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In Memoriam: M. Daniel (Danie) Overbeek

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Danie Overbeek

Michiel Daniel (Danie) Overbeek, 1920 - 2001
Michiel Daniel (Danie) Overbeek, a long-time AAVSO member, the AAVSO's most prolific observer, and a dear friend of the AAVSO, passed away on July 19, 2001. Danie--also known as "OB" to anyone who has ever pulled up a data file on a southern variable star in the AAVSO's database (and some northern variable stars as well while he was stationed for few years in New York)--began observing variable stars on August 22, 1951 with the Mira variable, W Pav, when he was 32 years old. During his lifetime he contributed 287,240 observations to the AAVSO International Database--far more than any other observer in the history of the Association. The variable star he observed the most was VW Hyi (3,837 observations), the brightest dwarf nova in the southern hemisphere. Many of the AAVSO southern hemisphere program stars owe a large portion of their light curves to Danie's persistence and dedication in observing variable stars.

In addition to variable stars, Danie was an active observer of occultations, sudden ionospheric disturbances, and monitored seismic activity around the world with the seismograph he built.

Jan, Janet, and Danie
Jan Smit, Janet Mattei, and Danie Overbeek at Jan's Garden in Pretoria, South Africa.

The AAVSO's 26th Merit Award was presented to Danie in 1986 " recognition of his dedicated devotion to observing variable stars in the southern sky...resulting in over 70,000 observations of variable stars, his excellent guidance of many variable star observers in South Africa, and his valuable service on the AAVSO Council." Danie was the recipient of three AAVSO Observer Awards: the first in 1994 for making over 100,000, another in 1997 for making over 200,000, and the third in 1999 for making over 250,000 visual observations of variable stars. He was the first recipient of the AAVSO Director's Award in 1994 for his vital contributions to variable star research. Minor Planet 5038 was named Overbeek last year to honor Danie for his contributions to astronomy.

Danie will be sorely missed--both in our archives as an observer and personally as a friend and mentor - Janet A. Mattei

The following messages were posted to the AAVSO Discussion in remembrance of Danie:

I never had the honor to meet Danie, but the stories I have heard about him and his most impressive observing life truly made him a legend in his own time. They also lay down a challenge to all of us to consider the contribution we make to amateur astronomy and then work just a little bit harder as family, jobs, etc. allow.—Chuck Pullen (PCA)

I am saddened to hear of the death of Dannie Overbeek. I don't believe I ever met him, but to me he falls into the category of a legend, much like Peltier. How a man could do as many variable star estimates as he did absolutely amazes me. For those who called him "Friend", my sympathies go out to you.—Chris Stephan (SET)

In 1976 I did visit Danie Overbeek of Edenvale South Africa with my wife Andrea. Danie introduced me in to variable stars observing and my first report to AAVSO was on my request checked by him. The demonstration of his observational technigue was quite astonishing. Using Cassegrain telescope with quite large setting circles he did find a particular variable in about 5 seconds and because he did know many variable fields by heart he was able to determine a magnitude in a few seconds also. The Cassegrain telescope he was using (10" or 12") was very compact and while observing and moving telescope by a mechanical setting circles he was in a sitting position behind eyepiece. His private observatory did have one piece roof with two hinges and two outside counterweights. After one latch release (inside observatory) complete roof opened by gentle push (one finger). Needless to say I was deeply impressed by just about everything I have seen and so was my wife Andrea. I now live and observe in Canada but my most valued astronomy time was in South Africa with Danie Overbeek, the late Jack Bennett and astrophotographer Christos Papadopoulos. —Miroslav Komorous (KMA)

I was saddened to hear of D. Overbeek's passing. I just did some simple arithmetic to see what 287,000 observations really meant. I assumed that one could make 6 observations per hour for 4 hours per nite for 3 nites per week for 20 years. This seemed like what a active observer like myself might set as a goal. After 20 years, one would amass a total of 75,000 observations--still a factor of 4x short of what D Overbeek accomplished. Quite Amazing. When I talked to him at one of our meetings, I casually mentioned that he must have good skies and clear weather to have observed so much. He replied that he did not have good weather, and that it was almost always cloudy where he lived. He used to get up in the middle of the night, after cat naps and seek out clear patches to make his observations. This adds to the accomplishment. He will be missed by us all.—Gary Walker (WGR)

I live in the same region as Danie did and we shared a number of observing targets. Looking at your (Gary Walker) assumptions "I assumed that one could make 6 observations per hour for 4 hours per nite for 3 nites per week for 20 years. This seemed like what a active observer like myself might set as a goal. After 20 years, one would amass a total of 75,000 " Make that rather 40 obs per hour (probably much higher during his top years!), possibly 1 to 1.5 hour at different times of the night, about 180 nights (mainly winter-) a year, and the number of active observing years was, I think, more than 20 years. I leave the calculations up to the readers. Variable stars were only part of Danie's astro interest. Planetary and moongrazing occultations, both observing them and organising observations as the Director of the ASSA occultation section must have taken quite some time and effort. He also monitored the effects of geophysical and atmospherical phenomena (seismo activitites, and magnetic waves from solar particles). From my personal dealings with Danie, he struck me as a warm and accommodating man. I dare take the liberty to quote from a recent e-posting I received from one of Danie's many professional astronomer friends, who wrote " ..... I see that WZ Sge has gone off 10 years early, and I read this as a tribute to a very fine man." Berto Monard (MLF)



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