The serendipitous discovery of a stellar ring at mid-infrared wavelengths

We present images and photometry of a stellar ring-like structure G052.4?00.0 discovered during visual inspection of the Spitzer GLIMPSE Atlas. Although G052.4?00.0 may correspond to one of a large variety of sources, it is argued that it is most likely to be associated with an early-type supergiant at a distance of ～8 kpc from the Sun. Where this is the case, then the radius of the ring would be of the order of ≈0.3 pc, comparable to those of similar structures about other supergiant stars, and the extinction   A _V   would be of the order of ～21 mag.