Space Telescope Imaging Spectrograph Parallel Observations of the Planetary Nebula M94-20

Abstract

The planetary nebula M94-20 in the Large Magellanic Cloud was serendipitously observed with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope as part of the Hubble Space Telescope Archival Pure Parallel Program. We present spatially resolved imaging and spectral data of the nebula and compare them with ground-based data, including detection of several emission lines from the nebula and the detection of the central star. We find that the total Hα+[N ii] flux is 7.3x10^-15 ergs s^-1 cm^-2, and we estimate the magnitude of the central star to be m_V=26.0+/-0.2. Many other Hα sources have been found in M31, M33, and NGC 205 as well. We discuss the use of the parallel observations as a versatile tool for planetary nebula surveys and for other fields of astronomical research.