Overview
- A peer‑reviewed study led by Beatrice Vaia published on 29 June used XMM‑Newton and Chandra observations to measure dust echoes from three gamma‑ray bursts spanning 2003–2022.
- The team tracked expanding ring‑shaped X‑ray echoes produced when GRB X‑rays scattered off interstellar dust and converted the ring expansion into precise distances to those dust clouds.
- Their direct measurements confirm the known distance to the Perseus arm and place the Outer Scutum‑Centaurus Arm and the Outer Arm up to roughly 10% farther away than earlier estimates.
- The revision modestly increases the mapped size of the Milky Way in the probed directions and provides an independent method that reaches farther than current Gaia parallax precision.
- Scientists say the result will guide future studies of Galactic structure and star formation and expect further refinement from Gaia DR4 and later from ESA’s planned NewAthena X‑ray observatory.