2 new star systems are first of their kind ever found

Ohio State University astronomers and their colleagues took this image of the dwarf galaxy Holmberg IX with the Large Binocular Telescope. The arrow indicates the approximate location of the newly... Click here for more information.

COLUMBUS, Ohio -- Astronomers have spied a faraway star system that is so unusual, it was one of a kind -- until its discovery helped them pinpoint a second one that was much closer to home.

In a paper published in a recent issue of the Astrophysical Journal Letters, Ohio State University astronomers and their colleagues suggest that these star systems are the progenitors of a rare type of supernova.

They discovered the first star system 13 million light years away, tucked inside Holmberg IX, a small galaxy that is orbiting the larger galaxy M81. They studied it between January and October 2007 with the Large Binocular Telescope (LBT) on Mt. Graham in Arizona.

The star system is unusual, because it’s what the astronomers have called a “yellow supergiant eclipsing binary” -- it contains two very bright, massive yellow stars that are very closely orbiting each other. In fact, the stars are so close together that a large amount of stellar material is shared between them, so that the shape of the system resembles a peanut.

Ohio State University astronomers and their colleagues have discovered a new type of star system, one that may be the progenitor of a rare type of supernova. The star system... Click here for more information.

In a repeating cycle, one star moves to the front and blocks our view of the other. From Earth, the star system brightens and dims, as we see light from two stars, then only one star.