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Table of Contents
2026 observing campaignTHEMIS 2026 observing campaign will take place approximately from early September to mid-september, 2026, lasting for about 70 days. The 1st half of 2026 shall be mostly dedicated to the on-going installation and commissioning of the Italian IBIS 2.0 spectro-imager. 2026 campaign scheduleThe 2026 campaign shall observe the following schedule:
Call for observation time during the 2026 campaign (open)The call for the 2025 observing campaign is now open!
Interested researchers are encouraged to check the available instrumentation for 2026, the information on THEMIS observing capacities, as well as the available data products. Inquiries : Applicants, in particular if they are not familiar with THEMIS observations, are encouraged to contact the THEMIS staff — in particular email themis.team@themis.iac.es —- directly to obtain more specific information or express their needs. Given the smaller amount of international time, interested international researchers can also contact the THEMIS staff to discuss possible joint campaign with French applicants, in case compatible observation targets/mode are envisioned. How to applyThe submission of proposals is specific to the category of users one belongs, based on rules of access:
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Available instrumentation for 2026
Adaptive optics
TAO is available and tested over sunspots and granulation with good results over significantly long periods of time (seeing dependent).
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A slowed-down (100Hz) version of the same system can be used to stabilize Mercury.
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At the moment it is not possible to use the AO over the solar limb (or for neighboring prominences).
MTR2 in spectroscopy mode
In this mode, up to 4 (old) EMCCD Andor iXon camera (512×512) and up to 2 (new) Andor Zyla (2kx2k) cameras are available. Both 6 cameras can be setup and used at the same time (with their respective specs), in accordance with the SP2 output physical limitations. More information about the MTR2 spectrograph.
MTR2 in spectropolarimetry mode:
In this mode, 3 cameras (hence 3 wavelengths) at most are available, from the above list. It is possible to combine polarimetric and non-polarimetric cameras. THEMIS polarimetric analysis scheme is based on a full-Stokes analyzer located at the F1 prime focus. For any solar polarization state to measure, the output of the analyzer is made of dual superimposed complementary linear polarizations. Thanks to THEMIS “polarization friendly” new optical scheme, this output travels through the telescope and arrives unperturbed on the spectrograph cameras. Just in front of the camera, a Wollaston splitter separates the beam into complementary Stokes components to form the spectral focal plane. More information about the MTR2 spectrograph.
Regarding the available analysis software:
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A Stokes map quick-look is now available.
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Thanks to V. Bommier, a basic magnetic field inversion software package (running locally in IDL) is available.
Broadband imaging context camera:
It is running concurrently with the spectrograph. Current setup is for 656 nm (red), but this can be changed optionally to G-band or other.
2024 known problems (and solutions)
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The optical diffusion problem that was detected in Sept 2024 (mostly affecting the He D3 observations) has been identified and corrected (November 2024).
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The data acquisition issue in polarimetric modes was tracked down to a bad synchronisation between the analyzer rotation and the camera exposure. This has been solved at the cost of slowing down the acquisition loop (roughly a factor 2 slower). This issue has been affecting all the September 2024 runs.
