“Upside-down planet” reveals new method for studying binary star systems

An image of the Sun used to simulate what the sun-like star in a self-lensing binary star system might look like. NASA.

Working with UW astronomer Eric Agol, doctoral student Ethan Kruse has confirmed the first “self-lensing” binary star system — one in which the mass of the closer star can be measured by how powerfully it magnifies light from its more distant companion star. Though our sun stands alone, about 40 percent of similar stars are in binary (two-star) or multi-star systems, orbiting their companions in a gravitational dance. Read more at Astronomy Magazine.