Visual vs CCD Observing

The AAVSO discussion forum has had some very interesting threads lately, but this one, Trends In Visual Observing,  seems to have struck a chord with many people. The conversation starts out with the statistics on the number of visual observations submitted to AAVSO annually. In 2009, visual observers contributed a little more than half the number of observations submitted in 1999.

I’ve given a fair amount of thought to why my production has waned as a visual observer. It’s a complicated equation, and there are several factors with different amounts of influence. To be honest, I think I know what happened to me, but I don’t like to think about it because it makes me sad.

The Simoquation of Visual Observations

E + T + W + Pc
----------------------  = Nv
 A + Nc + O

E -enthusiasm
T -available time to observe annually
W -weather (number of clear or partly cloudy nights annually)
Pc -perception of value
A -affects of aging
Nc -number of nights spent taking CCD data annually
O -other astronomical activities
Nv -number of visual observations reported annually

In the beginning, I had almost unlimited enthusiasm. The first five years were my most productive as I devised a system for observing as many CVs in a night as possible. My goal was to report 10,000 visual observations per year. If I averaged 100 observations 100 nights per year, it could be done, and that was the plan.

I achieved this dubious goal once, and had a few years of 7,500-9,500 or so. That commitment is approximately equal to a second full time job. It is a lot of work.

When the economy was good, I was able to survive on cruise control for several years. I could afford to invest more time to observing and losing sleep. As the economy tanked, it became necessary for me to invest a lot more time and effort into work, just to maintain the income I had settled for. So, while I still had the unbridled enthusiasm, my time was becoming more limited. I couldn’t stay up all night several nights in a row and still perform adequately at my job. I wasn’t getting any younger either.

Weather patterns, particularly in winter, have definitely played a role in the last three years. I used to do a lot of observing in November, January and March. May and December used to be the cloudiest months. Last year we had no clear nights from mid- November to March. This year has been almost the same. March 4 UT was the first time I had observed visually since November 22. Is this an anomaly or a pattern? I don’t know. But if it weren’t for AAVSOnet I’d have gone postal by now for sure.

My perception of the value of my visual observations has been all over the map. I used to think that thousands of negative CV observations were useful, especially if I was monitoring for rare outbursts of WZ Sge type dwarf novae or little studied systems. Not so much any more. I don’t think it’s particularly interesting to discover yet another UGSU in outburst so guys with CCDs can observe superhumps and determine a period. If it turns out to be a simple UG or UGSS nobody cares at all, even if it only goes into outburst once a decade.

That’s one of the reasons I decided to study Z Cams. There aren’t that many of them, and we don’t know that much about them. Observations done now might actually shed light on a new problem. Even there, the new discoveries probably will come from CCD data though. The stars in the visual range are well observed. They should continue to be observed, but that’s not a lot of stars.

I championed the ‘stars in need of observations’ lists for a few years, but now I question whether they are worthy of the attention they are given. Just because AAVSO doesn’t have enough data to predict a maximum or minimum doesn’t have any scientific relevance at all. If we don’t have enough data to produce a decent light curve and no one is observing the star, and nobody is writing about it in the literature, who cares? It’s a star in need of ignoring. The effort and time spent on it is probably better spent maintaining the long established curves of stars we have excellent data for going back 100 years.

We keep hearing how there will be an ASAS north any day now, but it still isn’t online. Don’t believe it. They can barely keep ASAS south online on a consistent basis. The next generation of surveys will be observing fainter stars, so I don’t really see the surveys taking over for visual variable star observers. But they will be placing a great demand on observers to follow up new discoveries, and they will want CCD data. Nobody publishes papers based on visual observations any more unless they are dealing with archival projects and can’t find what they want on photographic plates.

If I were going to observe Miras and SRs, I would observe the ones in the Legacy Program and LPV Program Stars on the LPV section site, and maybe one or two special project stars for curiosity and fun. That’s plenty of great stars with excellent sequences to keep you busy forever. There is also a nice sample of LPVs with humps in their curves that I have always thought would be a great project. Frank Schorr has some great stuff on the LPV section site about these stars. Most are great visual targets for a modest sized telescope.

The EB and RR Lyrae people have made it pretty plain they aren’t interested in visual observations for their programs at all. Door closed- don’t knock.

Age has had its affects. I am far less inclined to suffer in order to obtain visual observations. Some nights I’ll only observe stars above +20 declination because that means I can sit in my nice cushy office chair for hours, instead of perching on a smaller adjustable seat or straining my back. I don’t usually have the energy or enthusiasm to do marathon all-nighters any more either. Three or four hours are about as much as I’m willing to endure. My goal used to be to do 100 observations minimum. Now my goal is not to ruin tomorrow by staying out too late tonight.

Continuously reading and learning more about variable star science and astronomy, and keeping up with the latest news and advances takes a significant investment of time. I also spend an almost equal amount of time writing about variable stars and astronomy for blogs, podcasts, newsletters and magazines these days. I like to think this doesn’t influence my ability or enthusiasm for observing, but deadlines have interfered in recent years.

Strangely enough, the more involved I am with AAVSO the fewer observations I make. Included in my “other astronomical activities” these days are the chart and sequence team, mentor program, CV section, speaker’s bureau, writer’s bureau and council activities, as well as all the things I do that are actually part of my job.

But for me personally, the biggest factors have been CCD observing and the piss poor pointing of my Meade 12" GPS LX200. The complexity, expense and time investment does not equal the amount of joy extracted for me. I resent the time I’ve had to invest in learning to observe and reduce CCD data in a scientific manner.  It takes almost as much time to reduce the data as it does to take it, and there isn’t anything fun about it. I spend more time messing with equipment and computers and less time enjoying being out under the sky. I feel no connection to the cosmos observing with a CCD. I simply feel it is a necessary evil if I want to do science that anyone will take seriously.

But the pointing issues are the worst. That damn telescope has dampened my enthusiasm for observing altogether. If I'm observing visually I can deal with it to some extent, because its easier to slew up and over, or wherever I have to go to find the target. But trying to land 16th mag variables on the CCD chip on the first try is a joke. I waste so much time trying to get to the target that my night just becomes a giant headache. Every hour with the CCD and that stupid telescope is 25-30 observations I was robbed of at the eyepiece.

My goal is to have the best of both worlds, but that goal still eludes me. I want to be in the dome observing visually while the computer and CCD scope run essentially unattended in the roll off next door. I can think of enough worthwhile and fun visual things to do to keep me busy.

Some days I think I’d be better off burning down the roll off and simplifying my life. Other days I think it would be simpler to just cut the umbilical cord and go CCD all the way. My willingness to tolerate the cold and staying up late will probably be the deciding factor in the end. But I’m afraid my experience will be the poorer for it.

When you observe visually, the data is a byproduct of the experience you have at the eyepiece. When you observe with a CCD, the data becomes the thing. The wonder, magic, mystery, romance and beauty will be gone, as I sit in front of a computer monitor, determining the optimum size for an annulus around a comp star, for a time series of 300 observations I collected automatically, in a black box I bought online.

To each his own. But, if that sounds like fun to you, you are not a visual observer.

3 comments:

Professor Astronomy said...

I find data analysis to be a lot like cleaning the house or doing yard work: horribly tedious, but when done right, the results make it worthwhile (hopefully).

But I think that CCDs don't have to take the fun out of observing. Some of my favorite observing experiences are when something unexpected pops into view. Once our field happened to include a comet (known, but it was fun to figure that out!), another time I was tiling the field around a star cluster and an NGC galaxy popped into the field. And when I do time series work, those few exposures with exquisite seeing let all sorts of faint galaxies pop into view.

I suspect you'd easily find some project, like searching for new variables or exoplanet, that a CCD makes possible. Sure, maybe it is just another RR Lyrae or hot Jupiter, but it is yours. I personally get quite a charge out of that sense of ownership.

But I agree, nothing beats kicking back and using your own eyeball. After all these years, I still find Alberio one of my favorite things in the sky, even if it is just another wide binary.

Sakib said...

There's no greater joy than being under a dark (or even moderately light polluted) sky and witnessing the majesty of the heavens above, the tranquil and sweeping motion of the stars across the sky. It doesn't matter if you use your eyes or a CCD camera, as long as your enthusiasm and passion for astronomy is felt in your heart!

ShawnD said...

In my case I think my shift to 100% CCD work occurred because of a loss of dark skies and an interest in computers/electronics. The suburban area I live in has grown dramatically in the last 10 years, and the Milky Way is now a very rare sight. My enjoyment of the night sky is much less now that it's been reduced to just dozens of brighter stars, instead of hundreds scattered along with the hazy band of the Milky Way. I enjoy working with computers and electronics in general so putting together a CCD system, optimizing it, and then processing the resulting images is enjoyable. I can certainly imagine, though, that if this wasn't the case I would find the amount of work required tedious.