THE DUSTY NOVA V1065 CENTAURI (NOVA CEN 2007): A SPECTROSCOPIC ANALYSIS OF ABUNDANCES AND DUST PROPERTIES

We examine the ejecta evolution of the classical nova V1065 Centauri, constructing a detailed picture of the system based on spectrophotometric observations obtained from 9 to approximately 900 days post-outburst with extensive coverage from optical to mid-infrared wavelengths. We estimate a reddening toward the system of E(B - V) = 0.5 +/- 0.1, based upon the B - V color and analysis of the Balmer decrement, and derive a distance estimate of 8.7(-2.1)(+2.8) - kpc. The optical spectral evolution is classified as P(fe)(o)N(ne)A(o) according to the CTIO Nova Classification system of Williams et al. Photoionization modeling yields absolute abundance values by number, relative to solar of He/H = 1.6 +/- 0.3, N/H = 144 +/- 34, O/H = 58 +/- 18, and Ne/H = 316 +/- 58 for the ejecta. We derive an ejected gas mass of M-g = (1.6 +/- 0.2) x 10(-4) M-circle dot. The infrared excess at late epochs in the evolution of the nova arises from dust condensed in the ejecta composed primarily of silicate grains. We estimate a total dust mass, M-d, of order (0.2-3.7) x 10 (7) M-circle dot, inferred from modeling the spectral energy distribution observed with the Spitzer IRS and Gemini-South GNIRS spectrometers. Based on the speed class, neon abundance, and the predominance of silicate dust, we classify V1065 Cen as an ONe-type classical nova.