Max Waldmeier
Max Waldmeier (born April 18, 1912 in Olten ; † September 26, 2000 in Küsnacht ) was a Swiss astronomer and solar researcher. The Waldmeier classification of sunspots (around 1950) and the eruption hypothesis of solar activity (1935) go back to him.
biography
Waldmeier founded the Astrophysical Observatory in Arosa in 1939 and was director of the Swiss Federal Observatory in Zurich from 1945 . He is best known for his work on the classification of sunspots and the eleven-year cycle of solar activity .
His scheme of the types of spots from A to I (single spots) over the large groups of spots of type E and type F is easily recognizable and also corresponds to the development over time. The “Zurich sunspot scale” (also known as the Waldmeier classification ) differentiates between the size and shape of the spots, their grouping, the bipolarity of the magnetic field and the presence of penumbra ( penumbra ). It has been used internationally by Waldmeier since the 1940s.
In the mean sunspot cycle of around 11 years, Waldmeier identified a negative correlation between the duration of the rise from the minimum to the maximum and the height of the maximum: the shorter the rise, the higher the maximum. This relationship is also known as the Waldmeier effect . As a PhD student, Waldmeier investigated the course of the sunspot curve and formulated an eruption hypothesis in 1935 : The curve arises from a superposition of "spot humps" that resemble eruptions, spot minima are the superposition of the decreasing and the next increasing hump. After the minimum of the relative sunspot number R increases R is the faster, the higher its maximum in a few years be. However, the duration of the fall to the next minimum depends on Max ( R ). His standard works combine these ideas with the results of later and international research:
- Results and problems of solar research / Leipzig 1941 / 2. Erw. Edition Geest & Portig, Leipzig 1955
- Introduction to astrophysics / Basel 1948
- The sunspot activity in the years 1610 - 1960 / Zurich 1961
Waldmeier's other books and publications concern general topics in astronomy , space travel , radio astronomy , the sun - earth interactions , heliographic measuring methods and the solar corona .
literature
- Hermann Haupt : Max Waldmeier. Obituary . In: Almanach der Österreichischen Akademie der Wissenschaften , Vol. 151 (2001), pp. 459-469 ISSN 0378-8644 .
Web links
- Publications by M. Waldmeier in the Astrophysics Data System
- Christian Baertschi: Max Waldmeier. In: Historical Lexicon of Switzerland .
- Literature by and about Max Waldmeier in the catalog of the German National Library
- Obituary - Max Waldmeier. In: The sun. Bulletin of the amateur sun watchers. Vol. 25, March 2001. p. 30.
- Waldmeier classification. On: The INTER-SOL Program. Public observatory Paderborn.
Individual evidence
- ↑ Ashok Ambastha: Physics of the Invisible Sun: Instrumentation, Observations, and Inferences . CRC Press, 2020, ISBN 978-1-00-076071-2 , Chapter 4.7.5 The Waldmeier Effect, p. 105-106 .
- ↑ Brief excerpt from the dissertation: New properties of the sunspot curve . Swiss Federal Institute of Technology in Zurich for the award of a doctor of natural sciences approved doctoral thesis submitted by Max Waldmeier ais Hellikon (Aargau). Schulthess & Co., Zurich 1936 ( ethz.ch [PDF; 722 kB ]).
- ↑ Max Waldmeier: New properties of the sunspot curve . In: Astronomical communications from the Swiss Federal Observatory, Zurich . tape 14 , 1935, pp. 105-136 ( harvard.edu ).
| personal data | |
|---|---|
| SURNAME | Waldmeier, Max |
| BRIEF DESCRIPTION | Swiss astronomer and solar researcher |
| DATE OF BIRTH | April 18, 1912 |
| PLACE OF BIRTH | Olten |
| DATE OF DEATH | September 26, 2000 |
| Place of death | Küsnacht |