CEFCA announces a Call for Letters of Intent for Surveys with the JST250 Telescope operating at the OAJ. Deadline: 30 April 2026, 14:00 CEST.

JST250 is currently mostly devoted to conduct the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS), mapping thousands of deg² of the sky with a set of 54 narrow-band contiguous optical filters plus 3 broader ones. Following the survey spirit of the ICTS OAJ, and with the aim of maintaining the competitiveness of the facility in the next years, a specific open call for proposals (https://oaj.cefca.es/observingtime/cfp_legacy_surveys_jast80) was made public early 2022 for the definition of the second-generation Surveys to be executed with the JAST80. The selected proposals (https://oaj.cefca.es/observingtime/oaj_ls) started on 2023. In addition, a call for proposals for Shared-Risk Programs with JPCam at the JST250 telescope was issued in February 2025. Six projects were approved for observation (see list). The following competitive, open time call for proposals will be made public mid 2026 to define the second-generation, large Legacy Surveys with the JST250 Telescope. In this context, CEFCA issues a Call for Letters of Intent for Surveys with the JST250 Telescope operating at the OAJ. Observations are expected to start in 2027A.

Letters of Intent shall include the scientific rationale, emphasizing the Legacy Value of the data, and an overall description of the observing strategy and filter system. In the case of new filters is needed, brief technical description will be welcomed. All groups submitting a Letter of Intent will be encouraged to present and discuss their project during an open meeting at early June 2026, prior to the formal Request for Proposals process.

Summarizing, the expected call for proposals will have the following main characteristics:

• 240 hours per year will be offered during 5 years (total of 1200 hours) to perform legacy surveys with the JST250 telescope
• Available filters can be used, these include the J-PAS filter system, and the SDSS g,r,i filters.
• Projects requiring a different set of filters are also welcomed. In this case, the Letter of Intent shall include a description of the proposed filters characteristics.
• Available observing time includes dark, grey and bright hours in a 50%; 25%; 25% proportion, as well as both photometric (60%) and non-photometric (40%). Projects covering the different observing conditions are encouraged.
• The expected starting date for the observations of surveys using JPCam and existing filters is Q1 2027.

And the foreseen process milestones are:

• Letters of Intent submission deadline: 30 April 2026, 14:00 CEST.
• Open meeting to present JST250 Survey Mode and to discuss potential projects. Identification of Synergies: June 2026.
• Call for Proposals OPEN: July 2026
• Call for Proposals CLOSED: September 2026
• Awarded Surveys announcement: November 2026
• Agreements and Survey implementation: November - December 2026
• Beginning of observations: January 2027. If the Survey requires new filters the starting date will be accommodated.

Call for Letters of Intent (pdf 727.2 kB)