1995A&A...293L..33H

We report the detection of two nearby galaxies in Cassiopeia in HI. Their low heliocentric velocities, 35±2 and 112±5km/s, suggest they are members of the IC342-Maffei group. The smaller object (Cas 1) has been classified optically as an irregular dwarf. An HI linewidth of 49 km/s and a nearly gaussian shape of the profile support the classification. Its HI mass (at an assumed distance of 3Mpc) is 1x10⁸M_☉. The larger galaxy (Cas 2) has an HI mass of 3.7x10⁸M_☉ (same distance) and a linewidth (at half power) of 204km/s which corresponds to a rotational velocity (after correction for inclination, i∼65deg) of about 112km/s. This is a galaxy roughly of the mass of M 33. This galaxy has been discovered independently by another group with the Dwingeloo telescope (Kraan-Korteweg et al. 1994Natur.372...77K). Our search was based on an optical survey for galaxies in the Galactic Plane (see Seeberger et al. 1994, Proc. of the 4th DAEC-Meeting on 'Unveiling large-scale structures behind the Milky-Way', p.81) and included 10 objects from the neighborhood of IC 342 and Maffei 1/2. The other detected galaxies are background objects.