Sjur Refsdal

Sjur Refsdal (30 December 1935 – 29 January 2009) was a Norwegian astrophysicist, born in Oslo.

In 1970 he earned a doctorate at the Institute of Theoretical Astrophysics, University of Oslo.

Later that year he became professor in astrophysics at the Hamburg Observatory[1] in Germany, and remained in that position until he retired in 2001.

[2] He is particularly known for the "Refsdal Method", which describes how one may estimate the expansion rate of the Universe (Hubble constant) using the measured time-delay and lens properties of a gravitationally lensed Supernova (SN).

He was a member of the Norwegian Academy of Science and Emeritus at the Institute for theoretical Astrophysics at the University of Oslo.