A newly discovered carbon-poor planetary nebula : PN 242-37.1

Abstract

An emission line object with galactic coordinates l = 242.17 deg and b = - 37.11 deg corresponding to a previously unreported very high-excitation planetary nebula is described. The spectrophotometric data obtained in October 1988 is detailed, as well as the UV observations from a satellite in November 1988. Reddening and physical conditions are outlined along with ionic abundances. Numerical models calculated with a computer code solving the ionization and temperature structure of a steady-state spherically symmetric nebula photoionized by a central source are covered. It is pointed out that the low nebula C abundance in PN 242-37.1 suggests that its progenitor was a metal-poor star of low mass, which did not undergo the third dredge-up episode.