Science Daily has word of a millisecond pulsar in the wrong kind of binary system
that has astronomers scratching their heads. According to current models of pulsar evolution, such a system should have no way to develop. The pulsar J1903+0327, which rotates 465 times per second, seems to be in a highly elongated orbit around a Sun-like star. Quoting: "Astronomers think most millisecond pulsars are sped up by material falling onto them from a companion star. This requires the pulsar to be in a tight orbit around its companion that becomes more and more circular with time. The orbits of some millisecond pulsars are the most perfect circles in the Universe, so the elongated orbit of the new pulsar is a mystery."