The Teide Observatory (OT) is situated in the Nature Park of the High Forest. The National Institute of Astrophysics (INAF) of Italy (one of the signatories of the International Agreement of the Canary Observatories) in 2019 asked the IAC to explore the viability of an installation of Cherenkov telescopes (project ASTRI) in the OT. This project, if it comes to fruition, will be completely financed by Italy and will comprise the most advanced astrophysical installation of the Teide Observatory in the last 30 years. It will also provide observations of the internal structure of the Teide volcano, which could be the key to understand its future evolution. An agreement to build this installation in the Observatory has not yet been signed.

Proofs (tests of the terrain)

No constructions have been made in the Teide Observatory related to the ASTRI project. Only five  have proofs been carried out to establish its viability. They were performed at the suggestion of the architect of the project (contracted by the Galileo Foundation of the INAF, an entity which INAF has set up in the Canaries for its activities) because of the  peculiarity that these telescopes do not have a protective dome. Each proof comprises two perforations each of 7 cm in diameter, separated by 3 meters. Before performing these proofs the IAC sought environmental permission from the Cabildo of Tenerife, whose technicians verified their viability in situ. The report  was favourable, and the IAC followed the corresponding instructions that they gave.

Following the instructions of the Cabildo and to avoid movements of the ground, the line of access to three of the proofs (ASTRI 2, 5, 8) was modified. The new lines minimized the impact on the biological resources, and favoured a more rapid recovery of the surroundings. 

According to the Canary Law of the Ground (article 332) the provisional activities of sounding terrain, the opening of proofs, are subject only to prior communication, without requiring an urban license. These proofs were in the terrain of the Observatory which is situated within the municipality of Güímar, one of the three municipalities which provide ground for the Teide Observatory. In the month of March 2020, the Alcalde and the Secretary of the City Council of Güímar visited the Observatory to get to know its needs and plans for the future. They were attended by the deputy director of the IAC who gave them informal information about the interest of this and other projects, and the importance of a close collaboration between the two institutions. The IAC thanks the City Council of Güímar for its full collaboration and support in protecting the sky, and advancing Science in its municipality with front line installations.

Meteorological Center

The IAC gives its total support to the research work of the AEMET in Izaña, to the point of happily giving them the use of the systems of digital communication of the IAC. The experiments of the Centre for Atmospheric Research of Izaña rely to a large degree on our digital networks and enjoy our full collaboration. What we were warned that carrying out the proofs could affect one of their ongoing experiments we stopped the proofs. We carried out only five of the nine authorized proofs. Afterwards the IAC has asked the INAF to modify its project,  re-siting the telescopes to reduce the risk that, during their construction, there would be an impact on the measurements being made by the Centre of Atmospheric Research of the AEMET in Izaña.

The collaboration of the IAC with the AEMET has always been excellent and the agreement which has been in force for decades, which is about to come to an end, will be renewed in the coming months.The Director of the IAC has received a letter from the President of the AEMET, requesting the renewal of the agreement, and expressing his recognition of the collaboration which the IAC gives to the Centre for Atmospheric Research in Izaña, and thanking us for the measures which we have always adopted to facilitate the development and the continuity of their experiments. The IAC expresses its recognition and thanks to the AEMET for the highly valued and excellent work which they perform.

Future actions related to ASTRI

We are still awaiting the geotechnical evaluation of the proofs carried out, before proceeding to sign an agreement for installation. The Italian representatives have confirmed that they will assume all the procedures and costs of the licenses, construction, instrumentation and functioning, and that the Spanish scientific community would participate in the Science produced by this telescope system with full rights and without cost. For the Teide Observatory and for the Island of Tenerife this would imply a significant impulse to its international importance and scientific visibility.

The IAC trusts that the ASTRI project will be viable and will endow Tenerife with cutting edge infrastructure for a better understanding of the Universe and of our volcano, Teide.