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Credit: Ruslan Merzlyakov

What is offered

In this call, the Nordic Optical Telescope (NOT) offers access to observing time in return for a contribution to the operational cost.

The Nordic Optical Telescope is located at the Roque de los Muchachos Observatory on the Canary island La Palma, Spain, which provides some of the best observing conditions on the northern hemisphere. The observing conditions, instrumentation and observing modes offered at the NOT allow to do state-of-the-art observations, at the forefront of many areas in modern astronomical research, as is also shown by its strong publication record.

The call is open to anyone from anywhere, be it projects, research groups, institutes or larger (national) communities. The scale of any agreement can range from small observing time allocations in a single semester, up to more extensive allocations over various years (possibly as a full member).

User contributions

The baseline cost per night is €5,620. The general rules for the allocation of observing time and the related user contributions can be found here, in particular see Chapter 7 'External projects' of that document.

Instrumentation and telescope

An overview of the instrumentation at the NOT can be found here.

The workhorse instruments are an optical imager and low-resolution spectrograph ALFOSC, a NIR imager and low-resolution spectrograph NOTCam, and a fibre fed echelle spectrograph FIES which offers resolutions up to ~67,000, and is located in a separate building in a controlled environment, and provides a radial-velocity stability of ~4 m/s. A further upgrade of the spectrograph, with the aim of improving the radial velocity stability to ~2 m/s, is in progress.

Over the last several years, we have expanded the capabilities of the telescope to observe solar-system objects, in particular very fast moving objects such as (hazardous) near-earth asteroids and comets, and space debris. We have done multiple observations of GPS satellites, which move with speeds of 50-100 "/sec relative to siderial rates, and we believe we can do observations of objects with speeds in the order of ~1000 "/sec.

Observing modes

Scientific programs

One of the strengths of the NOT is that it provides a wide range of options for flexible scheduling. Broadly speaking, we provide the following observing modes:

  • Visitor mode: This is the classical observing mode, with specific observing runs, normally consisting of several consecutive nights, where visiting observers execute the observations themselves. Astronomical and support is provided on the first night, and technical support is provided on the remaining nights
  • Service mode: In principle the same as for regular visitor mode observations, except that the observations are executed by the NOT staff
  • Monitoring mode: This is in effect a sub-category of service mode, where the observing time is divided in smaller chunks (being only a part of a night) that are spread over various nights, where we do the observations. The naming is more an indication on the scheduling (a couple of nights in a single observing run versus various small chunks of time spread over multiple nights)
  • Target-of-Opportunity(ToO)/Queue mode: These are also observations executed in service mode, but the observations are executed depending on specific requirements. This can, in the case of a ToO program, be the requirement of prompt (immediate) execution of observations triggered by a transient event, or this can (also) be the requirement for specific observing conditions (e.g., a seeing limit) under which the observations are to be executed
For the execution of the observations, we provide a system of Observing Blocks (OBs), in which observation can be fully defined. The use of OBs is in principle mandatory, except for visitor mode observations.

Educational use

Beyond the use for scientific programs, the NOT also provides dedicated facilities for both on-site and remote observing courses. For general information, look here.


For any questions and/or more detailed information, please contact the NOT Director Dr. Thomas Augusteijn (email