Collaborative research: NSF-BSF the sephira project

The National Science Foundation Directorate for Mathematical and Physical Sciences awarded Carnegie Institution of Washington $980,286 on September 1, 2026, to extend a three-telescope intensity interferometry prototype into a six-telescope pathfinder array at the Weizmann Observatory. The project, conducted under the Mathematical and Physical Sciences program (CFDA 47.049), advances intensity interferometry techniques to image bright stars at extremely high resolution by measuring photon correlations across separated telescopes using single-photon quantum detectors and picosecond-precision timing electronics. The technical objective is to recover higher-order imaging information using second and third-order photon correlations, not previously demonstrated, and to image binary stars including Spica, Algol, and Beta Lyrae to measure binary parameters. A secondary goal establishes a quantum-ready workforce through hands-on student experience with quantum optics technologies and exposure to international U.S.-Israeli scientific collaboration. The intensity interferometry technique leverages the Hanbury Brown-Twiss effect to measure temporal correlations in stellar intensity, rendering the method insensitive to atmospheric turbulence and telescope optical errors that constrain conventional interferometers. Performance runs through August 31, 2029, with place of performance at Washington, DC.

Abstract

This project makes a fundamental scientific advance in intensity interferometry to image bright STARS at extremely high resolution. The measured correlation between photons arriving across several telescopes will be used to reconstruct stellar surfaces. These correlations come from the quantum nature of light. Single-photon quantum detectors and very precise timing electronics make this measurement possible now for the first time. The project?s primary goal is to extend a proven three-telescope prototype at southern connecticut state university into a six-telescope pathfinder array at the weizmann observatory. A second goal is establishing the foundation of a quantum-ready workforce of builders and users to create more powerful telescope arrays in the future. Students will gain hands-on experience with quantum optics technologies highly valued in both academia and industry. The project will expose students to international collaborations and strengthen the U.S.-israeli scientific partnership. This project develops intensity interferometry into a scalable, low-cost path to high angular resolution optical astronomy using a quantum optical technique. The technique measures temporal correlations in stellar intensity between separated telescopes, the hanbury brown-twiss effect, insensitive to atmospheric turbulence and telescope optical figure errors that constrain conventional interferometers. Single-photon avalanche diodes and time-to-digital converters now provide the picosecond timing that makes this competitive on small telescopes. The central goal is to recover higher-order imaging information using second and third-order photon correlations, a result not previously demonstrated. The team will extend a three-telescope prototype at southern connecticut state university into a six-telescope pathfinder array at the weizmann observatory, image spica, algol, and beta lyrae, and measure binary parameters. This establishes the basis for future large-number, small-diameter arrays enabling milliarcsecond imaging of exoplanet host STARS. Organized as an NSF-BSF collaboration spanning carnegie, weizmann, and southern connecticut state university with open-source software, the project supports training a quantum workforce. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.