Call for proposals – semester 2019A


The deadline for the submission of proposals for Spanish CAT night observing time for semester 2019A is Tuesday, 2 October 2018, at 23:59 h Canarian local time (+1 h in the mainland, or 22:59 UT).

The call for collaborative proposals between Spanish and Mexican astronomers at the GTC and GTM will be issued 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 an Institution in Spanish soil. 
  • The start and end of the semester change with telescope as illustrated next:
    • WHT, INT, Stella:   February – July.
    • NOT, TNG, Mercator:   April – September. 
    • GTC:   March – August. 
    • Liverpool (LT):   January – August (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, WHT, 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 is also evaluated by the CAT.
  • The application does allow to request multiple observations using different instruments and telescopes, including GTC. 
  • Proposals are evaluated at the next meeting of the CAT and recommendations are made to the Director of the various Observatories/Telescopes. 

Please, read carefully the following highlights and recommendations made for each telescope and for large programs. There are IMPORTANT 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 2019A, no Large Programs are offered.
  • OSIRISEMIR, MEGARA, CANARICAM, and HiPERCAM are offered in this call. CIRCE is no longer offered. 
  • MEGARA is the new optical spectrograph of GTC that has both IFU and MOS intermediate-to-high spectral resolution capabilities, both of which are offered in the call-for-proposals.
  • EMIR broad- and narrow-band imaging, long-slit and MOS 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, and NEFER),  “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 bands A and B of the Spanish CAT final list. However, any proposal in band C that has the MOS masks already fabricated from previous semesters will be also included in the observing queue (still in band C). Applicants must indicate whether their MOS masks are to be fabricated or are available from previous semesters (there is a box named “masks” in the submission tool 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 between June and August, 2019.
  • CANARICAM is offered on a shared-risk basis in 2019A. The instrument is not at GTC at the time of the release of this call-for-proposals. Observing modes and final observing period within 2019A will be confirmed at the beginning of the semester.
  • CANARICAM and HIPERCAM will likely not be available during 2020. Therefore, applicants can take advantage of this opportunity window.
  • 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 bands A and B. C-band proposals requesting visitor mode will be included in the observing queue, but are not admitted as “visitor”. 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 (ToO) proposals are accepted (see here and here for further details). ToO proposals will be recommended with their corresponding priority whenever they fall in bands A and B of the ranked proposal list. ToO proposals in band C will not be approved.
  • For all approved proposals (bands A, B, C, and filler), GTC Phase 2 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.). Filler proposals must request common-user instruments (OSIRIS, EMIR, MEGARA) with simple instrumental configurations (filler proposals should not request OSIRIS MOS or tunable filter observations) and must contain targets spanning a wide range in right ascension (RA). Filler proposals will only be executed if the observing conditions do not permit observations of proposals in A-, B-, or C-bands. 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.
  • Filler proposals cannot contain ToOs.

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

Filler proposals must be identified by ticking the “filler” box in the proposal submission tool

IMPORTANT NOTE: starting in semester 2019A, all proposals (including ToO) will be ranked in bands A, B, C, and filler. Principal Investigators of A-, B-, and C-ranked proposals and filler projects must complete GTC Phase 2 of ALL approved observations in due time. The bands assigned to each proposal are defined as follows:

  • A-band proposals have very high priority and all possible efforts will be made to execute all of the required/approved observations in the requested semester. If for any reason, A-band proposals remain unfinished by the end of the corresponding semester, the existing GTC Phase 2 will be granted an extended life-time of two additional semesters, or until its completion, whichever comes first. Unfinished A-band proposals do not have to be re-submitted in the following two semesters because of their carry-over status. Approximately one quarter (according to the CAT ranking) of the total amount of GTC available observing time falls in this band.
  • B-band proposals will be executed on a best-effort basis during the requested semester, and do not have a carry-over status. Approximately three quarters (according to the CAT ranking) of the total amount of GTC available observing time falls in this band. 
  • C-band proposals will be executed in extraordinary cases when no A- or B-band objects are available but the good weather conditions permit observations during the requested semester. C-band proposals do have very little opportunity of execution until completion of the project, yet they are included in the GTC observing queue. 
  • Filler proposals, see above.


Detailed information provided by the ING Observatory can be found in the ING call for proposals. All 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 2019A are:

  • See the complete list of ING instruments here. Offered instruments 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 and WHT observing time over two semesters (2019A and 2019B) can be submitted. Any instrument can be requested in this category. The number of nights available for large programs are indicated below
  • 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 medium-resolution fiber is now also working, and tests have shown the stability to be similar to that of the high-resolution fiber. More extensive tests are on-going.
  • We acquired a holographic diffuser to do high-precision photometry. The diffuser effectively scrambled the incoming light, providing a more constant and optimal (`top-head’) shape, with minimal light  loss, significantly reducing any systematic effects in the photometry. The diffuser provides a very stable stellar image with a width (~FWHM) of 5.46 arcsec. A second diffuser, giving a stellar image with a width of 8 arcsec, is expected to arrive soon.
  • The SOFIN high-resolution Echelle spectrograph is again available. It is offered only to do  circular spectro-polarimetry with the medium-resolution (R~80,000) camera. SOFIN is not a common-user instrument: only limited support is provided, and explicit approval for a proposal should be obtained. 


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

  • GIARPS (simultaneous use of GIANO-B + HARPS-N) shared risk offer. Proposals requesting GIARPS must provide a backup program with one instrument only (GIANO-B or HARPS-N) in case the GIARPS configuration is not available.
  • Objects included in the TNG Protected Target List (GAPS protected targets) cannot be requested.
  • The execution of the observations related to the long-term program A38TAC_29, “Follow-up of electromagnetic counterparts of gravitational wave sources at TNG”, may have a significant impact on the schedule of the whole 2019.


The instruments WiFSIP and SES are offered:

  • WiFSIP: the small-band filters and H-beta narrow and wide are not available. WiFSIP gets a new CCD in October 2018, featuring twice-as-fast readout and better cosmetics.
  • SES has no change with respect to previous calls for proposals. 

Liverpool Telescope (LT)

The offered instruments for 2019A are available here. Note the following points:

  • RINGO3 may be replaced with MOPTOP during the semester. MOPTOP has similar functionality but better sensitivity.
  • Check the restrictions and guidance notes for the Liverpool Telescope.

Mercator Telescope

Offered instruments (HERMES and MAIA) can be found at Mercator. The low-resolution, high stability mode of HERMES is no longer available. Instead, the high-resolution mode is slightly more efficient, and a mode in which the object’s spectrum is interleaved with a simultaneous ThArNe exposure is offered.

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 2019A the following time is available for Large Programs:

  • TNG: 10 nights per semester (maximum of four semesters). 
  • WHT: 5 nights per semester (maximum of two semesters).
  • INT: 30 nights per semester (maximum of two semesters).
  • NOT: 5 nights in 2019A, 10 nights in subsequent semesters (up to maximum of four)
  • Mercator: 20 nights per semester (maximum of four semesters).
  • Liverpool: 75 h in 2019A, and 100 h in following semesters (up to a maximum of four).
  • Stellar-SES and Stella-WiFSIP: 60 h per robotic telescope and semester.
  • GTC: not offered for large programs in 2019A.  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 30 Aug 2018.

Contact e-mail: catiac at