Application for Observing time
at the Calar Alto Telescopes

- General Information -

Applications for observing time at the 2.2m and 3.5m telescopes for Spring semester 2019 (January 1 through June 30).

Spanish Open Time at the 2.2m and 3.5m telescopes.
The Principal Investigator (PI) of the proposal and at least half of the team must be affiliated with a Spanish Institution.
  • Earliest date for submission is September 20.

Deadline for Spring 2019 proposals

  • October 18, 2018 23:59:59 CEST

Proposers coming from other European countries are kindly asked to apply via NorthStar/Opticon. Travel funds are available for accepted OPTICON proposals. Please also note the possible different deadlines!

If you would like to get an email reminder in the future to inform you about the start of the next proposal round, send an email to notice"at" with the subject line "CfP subscribe". In the same way you can unsubscribe from this list with the subject line "CfP unsubscribe".

News and remarks
  • 3.5m and 2.2m telescopes
    As an ICTS (Spanish Singular Scientific Facility) Calar Alto offers a minimum of a 20% of the available observing time. Due to the new status of the observatory, the number of available observing nights, for the Spanish community, will be larger from 2019. For this reason, Calar Alto encourages Spanish teams to send their proposals and take advantage of the new situation.

    Calar Alto also offers the option to buy observing time at the 3.5m and 2.2m telescopes.
    A separate operations agreement between CAHA A.I.E. and the respective user institution shall be signed. For further information, please don't hesitate to contact CAHA director (

  • 1.23m telescope
    There is no definite deadline for this telescope.
    For any use of the 1.23m telescope, a separate operations agreement between CAHA A.I.E. and the respective user institution shall be previously signed. Please, contact CAHA director (

    The main science case of the CARMENES Guaranteed Time Observations is the detection, follow-up and characterization of planets around M dwarfs with radial velocities. The agreement between CAHA and the CARMENES consortium protects this science case. Principal investigators of Open Time proposals to CARMENES which might overlap with this science case are encouraged to contact the CARMENES consortium for collaboration. In all other cases, arguments explaining why the science case does not overlap should be provided in the "Astrophysical Context" subsection (8a) of the proposal.
    CARMENES is also available for Open Time programs in 2019 Spring semester.

  • CAFE
    After the upgrade of the spectrograph, CAFE will also be available for the Spring 2019 Semester.

  • PANIC- The wide-field infrared camera is not available
    The four HAWAII-2RG mosaic of PANIC will be replaced by a new HAWAII-4RG detector. The upgrade of the camera will be carried out during the next months and will not be available for this semester.

  • PlanetCam- The two-channel (0.38-1.7 microns) lucky-imaging camera is fully operational at Calar Alto
    Although the camera utilization corresponds to its owner (the Group of Planetary Sciences GPC of UPV/EHU), in its visiting instrument mode at Calar Alto Observatoriy, the use of PlanetCam can be requested for any other program through a collaboration with the GPC.
    Potential applicants please contact Prof. Agustín Sánchez-Lavega (

  • TWIN and MOSCA
    These two instruments are not offered this Spring 2019 semester.

  • Visitor, Service A and Service B programmes
    CAHA will approve programmes in visitor and service mode. Service programmes will be executed as A (priority) and B (backup). Visitor mode proposals will have higher priority to be scheduled.

    1. Service A: Only for highly ranked proposals. The observations will be done in queue mode (exceptions see below) and buffer time is allocated to ensure that the obtained data set is complete.
    2. Visitor mode: The observations will be performed by the visiting astronomer in a fixed period. No buffer time will be reserved. If the requested observing conditions are demanding (good seeing, photometric, etc), a back-up programme should be included. It should be also discussed and approved by the TAC.
    3. Service B: These programmes are scheduled as backup, when all Service A programmes (including those for guaranteed time) have got their data or they cannot be executed. This implies that time for these programmes is allocated generally towards the end of the semester and only proposals whose objects have the appropriate RA can be considered, or when medium weather conditions are acceptable.

  • Rules for Open Time service observations
    Programmes in service mode are generally performed during service blocks. Although tentatively observing slots are assigned for each programme, the observations will be performed in a kind of queue mode. This gives the observatory more flexibility to react on changing observing conditions, so that the programmes will benefit from higher efficiency.

    At the 2.2m telescope, due to the cadence requirements of the Black Hole project in progress, the observations of approved Open Time programs will be carried out in blocks of no more than three nights in a row.

    In contrast to other instruments, whose configuration can be changed quickly between one programme and another, PMAS needs more time for setup changes. This implies that the configuration cannot be changed during the night and thus a queue scheduling is difficult, if not impossible. For this reason (and only for this instrument), the rules for observations in service mode are changed in the sense that:

    • "Service mode" means "delegated service", i.e CAHA staff will carry out the observations, but on specific dates, without compensation for weather losses.
    • The TAC will approve only programmes requesting whole nights. Programmes requesting few hours for several nights will not be approved. They should propose a secondary program (in the back-up section) for the rest of the night, which has to be approved by the TAC, and being above the cut-off.
    • If the requested observing conditions are demanding (very good seeing, photometric night, etc), a back-up programme should be included, just as in the case of the "Visitor Mode" programs.

    For instruments different to PMAS, proposals requesting fraction of nights can be accepted only as "Service mode". They should be exceptional and very well justified, and should receive a high grade by the TAC.

  • Available instruments for Spring 2019

    3.5m telescope

    2.2m telescope

    1.23m telescope

    Visiting instruments

      Calar Alto offers the option of installing your own instrument at the observatory telescopes. Please contact CAHA director ( well in advance, to consider the feasibility.

  • Proprietary period for observing data
    All observing data, from Open Time Programs, will be made public by the Virtual Observatory (VO), Madrid, after a proprietary period of one year after the end of the observation.

  • Report the published articles
    Calar Alto Observatory kindly asks you to inform us ( of any publications that makes use of data collected at our facilities.

    Publications must contain a footnote as follows:
    'Based on observations collected at the Centro Astronómico Hispanico en Andalucía (CAHA) at Calar Alto, operated jointly by the Andalusian Universities and the Instituto de Astrofísica de Andalucía (CSIC)'.

  • OPTICON funding
    This semester up to 10 nights can be available in the 3.5m telescope and 10 nights for the 2.2m.

    Observers who intend to apply for funding have to submit their application via the NORTHSTAR tool:
    Please note the possible different deadlines.

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Last updated: 19 September, 2018