  The total number of Galactic planetary nebulae is highly uncertain; the most
inclusive current catalog contains only ~ 1,500. We will use the PRISM
wide-field imager on the 1.83 m Perkins Telescope to conduct a pilot survey of
the Galactic plane in search of [S III] emission from planetary nebulae
obscured by dust and missed by surveys of H-alpha. We are employing the method
of Jacoby & Van de Steene, who surveyed the bulge for 9532 Angstrom [S III]
emission. In addition to seeing through more of the extinction, use of the [S
III] emission line will a priori reject the most troublesome catalog
contaminants: ultracompact H II regions.
