Leiden Observatory
The survey designation "T-3" stands for the third Palomar–Leiden Trojan survey, named after the fruitful collaboration of the Palomar and Leiden Observatory conducted in 1977. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets.