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; started in 2023) and the Javalambre Photometric Local Universe Survey (J-PLUS; since 2016). 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

JST250

For the first time, we are offering competitive time with JPCam at the JST250, open to the astronomical community. We are providing a total of 200 hours over two semesters, 2025B and 2026A. This corresponds to 20% of the expected total available time. The JST250 will undergo a shutdown of approximately four months during this period due to an upgrade of the mount control system.

The JST250 and JPCam were designed to conduct large-area sky surveys. However, this first allocation of open time is dedicated to Shared-Risk Programs (SRP), to be observed over a one-year period without time restrictions, apart from target observability. This initial open-time period will help the OAJ manage and conduct, for the first time, observations for different projects beyond the one that originally defined the design of JPCam and the JST250 (J-PAS). Observations on this first occasion are shared-risk, meaning they are not guaranteed to be executed, nor is data quality assured. However, the OAJ will make every effort to carry out the observations and deliver data that meet each project's objectives.

Following this first period, a call for Legacy Surveys with JPCam will be issued. Therefore, this initial call presents a valuable opportunity to assess on-sky performance for various projects before committing time to long-term legacy survey programs.

Details of the call are available in the CfP document. The document also describes the observation modes offered with JPCam, tools for planning observations and estimating exposure times, as well as instructions and links for proposal submission.

We hosted a live online session to support users with the CfP details, observing tools, and the proposal submission process. The recorded video can be found at:

https://www.youtube.com/watch?v=zIYD_nQ6XIY

You can find the presentation in PDF format: here

JST250 DDT

Additionally, the Director's Discretionary Time is open for proposing observations with the JST250.

OAJ JST250 Director’s Discretionary Time (OAJ-JST250-DDT), up to 15h/semester. OAJ-JST250-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, for astronomical unexpected events, or for high impact science cases for which the JPCam FoV and its filter system are specially suitable to the point that it could hardly be conducted with other accessible infrastructures. OAJ-JST250-DDT proposals are evaluated by an internal committee chaired by the Director of CEFCA.

OAJ-JAST250-DDT proposals can be submitted at any time. Details of the call are available in the CfP document.

JAST80

The OAJ regularly offers 80h of Open Time with T80Cam at the JAST80 per semester to the astronomical community. The rest of the available time is devoted to conducting large-sky surveys or Legacy Surveys. In total, more than 25% of the observing time of the JAST80 is offered.

Here only the call for regular observing time is described.

Two different categories of Open Time are defined for the JAST80:

• OAJ JAST80 Regular Programmes (OAJ-JAST80-RPs). OAJ-JAST80-RPs are defined as short observing projects that require no more than 40h/semester. These projects are expected to benefit from the large FoV and/or the unique filter set of the OAJ telescopes. Notice that the only available observing mode is the Target of Opportunity (ToO).
• OAJ JAST80 Director’s Discretionary Time (OAJ-JAST80-DDT), up to 30h/semester. OAJ-JAST80-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, for astronomical unexpected events, or for high impact science cases for which the T80Cam FoV and its filter system are specially suitable to the point that it could hardly be conducted with other accessible infrastructures. OAJ-JAST80-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.All the different categories of Open Time are split into the same 1:2:1 ratio of Dark:Gray:Bright time conditions.

In case that the open time allocated for OAJ 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.

Notice that, besides the observing time described here, Legacy Surveys with JAST80 telescope for up to 5 years are offered by CEFCA. You can see the details here.

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 for JAST80

The opening and deadlines of the call for proposals for OAJ-RPs for JAST80 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.

Acknowledgments

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

“Based on observations made with the (JAST80 and/or JST250) 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 Department (DPAD) for reducing and calibrating the OAJ data used in this work, as well as the distribution of the data products through a dedicated web portal.”