Measuring a white dwarf’s gravitational redshift can help us figure out its mass, but for one of the closest stars to us (Sirius B) the numbers didn’t match with other methods. Today’s paper investigates the discrepancy.
One prediction of General Relativity is that because of the way that gravity affects time, the frequency of electromagnetic radiation (light) emitted at the solar surface should decrease as it escapes the Sun’s gravitational potential well, i.e., the solar spectrum should appear gravitationally redshifted. Surprisingly, according to this recent paper by Takeda and Ueno, that prediction had yet to be definitively verified…until now.