The Case Low-Dispersion Northern Sky Survey

Abstract

The Burrell Schmidt-type telescope of the Warner and Swasey Observatory in its new location on Kitt Peak in Arizona is being used for a spectroscopic survey of the region b > +30°. and δ < +30°. The plates, which cover 5° × 5°, are taken with the 1 ^o_. 8 prism which provides a dispersion of 1350 Å mm at Hγ. Eastman Kodak IIIa-J plates, baked in forming gas, are used without filter to cover the spectral range 3300 to 5350 Å. The exposure times of 75 minutes reach a limiting blue magnitude of ~ 18.0 for threshold detection of an unwidened stellar continuum. The categories of objects which are being catalogued are blue and/or emission-line galaxies, probable HII regions, blue and/or emission-line stellar objects, known and probable blue stars, main-sequence late B and A-type stars, suspected field horizontal-branch stars of types A and F including RR Lyrae variables, suspected F and G-type subdwarfs showing a UV excess, faint carbon and late M suspected halo giants, and peculiar objects.