Triangulum is classified as unbarred, but an analysis of the galaxy shape shows what may be a weak bar-like structure about the galactic nucleus. The radial extent of this structure is about 0.8 kpc. The nucleus of this galaxy is an H II region, and it contains an ultraluminous X-ray source with an emission of , which is the most luminous source of X-rays in the Local Group of galaxies. This source is modulated by 20% over a 106-day cycle. However, the nucleus does not appear to contain a supermassive black hole, as an upper limit of 3,000 solar masses is placed on the mass of a central black hole based upon the velocity of stars in the core region.