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arXiv · astro-ph/9810432

Discovery of a Nearby Low-Surface-Brightness Spiral Galaxy

W. B. Burton·R. Braun·R. A. M. Walterbos·C. G. Hoopes
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Abstract

During the course of a search for compact, isolated gas clouds moving with anomalous velocities in or near our own Galaxy (Braun and Burton 1998 A&A, in press), we have discovered, in the data of the Leiden/Dwingeloo survey (Hartmann and Burton 1997, Atlas of Galactic Neutral Hydrogen, CUP) of Galactic hydrogen, the HI signature of a large galaxy, moving at a recession velocity of 282 km/s, with respect to our Galaxy. Deep multicolor and spectroscopic optical observations show the presence of star formation in scattered HII regions; radio HI synthesis interferometry confirms that the galaxy is rich in HI and has the rotation signature of a spiral galaxy; a submillimeter observation failed to detect the CO molecule. The radio and optical evidence combined suggest its classification as a low-surface-brightness spiral galaxy. It is located in close spatial and kinematic proximity to the galaxy NGC 6946. The newly-discovered galaxy, which we call Cepheus 1, is at a distance of about 6 Mpc. It is probably to be numbered amongst the nearest few LSB spirals.

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W. B. Burton, R. Braun, R. A. M. Walterbos, C. G. Hoopes. 1998-10-27. Discovery of a Nearby Low-Surface-Brightness Spiral Galaxy. https://doi.org/10.1086/300700

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