What was the First Extrasolar Planet Discovered?
The first extrasolar planets discovered were a pair of rocky objects orbiting PSR B1257+12, a pulsar in the constellation of Virgo, 980 light-years from the Earth. Radio astronomers Aleksander Wolszczan (Polish) and Dale Frail (Canadian) were credited with the find, which was announced in 1992 and quickly confirmed. As of 2007, 242 extrasolar planets are known. It is suspected that at least 10% of Sun-like stars have planets, though the actual value may be much higher. The discovery of planets orbiting PSR B1257+12 was a surprise to astronomers at the time, because these were pulsar planets, and it was generally assumed that planets only formed around main sequence stars. The two extrasolar planets are now known as PSR B1257+12B and PSR B1257+12C. A third planet, PSR B1257+12A, which orbits closest to the star, was discovered a couple years after the others. The two larger planets are around four times the mass of the Earth. The pulsar they orbit is the remnant of a supernova. It is un
