Cepheus

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

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

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

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

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

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

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.