http://www.newsweek.com/incredibly-rare-supermassive-pulsar-stuns-scientists-949127

Every year, scientists spot a dozen or two new examples of what they call galactic millisecond pulsars—the incredibly dense corpses of stars that spin hundreds or even a thousand times a second.

But even among these extraordinary stars, there are some that stand out. Like one known as PSR J2215+5135, which scientists describe in a recent paper published in The Astrophysical Journal.