Tycho and Longomontanus
*** Click for larger image ***
Longomontanus is seen to have a relatively smooth crater floor (fluidized Orientale ejecta?)
and two large clusters of cratering impacts, one at the NW and the other at the SE crater rims
(probably secondaries from Orientale) - but apart from that, "Longo" is rather unremarkable...
In medieval times, astronomy was primarily what we would today refer to as solar system positional astrometry, -- it was taught as a branch of mathematics in monasteries, and used as a tool for calendar planning and astrology.
After Tycho Brahe’s ground breaking observational work (described here), a separate chair in Astronomy was set-up in Denmark at the University of Copenhagen (1605), and one of Tycho’s pupils: Christian Sørensen Lomborg, was granted the first astronomy professorship in Denmark. (the surname ‘Lomborg’ indicates the place he was born, and was translated to Latin as Long Mountain = Longomontanus). Longomontanus was the son of a low-rank farmer, but he had an outstanding talent for mathematics, especially calculation of and use of logarithmic tables (before the logarithmic formulae were properly formulated), so - typical for Tycho - he employed Longomontanus as a member of his observatory staff.
Longomontanus’ greatest contributions to astronomy were writing the university textbook “Astronomia Danica” and establishing the new Danish Observatory at the Round Tower in central Copenhagen, after Tycho disbanded his own observatory at the island of Hven and finally left the country for Pragh in 1598, following disputes with the Danish king Christian IV.
The textbook Astronomia Danica contains chapters on spherical astronomy, astronomical instruments and observation methods, calculations and tables (all subjects he learned from Tycho). The textbook was used widely over most of Europe in the following half century, and the Round Tower is still in use today as the oldest functioning observatory in Europe, -- but now for public astronomical outreach events. The instruments of Longomontanus (sextant, azimuthal quadrant etc.) have of course been substituted by a modern telescope (a 150mm refractor from 1929). Apart from preserving the Tycho Brahe legacy, Longomontanus was a conservative mind who was not prepared to think out of the box with regards to new instruments (telescopes) or Keplerian cosmology, so maybe it's fitting that his name was attached to the large but in other ways rather anonymous crater just SW of Tycho (though it would have fitted better to what is now known as Schiller...).
Edited by AllanDystrup, 11 November 2020 - 08:43 AM.