Breakthrough Listen and Sardinia Radio Telescope

Since 2015 Breakthrough Listen has leveraged the planet’s largest radio telescopes to search for technosignatures. Even in the era of large arrays with commensal programs, big single dishes continue to play a role. The combination of wide frequency coverage, large collecting area, and the flexibility to point to targets of interest for long periods, unconstrained by the complexities of a commensal observing program, continues to be important for Listen.

The Sardinia Radio Telescope, a 64-meter antenna near Cagliari in Italy, recently completed commissioning of a new suite of receivers and a refurbishment of the antenna surface, enabling observations up to 116 GHz. Listen is collaborating with the SRT team at the Italian National Institute for Astrophysics (INAF) on a technosignature search program taking advantage of these new capabilities. A backend instrument for data processing and recording, based on similar technology to those deployed at Listen’s other facilities, has been installed at SRT and has completed an initial study of the Galactic Center and of 72 stars identified by NASA’s TESS satellite as potential hosts of planetary systems, at frequencies around 18 GHz – a region of the spectrum underexplored in previous studies.

A key component of the new program at SRT has been the involvement of student researchers. Beginning in summer 2022, groups of three or four students have spent the summer in Cagliari working with SRT scientists Maura Pilia and Andrea Melis. In collaboration with Listen’s Vishal Gajjar and Karen Perez, several of the students have continued their research after the completion of the formal component of the summer program. The Italian students have also benefited from integration with the overall summer research program led by Steve Croft. This included the opportunity to attend the 2024 Breakthrough Discuss meeting in Oxford, where a variety of ancillary activities and presentations were organized for the summer interns from the US, Italy, Ireland, and UK.

The 2022 Italian student cohort recently completed their analysis of data from the initial survey of the Galactic Center and TESS targets, in a paper submitted to Acta Astronautica and published on the arXiv preprint server. The paper was accompanied by press releases from INAF, Oxford University, and the Breakthrough Initiatives. Lead author, 2022 intern Lorenzo Manunza, was interviewed by Italian local and national media about the results, along with other members of the SRT team.

The press release and paper submission were timed to coincide with a workshop held in Cagliari in October 2024, co-hosted by INAF, SRT, and Listen, which attracted over 100 participants to discuss the future of technosignature searches in Italy and beyond. The meeting was scheduled immediately prior to the International Astronautical Congress in Milan, where Manunza, Gajjar, Pilia, and Perez also presented at a well-attended SETI Science session. Breakthrough Listen has played a key role in this “Italian Renaissance” of technosignature research and we anticipate continued high-quality science output alongside training of the next generation of researchers into 2025 and beyond.