Consider two identical microscope slides in air illuminated with monochromatic light. the bottom slide is rotated (counterclockwise about the point of contact in the side view) so that the wedge angle gets a bit smaller. what happens to the fringes

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?