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We report five Local Volume dwarf galaxies (two of which are presented herefor the first time) uncovered during a comprehensive archival search foroptical counterparts to ultra-compact high velocity clouds (UCHVCs). The UCHVCpopulation of HI clouds are thought to be candidate gas-rich, low mass halos atthe edge of the Local Group and beyond, but no comprehensive search for stellarcounterparts to these systems has been presented. Careful visual inspection ofall publicly available optical and ultraviolet imaging at the position of theUCHVCs revealed six blue, diffuse counterparts with a morphology consistentwith a faint dwarf galaxy beyond the Local Group. Optical spectroscopy of allsix candidate dwarf counterparts show that five have an H$\alpha$-derivedvelocity consistent with the coincident HI cloud, confirming their association,the sixth diffuse counterpart is likely a background object. The size andluminosity of the UCHVC dwarfs is consistent with other known Local Volumedwarf irregular galaxies. The gas fraction ($M_{HI}/M_{star}$) of the fivedwarfs are generally consistent with that of dwarf irregular galaxies in theLocal Volume, although ALFALFA-Dw1 (associated with ALFALFA UCHVCHVC274.68+74.70$-$123) has a very high $M_{HI}/M_{star}$$\sim$40. Despite theheterogenous nature of our search, we demonstrate that the current dwarfcompanions to UCHVCs are at the edge of detectability due to their low surfacebrightness, and that deeper searches are likely to find more stellar systems.If more sensitive searches do not reveal further stellar counterparts toUCHVCs, then the dearth of such systems around the Local Group may be inconflict with $\Lambda$CDM simulations.

A Comprehensive Archival Search for Counterparts to Ultra-Compact High Velocity Clouds: Five Local Volume Dwarf Galaxies