2-6 September 2024
CJD Bonn Castell
Europe/Berlin timezone
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Contribution

CJD Bonn Castell

e-MERLIN and e-VLBI observations of Dyson Sphere Candidates

Speakers

  • Prof. Michael GARRETT

Primary authors

Content

Project Hephaistos recently identified seven M-dwarfs as possible Dyson Spheres (DS) candidates. We cross-matched the sources in archival radio survey catalogues and found that three of these candidates (A, B & G) have radio counterparts. The radio sources are offset from the Gaia stellar positions by ∼ 4.9, ∼ 0.4 and ∼ 5.0 arcseconds (candidates A, B, and G respectively). We proposed (Tongtinan+ 2024) that Hot DOGs (Dust Obscured Galaxies) have contaminated the original Mid-IR measurements of the DS candidates. In June, we observed one of the DS candidates (G) with e-MERLIN and e-VLBI. e-MERLIN resolves the radio source associated with G into 3 components. The central component is detected by e-VLBI implying a brightness temperature > 10^6 K . These observations support our hypothesis that an obscured AGN contributes to the measured WISE W3 and W4 flux densities for candidate G, with the foreground star being a normal M-dwarf lying close to the AGN line of sight. We believe that most (if not all) of the Project Hephaistos DS candidates can be explained in this way.