A MULTIWAVELENGTH STUDY OF THE CLASSICAL NOVA V4169 SAGITTARII

We present multiwavelength observations of V4169 Sgr (Nova Sgr 92#2) f rom 1000 Angstrom to 2 cm for the first year following visual maximum. V4169 Sgr was an 'Fe II' type nova, and evolved from P-fe(o) to N-o i n the Tololo nova classification scheme. The ultraviolet spectrum was very similar to that of nova PW Vul, and the near infra-red spectrum w as dominated by Ly beta pumped O I emission in the early decline. Ther e was significant apparent deceleration of absorption lines before opt ical maximum. High resolution optical spectroscopy reveal unusual deta ils 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 emissi on 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 dis tance of similar to 6.5 kpc. The nova shows significant enrichment of helium and nitrogen relative to solar, but not of carbon or oxygen; ho wever our abundances are probably underestimated.