Saturday science subject: A quad-star system
HD 98800. Source: NASA.
We know planets can form in star systems that just have one star—our own solar system is example enough—but what if you add more stars? More specifically, can planets be born in a star system that has not two or three stars but four? HD 98800 is such a system, and as NASA discovered, planets may have started forming
in a dusty disk that surrounds two of its orbiting stars.
Astronomers used [NASA's Spitzer Space Telescope]'s infrared vision to study a dusty disk that swirls around a pair of stars in the quadruple-star system HD 98800. Such disks are thought to give rise to planets. Instead of a smooth, continuous disk, the telescope detected gaps that could be caused by a unique gravitational relationship between the system's four stars. Alternatively, the gaps could indicate planets have already begun to form, carving out lanes in the dust.
HD 98800 lies 150 light years away from Earth in the constellation TW Hydrae. According to NASA, the star system is 10 million years old—a mere infant compared to our own solar system, which is around 4.6 billion years old.