KK 246: A DWARF GALAXY WITH AN EXTENDED H I DISK IN THE LOCAL VOID

We have found that KK 246, the only confirmed galaxy located within the nearby Tully Void, is a dwarf galaxy with an extremely extended H I disk and signs of an H I cloud with anomalous velocity. It also exhibits clear misalignment between the kinematical major and minor axes, indicative of an oval distortion, and a general misalignment between the H I and optical major axes. We measure an H I mass of (1.05 +/- 0.08) x 10(8) M-circle dot, and an Hi extent five times that of the stellar disk, one of the most extended H I disks known. We estimate a dynamical mass of 4.1 x 10(9) M-circle dot, making this also one of the darkest galaxies known, with a mass-to-light ratio of 89. The relative isolation and extreme underdense environment make this an interesting case for examining the role of gas accretion in galaxy evolution.