AIP Calendar

Public Event

Virtual Babelsberg Starry Night

Talk (in German): Aufgelöste Sternpopulationen: Von Galilei zum Extremely Large Telescope (Martin Roth)

On Thursday, starting at 6 p.m., Professor Martin Roth's lecture on the topic "Resolved stellar populations – from Galileo Galilei to the Extremely Large Telescope" from the Babelsberg Starry Night series will be online.

Galileo Galilei is (presumably) the first person to succeed, with the help of a first-generation telescope, in resolving the band of the Milky Way, which shines diffusely in the sky for the naked eye, into stars. At any rate, he first published this in his famous book "Siderius Nuntius" in 1610. Starting from this historical milestone, the lecture recapitulates the development of important methods of modern astrophysics for the determination of stellar parameters, such as photometry and the construction of colour-brightness diagrams, and spectroscopy and the construction of the Hertzsprung-Russel diagram. The importance of the development of technology since observation by eye, via photography to modern semiconductor image sensors is described. A local reference to the Babelsberg Observatory is the use of the photoelectric effect for objective brightness measurement, first applied by Paul Guthnick in 1913: in analogy to electronics, the emergence of a technology now called photonics. 

The main part of the lecture is devoted to the still young field of integral field spectroscopy for the spatial resolution of densely packed stellar populations in globular clusters and nearby galaxies. As a further development of the extremely successful investigation of resolved stellar populations by means of "crowded field photometry", in particular with the Hubble Space Telescope, to "crowded field spectroscopy", it will be shown by means of examples that the unique instrument MUSE opens up a completely new dimension of quantitative spectroscopy, which promises brilliant prospects for groundbreaking work by astrophysicists, especially with the future Extremely Large Telescope of the ESO.

This season, the Babelsberg Starry Nights will not take place on site at the AIP, but will come straight to your home: on the 3rd Thursday of each month from 6 p.m. The lectures are available at

or via the YouTube channel Urknall, Weltall und das Leben (Big bang, the Universe and Life) and can be viewed at any time afterwards.

Last update: 20. January 2022