A multiwavelength study of the classical nova V4169 Sagittarii

Abstract

We present multiwavelength observations of V4169 Sgr (Nova Sgr 92 # 2) from 1000 Å to 2 cm for the first year following visual maximum. V4169 Sgr was an ‘Fe n’ type nova, and evolved from Pfeoto N0 in the Tololo nova classification scheme. The ultraviolet spectrum was very similar to that of nova PW Vul, and the near infra-red spectrum was dominated by Lyβ pumped OI emission in the early decline. There was significant apparent deceleration of absorption lines before optical maximum. High resolution optical spectroscopy reveal unusual details of the evolution of blue-shifted P Cygni absorptions; we show that these are consistent with the advance of an ionisation front through the absorbing material. The evolution of absorption systems and emission line profiles are consistent with accelerating wind models of nova ejection. We find an extinction of E(B — V) = 0.35 ± 0.05, and a distance of ~ 6.5 kpc. The nova shows significant enrichment of helium and nitrogen relative to solar, but not of carbon or oxygen; however our abundances are probably underestimated.