New identification of the near infrared Source in the "born-again" planetary nebula A58 (=V605 Aql)

Abstract

The central dust knot V605 Aql (= Nova Aql 1919) in the planetary nebula A58 is the result of a late-helium flash. Previous near infrared (NIR) measurements yield very bright fluxes. This exceeds model predictions, based on other wavelengths and estimates of the visual extinction within the object, by a factor of 100. Using NIR imaging by the DENIS instrument, we found that the source was misidentified in previous (single channel photometer) observations. We present the NIR flux of A58 and identify an unrelated stellar field source, which in fact represents the NIR source attributed to A58, according to the literature. The new identification is consistent with model predictions for the source. An accurate astrometry for the core of A58 is also provided.