Tom Field – RSpec and Real-Time Spectroscopy

Tom Field at NEAF Amateur astronomers frequently spend the majority of their time focused on one of three activities: visual observing, imaging or science. The scientists often specialize in photometry or spectroscopy. At NEAF 2011, I finally got to meet two very influential and important people in the world of amateur spectroscopy: Olivier Thizy of Shelyak Instruments and Tom Field (shown in the image to the left) the creator and developer of the RSpec program. I had interviewed Olivier in August, 2010 but I hadn't interviewed Tom yet. When I got back to San Diego I wrote Tom and asked him if he would be willing to do an interview and I'm happy to say that he graciously agreed. Included below is our email interview.

What functionality is provided by RSpec?
RSpec is a program that allows a beginner or expert to capture and process spectrums of stars and planets. The program makes it easy to convert the rainbow-like smudge of a spectrum to a calibrated, annotated graph. These graphs reveal the composition and other physical properties of the star or planet you're observing. It's really quite exciting to be able to do this easily.

Your logo says "RSpec Real-time Spectroscopy". What do you mean by "real-time spectroscopy"?
Up until now, the process of processing that rainbow-smudge into a graph was something you did in several typical steps. First, you'd attach a simple grating or spectroscope to your telescope. Hoping that it was aligned, you'd take some images with your FITS camera. And then, the next morning, you'd process the images and see what kind of curves you got. That's soooo 20th century!

These days, the hardware and software can do the preliminary processing on bright objects in real-time while you're observing. Imagine being able to see the graph of the spectrum of a star as your FITS or even webcam or video camera capture it. There's no more guessing, "Am I getting a spectrum?" or "Is this over-exposed?" You can see the results in real-time. And for us impatient, 21st century attention-deficit amateurs, that's a big deal. And, the colorful spectra make a great outreach tool!

How did you get interested in spectroscopy? Do you have a science background?
Well, I had done some imaging over the years. Like many of us, visual imaging captured my attention, and offered challenges and excitement in the beginning. But after a few years, it was a matter of diminishing returns. I mean, how many times could I image M42, or some distant galaxy before it got a little too familiar? I was ready for something new!

I was looking for something new to get me excited again about the hobby. And, frankly, I wanted something that was more scientific than qualitative. I enjoy beautiful photos as much as the next guy, but I wanted something more; I wanted data!!

I was trained as an engineer; was considered a "physics jock" in college; and have always loved learning the science behind the stars! Spectroscopy is a natural fit to most amateurs because we love understanding new things about the stars.

What motivated you to write RSpec? How long has it been around?
Several years ago, I purchased an inexpensive diffraction grating that was mounted in a standard 1.25" filter cell. I went out in my backyard one night, mounted it on my C8 and made some video recordings with a cheap webcam. The next morning, when I tried to convert the images to graphs, I was unable to figure out how to do it. I say this very honestly! Here I am, a software developer for more than 15 years, and I couldn't figure out how to make the software that was available actually work! The first problem was that I had to jump through three or four programs to convert the data. No one should have to do that! Then, when I finally started processing my image, the software I was using kept crashing. It was one of those typically frustrating experiences we have all had with computers.

I figured I'd bolt together a small program for myself to do the necessary steps. When I posted it on the web to show off my work to some friends, they got all excited and urged me to take my prototype to the next step – they wanted to use it too!

How does RSpec compare to other spectroscopy programs?
Well, of course I'm a little biased, so I'm not the best person to ask! But, there are a lot of RSpec users who absolutely love the program. The only other software out there that does this kind of thing is a freeware program named VSpec, written by my good friend Valerie Desnoux. It's a great program and a lot of experts use it. But, it's tough to learn, and has been around for many years, which means that it doesn't have the benefit of being developed with the kinds of state-of-the-art software engineering tools that are available these days. And of course, it's not real-time.

I know you were at NEAF for the first time this year. How was the response?
I was expecting to be busy at NEAF. But I wasn't expecting to be so totally swamped as we were at the booth. I had a crowd at the booth almost non-stop for the entire show. There was a lot of interest, which just proved to me what I already had thought: once amateurs know how easy and exciting spectroscopy is, they'll be flocking to it!

Do you think more amateur astronomers are becoming interested in spectroscopy? Why?
I don't have any doubt that we're in the dawn of a new age for astronomical spectroscopy. Frankly, the tools are now available. They're inexpensive and easy to use. What's missing now is that amateurs just don't know what's possible! As the amateur community learns what spectroscopy is all about, and that it's not just for professionals or high-end experts, we'll continue to see more and more "converts!"

What types of spectroscopy projects can amateurs do?
Wow.. the list of possible projects is quite long! The easiest thing is to study stars, classifying them as OBAFGKM. With a simple spectrum, that's easy… but exciting too. You can easily detect the methane gas in the atmosphere's of Uranus or Neptune. You can see the emission lines on M42. One thing that really excites me is to see the emission lines of a Wolf-Rayet star! You can actually see the exposed core of the star where the Carbon by-product of nuclear fission is glowing!

I've seen amateurs with an 8" SCT and a relatively inexpensive camera be able to detect the red-shift of quasar 3C273. No, I'm not kidding. They did this from the suburbs too! Which reminds me: I wanted to mention that compared to most astro-imaging, spectroscopy is relatively immune to light pollution. That's because we're smearing out the light and can just ignore the wavelengths where light pollution is interfering. So unlike astro-imaging, a lot of interesting spectroscopy can be done from suburban locations.

We've seen the AAVSO make some significant contributions to astronomical research. Are there similar opportunities in spectroscopy?
Yes, yes! First of all, spectroscopy dovetails well with variable star observing itself. A spectrum can easily reveal the type of nova or supernova (although SN are a bit too dim for everyday imaging by amateurs). And, there's active pro-am cooperation going on in several areas of research, including the study of Be stars. Some amateurs have been cited in publications, and attend professional conferences to make presentations.

What is the best way for an amateur astronomer to get started in spectroscopy? What skills and equipment are necessary?
It's surprisingly easy to get started in spectroscopy, Ken. All you need is a small grating for about $180 dollars. It screws right into your camera nosepiece. You can use almost any camera you've got, even an unguided DSLR! If you can point your scope at Vega and track it (even poorly like I do!), you're ready to take the first step into spectroscopy!

What is the best way to learn RSpec? Is there somewhere that newbies can ask questions?
Let's face it, most of us don't spend a lot of time reading user manuals. Who's got the time?! With that in mind, we ship RSpec with about twenty-five 3-minute videos that demonstrate real-world use of the software. These videos start at step 1 and make it really easy to get started. In fact, the videos are posted on our web site for anyone to watch.

There's a free, 30-day trial version of the software. People can always email me with questions. And we've got a very active Yahoo group. There are experts and beginners there, all enjoying spectroscopy together. It's a real community and it welcomes newcomers. After all, who amongst us doesn't like to share what we enjoy with others?

What's next for RSpec?
Hmmm… next for RSpec? I'm very lucky to have a very supportive group of users who never cease to amaze me with their good ideas for new features. There are a lot of exciting new features in the pipeline! RSpec is a young program; it's only 18 months old. But like any toddler, it's easy to love, is getting brighter every day, and has a great future ahead of it. (Just ask the proud father … oh … you just did.)

You can find information about RSpec at

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1 Response to Tom Field – RSpec and Real-Time Spectroscopy

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