In our quest to identify new stellar members within the nearby Coma Berenices open cluster using Gaia DR3 data, we have serendipitously discovered a previously unrecognized stellar structure located beyond Coma Berenices with around 500 members, which shows typical characteristics of Galactic open clusters, including a main sequence and age consistent with known clusters. We employ the HDBSCAN algorithm with astrometric and photometric data to identify the members of the structure. In addition, we characterized its stellar parameters with PARSEC isochrones. The structure, whose distance exceeds 118 parsecs, shares a remarkably large angular size (~12 degrees) with Coma Berenices. This considerable angular extent, combined with its larger distance, probably explains its previous elusiveness in astronomical studies. In this study, we investigate the possibility that this structure represents a bona fide galactic open cluster.
