Original Title:

Microlensing

Keywords:

demonstrator lensing Galaxy general relativity mass

Description:

This scenario is based on the deviation of the light by massive objects. The light is emitted by a background source (star or galaxy) and received on Earth. In the absence of deviation, only one ray is received on Earth, along the direction to the source. If a mass (the lens) is located between Earth and the source, general relativity states that light rays are deviated towards Earth. The students will discuss the geometrical aspect of this phenomenon, the different orders of magnitude of the lensing, and then apply this to a case of ‘microlensing’ to infer the mass of a lens in our Galaxy.