A Spanish Scientific and Technical Infrastructure

40m RT call for proposals

Standard Call for 2024B is open

The Observatory of Yebes (IGN) invites astronomers around the world to submit scientific proposals for observing with the 40 m radiotelescope in the second semester of 2024. The accepted proposals will be observed between August 1st, 2024 and January 31st, 2025. The call will be opened between May 13th, and June 14th, 2024 (15:00 UTC). This call is oriented to single-dish observations and VLBI observations not included in the EVN or GMVA calls.

Beginning this semester, we are introducing a new kind of proposal, Long Term Proposals (LTP), which are intended for proposals needing observations to span over 2, 3 or 4 semesters (e.g. long term monitoring programs), and have similar requirements in terms of page limits as regular proposals. Up to 10% of the total time for semester will be devoted to LTP observations.

We recall that the subreflector has recently been replaced with a new one that allows wobble-switching operations, and is still under commissioning work. This new subreflector will be offered for regular observations in the first semester of 2025.

The 40 m radiotelescope is operated by the Observatory of Yebes, Instituto Geográfico Nacional. It is equipped with receivers at different frequency bands between 2 and 90 GHz. Single-dish observations are offered at 7 and 3 mm wavelengths (the latter only in night time). Position, frequency switching, and on-the-fly mapping can be used at both bands. Note that single-dish observations at 13, 35 and 60 mm (K, X, and C bands) are currently offered in Director's Discretionary Time only (see below). For more information on the telescope, modes offered and useful advices concerning this call, please refer to the 40m RT page.

The proposal preparation tool, RAYO, can be accessed here.

Director's Discretionary Time (DDT)

Since 2019, a small fraction of the observing time is open, through the whole year, to proposals classified as Director's Discretionary Time (DDT). Under this type we consider:

  • Target-of-Oportunity (ToO) proposals for sources which show transients.
  • Urgent proposals which require immediate observations due to their high impact or highly competitive goals that lead to exceptional results or continuation observations of recent discoveries that need to be complemented.
  • Proposals that want to test new ideas which are potentially disruptive and which can be performed in a short time.

Long Term Programs (LTP)

Long Term Proposals are regular-like proposals meant for projects needing observations to span across 2, 3, or 4 semesters (e.g. long term monitoring programs). The need for splitting observations across semesters must be adequately justified in the proposal text. Note that up to 10% of the total time for semester will be devoted to LTP observations. To create a LTP, check the appropriate box during proposal creation in RAYO, and specify the number of semesters requested.


Apart from filling the application form, it is mandatory to include a scientific and technical justification that must be uploaded as a separate PDF file. The maximum extension of regular and LTP proposals is 2 pages of text + 2 pages for Figures, Tables and References. The format must be A4, with a font size 11pt or larger, and single spacing. The scientific justification of DDT proposals has a maximum extension of 2 pages for everything, in the same format. A simple LaTeX template is provided here for these purposes. Please note that failure to comply with these rules could result in proposal rejection.

Program Committee

The RT40m programme committee that evaluates proposals for the regular calls is composed of four members from outside our institution and one internal member. The current composition of the committee is as follows:

  • Izaskun Jiménez-Serra, Centro de Astrobiología (CAB)
  • Aina Palau Puigvert, Instituto de Radioastronomía y Astrofísica (IRyA - UNAM)
  • Carmen Sánchez Contreras (CAB)
  • José Carlos Guirado (Universitat de València)
  • Miguel Santander-García (Yebes Observatory)

Any questions regarding the submission process should be addressed to m.santander at

Pablo de Vicente.
Director of the Observatory of Yebes, Centro de Desarrollos Tecnológicos