Like most astronomical sources, pulsars are named after their position in the sky. Those pulsars discovered prior to the mid 1990s are named based on the Besselian equatorial coordinate system (B1950) and have a B prefix followed by their right ascension and declination. More recently discovered pulsars follow the Julian (J2000) epoch. Pulsars in globular clusters, where the positional designation is not unique, have additional characters to distinguish them. For example PSR J1748–2446ad in the globular cluster Terzan 5 [144Jump To The Next Citation Point].