Observing Time Description

The OAJ offers 20% of Open Time to the astronomical community through periodical calls. The rest of the available time is devoted to conduct large-sky surveys. During the first years of operation, the OAJ telescopes and cameras will be mostly devoted to conduct the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS; 2017—2024) and the Javalambre Photometric Local Universe Survey (J-PLUS; 2016—2020). Both J-PAS and J-PLUS will provide powerful 3D views of the Universe that will be made publicly available to the community as legacy projects.

The OAJ Open Time

The OAJ Open Time is splitted in semesters as given below:

  • Semester A: January 1st – June 30th
  • Semester B: July 1st – December 31st

Three different categories of Open Time are defined:

  • OAJ Regular Programmes (OAJ-RPs), up to 120h/semester. OAJ-RPs are defined as short observing projects that require no more than 48h/semester. These projects are expected to benefit from the large FoV and/or the unique filter set of the OAJ telescopes.
  • OAJ Large Programmes (OAJ-LPs) up to 148h/semester. OAJ-LPs are defined as long observing projects that exploit the large FoV and the unique filter set of the OAJ telescopes to conduct small or intermediate-size surveys that require, at least, 48h/semester. The requested time can be distributed in up to 4 semesters. OAJ-LP proposal shall demonstrate the scientific and technical capabilities of the research team to handle and analyze the large volumen of data gathered by the program as well as to publish the results in due time.
  • OAJ Director’s Discretionary Time (OAJ-DDT), up to 40h/semester. OAJ-DDT proposals are reserved for testing the feasibility of potential future observing cases of great scientific impact, for the follow-up of objects in which a quick response is key for the scientific return, of for unexpected events. OAJ-DDT proposals are evaluated by an internal committee chaired by the Director of CEFCA.

The average length of the astronomical night at the OAJ is about 8.4h. OAJ-RPs, OAJ-LPs and the OAJ-DDT amount to 20% of the available time. All the different categories of Open Time are splitted in the same 10:20:10 ratio of Dark:Gray:Bright time conditions.

In case that the time allocated for OAJ-RP or OAJ-LP projects is not awarded completely (either due to a scarcity of proposals or to their unfeasibility and/or low quality), the OAJ-TAC may decide to move this time to any other category with overpressure of high quality proposals. Otherwise, this time will be moved to the OAJ-DDT and the J-PLUS/J-PAS time in the ratio decided by the OAJ-TAC.

Calls for open time currently available are indicated below:

OAJ Time Allocation Committee (OAJ-TAC)

OAJ-RPs and OAJ-LPs are evaluated by the OAJ Time Allocation Committee (OAJ-TAC). The OAJ-TAC consists of a single pannel constituted by 5 members. Two of them will be senior members of CEFCA with a strong scientific background and a good knowledge of the technical capabilities of the OAJ telescopes and cameras. Other members will be selected among senior postdocs and staff astronomers in Spanish institutes, chosen to cover different areas in Astronomy and Astrophysics. The OAJ-TAC is appointed by the Director of CEFCA for up to two years.

The meetings of the OAJ-TAC will take place at CEFCA at least 2 months in advance to the beginning of the observing semester under review. By default, meetings will happen during the second halfs of October and April for Semesters A and B respectively.

Applying Conditions & Submission Instructions

The OAJ Open Time is offered to members of research institutions in the European Union and Brazil. All OAJ proposals shall be leaded by up to two Principal Investigators (PIs). At least one PI and 1/3 of the members of the proposal shall belong to a Spanish institution.

The opening and deadlines of the call for proposals for OAJ-RPs and OAJ-LPs in each semester are:

  • Semester A – Openning: August 1st; Deadline: September 15th.
  • Semester B – Openning: February 1st; Deadline: March 15th.

OAJ-DDT proposals can be requested at any time.

Proposals shall be filled in and submitted following the OAJ Observing Proposal Tool and the instructions available at this website. To access this tool, you must be logged in, for which you must have registered previously at the OAJ website. If you have any problem to log in, please contact us.

Observing at the OAJ

By default, OAJ proposals are executed in queue mode. The visitor mode can be considered upon request depending on the available resources and logistics at the OAJ.

Deliverables and Proprietary Time

The data collected at the OAJ as part of an Open Time proposal will be provided to the contact person indicated in the proposal form, once the observations are concluded and validated by CEFCA.

The delivered data account for:

  • Raw scientific data
  • Calibration frames (bias, darks, flatfields and spectrophotometric standards)
  • Scientific data reduced and photometrically calibrated in a standard way with the specific OAJ pipelines developed by the CEFCA team for each instrument

After a proprietary time of one year, the data will be made public through the OAJ External Data Access Machine.


Publications derived or partly based on OAJ observations shall be acknowledged as follows:

“Based on observations made with the (JAST/T80 and/or JST/T250) telescope/s at the Observatorio Astrofísico de Javalambre, in Teruel, owned, managed and operated by the Centro de Estudios de Física del Cosmos de Aragón.” This sentence shall be included as a footnote in the first page of the publication. If this is not possible, it will be included in the Acknowledgment section of the manuscript.

In case of a publication derived from the OAJ DDT, the Acknowledgment section of the manuscript shall include the sentence: “We thank the Centro de Estudios de Física del Cosmos de Aragón for allocation of Director’s Discretionary Time to this program”.

In case of a publication that makes use of OAJ data reduced by CEFCA with the OAJ pipelines, the Acknowledgment section of the manuscript shall include the sentence: “We thank the OAJ Data Processing and Archiving Unit (UPAD) for reducing and calibrating the OAJ data used in this work”.