Abstract

Invited Talk - Plenary

Thursday, 18 September 2025, 11:30   (Synagoge - Kuppelsaal / virtual plenum)

Time Domain Astronomy

Thomas Kupfer
Universität Hamburg

The vast amount of large-scale photometric sky surveys has shown us that the sky is not static but highly variable. This ranges from slowly transiting exoplanets to powerful stellar flares, up to hungry supermassive black holes in the cores of massive galaxies to the most violent explosions in the universe. Due to many new developments in detector technology, data processing and data storage, the amount of new data coming each night has already reached a level that not every source can be followed making population studies of rare object types difficult as well as possibly missing new types of objects teaching us new physics. In the late 2030s this is expected to only get worse. For example, the upcoming space based gravitational wave detector LISA is expected to detect 10s of thousands of Galactic binaries individually with possibly thousands to be detected both in gravitational waves and electromagnetic waves. The Einstein Telescope which is expected for the early 2040s is expected to detect hundreds of neutron star mergers per year, many of them sufficiently bright to be detectable in the electromagnetic bands. So far, no facility is either available nor planned to have both the flexibility as well as the aperture to quickly react with spectroscopy to the large number of brightness variations on the sky while maintaining the possibility for regular queue based observations. In this talk, I will present the idea of the Time-Domain Telescope where you will get a spectrum, anywhere, anytime. The Time-Domain Telescope is a planned spectroscopic facility consisting of a large number of medium size telescopes which can either operate as individual telescopes or be combined to a single large telescope.