A preliminary optical study of the intergalactic H I cloud in Virgo

A possible optical counterpart of the intergalactic H I cloud in the Virgo Cluster, discovered by Giovanelli and Haynes, is reported. It is a blue, 17 mag, irregular galaxy, and it is located near the peak of the H I emission. No other optical objects which can be obviously associated with the cloud are found in the area from which the H I emission was detected, and no extended, low surface brightness counterpart is seen in these data. If the irregular galaxy is really associated with the H I cloud, the overall properties of the system would be similar to those of a number of other known gas-rich dwarf galaxies. However, the system has an unusually large hydrogen to light ratio, and a large spatial extent, and it could be dynamically young. Optical spectroscopy is needed in order to establish whether the proposed optical counterpart is indeed correct, and if so, to determine the stage of its chemical evolution.