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Magazine the Essential Journal for Amateur Astronomers Around the World! Amateur Astronomy Magazine The Essential Journal for Amateur Astronomers Around the World! Binocular Summation Part II - Arne Otte does comparative analysis. How much can you see with two mirrors and two eyes versus one? The Grind: A Mirror Maker’s Journal of inspiration and perspiration Working with Photoshop Layer Masks - How to Get the Most Out of Your Data Observing Deep Dky Treasures Looking South Touring The Trumpler Classes Sunspots Amateur Astronomy Visits Ewen Whitaker - The Man who named the Moon Star Party Calendar Uncle Rod’s Cracker Barrel Image Gallery Shorts From Down Under Remembering John Dobson Mel Bartels recounts his personal interaction Issue 82 with this inspiring amateur astronomy legend Spring 2014 $6.50 US Uncle Rod’s Cracker Barrel Article and images by Rod Mollise Unk Takes the Fingerprints descriptive discipline, like the zoolo - classification, and have been teaching gists of old who spent all their time col - the basics of those things for going on of the Stars lecting butterflies. The serious stuff is two decades. Emailing with Mr. Tom, it As y’all have no doubt gathered if for the classroom. dawned on me I had never got out and you’ve met me, or even if you have just That’s just changed a little bit. I taken stellar spectra of my own with been reading my column in Amateur don’t think I will suddenly and com - my own telescope. Maybe it was time Astronomy for a while, I am not the pletely stop being that most amateur of to get a little more hands on. world’s most serious amateur amateurs when I am out on the observ - astronomer. Oh, I am serious about ing field hanging with my buddies and Not that I wasn’t skittish about mak - having fun with astronomy, mucha - oohing and ahhing over M13, but, as I ing it all work. A look at Tom’s RSpec chos. And I am serious about showing wrote here not long ago, change is website, “Real Time Spectroscopy,” other people how to have fun in our sometimes good in astronomy. Doing (http://www.rspec-astro.com/) clued avocation. But doing Real Science as different things is the way to avoid me in that this was one powerful pro - part of my amateur astronomy career? burnout. gram. Reading there, and looking at the No. Not until lately, anyhow. posts on the RSpec Yahoogroup So it was that when I got an email revealed people are doing stuff like tak - I am an astronomy educator at a uni - from Tom Field, author of the RSpec ing the spectra of quasars and demon - versity, but I’ve kept that part of my spectroscopy software asking me if I’d strating their redshifts with the aid of involvement in the science more or less like to try his program and Robin the software. Unk? About as far as I’ve separate from the amateur side of life. Leadbeater’s Star Analyser diffraction gone is showing undergraduates how to When I’m wearing my amateur hat, I grating, to try my hand at taking stellar use a simple spectrometer to look at the just like looking at pretty stuff and tak - spectra, I didn’t say “no.” It actually emission spectra given off by discharge ing pictures of pretty stuff. As an ama - sounded like fun. I’ve long been inter - tubes in a warm, quiet classroom. teur, I approach astronomy as a ested in stellar evolution and spectral 40 www.AmateurAstronomy.com Spring 2014 Issue # 82 The Star Analyser 100 1.25” filter cell and looking through the cell at the grating and spectra Mr. Field, however, assured me I it was also amazingly user friendly. Its to use in Chaos Manor South’s dining could do it, gave me instructions for interface is very well designed, and it room, but I suspected it would be a dif - downloading the program from his was easy for me to figure out basic ferent story out on a dark field in the website, and got the grating, a 100-line operation of the software. That was the middle of the night when I began tak - job (http://www.rspec-astro.com/star- good. The bad, as you might expect, ing my own spectra. Before I could analyser/), on its way to me. I hoped he was that the weather took a turn for the even think about doing that, though, I was correct, because I suddenly found worse as soon as the Star Analyser 100 had to decide which camera to use myself getting right excited about tak - grating arrived. with the Star Analyser and RSpec. ing stellar spectra. Luckily, Mr. Field had sent me a What I had on hand was an SBIG When I got Tom’s program down - sample image of Vega and its spectrum ST2000 CCD, a Mallincam Xtreme, a loaded and installed, I was relieved to to play with, so I was able to sit down couple of Canon DSLRs, a webcam- find that while it was obviously very and get acquainted with the program like ZWO ASI120MC planetary cam - capable and featured a ton of options, indoors. RSpec was resoundingly easy era, and my old Meade color DSI. Tom of the Star Capella Spring 2014 Issue # 82 www.AmateurAstronomy.com 41 The RSpec Display suggested the Mallincam might be a good place to start, but I demurred. I’d have had to involve a frame-grabber and software to convert the Xtreme’s analog video to digital form. As for the still CCDs and the DSLRs? I thought any of them might be a bit of a handful in the beginning. Well, what about that ZWO? People are using them for everything from the Moon and planets, to hydrogen alpha imaging of the Sun, to deep sky astrophotography. Why wouldn’t it work as a spectrograph? (If’n you are new to this stuff, a spec - trograph is an instrument that takes images, spectrograms, of spectra, the pretty rainbows.) It appeared it would work with RSpec—the program recognized the camera/driver, anyway. As soon as I plugged it into the PC, RSpec’s video module began displaying video, and indicated it was ready to record. When I finally got clear skies on a clear but cold January Friday, I loaded up the telescope, mount, camera, and laptop and headed for our club dark C-8 Rear cell setup with flip mirror 42 www.AmateurAstronomy.com Spring 2014 Issue # 82 Rigel site. Which scope? My most used SCT, a Celestron Edge 800, “Mrs. Emma Video of Rigel Peel.” As long as your telescope can achieve focus with a camera, it will probably work with RSpec and the Star Analyser grating, but my sense is that more focal length is probably better than less for this application. The mount was my Celestron VX GEM, which is light and easy to tote around and has great tracking and go-to. The sky was almost 100% cloud- free when I pulled onto the club field, went directly into the flip mirror with - Girl Kiss Me,” I hope). When you are which was a good thing for observing, out a Barlow. I figgered a smidge over calibrating your spectra later, you will if not such a good thing for comfort. I 2000mm would be enough focal length need to find the star’s h-beta line, and glanced down at the temperature dis - for spectroscopy. that is strong and obvious in A stars, play on the dashboard of the truck. 39F and especially in bright Vega. Alas, already and the Sun wasn’t even down Why did I use the flip mirror? The Alpha Lyrae was within 10-degrees of yet. Bundled up in my heaviest coat, ZWO’s chip is small, 1/3-inch, and the western horizon, and given the see - the one that allowed me to survive even without a Barlow and with accu - ing—even higher altitude stars were Bath, Maine one winter, I got to work rate go-to, I thought the flipper would twinkling like crazy—was a no-go. assembling the telescope, mount, and make star centering easier. With the flip What then? Rigel was perfectly placed camera. mirror in place, I flip the mirror down, in the east. It’s a B type star, not an A, center the target in its eyepiece, flip the and the Balmer lines are not as promi - The setup on the SCT’s rear cell was mirror up, and the object is guaranteed nent in its spectrum, but I reckoned it the almost the same as what I use for to be in the field of the camera. In addi - would do. lunar and planetary imaging: Meade tion, the flip mirror is set so what’s in flip mirror screwed onto the rear port, focus in its eyepiece is in focus in the The most surprising thing? Despite 12mm reticle eyepiece in its focuser, camera with maybe just a little fine- the cold and my relative inexperience and the ZWO in the camera port. The tuning required. with RSpec, I had no trouble getting the Star Analyser grating, which comes in a star onscreen. Centered Rigel in the ret - standard 1.25-inch filter cell, was Alright, time to get to work. Tom icle eyepiece. Flipped the mirror up. screwed onto the camera’s 1.25-inch Field suggests starting with Vega or Lit-off RSpec, hit the Live Video tab, nosepiece. The only difference from another bright star of spectral type A and there was Rigel.
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