing to new astrophotographers. Covington explains the difference between dark, bias, and flat frames well but consistently uses MaxDSLR for his examples. This obviously works well for readers already using that particular software package, but may not be as clear for beginners using some of the free software packages. Nevertheless, this section is a real strength of the book, and will definitely aid the beginner in understanding some of the complexity involved in serious DSLR astrophotography.

An appendix of about 10 pages briefly mentions WebCams and their use for planetary photography. The inclusion of this seems odd, and out of place, as if, after having read the entire book, a beginner decides DSLR photography is not for them and perhaps they would be interested in WebCams instead.

Overall, Covington has done a good job of providing an introduction to the topic that also presents the reader with some of the options they can face in the hobby as well as potential solutions to problems that will inevitably occur. As a primer the book is first rate. Covington's strengths are evident in his handling of some of the more confusing topics; he explains them well. The diagrams provided are clear and informative. However, a serious drawback of the book is that photographs (all black-and-white} are often unhelpful and in some cases confusing. Perhaps due to the black-and-white nature, this can be annoying and for a book that cost $45 may leave the reader feeling less than inspired. For example, when discussing the pros and cons of modifying an DSLR to be more sensitive to hydrogen alpha emissions, side-by-side photos are given to display the difference. Now, Covington's point is to show how well an unmodified camera can do, so some similarity is expected, but I have yet to detect any difference between the two photos. Secondly, for a book whose purpose is astrophotography, it is criminally bereft of any striking photos that typically inspire beginners into the hobby in the first place. Covington would have been well served by including even a small section of color plates illustrating some of the superior photos being taken with relatively inexpensive equipment by amateurs using DSLRs. Still, Digital SLR Astrophotography fills a much needed role as an introductory text on the subject.

The Great Orion Nebula

2007-12-31T09:45:00.000-06:00

Last night I decided to take another stab at M42. After capturing my light frames, I started to change the battery and accidentally bumped the camera. There was no way for me to get back in exactly the same position. Discouraged, I only took a few dark frames since I did not think it would matter. This morning I processed them both with and without the darks. I also forgot to bring out my material to give my flat field frames. So not an optimal night, and I also have a sore throat this morning! Then I continue to be inexplicably drawn to this hobby, HA! Here is the result of both, the first without darks and the second with them.

Information for the photos:

8 inch Newtonian reflector mounted on an Atlas
unguided, approximately 11 frames at 15 second
approximately 40 frames at 30 seconds
unmodified rebel 6.8 megapixel version
baader 2 inch UV IR cut filter

Processed using deep sky stacker, pixinsight, and the gimp

Things to improve:

Get a coma corrector!
Get guiding to work!
Learn how the process image functions work better!
Be sure to accurately capture dark and flat frames!

December Full Moon

2007-12-26T09:23:00.000-06:00

Here's a quick one. Full moon, December 2007.

Merry Christmas!

2007-12-24T15:48:00.000-06:00

Here is a photo of my third attempt at Mars as well as a shot of the Moon. Hope everyone has a good Christmas!

finally a clear night!

2007-12-18T12:07:00.000-06:00

Last night the sky finally cleared after weeks of cloudy weather and rain. With the closest approach of Mars upon us for the next 10 years, I wanted to try and grab some photos while I could. Using an off-the-shelf WebCam with my existing telescope and mount, I captured several short video clips and then used software to select the best frames and combine them into a single image. This is a new process for me so it took awhile to get everything working properly. This image is a composite of the images resulting from each of movies. The polar ice is clearly visible, as well as numerous albedo features. Mars is currently bright red and high in the sky by 10:00 p.m.

This image is a single frame of 30 seconds showing M42, commonly known as Orion Nebula. I snapped this with a DSLR at prime focus before putting everything up for the night. Later this winter I will be taking numerous photos of it so I wanted to get an idea of how well it filled the frame. This is one of the brightest nebulas in the night sky, and appears to hang in the middle of Orion's sword belt where a scabbard would be.

This image is a single frame of 4 1/2 minutes, unguided, showing the Flame Nebula in Orion's belt. Designated NGC 2024, it is much fainter than M42, appears next to Alnitak, the third star in the belt, which shines at magnitude 1.74 and lives 817 light-years away. The smudge in the upper right is a nebula, NGC 2023, surrounding a smaller bright star.

I could not resist snapping at least one image of the first quarter moon!

double cluster in Perseus

2007-11-07T13:45:00.001-06:00

here's another image from this past weekend, this is the famous double cluster in Perseus, a pair of open star clusters.

new setup!

2007-11-05T08:34:00.000-06:00

I finally have my telescope setup where I can take photographs directly through it. With my Canon Rebel set at prime focus, I can gather more light and reduce the time needed for my exposures. Here are a couple of examples using the new setup. The second image is the galaxy M33, also known as the Pinwheel Galaxy. It is a composite of 25 exposures of 30 seconds each.

The first image is the comet Holmes, currently about a second magnitude object in Perseus, easily visible with the naked eye. This comet is notable because it brightened unexpectedly over a millionfold in the past couple of weeks.

2007-10-30T12:01:00.001-05:00

The North America Nebula

2007-10-03T10:14:00.000-05:00

The last night provided another chance to image the North American nebula in Cygnus. This photo is my result, the first image I posted covered the same general area, although at a much smaller scale. (For all of you non geographers, smaller scale meaning a wider area) while this one is an improvement, I am still not terribly pleased with the result. Processing images stinks!

Color!

2007-09-18T07:35:00.000-05:00

Here is another pic from this weekend. I have finally managed to find my color data. This image shows the Andromeda Galaxy also known as M31. To the upper left, the faint fuzzy is a companion Galaxy, and there is a second one directly to the right of the galactic core that looks more starlike. This object is visible to the naked eye, and appears as a faint smudge on the sky looking to the east around 9:30 p.m. between Cassiopeia and the great square of Pegasus.

First photo taken with the Atlas Mount

2007-09-15T10:41:00.000-05:00

I finally had a chance to try some long exposure photography with the new mount. This is the only photo I could get before dew became a problem.

Photo taken with a canon rebel dslr with a 70-300 mm zoom lense set to 70 mm at f/5.6 at 800 ISO. Four exposures of approximately 90 seconds with three dark frames.

The area pictured is the Milky Way around the North America nebula. The brightest star is Deneb, in the constellation Cygnus, one of the three stars of the summer triangle.