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Of Light Curves and the AAVSO Bulletin and the Light Box

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Posted by weo on February 28, 2011 - 2:48pm

I started working at the AAVSO in August 1979. My responsibilities included processing the monthly data and supervising data entry. As Janet Mattei’s assistant, over the years I was assigned a wide variety of tasks, all in the service of the AAVSO and its mission.

The very first non-data processing assignment I (and any other AAVSO assistant in those years) received was to catch up on the handplotting of the monthly data. At that time the only practical visual representation of a star’s data was a handplotted light curve, with a pencil dot for a positive observation and a tiny checkmark for a fainter-than. Even then we were receiving a few hundred thousand observations a year, so there was a lot of plotting do to! This work had to be done with great care and concentration, but it shouldn’t be considered tedious, Janet told me, as it was the best way to learn the behavior of the stars and the observers in a very personal way. She certainly was right - when you inch your way through a year’s light curve one point at a time for several hundred stars, and then you do that the next year and the next… believe me, you know the stars and you know the observers! (Many longtime observers wonder that I know their observer initials – all that plotting for several years is a big reason!)

One thing I thought about as I plotted was how I was doing the same work that William Tyler Olcott had done, and Leon Campbell, Margaret Mayall, Janet Mattei, and a host of assistants had done over the decades, and how the light curves I was plotting would join theirs in the permanent archives of the AAVSO and be used by future researchers. That was a remarkable thought and pleased me very much.

The handplots were used for many things, including preparing the annual AAVSO Bulletin – the predicted maxima and minima of over 550 long period variable stars for January through February of the following year.  That first winter, Janet introduced me to the Bulletin preparation as I helped her with the multi-step project.

Part of the project was to determine the observed maxima and minima from the year just concluded. This was done by laying the handlplot of a star on top of the drafted mean light curve for that star, moving the handplot around to fit the mean curve to each maximum and minimum, and marking a line (with a red pencil for an observed date) on the handplot  on the JD of maximum or minimum. Then, after marking the most recent maximum and minimum, one marked (with a black pencil for a predicted date) the predicted dates, based on the mean curve. Those mean curves had been drawn by Leon Campbell and used by him and Margaret and Janet year after year. As I used them to double-check Janet's work at her request, and more recently to prepare the Bulletin myself, I thought how remarkable that we were still using them and it pleased me.

And the light box? Fitting the mean curve was really practical only when using a light box (occasionally I have used a window and that works but you can’t do that for hundreds of stars). Our light box is handmade – by Leon Campbell – of scrap lumber and is triangular, rather like a book or music holder, with the light surface at just the right angle and a lip at the bottom to put your pencils on. The white glass is broken in one corner and taped together with ancient masking tape and less ancient plastic tape; the wood is worn smooth from all the hands and forearms and shirtsleeves rubbing on it  and carrying it around. Sara Beck replaced the dried out power cord once and I replaced it again as it dried out again and cracked, inserting an on/off switch into the new cord so we could turn it on and off more easily than by crawling under or behind furniture to reach the outlet to pull the plug. I don’t think the fluorescent bulb has been changed in over 30 years. That I was using that original light box was remarkable to me and pleased me.

Now, alas, the light box gathers dust as I overlay the mean curves on the data plots in the computer, thanks to the brilliant programming of Kate Davis and Sara Beck. That we can do this is a dream come true of Janet’s and mine, is a wondrous time saver, and is remarkable to me. (But I really miss the light box and the warmth it generated, both from the light inside it and from the spirits of its former users.)

Every time I work on the Bulletin, I think of Janet and Margaret and Mr. Campbell and William Tyler Olcott, and I think of all of you observers today and yesterday and over the decades, and how we have all been working together – individually – in the service of the AAVSO and its mission for over a century.  And that is a truly remarkable thought and it pleases me very much indeed.   --- Elizabeth Waagen


Hi Lisa,

Your thoughts and feelings are also felt by me. When I look at an old diary of observations made ​​more than 100 years, somehow I feel connected to that observer. As I said in my local lectures:
"Visual observations of the future begins with the rescue of observations of the past."

with regards,


Thanx, Elizabeth for sharing the story of light boxes, light curves and the AAVSO Bulletins! This realy gives us some insight to the everydays and the history of AAVSO...

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