Researchers at the University of California at Berkeley have been monitoring the star by aiming the Infrared Spatial Interferometer, atop Mt. Wilson in Southern California, toward the star’s home in the constellation Orion. Since 1993, Betelgeuse (pictured in a NASA image at left) has shrunk in diameter by more than 15 percent.

Betelgeuse is so big that in our solar system it would reach to the orbit of Jupiter.

Its measured shrinkage means the star’s radius has shrunk by a distance equal to the orbit of Venus.

we do not know why the star is shrinking

Considering all that we know about galaxies and the distant universe, there are still lots of things we don’t know about stars, including what happens as red giants near the ends of their lives

Whenever you look at things with more precision, you are going to find some surprises

very fundamental and important new things