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Welcome to the new online version of Current Astronomy, the River Bend Astronomy Club’s newsletter of observations, essays, and meeting reports:. It's a little bit serious science, a little bit fun, and we look for creative ways to chronicle our adventures in outer space as we pursue what for some of us is a fascinating hobby, for others, a consuming avocation. December 2007 Review of TeleVue 13mm Nagler Type 6 Eyepiece By Bill Breeden December 14, 2007 For my 43^rd birthday, I decided to take the Nagler plunge. I already had nine eyepieces, as follows: 26mm Meade Series 4000 Plossl 12.4mm Meade Series 4000 Plossl 9.7mm Meade Series 4000 Plossl 32mm Orion Highlight Plossl 20mm Orion Expanse 15mm Orion Expanse 7-21mm Orion Explorer II Zoom 9mm Orion Expanse 6mm Orion Expanse Do I really need another eyepiece? Well, no, but I’ve wanted a Nagler for so long, and turning 43 seemed like just the excuse I needed. My collection began with the 26mm Meade Series 4000 Plossl that came with the telescope, a Meade LX-90 8-inch Schmidt-Cassegrain. It was a simple and natural progression to go for the next two Meade Series 4000 Plossls listed above. A Plossl gives you a 50° apparent field-of-view, which is pretty decent for all types of observing. Plossls are also nice in that they do not suffer from kidney-beaning, which can make it hard to get your eye in the right spot without seeing blackouts moving about the field. Plossls are also reasonably priced. One drawback is that their eye relief, the distance your eye must be from the eyepiece, gets uncomfortably short with shorter focal lengths. Still, my Meade Plossls got a lot of use in the telescope. As my experience observing grew, so did my desire for low power views. My lowest power eyepiece got the most use, so my next eyepiece would be the 32mm Orion Highlight Plossl. This has been nice for open clusters and galaxies, but in my LX-90 at f/10 it suffers from some kidney-beaning. It performs better in our 3.5 inch Celestron refractor that we use for outreach. The Orion Expanse line of eyepieces had always caught my attention in the Orion catalog, with their advertised 66° apparent field-of-view. I ordered the 20mm and 15mm, and I was not disappointed. At less than $70 each, they are incredible. These have been my workhorse eyepieces for two years. They provide a crisp, sharp view of double stars, planets, nebulae, and just about any object. I love these two eyepieces so much that I almost never use them during public outreach, because I don’t want someone’s kid touching them. Speaking of outreach, this is where the 7-21mm Orion Explorer II Zoom eyepiece comes in handy. Most outreach events feature planets or the Moon, and it is nice to be able to change the magnification easily. This also impresses the public, many of whom think adjusting magnification is the main purpose of a telescope. As a plus, this eyepiece cost under $70, so it makes a good outreach eyepiece, since I don’t flinch every time a kid’s fingers go for it. The last two eyepieces completed my Orion Expanse collection. They are nice, but the 15mm and 20mm Expanses are far better. At the 9mm and 6mm focal lengths, kidney-beaning is annoyingly noticeable, and you have to work at it to get a good view. When you do get the view, it is clear and sharp, so I save these for the occasional look at a planet under high power. Now, why do I need a 10^th eyepiece? In some ways, I don’t see it that way. I see it as my first serious eyepiece. TeleVue had just released their new Ethos eyepiece, with a stunning 100° apparent field-of-view, and to celebrate they were selling their other eyepieces at 13% off. What a perfect time to join the TeleVue family. I made up my mind to get my first Nagler and this was the time to do it! TeleVue Nagler eyepieces boast a wonderful 82° apparent field-of-view, the largest available until the release of the Ethos. 82° still made me salivate to think about it. Now that my mind was made up, I had to choose a focal length. TeleVue’s website has a section aimed at 8-inch SCT owners, and the 13mm Nagler Type 6 is listed under “medium power.” The 13mm has an actual field of view of 0.50° with my telescope, the same as my 26mm Meade Series 4000 Plossl and my 20mm Orion Expanse. Wow! If I read that right, the 13mm Nagler Type 6 eyepiece will give me the same actual field of view as my 26mm Plossl, but with twice the magnification! How on Earth is this possible? How can an eyepiece with half the focal length (13mm vs. 26mm) give me the same actual amount of sky? It took me some time to wrap my brain around the concept of apparent field-of-view. It’s like the difference between looking through a paper towel tube and a soda straw. Both provide a magnification of 1x, but the paper towel tube shows you more sky. I guess that makes sense! TeleVue Nagler 13mm Type 6 Eyepiece Specifications Focal Length: 13mm, Barrel Size: 1.25 in., Apparent Field-of-View: 82°, Actual Field-of-View with 2000mm f/10 SCT: 0.50°, Weight: 6.4 oz., Price: $290.00 It was time to take the eyepiece out and see what it can do. As luck would have it, it’s also Mars season, a time when Mars is growing very near to the Earth in its orbit. In my 2^nd-magnitude light-polluted backyard, Mars would be a great target to observe. So, on December 13, I set up my telescope, found Mars in my 26mm Plossl, and then switched to the Nagler. Oh.my.goodness! What a view! 155x, the power I get at 13mm, is enough to show some surface markings on the Red Planet, as well as one of the polar caps! Mars is now about 14” wide, and surrounded with the 82° apparent field-of-view, it was simply breathtaking. How would a deep-sky object look through this eyepiece? Too bad I haven’t yet had the chance to trot out to dark site to try it. I pointed my telescope at the Orion Nebula (M42), and took a look. Gulp! 155x is enough power to pull the nebula out of the horrid light pollution, and 0.50° actual sky is enough to give me a good view of M42. The Trapezium showed five stars, instead of the four I usually see. This was fantastic. The Double Cluster (NGC869 and NGC884) looks absolutely spectacular in this eyepiece. Although my f/10 telescope doesn’t give this eyepiece as much sky as an f/5 Dobsonian would, it is still a wonderful wide-field view, and I can see one entire cluster and the very edge of the other one. This is how much I see with the 26mm Plossl, but my view in the Nagler is huge, and it is much less affected by light pollution. This eyepiece cost me $262 after the 13%-off sale, with tax, shipping, and handling. Even though I have not yet used it under a dark sky, I can say this eyepiece was worth every cent. I spent a whole hour staring trance-like at Mars. This eyepiece makes me feel as if I have a whole new telescope, and actually makes it possible to do more stargazing from my light-polluted backyard. I only wish I hadn’t waited so long! If I had it to do over again, I would have just five eyepieces: The 26mm Plossl that came with my telescope, a 12.4mm Plossl, and 3 TeleVue eyepieces. The two Plossls would be for outreach (low and medium power), and the three TeleVues would be for my viewing pleasure. Clear Skies, Bill Breeden, St. Louis, Missouri River Bend Astronomy Club River Bend Astronomy Club meeting and Christmas Party, December 8, 2007. Front, left to right: Bill Breeden and Gary Kronk. Back, left to right: Bill Kolling, Mike Veith, and Lee Paul. Members enjoyed good fun, good friends, and plenty of astro-speak. VIDEO EYEPIECE SEES IN CaK By Bill Breeden November 6, 2007 Our new Calcium K Personal Solar Telescope (CaK PST) has been somewhat of a disappointment to members of RBAC who have had a chance to peer at the Sun through it. The images tend to be dim, especially to middle-aged eyes. The image is very far into the violet range and into the ultra-violet, just on the threshold of vision for many observers. Hence, you see a dim, unimpressive view of our nearest star. For all its disappointment, there is still something exciting about gazing at the Sun in a different wavelength, even different from the Ha view provided by the Ha PST. In order to get a better look at the image, the club purchased a video eyepiece. Actually, the CaK PST was designed more for imaging than for visual observing. Jamie took this photo through the new video eyepiece, and Eric further enhanced the image. Notice the detail visible underneath the Sun’s outer layer, visible here in the CaK wavelengths. The Sun in CaK, taken through Video Eyepiece. Photo by Jamie Goggin and enhanced by Eric Brown. Ultraviolet Surprise by Patrick L. Barry and Tony Phillips How would you like to visit a universe full of exotic stars and weird galaxies the likes of which astronomers on Earth have never seen before? Now you can.  Just point your web browser to galex.stsci.edu and start exploring. That's the address of the Galaxy Evolution Explorer image archive, a survey of the whole sky at ultraviolet wavelengths that can't be seen from the ground. Earth's atmosphere blocks far-ultraviolet light, so the only way to see the ultraviolet sky is by using a space telescope such as NASA’s Galaxy Evolution Explorer. About 65% of the images from the all-sky survey haven't been closely examined by astronomers yet, so there are plenty of surprises waiting to be uncovered. “The Galaxy Evolution Explorer produces so much data that, beyond basic quality control, we just don't have time to look at it all,” says Mark Seibert, an astronomy postdoc at the Observatories of the Carnegie Institution of Washington in Pasadena, California. This fresh view of the sky has already revealed striking and unexpected features of familiar celestial objects. Mira is a good example. Occasionally visible to the naked eye, Mira is a pulsating star monitored carefully by astronomers for more than 400 years. Yet until Galaxy Evolution Explorer recently examined Mira, no one would have guessed its secret: Mira possesses a comet-like tail 13 light-years long. “Mira shows us that even well-observed stars can surprise us if we look at them in a different way and at different frequencies,” Seibert says. Another example: In April, scientists announced that galaxies such as NGC 1512 have giant ultraviolet spiral arms extending three times farther out into space than the arms that can be seen by visible-light telescopes.  It would be like looking at your pet dog through an ultraviolet telescope and discovering his ears are really three times longer than you thought! The images from the ultraviolet space telescope are ideal for hunting new phenomena. The telescope's small, 20-inch primary mirror (not much bigger than a typical backyard telescope) offers a wide field of view. Each image covers 1.2 degrees of sky—lots of territory for the unexpected. If someone combing the archives does find something of interest, Seibert advises that she or he should first search astronomy journals to see whether the phenomenon has been observed before. If it hasn't, email a member of the Galaxy Evolution Explorer science team and let them know, Seibert says. So what are you waiting for?  Fire up your web browser and let the discoveries begin! This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Astronomers looking at new ultraviolet images from the Galaxy Evolution Explorer spacecraft were surprised to discover a 13-light-year long tail on Mira, a star that has been extensively studied for 400 years. Submissions to Current Astronomy are welcome. Please contact the editor for more information.