An Unexplained Radio Source Bursts Toward the Galactic Center

In 2002 the Very Large Array caught an unusual radio source, GCRT J1745-3009, in the direction of the Galactic center. It produced five bursts at an apparently regular interval of about 77 minutes, and each burst decayed in roughly 2 minutes. A 2003 observation found only one weaker burst, and the source is active only about 10 percent of the time, which makes it hard to study. Astronomers have not settled what it is. Proposed explanations include a precessing pulsar and a pair of orbiting neutron stars.