40 meter radiotelescope

The National Geographic Institute operates a 40-meter radio telescope at the Yebes Observatory, a Singular Scientific Technical Infrastructure 50 km east of Madrid. The radio telescope, 40 meters in diameter, is mainly used in centimeter and millimeter wavelengths for observations of spectral lines corresponding to molecules in circumstellar envelopes, interstellar medium of our galaxy, extragalactic objects, and also for astronomical and geodetic VLBI observations.

Calls for observation proposals

Standart call

The standard call is for single-dish and VLBI observations that are not part of the EVN, GMVA, or IVS networks.

This call opens semi-annually. The last call can be found here.

Yebes Observatory and OAN staff will be able to assist in preparing proposals and making observations. All cases are studied individually.


Director’s Discretionary Time (DDT)

Since the first half of 2019, a small fraction of Yebes 40m radio telescope observation time is open for proposals rated as Director’s Discretionary Time. For a proposal to be considered suitable for the DDT program, it must meet the following requirements:

  • Proposals that require observing objects classified as Target-of-Opportunity (ToO. That is, they are short, unforeseen or transitory events.

  • Proposals that require urgent observations due to its high-impact, highly-competitive objectives that lead to exceptional results, or follow-up observations of recent discoveries that require complementary observations with the Yebes 40m radio telescope.

  • Proposals that seek to test new and potentially groundbreaking ideas that can be carried out in relatively short telescope time.

EVN observations call

The 40m radio telescope is part of the EVN (European Network of VLBI), and as such carries out EVN observations at three different times throughout the year. Besides, there are about 10 eVLBI sessions per year, and transitional events like Targets-of-Opportunity,which are evaluated promptly. All proposals go through the EVN program committee.

For information on how to request observation time in the EVN, check here.

GMVA observations call

The 40m radio telescope is part of the VLBI Millimeter Network (GMVA), and as such, it observes twice (spring and autumn) per year. For more information on the observation time at the GMVA, please visit: https://www3.mpifr-bonn.mpg.de/div/vlbi/globalmm/


Proposal submission:

For preparing and submitting proposals for the 40m radio telescope, the in-house RAYO (available here ) tool must be used.

Information on applicants, instruments, objectives, sources, etc., must be provided in the RAYO tool. The scientific and technical justification must be prepared separately and uploaded as a PDF file in the same way that the sources to be observed must be uploaded.

The proposal must contain a scientific-technical justification, including an explanation of how the requested time has been calculated. The maximum document length is 2 A4 pages, plus references, figures and tables, if necessary. The maximum total length is 4 A4 pages. Any word processor capable of producing PDF files can be used for this, although the use of LaTeX is recommended. A suitable LaTeX template is provided.

Researchers must mention in their proposals any relevant observations made with the 40m Radio Telescope or other telescopes, and show any preliminary results, if available. The online calculator must be used for estimating the required time. Besides, it must be indicated if the observations are part of any ongoing PhD.


Technical specifications

At this time, only spectral observations are possible. Continuous observations are reduced to total power drifts and focus scans. No position switch continuum drifts are available. However on-off and frequency switch scans are possible. On-the-Fly mapping mode is also available for speectral and continuum observations. The main continuous and spectral detectors are Fast Fourier Transform (FFT) spectrometers with bandwidths of 2.5 GHz, 1.5 GHz, 500 MHz and 100 MHz.

Available observation frequencies

  • C band: 4.9-5.4 GHz and 6.1 – 6.6 GHz

  • X band: 8.1 - 8,9 GHz

  • K band: 21 - 25 GH.

  • Q band: 41 - 49 GHz

  • W band: 72 - 90 GHz

Detector bandwidth and spectral resolution

  • C band: 500 MHz. 6.1 & 30 KHz

  • X band: 500 MHz. 6.1 & 30 KHz

  • K band: 500 MHz. 6.1 & 30 KHz

  • Q band: 18 GHz. 38 KHz

  • W band: 18 GHz. 38 KHz

Angular resoultion (θb) and apperture efficiency (ηA)

  • C band: θb=260’’, ηA=0.46

  • X band: θb=180’’, ηA=0.70

  • K band: θb=80’’, ηA=0.50

  • Q band: θb=40’’, ηA=0.41

  • W band: θb=20’’, ηA=0.18

The instantaneous detection band expansion up to 18 GHz in the Q and W bands was done within the Nanocosmos project (ERC-2013-Syg-610256-NANOCOSMOS), in 2019.


Observation modes and procedures

Observations are run by the Yebes Observatory operators, using macros and procedures prepared by the support astronomers staff, who will contact in advance the researchers who have been granted time to optimize the observations. Observers are encouraged to visit the Yebes Observatory for preparing their macros and procedures.


Publications acknowledgement

The following should be added on each contribution that uses data acquired with the 40 m radiotelescope. We appreciate if you include the proposal ID: “Based on observations with the 40-m radio telescope of the National Geographic Institute of Spain (IGN) at Yebes Observatory, under proposal XXXX. Yebes Observatory thanks the ERC for funding support under grant ERC-2013-Syg-610256-NANOCOSMOS”