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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. What was really my planetary rig was that the camera (y’all still remember “Oh Be A Fine cool, though, y’all? In the main display

Spring 2014 Issue # 82 www.AmateurAstronomy.com 43 Sirius

area of the program, I was seeing the he was low in the sky and hopping al on his to-do list, but tells Unk that graph of the star’s spectrum—live. So, around like mad in the poor seeing. I thus far he’s been too busy getting the that’s why Tom calls his program hoped RSpec’s image-averaging fea - program working as well as possible to “Real Time Spectroscopy.” ture could fix that. get to that. In lieu of a manual, there is a series of excellent instructional It was far too cold to make me want What then? It was now truly, no videos on the web you can access from to play with Rigel’s spectrum out on fooling, honest-to-god c-o-l-d. I’d within the program. I watched the the field, so I recorded it for later pro - chugged about half a Monster Energy videos and made up my own shorthand cessing. One thing was obvious with - Drink earlier, and had set it aside while list of instructions on how to calibrate out processing of any kind; the graph I was doing my spectroscopy. I went spectra. was showing plenty of the dips that back to it now and was not exactly sur - represent absorption lines. It was clear prised to find what was in the can was When RSpec is running, you open the simple rig was picking up a fair a Monster slushy. Chaos Manor your video file, and once more rotate amount of detail in the star’s spectrum. South’s warm den was sounding better the image with the slider control till Before mashing RSpec’s record and better. Especially when the next the star is on the left and the spectrum button on, I centered the star a little cold front began to push in at mid- on the right (RSpec records raw video, better on the program’s video display evening. Ice was forming on my equip - so your rotation of the star in live and placed it within the two movable ment cases, scope, and me. Time to mode is not preserved). When that’s bars that are used to bin the image for load up and skedaddle. done, you again position the star and the best image scale. I positioned Rigel spectrum inside the two mouse-mov - on the left and its rainbow on the right Back at home at Chaos Manor able bars on the video display for cor - using the program’s rotate tool slider South with the gear unloaded, I was rect image scaling. If the graph isn't (star on left and spectrum on right is happy to be out of the cold and sipping moving around too much, you can just the normal format for spectroscopic “sarsaparilla.” Scanning the cable pause it, scroll through it with a slider images, and that’s the way your stars channels revealed Friday night TV is a to pick out a particularly nice frame, and spectra need to be for RSpec to wasteland, with nothing at all on 300 and proceed to calibration. If it is work right). plus freaking channels. I settled for jumping around due to seeing, you another amazing (uh-huh) episode of might want to click the “average” box I fired off 15-seconds of video of Finding Bigfoot and was soon snooz - to steady it down a bit before choosing Rigel, took another sequence as ing in my chair. a frame and beginning calibration. “insurance,” and began pondering Calibration is the heart of your task. what else to shoot. Alnitak was nearby, Come Saturday morning I was ready to start on what I figgered would You've got a spectrogram of your star, and while it’s even hotter than Rigel a graph showing dips that represent and has even less prominent Balmer be the real work of spectrometry with RSpec, processing the sequences I’d absorption lines. However, the X-axis lines, I went for it anyway. I followed of the graph is in pixels, not up with a cooler star, Capella, since it taken. First, however, I needed some instructions. RSpec really doesn't have angstroms, and is useless for figuring was bright and nearby, and finally got out which lines are which, which lines an A star with Sirius, a natural, though any yet. Mr. Field has writing a manu -

44 www.AmateurAstronomy.com Spring 2014 Issue # 82 represent which elements, that is. You the window that appears, select calls “Profiles,” can be saved, export - fix that by calibrating your spectro - “Hydrogen Balmer Series.” That makes ed, and printed. gram, changing those pixels to vertical lines representing the good old angstroms (or nanometers if’n you pre - Balmer lines appear overlaid on your What you do with your profiles after fer). spectrogram (the graph). Does the you have them is up to you. It’s fun just hydrogen beta line (you can run your to be able to see for yourself how spec - Despite my fears, calibration turned mouse over the lines to identify them) troscopy works, and to marvel at the out to be easy. Step one is to open the pass through the dip you identified as fact that you can see what the stars are calibration window, natch. You then the hydrogen beta line on the graph? made of using your little telescope. click on the peak in the graph formed Do the other Balmer Series lines coin - There are also opportunities for ama - by the star’s image, the big spike on the cide with dips on the graph? If so, you teur spectroscopists to contribute to sci - graph on the left. Next, and a little are in like Flynn. ence. Amateur spectra of transient phe - trickier, you have to click on the dip on nomena like novae and comets can be the star’s spectrum that represents the My results? Purty good. Maybe not particularly important, since the pros hydrogen beta absorption line. That is perfect, but purty good, though some of sometimes don’t have time to get not difficult if your star has a prominent my dips didn't quite line up perfectly data—or enough data—during those line at the h- beta wavelength. While with the superimposed lines. I suspect fleeting events. Rigel didn't show as prominent a line as that was mostly due to seeing. Unk’s Vega would have, it wasn’t too hard to fumble-fingeredness in clicking in the To say I was thrilled with my results pick out the h-beta absorption line. right spots on the graph was also no with this incredible program and grat - How do you know which dip in your doubt responsible for some of the error. ing would be an understatement, graph is the one for the h-beta line? It What next? Once you’re calibrated, muchachos. I was frankly dumbfound - should be the first big valley to the left you can go on to identify the other lines ed by how well and easily RSpec and of the spectrum’s peak. Calibration in your spectrogram. RSpec provides the Star Analyser worked. Will this lead done, click “apply” to get to the libraries of professional spectra for to Uncle Rod becoming more science- moment of truth. comparison purposes as well as a selec - centered in his amateur astronomy? tion of elements (the vertical overlaid Well, I wouldn’t say that, but I will say To find out if you did good nor not, lines) in addition to the Balmer Series. I am having a wonderful time taking you mash the “elements” button in the Your finished spectra, which RSpec the fingerprints of the stars. toolbar up top (three vertical lines). In

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