First fringes for Asgard Phase 1 at the VLTI

Rendering of the Asgard instrument suite, with Heimdallr, Baldr, Solarstein, BIFROST, and NOTT labelled.

Asgard is a visitor-instrument suite for ESO’s Very Large Telescope Interferometer, built to deliver high-contrast interferometry from the near-infrared into the L band. Phase 1 — Solarstein, Baldr, and Heimdallr — was installed on the former AMBER table in the VLTI laboratory in mid-2025 and commissioned on the Auxiliary Telescopes in September 2025.

The Messenger article reports first-light results: robust fringe acquisition and stabilisation on all six baselines in both K-band sub-filters, with Heimdallr group-delay tracking down to mK ≈ 9.5. Early on-sky tests also show Baldr improving the delivered wavefront. Phase 2/3 instruments, including BIFROST and Asgard/NOTT, are now entering integration.

I am a co-author of the paper and PI of the ERC-funded SCIFY project that is building NOTT.

Read First Fringes for Asgard — Phase 1 in The Messenger 196 (March 2026).