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We present a Hubble Space Telescope/WFPC2 narrow-band H-alpha image of aregion on the northeastern limb of the Cygnus Loop supernova remnant. Thislocation provides a detailed example of where the primary blast wave firstencounters the surrounding interstellar medium. The filament structure is seenin exquisite detail in this image, which was obtained primarily as an EARLYACQuisition image for a follow-up spectroscopic program. We compare the HSTimage to a digitized version of the POSS-I red plate to measure the propermotion of this filament. By combining this value for the proper motion withprevious measurements of the shock velocity at this position we find that thedistance to the Cygnus Loop is 440 (+130, -100) pc, considerably smaller thanthe canonical value of 770 pc. We briefly discuss the ramifications of this newdistance estimate for our understanding of this prototypical supernova remnant.Comment: 18 pages, 3 Figures (2 JPEG and one Postscript

Distance to the Cygnus Loop from [ITAL]HUBBLE SPACE TELESCOPE[/ITAL][ITAL]Hubble Space Telescope[/ITAL] Imaging of the Primary Shock Front