JST250, the largest telescope at the Observatorio Astrofísico deJavalambre, successfully passed the Preliminary Design Review (PDR) on October 27th 2010. The Final Design Review is expected to take place at the beginning of March 2011.

The first PDR meeting took place in Teruel, during August 11th and 12th, at the headquarters of the Gobierno de Aragón in Teruel. The PDR Committee was constituted by experts in astronomy, telescopes and instrumentation: Steve Eikenberry (University of Florida, USA; Chair), Bernard Delabre (European Southern Observatory, Germanyq), Jesús González (Universidad Nacional Autónoma de México, México), Keith Taylor (Sao Paulo University, Brazil), Vicente Sánchez (Instituto de Astrofísica de Canarias, Spain), Jose Antonio Rodríguez Losada (Grantecan, S.A., Spain), and Javier Cenarro (Centro de Estudios de Física del Cosmos de Aragón, Spain).

The picture illustrates the attendants to the PDR meeting: the PDR Committee, engineers from AMOS; the company in charge of the design and manufacturing of the JST250 telescope, part of the UTE-OAJ), CEFCA staff, and other experts in astronomy and instrumentation who collaborate actively with CEFCA in the development of the J-PAS project.

During the PDR meeting in August it was mainly concluded the suitability of including a wavefront sensor (curvature sensor) and a autoguiding system at the focal plane level of the JST250, for the active control of the telescope focus through the M2 hexapod. The design, based on solutions similar to those considered for LSST, was finally reviewed and accepted on October 27th. The JST250 Preliminary Design was hence succesfully passed.