YMCA-1: A New Remote Star Cluster of the Milky Way?

Abstract

We report the possible discovery of a new stellar system (YMCA-1), identified during a search for small scale overdensities in the photometric data of the YMCA survey. The object's projected position lies on the periphery of the Large Magellanic Cloud about 13° apart from its center. The most likely interpretation of its color-magnitude diagram, as well as of its integrated properties, is that YMCA-1 may be an old and remote star cluster of the Milky Way at a distance of 100 kpc from the Galactic center. If this scenario could be confirmed, then the cluster would be significantly fainter and more compact than most of the known star clusters residing in the extreme outskirts of the Galactic halo, but quite similar to Laevens 3. However, much deeper photometry is needed to firmly establish the actual nature of the cluster, and the distance to the system. * This work is based on INAF-VST guaranteed observing time under ESO program: 0104.D-0427(A).