2001A&A...377..425D

To investigate the physical nature of the observed deficiency of stars in the very center of the Ursa Minor Dwarf Spheroidal galaxy, we recently obtained JCMT-SCUBA 850µm photometry of this region. The observed void could be explained by ≃0.5mag of extinction. While the amount of dust needed to produce such absorption (under certain assumptions for the dust temperature and the β exponent in the dust emissivity term) would yield a 5mJy signal - easily detectable by SCUBA - we found no signal at 850µm, after 256min of integration. This finding rules out the presence of a few solar masses of cold dust cloud as the explanation for the central lack of stars observed in Ursa Minor. We discuss possible explanations.