Overbeek M.D.

OVERBEEK, Michiel Daniel
[BSc; Pr Ing; AFRAES]
Amateur AstronomerBorn: 15 September 1920, Ermelo, Mpumalanga, South Africa.
Died: Johannesburg, South Africa.

In brief :
Famous for:
More than 250 000 observations of Variable Stars. (The world record for any observer: Amateur or Professional)
Elected twice as President of ASSA (1961/2 and 1998/9)

Danie Overbeek learned his love for astronomy at a young age from his Grandfather. It was one of his courses at University. Although he worked as an aeronautical engineer (and traveled the world) he consistently observed variable stars and send in the reports to the AAVSO (American Association of Variable Star Observers). The precious observing time of Hubble Space Telescope was even on occasion scheduled according to data supplied by Overbeek. He is the most recognized variable star observer

Historical background :
Most of the details below (unless otherwise stated) were taken from a Curriculum Vitae drawn up by Danie Overbeek. [ASSA Archive: Overbeek Collection; Curriculum Vitae]. He describes the events as milestones (mostly milepebbles) in his life.
15 September 1920. Danie was born in Ermelo, South Africa and Christened on 5th December of the same year.[ASSA Archive: Overbeek Collection; Personal Documents]
At the approximate age of five years he went to his parents in terror to report that “the stars are moving” He said it must have been to wavy, pre-float glass window panes.
In July 1928, at a camp fire on the beach below the Polana Hotel, Lourenco Marques (Maputo) Mozambique his Grandfather pointed Mars out to him. He was so intrigued by the fact that the heavenly bodies have names that he started reading any Astronomical material he could get hold of.
1935: Made his first telescope. (15 years old) It was manufactured from a reading glass for which he used a pocket microscope as an eyepiece. It worked (after a fashion) “Over the years proceeded to more powerful instruments with 1 – 2 dioptre spectacle lens OG’s.
1937: Bought a “powerful 60x telescope” by post from Brownscope Company in New York for about $4.48. Danie’s comment: “worked fine at about 10x once the terrestrial erector lenses had been removed. Showed the Galilean satellites well.”
1938: Matriculated (finished High School) at EHS (Ermelo High School)
1951: (Age of 31) Constructed a 6-inch Newtonian and started observing occultations and variable stars.
1953: Built 12 ½ inch Dall-Kirkham Cassegrain.
1956: Chairman Transvaal Centre of ASSA. (Astronomical Society of Southern Africa)
1958: BSc, Unisa in mathematics and astronomy.
1961: President of ASSA.
1971: AFRAES (Associate Fellow, Royal Aeronautical Society)
1971: Pr Ing (Register of Professional Engineers)
1977: Council Member of AAVSO (American Association of Variable Star Observers)
1981: Started with solar flare SID/SES recording.
1981: Built a magnetometer for fun and started monitoring the Earth’s magnetic field.
1990: Built a seismograph and monitor seismic activities.
1998: President of ASSA

Honours bestowed on Overbeek:

AAVSO stands for American Association of Variable Star Observers.
ASP stands for the Astronomical Society of the Pacific.
ASSA stands for the Astronomical Society of Southern Africa.

1978: Honorary Member of the Transvaal Centre of ASSA.
1980: Honorary Member of ASSA.
1986:Gill Medal of ASSA.
1986 August 9: AAVSO Merit Award. “Recognition of 70 000 observations”.
1994 May 21: AAVSO Directors Award. “Recognition of 188 103 variable observations during the years 1952 – 1993”.
1995:Christos Papadopoulos Trophy of the Transvaal Centre of ASSA “for meritorious activity”.
1996 March 11: ASP Society’s Amateur Achievement Award.
1997 May 26: AAVSO “Recognition of Variable Star Observer 200 000 observations”.
1999 July 3: AAVSO Award “for over 250 000 observations”.
1999 October 30: AAVSO Observer Award.


1920 September 15: Born at Ermelo in the old Eastern Transvaal, now Mpumalanga.
1920 December 5: Christened at the Dutch Reformed Church in Ermelo.
1938: Matriculated (finished High School) at EHS (Ermelo High School)
Married his school sweetheart Jean Preddy
Died: Johannesburg, South Africa.

Overbeek was a ferocious letter writer to the Newspapers. The topics ranged from National Politics (emigration and national transportation system); Local Politics (traffic signs, bus tax, the local library) to everyday topics like musical performances to the metric system.
Recollection written by his wife Jean:
I have just been introduced to a dimension of beauty not ever witnessed by me before,
a power supplier, a multimeter, two potentiometers, crocodile clips attached to fine strands
of almost gossamer like copper thread or wire, all this to allow the voltage to pass through
from the power supplier across an airflow sensor into which the creator had threaded oh so carefully
and lovingly a tiny circle of thread. To watch the creativity of this man and the sensitivity of
his while approach to which his entire mind and physical ability were so wonderfully attuned
was for me a ballet performance of such dedication that it was touching. The final result is yet to come.
It was an art form with skill, patience and beauty.

This is another dimension to the creative man, in fact it goes back many years. Age approaching
eighteen years, an undergraduate of the witwatersrand university, all his desires and interests
were on a higher plane, the southern sky literally. This led him to parks in the johannesburg area. he would wend his way to the chosen spot, fling himself down on the grass and then
proceed to remove from his pocket his precious tool. one small hand fashioned telescope,
and that brought his beloved southern sky nearer to him. time was of little essence. he would
dedicate hours to his star gazing. his two young friends one a medical student, the other
a female accomplice. they knew just where to find him, and knew that the pocket contained
a delicacy. a small piece of very dry, hard biltong [dried meat]. with a great deal of affection and respect
for their astronomical friend they made themselves oblivious as were their intentions. a tiny slice of
biltong before silently departing. Friend being of a sensitive nature knew exactly what they were after,
brought forth the dried meat and with a tiny saw-like blade created three slices which he then shared
with the interlopers. a satisfied “goodnight” was said. The three young people became older,
perhaps wiser and the respect and affection never, ever changed adding. A valued dimension to
our lives. we were very conscious of the worth of Danie Overbeek and, like to know that his
Grandfather was responsible for introducing him to his star gazing.
I have just been introduced to a dimension of beauty not ever witnessed by me before.

The following story was told to me about Danie: late afternoon one day Danie travelled somewhere to be in a premium place to observe a predicted GRAZING OCCULTATION. He found a promising observing spot in a GRASS FIELD close to a road, and as it became dusk he was setting up his instruments. Next moment a policemen saw “this suspicious person next to the road.” He asked Danie what he was doing, and imagine the consternation on his face when Danie replied; GRAZING! [cdc]


Link to the Telescope Manufacturers.

Reading Glass telescope. Handmade his first telescope in 1935. (15 years old)
Handmade: “Over the years proceeded to more powerful instruments with 1 – 2 dioptre spectacle lens OG’s.
Telescope by Brownscope Company of New York. (60x magnification)
Handmade: 6-inch Newtonian in 1951.
Handmade: 12 ½ inch Dall-Kirkham Cassegrain in 1953.
Handmade: Magnetometer in 1981. Measured Earth’s magnetic field.
Handmade: Seismograph in 1990. Measured Earth’s seismic activities.


Link to the Main Bibliography Section and more information about Sources.

Remaining Artifacts:

ASSA Archive: Overbeek Collection

By Overbeek:
Publications authored / co-authored by MD Overbeek:
MNASSA stands for Monthly Notices of the Astronomical Society of Southern Africa.
MNRAS stands for Monthly Notices of the Royal Astronomical Society.


Grazing Occultation of Antares, 1968 August 3; MNASSA Vol. 27 p.112, with GFC Knipe.
Grazing Occultation of ZC 2298, 1969 October 14; MNASSA Vol. 29 p.42.
Three Grazing Occultations; MNASSA Vol. 30 p. 85, with J. Hers.
Visual Observations of the Occultation of Beta Scorpii by Jupiter 1971 May 13; MNASSA Vol. 13 p. 64, with J. Hers.
Observing Occultations: Those Reappearances; MNASSA Vol. 32 Centrepiece.
Slow fading during Lunar Occultations; MNASSA Vol. 32 p. 41.
Grazing Occultation of ZC 2797, 1973 October 4; MNASSA Vol. 33 p. 42.
Photoelectric Observations of Eclipses and Occultations of Europa by Io, 1973; MNASSA Vol. 33 p. 111.
Observing Occultations: Amateur photoelectric work; MNASSA Vol. 33 Nos. 1 & 2 Centrepiece.
An Occultation Expedition; (To Venezuela) MNASSA Vol. 39, Centrepiece.
Report on Occultation of SAO 77636 by 15Eunomia, 1982 March 30; MNASSA Vol. 41, p.25
A possible Minor Planet Occultation; MNASSA Vol. 41, p.73, with P. van Blommestein.
Occutations during the Total Lunar Eclipse of 1985 May 4; MNASSA Vol. 44, p.102.
Two Minor Planet Occultations observed from the Transvaal; MNASSA Vol. 48, p.9, with T. Cooper.

Variable Stars:
A Great Variable Star Observer (AW Roberts); MNASSA Vols. 34 & 35, Centrepieces.
Variable Obsvuration of the Carbon Star R Fornacis; with MW Feast, PA Whitelock and RM Catchpole.
TU Ophiucci: A Mira Variable, not a Dwarf Nova; Astrophysics and Space Science, Vol. 143, pp. 211 – 213, with B Warner and AP Fairall.
Mass-loss variations among carbon-rich AGB variables; MNRAS Vol. 228, 1997, pp. 512 – 532, with PA Whitelock, MW Feast and F Marang.
The 1987 outburst of the recurrent Nova U Sco; No publication details. With K Sekiguchi, MW Feast, PA Whitelock, W Wargau and J Spencer-Jones.

An Identified Flying Object; MNASSA Vol. 30 p. 155, with AD Thackeray.
The Ultimate Graze; MNASSA Vol. 38, Centrepiece. (Account of Midnight Sun)
Observing the Sun without a Telescope; MNASSA Vol. 41 Centrepiece.
A Sky light stop for Cassegrains; MNASSA Vol. 41, p.26.
The Green Flash by reflected light; MNASSA, Vol. 48, p. 16.
Amateur Astronomy in South Africa; Astrophysics and Space Science, 1995, Vol. 230, pp. 479 – 493.
The Contribution of Amateur Astronomers to Astronomy; MNASSA, Vol. 46, Nos. 9 & 10, Oct 1987, pp. 117 – 120, with JAS Campos.
Chapter, The Edenvale Observatory in Patrick Moore’s Small Observatories.
Presidential Address: “Roberts to the CCD”, A review of Southern African amateur astronomy during the Twentieth Century; MNASSA, Vol. 58, Nos. 9 & 10, Oct 1999, pp. 127 – 138.

Various articles for different ASSA Centre Newsletters.





Due to the available amount of material a second page has been created for the Gallery of MD Overbeek


Danie Overbeek.
Source: A.S.S.A. Symposium 2002: Paper 02 Mattei:  Danie Overbeek Memorial Lecture
ource: A.S.S.A. Symposium 2002: Paper 02 Mattei:  Danie Overbeek Memorial Lecture
Source: MNASSA 1991, Vol. 50, No. 9, Cover .
Danie Overbeek and Peter Kirchhoff at the pier of the 9 inch telescope at Republic Observatory.
Source: A.S.S.A. Symposium 2002: Paper 02 Mattei:  Danie Overbeek Memorial Lecture