We present the serendipitous discovery of a new radio-continuum ring-like object nicknamed Kyklos (J1802-3353), with MeerKAT UHF and L-band observations. The radio ring, which resembles the recently discovered odd radio circles (ORCs), has a diameter of 80 arcsec and is located just 6 deg from the Galactic plane. However, Kyklos exhibits an atypical thermal radio-continuum spectrum ({\alpha} = -0.1 +/- 0.3), which led us to explore different possible formation scenarios. We concluded that a circumstellar shell around an evolved massive star, possibly a Wolf-Rayet, is the most convincing explanation with the present data.
@article{arxiv.2408.07727,
title = {MeerKAT reveals a ghostly thermal radio ring towards the Galactic Centre},
author = {C. Bordiu and M. D. Filipovic and G. Umana and W. D. Cotton and C. Buemi and F. Bufano and F. Camilo and F. Cavallaro and L. Cerrigone and S. Dai and A. M. Hopkins and A. Ingallinera and T. Jarrett and B. Koribalski and S. Lazarevic and P. Leto and S. Loru and P. Lundqvist and J. Mackey and R. P. Norris and J. Payne and G. Rowell and S. Riggi and J. R. Rizzo and A. C. Ruggeri and S. Shabala and Z. J. Smeaton and C. Trigilio and V. Velovic},
journal= {arXiv preprint arXiv:2408.07727},
year = {2024}
}