High-resolution imaging of the radio source associated with Project Hephaistos Dyson Sphere Candidate G

TL;DR

This study uses high-resolution radio observations to identify that some Dyson Sphere candidates are actually background active galactic nuclei, not the stars themselves, aiding in the accurate selection of genuine candidates.

Contribution

It demonstrates that high-resolution radio imaging can effectively distinguish between true Dyson Sphere candidates and background AGN contamination.

Findings

The radio source shows characteristics of a radio-loud AGN.

No radio emission detected at the M-dwarf star's position.

Background AGN contamination can mimic Dyson Sphere signals.

Abstract

We present high-resolution e-MERLIN and EVN (e-VLBI) observations of a radio source associated with Dyson Sphere candidate G, identified as part of Project Hephaistos. The radio source, VLASS J233532.86-000424.9, is resolved into three compact components and shows the typical characteristics of a radio-loud active galactic nucleus (AGN). In particular, the European VLBI Network (EVN) observations show that it has a brightness temperature in excess of $10^{8}$~K. No radio emission is detected at the position of the M-dwarf star. This result confirms our earlier hypothesis, that at least some of the Dyson Sphere candidates of project Hephaistos are contaminated by obscured, background AGN, lying close to the line of sight of otherwise normal galactic stars. High-resolution radio observations of other Dyson Sphere candidates can be useful in distinguishing truly promising candidates from those contaminated by background sources.