Northern Sky Narrowband Survey DR0.2: First [O iii] and [S ii] Results

Data release (DR) 0.2 of the Northern Sky Narrowband Survey, with a complete set of H α , [O iii ], [S ii ], and continuum data of the northern hemisphere down to a decl. of −16°, is presented. To the best of my knowledge, this is the first time ever that [O iii ] and [S ii ] data of such a large region have been published. The first part of this article briefly introduces the project and provides an overview of the available resources. In the second part, some remarkable observations are presented: a 17°-large O iii arc in Gemini that partially overlaps with the Monogem Ring; the possible closest planetary nebula around the hot subdwarf BD+28 4211 with an apparent diameter of 6°; a faint 2 . ° 7 -large O iii ring, which also might be a planetary nebula; and a smaller but relatively bright object in Auriga, which can be seen at all observed wavelength.