PSR B1257+12 is a pulsar located in globular cluster M4 and within the constellation Virgo. It is a fairly typical neutron star, established to have a mass of 1.4 solar masses. What makes this particular pulsar so interesting, however, is that it is the home of the first ever discovered exoplanets. It's located 2300 light years from Sol, and the discovery of these extrasolar planets was announced by Aleksander Wolszczan and Dale Frail in January of 1992. The pulsar rotates 161 times per second, with a period of 6.2 miliseconds, and spewing forth massive amounts of electromagnetic radiation. The three planets are fairly typical rocky worlds, but because they orbit a pulsar they are bombarded with too much radiation to support organic life.
The pulsar itself was discovered in 1991 by astronomers using a radio telescope at the Arecibo Observatory. The exoplanets orbiting the pulsar were disclosed by variations in the time between the pulses observed in the pulsar. The planets orbit between 28 and 69 million kilometers (18 and 43 million miles). PSR B1257+12 B and C were discovered initially in 1992, but PSR B1257+12 A wasn't discovered until 1994.
Of further interest, PSR B1257+12 A is the least massive exoplanet discovered with any observational technique. Since the discovery of B and C, over 5,000 exoplanets have been discovered. Exoplanets around pulsars are particularly rare, with only one other pulsar as of yet discovered with exoplanets orbiting (PSR B1620-26)
// Brevity Quest 2023