Application for Observing time
at the Calar Alto Telescopes

- General Information -

Applications for observing time at the 2.2m and 3.5m telescopes for Autumn semester 2018 (July 1 through December 31).

MPIA and Spanish Guaranteed time for 2.2m telescope,
Open time for 2.2m and 3.5m telescopes:
  • Earliest date for submission is March 1.

Deadline for Autumn 2018 proposals

  • April 4, 2018 23:59:59 CEST

Proposers coming from European countries different than Germany and Spain 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 telescope
    37 nights are offered for Open time.

  • 2.2m telescope
    Besides the option of buying observing time (see below), for this semester free Guaranteed (MPIA and Spanish) and Open observing time is also available. A minimun of 32 nights are offered for free Open time.

    Pursuant the agreement between Max Planck Gesellschaft (MPG) and Consejo Superior de Investigaciones Cientificas (CSIC), Calar Alto offers the option to buy observing time at the 2.2m telescope. 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 2018 Autumn semester.

  • CAFE
    The upgrade of the spectrograph is foreseen to be completed before July. So, CAFE will be available again for the Autumn 2018 Semester. For the first runs, during the summer, CAFE will be offered on a shared-risk basis.

  • 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 Autumn 2018 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 Autumn 2018

    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 Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie 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 5 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.

  • DFG funding
    The deadlines for applications for DFG funding are as follows:
    • Spring semester: November 15.
    • Autumn semester: May 15.
    Please note: The proposal has to follow the current format of Sachbeihilfe/Research Grant as described in the DFG Guidelines 50.01 and has to be submitted via Please comment in the project description (form 54.012) on the relation of the observations to other own DFG projects.

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Last updated: 22 February, 2018
Santos Pedraz