Spectroscopy and near-infrared photometry of the helium nova V445 Puppis

V445 Pup (Nova Puppis 2000) is the first observed example of a helium nova (Kato & Hachisu 2003). Here we present Magellan spectroscopy of V445 Pup, obtained three years after outburst (V = 19.91 mag). The optical spectrum consists of He I, [O I], [O II], [O III] emission lines; no hydrogen is present. The emission lines show multiple velocity components (around 850 km s(-1) and 1600 km s(-1)), associated with an expanding and clearly asymmetric nova shell. Images of V445 Pup obtained under good seeing conditions show this object to be elongated and extended. The expanding nova shell should allow an accurate distance determination of V445 Pup through high-resolution imaging and integral field unit spectroscopy. We have continuously monitored the near-infrared (J, H, K,) secular evolution since 2002 March with the Infrared Survey Facility (IRSF) from the Sutherland site of the South African Astronomical Observatory (SAAO). Nearly four years of the outburst, V445 Pup is still covered by an optically thick dust shell (2004 September 29: E (J - K-s) similar to 4.6 +/- 0.1 mag).