MDW Halpha Sky Survey DR1

The survey was founded by amateur astronomers, and the northern sky (decl. >=0{deg}) is presented here in its second stage of refinement for academic use. Each 3.6 deg^2^ MDW field has 12 20 minutes individual exposures with a pixel scale of 3.2", a typical point-spread function of 6", and a stack point-source depth of 16-17 mag.

The northern MDW Survey Data Release 1 (DR1) includes calibrated mean and individual images, star-removed mean fields, and point-source catalogs for all images matched to Data Release 1 of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) and the INT Galactic Plane Survey. (All DR1 components are available at mdw.astro.columbia.edu. The catalogs are also made available in the AAS Journals Zenodo repository: doi:10.5281/zenodo.17307324.) Our initial study of H{alpha} filament widths finds a typical FWHM of 30"-45" in the Lyra region.