HISTORY OF SCIENCE AND TECHNOLOGY

DAVID FABRICIUS (1564 - 1617)

David Fabricius was born in Esens, Frisia, in what is now Germany. He was a Pastor in Osteel and, like many of the clergy at that time, Fabricius was an amateur astronomer. He was a follower of Tycho Brahe and is known to have corresponded with Johannes Kepler.

Between August 3^rd and August 21^st 1596, Fabricius observed a star that increased in brightness over the eighteen days. By September the star had become less bright and in October it had disappeared entirely from his view. Fabricius recorded his observations and concluded that he had witnessed a nova. However, on February 15, 1609, the star re-appeared and, over the next few days, started to get brighter again. Fabicius had identified the first periodic, variable star, Mira or omicron Ceti, in the constellation of Cetus.

Fabricius and his son, Johannes, while making naked-eye observations of the sun, identified sunspots. In 1611 Johannes returned home from university with two telescopes. On March 9^th, with the aid of their new telescopes, they observed several sunspots on the sun as it appeared over the horizon at dawn. They followed these sunspots as they moved across the sun’s surface over a period of several months. They used a camera obscura telescope (that projects an up-side-down image onto a screen in a darkened area) to protect their eyes. The sunspots moved from east to west across the sun’s surface and then re-appeared from the east after a period of time. This was the first real evidence that the sun rotates on its axis.

David Fabricius is also remembered for the way he died. During a sermon he indicated that he knew the identity of a person who had been stealing geese and chickens from the local neighbourhood. He was murdered soon after this sermon, by being hit on the head with a shovel. It is presumed that the poultry thief was the murderer.

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© Shirley Burchill 2009