We report the discovery of a compact object ( R _ { e } = 32 pc , M _ { B } = -12.34 mag ) at a projected distance of 9 kpc from Messier 59 , a giant elliptical in the Virgo cluster .
Using HST imaging and SDSS spectroscopy , both available in the Virtual Observatory , we find that this object has a blue core containing one-quarter of the light , and a redder n = 1 Sérsic envelope , as well as luminosity-weighted age of 9.3 \pm 1.4 Gyr , a metallicity of -0.03 \pm 0.04 dex and a velocity dispersion of 48 \pm 5 km s ^ { -1 } .
While ultra-compact dwarfs ( UCDs ) in the face-on view of the Fundamental Plane are found to form a sequence connecting the highest-luminosity globular clusters with the lowest-luminosity dwarf ellipticals , the compact object near M59 lies in between this UCD sequence and the positions of compact ellipticals .
Its stellar age , metallicity , and effective surface brightness are similar to low-luminosity ellipticals and lenticulars , suggesting that SDSSJ124155.33+114003.7 is a result of the tidal stripping of such an object .