English: RAD J131346.9+500320 (RAD J131346) is a type of astronomical object called an odd radio circle (ORC) that has a redshift z=0.94, placing it when the universe was half its current age. ORCs are recently-discovered with RAD J131346 being the most distant and the most powerful to date. Previous research has suggested that ORCs might be caused by shockwaves from merging black holes, whereas recent research published in 2025 links them to superwind outflows.

RAD J131346 was found by the RAD@home, a citizen science research collaboratory, using the LoTSS survey data from the Low-Frequency Array (LOFAR). The image shows a LoTSS 144 MHz radio image with 6 arcsec angular resolution of RAD J131346, where only emission above 3 sigma is shown, and the sigma (rms noise) is nearly 50 micro Jansky per beam. The white cross shows the location of the object’s host galaxy. Note the two faintly visible circles (here in pink/purple) that are seen overlapping with the host galaxy at the centre. (Ananda Hota et al. 2025 link below).

Content is taken from the Royal Astronomical Society website: Most powerful 'odd radio circle' to date is discovered.

Original study RAD@home discovery of extragalactic radio rings and odd radio circles: clues to their origins Ananda Hota et al. 2025 Monthly Notices of the Royal Astronomical Society (MNRAS)

MNRASː "This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited."

Host galaxy isː SDSS J131346.92+500319.3

The original montage labelled fig. 1 was downloaded from the study. The image to the top left was cropped and scaled using GIMP v3. (R.Nowell)