Session 53 -- Recent Observational Results on Nova Cygni 1992
Oral presentation, Wednesday, 1, 1994, 2:00-5:30

## [53.03]

J. Gallagher, J. Mathis, J. Cardelli (U. Wisconsin), A. Barger (Cambridge U.)

We present an initial analysis of physical conditions in Nova Cygni during the 1992 nebular phase. At this stage the nova showed strong optical emission from [Ne III] and [Ne V] confirming this object's status as a neon nova. This nova has the advantage over most previous classical novae during outburst in that the approximate nature of the photoionizing stellar spectrum is directly known from ROSAT x-ray observations. However, a wide range in density is present in the nova shell which considerably complicates the modelling of the emission spectrum. We have therefore constructed simple multi-component nebular models with G. Ferland's CLOUDY code which we constrain to fit optical and ultraviolet emission line ratios and the approximate H$\beta$ emission luminosity determined from our Pine Bluff Observatory spectrophotometry. The results from this exercise yield insights into abundances in the ejecta of Nova Cygni and thus into the neon nova phenomenon.