Catalogue and alternative designations


Type Planetary Nebula
Position 17 31 29, -08 19 10
Constellation Ophiuchus
Camera and Telescope STXL6303E and 36.8 cm Ritchey Chretien
Focal Ratio F9
Exposure Details This is a bi-colour image (HaOIIIOIII) with exposures through 3nm Astrodon filters binned 2x2.  Hydrogen alpha = 495 minutes and OIII = 405 minutes
Description Abell 42 is one of the fainter members of the Abell planetary nebula catalogue. The apparent magnitude is 16.5 and the central star magnitude is 20.3.  The size is 60" x 57" for the central shell and the outer halo has an approximate size of 2.5 arc-minutes.

The outer halo around this planetary nebula was discovered by the Galactic Planetary Nebula Halo Survey (GPNHS) team in March 2015.