Solar telescopes GREGOR and VTT

Period 2020B (15 Oct – 30 Nov)
Proposal Submission Deadline: 19 September 2020, 23 UT
Send proposals to

Proposals are hereby invited for observing time at the solar telescopes GREGOR and VTT at the Observatorio del Teide in Tenerife. This call is for observing time awarded under the SOLARNET Trans-National Access Programme and a small amount of time in the International Time Program (ITP). All proposals will be treated as being for both programmes, if eligible.

GREGOR Solar Telescope

GREGOR is a 1.5 meter on-axis solar telescope operated in PI visitor mode. Its optical train has recently been redesigned, leading to higher performance. For this call it is offering GRIS spectropolarimetry in slit mode at wavelengths 1.0–1.3 or 1.5–1.8 microns. GRIS observations can be complemented with fast context imaging in any wavelength below 900 nm if a suitable filter is available or provided by the observers.

VTT Solar Telescope

VTT is a coelostat with a 70 cm main mirror, operated in PI visitor mode, with three instrumentation options available.

  • The chromospheric or photospheric grating for spectroscopy in up to 3 spectral regions simultaneously.
  • Instrument setups provided by the user.

Proposal Submission

Time is typically awarded in blocks that are of the order of 10 days long. We expect that there will be about 20 d available on GREGOR and about 20 d on VTT.

Proposals requesting simultaneous use of GREGOR and VTT (co-observations) will be treated as one proposal to be accepted or rejected in its entirety. For the possibility of using only one telescope, please submit also a separate proposal for that telescope.

The SOLARNET call is open for all countries of the world with the exception that the PI and the majority of the users must be affiliated with institutions outside Germany and Spain.

For ITP time, applications must include researchers with affiliations in at least two of the following countries: Spain, UK, Germany, France, Italy, Finland, Belgium.
Proposals will be handled by the EAST TAC, a common European time allocation committee installed by the European Association for Solar Telescopes.

The proposal form and additional information on the instrumentation can be found here:
and on the adjacent “Scientific instruments” pages.

For technical questions about the GREGOR & the VTT telescope, please contact T. Berkefeld (Email: and C. Fischer (Email:

Data acquired in the SOLARNET Access Programme will become public one year after being delivered to the PI.


  • Travel restrictions to Tenerife Observatory caused by COVID-19 may affect these PI-mode observations.
  • For GREGOR, we expect that remote observations will be possible in that case.
  • Following the eligibility rule, SOLARNET sponsorship/support will be available to travel to KIS, Freiburg, and execute the remote observation (contact: