gravitational lensing natures telescope 120323 676709  Dead star found to be warping light of its companion

The Kepler telescope has observed the effects of a dead star bending the light of it's companion star, through the immense gravitational forces it harbors.

NASA’s Kepler space telescope has observed, through use of the UV-activity data supplied by Cornell University, that a dead star called KOI-256 is warping the light coming from its red dwarf companion star.

The dead star, otherwise known as a white dwarf, is the burnt out remains of a star of similar size to that of our sun. White dwarves are composed of highly compressed matter and though they are about the size of the earth, they have the equivalent mass of our sun. Because of this, even though the red dwarf is much larger, it actually orbits the white dwarf. This immense gravity well caused by the white dwarf is what creates the warping effect: The dwarf’s gravitational pull literally bends the light that passes around it, so the light from the companion star looks bent as well, like looking at it through a rounded lens.

 

130405094732 large Dead star found to be warping light of its companion

Artist's conception of the warped light

 

Jim Fuller, graduate student and co-author of the study, explains the fascinating properties of the star system: The red dwarf orbits the white dwarf at close range in just 1.4 days. Fuller says this is indicative of a previous “common-envelope” phase in the system, where the red dwarf orbited the other star within the outer layers of its atmosphere (this being before it died). Furthermore, the immense gravity of the white dwarf means the red dwarf will one day be caught in its gravity well and will be systematically stripped of mass until it forms a disc of hot matter

 

"This system is especially exciting because it allows us to accurately characterize the peaceful state of these systems before the violent mass-transfer phase begins," says Fuller.