Astronomical Observatory, Warsaw University
The Milky Way is a spiral galaxy. This is inferred from various methods, such as radio observations of Galactic gas, star counts, as well as from our extrapolation of structures seen in other galaxies. However, these methods are indirect and rely on many assumptions. Precise mapping of the Milky Way is also difficult because we may only observe it from the inside through clouds of gas and dust. In result, the exact picture of our Galaxy is still under debate.
However, distances can be accurately measured to Classical Cepheids, which are young pulsating variable stars. I will present a new comprehensive picture of our Galaxy in three-dimensions based on the positions in the sky and precisely measured distances of thousands of these objects.
NOTE: The Colloquium will be exceptionally held at 13:00 hrs.