A Spanish Scientific and Technical Infrastructure

40m RT call for proposals

Call for proposals: 23B call cancelled

The 40 metre radio telescope will cease regular operations in July 2023 in order to carry out several upgrades. During the summer and early autumn the subreflector will be replaced with a new one that will allow wobble-switching operations. A new K-band receiver will be installed next autumn as well. Work in the antenna, including the commissioning of the wobbler-switching mode, will continue until the end of 2023.

We expect to offer these new capabilities in 2024. The telescope will resume operations after the 24A call which is due January 2024. Further news will be posted on this web page.

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.


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 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)
  • José Pablo Fonfría, Centro de Astrobiología (CAB)
  • 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