Applications of image sharpening techniques. I. Nebular structure in H-alpha of AG Peg.

H-alpha observations of AG Peg, obtained using an IPCS detector on the 2.5-m Isaac Newton Telescope of the Observatorio del Roque de Los Muchachos on November 13-14, 1986, are reported. A mask reducing the effective entrance aperture to 55 cm and a neutral filter limiting the photon flux to 14 photons/frame were employed in 15-msec/frame exposures (total exposure time 790 sec), and the frame recentering and selection algorithm of Rosa and Fuensalida (1987) was applied to improve the sharpness of the H-alpha image. AG Peg is shown to have a SE lobe about 4 arcsec from its center, a more intense and concentrated NW lobe about 5 arcsec from center, and an unresolved emission source less than 1.7 arcsec NE of center. With background subtracted, the external nebulosity is found to account for about 33 percent of the total H-alpha emission.