Call for proposals – semester 2018B

The deadline for the submission of proposals for Spanish CAT night observing time for semester 2018B is Tuesday, 3 April 2018, at 23:59 h Canarian local time (+1 h in the mainland).

The call for collaborative proposals between Spanish and Mexican astronomers at the GTC and GTM will be issued soon when the conversations that are being held to combine both telescopes following the agreement of this joint time are concluded.

  • We recall that every proposal within the Spanish CAT scheme must be led by a principal  investigator (PI) affiliated to a Spanish Institution. 
  • The start and end of the semester change with telescope as illustrated next:
    • WHT, INT, Stella:   August – January.
    • NOT, TNG, Mercator:   October – March. 
    • GTC:   September – February. 
    • Liverpool (LT):   July – February (a two-month overlap period is adopted at the start and end of each semester, when proposals from both semesters may be observed in order to reduce problems with under-filled observations queues).
  • Large programs requesting observing time with TNG, NOT, STELLA, LT, Mercator, and/or INT are accepted.  See below.
  • Proposals in visitor mode (including those of GTC) should include a proper backup scientific program that does not require good weather conditions. The backup program are evaluated by the CAT.
  • Proposals are evaluated at the next meeting of the CAT and recommendations are made to the Direction of the various Observatories/Telescopes. 

Please, read carefully the following information and recommendations made for each telescope and for large programs. There are changes with respect to previous calls for proposals. Pay special attention to the new (latex, word, pages) form for the preparation of proposals.

To submit proposals, see “how to submit” at the end of this document.


Detailed information about the feature of GTC for this semester can be found on the GTC call for proposals. A short summary is provided next:

  • In semester 2018B, no Large Programs are offered.
  • OSIRISEMIR, MEGARA, and HiPERCAM are offered in this call. CanariCam and CIRCE are no longer offered. 
  • MEGARA is the new optical spectrograph of GTC that has both IFU and MOS intermediate-to-high spectral resolution capabilities. MEGARA is offered starting from July 1st, 2018. Applicants may take advantage of this broader window of observations only for MEGARA proposals.
  • EMIR broad- and narrow-band imaging and long-slit spectroscopy are offered. All applicants are recommended to use this tool (which does not include overheads) to optimize the observing time of EMIR targets. 
  • OSIRIS “imaging” (broad-band, SHARDS filters, tunable filters),  “spectroscopy” (long-slit, MOS), and “frame transfer and fast photometry” are offered. Multi-Object Spectroscopy (MOS) observations will be part of the observing queue only if the proposals are ranked in the top half (first and second quartiles) of the Spanish CAT final list. However, any proposal in the third and fourth quartiles that has the MOS masks already fabricated from previous semesters will be also included in the observing queue. Applicants must indicate whether their MOS masks are to be fabricated or are available from previous semesters. For overheads related to the various observing modes, see the GTC document.
  • HiPERCAM is a high-speed, multi-band imager and a new GTC visitor instrument (Principal Investigator Vik Dhillon). It is offered on a shared-risk basis to the community quite likely by the beginning of the semester: September – October 2018.
  • For the calculation of overheads, the GTC Observatory strongly recommends the use of the following Phase 2 simulator.
  • Visitor programs are welcome, but will only be admitted whenever they fall in the top half of the ranked proposal list. The applicants must clearly indicate they are applying for visitor mode. A backup program (in visitor mode) should be defined in the case the observing conditions for the main program are not met.
  • Target-of-opportunity proposals are accepted (see here for further details). Target-of-opportunity proposals will be recommended whenever they fall in the top half of the ranked proposal list.
  • Approved CAT proposals ranked in the first quartile, will be granted an extended life-time of three semesters, or until their completion, whichever comes first. Note that all phase II information must be submitted to the GTC at the deadline corresponding to the semester in which the proposal is accepted.

PROTECTED OBJECTS. Due to the execution of Guaranteed Time Observations (GTO) of various instrumental teams, all applicants are kindly requested to check the list of protected objects here (follow the links to the corresponding instrument). Protected objects cannot be proposed for observation by other users, unless an instrumental setup different to that of the GTO is required.

FILLER PROPOSALS: In order to have an efficient queue-scheduled observations scheme for the GTC, it is useful to have a set of “filler” programs that can be executed under adverse observing conditions (bad seeing, poor sky transmission, etc.) and with targets spanning a wide range in right ascension (RA). Proposers may request filler status for their program, and during the proposal selection process CAT will evaluate their suitability for this category. Such proposals can request a large number of observing hours. In order to be considered as filler proposals they must fulfil the following requirements:

  • Their observing requirements should be very relaxed, i.e. little or no restrictions on seeing or cloud coverage. 
  • The chosen observing mode should be a frequently used mode (MOS observations are not accepted for filler programs).
  • There is a scientific gain even if only a small fraction of the requested observations are executed.
  • A list of targets with a broad RA coverage is provided or,  if only few targets are included, they must have good visibility during the semester.

Note that filler proposals have generally been highly successful in the last semesters.


Detailed information provided by the ING Observatory can be found in the ING call for proposalsAll potential applicants must become familiar with the series of changes in instrument availability and of observing time at the WHT and INT driven by the arrival of new survey instruments. The changes are summarized here

The main changes for 2018B are:

  • See the complete list of ING instruments here. Offered instruments for 2018B are: 
  • Investigators wishing to submit proposals to use an established WHT visitor instrument (GHaFaS, PAUCam, PN.S) should follow the instructions given in the ING call for proposals.
  • Applicants are encouraged to submit proposals for large time allocations, even within one semester, particularly for the INT.
  • Large program proposals requiring INT observing time over two semesters (2018B and 2019A) can be submitted. Any instrument can be requested in this category. The number of nights available for large programs are indicated below. No Large Programs requiring WHT observations are accepted in 2018B.
  • At the INT, service observations of approved CAT programs are offered through collaboration with the INT student support astronomers. Details are provided in page 3 of the ING call for proposals.

About 35% of the observing time at the WHT is managed by CAT. Starting from semester 2013B, 20% of the time is distributed to the best-ranked proposals from the Spanish community, and the remaining 15% will be reserved for proposals led by PIs affiliated to the IAC.


Offered instruments are listed here. Updates with respect to previous semesters are as follows:

  • A new fiber bundle, using octagonal fiber, was installed in FIES. This new bundle is expected to improve the radial-velocity stability. Preliminary tests have shown the stability with the high-resolution fiber to be ~2 m/s on time-scales of a day, and below ~4 m/s on longer time-scales. More extensive tests are on-going.
  • The SOFIN high-resolution Echelle spectrograph is again available. It offers spectropolarimetry with the medium-resolution (R~80,000) camera. SOFIN is not a common-user instrument, and explicit approval for a proposal should be obtained. 


Offered instruments (GIANO-B, HARPS-N, Nics, Dolores) are summarized here.

  • GIARPS (simultaneous use of GIANO + HARPS-N) shared risk offer. Proposals requesting GIARPS must provide a backup program with one instrument only (GIANO or HARPS-N).


The instruments WiFSIP and SES are offered:

  • WiFSIP: the small-band filters and H-beta narrow and wide are not available.
  • SES has no change with respect to previous calls for proposals. 

Liverpool Telescope (LT)

The offered instruments for 2018B are available here. Note the following points:

  • LOTUS: this instrument is not offered because it will be taken off the telescope to make room for a new instrument prototype. 
  • Check the restrictions and guidance notes for the Liverpool Telescope.

Mercator Telescope

Offered instruments (HERMES and MAIA) can be found at Mercator.

Large programs

Large programs are expected to accommodate projects that require long-term or synoptic coverage, and large-size projects. They must satisfy these four requirements: 
  • involve novel ideas, opportunities for great advance, or legacy programs, 
  • span between two and four semesters, 
  • publicly release their final high-level products in an appropriate format, and 
  • be led by a Spanish institution (a large fraction of the team should be affiliated to a Spanish institution).

Considering the time allocated to on-going large-programs, in 2018B the following time is available for Large Programs:

  • TNG: 3 nights in 2018B and 10 nights in subsequent semesters. 
  • WHT: not offered for large programs in 2018B.
  • INT: 30 night in 2018B and 2019A.
  • NOT: 5 nights in 2018B and 2019A, 10 nights in subsequent semesters.
  • Mercator: 20 nights per semester.
  • Liverpool: 30 h in 2018B, 75 h in 2019A, and 100 h from 2019B on.
  • Stellar-SES and Stella-WiFSIP: 60 h per robotic telescope and semester.
  • GTC: not offered for large programs in 2018B.  See here for additional information. 

All large programs will be evaluated by the CAT and advised by external expert referees, based on the above criteria. Yearly progress reports are expected, and a final report to the CAT is due at the end of the project.  Raw data from long-term programs will follow the same proprietary period as regular proposals. Up to 66% of the time distributed by the CAT on the Liverpool (LT), Mercator, STELLA, and INT, up to 33% of the time on NOT and TNG, and up to 15% of the time on the WHT may be assigned to large programs.

How to submit

Applicants must ensure that their proposals comply with the required page limits and layout indicated below. The use of English is recommended for normal proposals. Large program proposals must be written in English. To send proposals, use the night time CAT application tool at  A simple manual to learn how to deal with this application is available in this pdf document. To submit a proposal, the PI and co-Is need to be registered. If you are already registered but you do not remember your password, please do NOT register twice (in order to avoid confusions for statistical purposes). You can find instructions about how to reset your password in the same webpage or contact the CAT for additional help.

THERE IS A NEW FORM to build the scientific case of the CAT proposals. All applicants of standard and large proposals are kindly requested to use this new form, which is available here  (a “tar” file will be downloaded; read the README file first).  Please note that applications forms are different for LARGE (long-term) and REGULAR programs. Note also that the time request in the on-line application tool has changed, as one should now specify the  time requested for each semester by creating as many “Observations” as needed.

In the evaluation of proposals, CAT will take into account the publications derived from previous observations with the CAT telescopes. Therefore, in the BIBCodes menu of the application tool, remember to update the fields Comment and Bibliographic code  for all proposals approved in the last two years.

Before the deadline expires, please check that the uploaded pdf file (created with the new form) contain the latest version of your proposal, and that it prints correctly. No replacement or updating of the proposal content will be made after the deadline, and those proposals which do not correctly print out or lack relevant sections will be automatically withdrawn from the evaluation process. Those proposals where the font size (10pt) has been reduced or the text of the scientific justification exceeds limitations (one page for common/regular proposals and two pages for large programmes) will also be withdrawn. Figures and Tables cited in the scientific justification should fit a maximum of one page (normal proposals) and two pages (large programs). It is advised to follow the instructions described at


UPDATED on 1 Mar 2018.

Contact e-mail: catiac at