The sub - millimetre evolution of V 4334 Sgr ( Sakurai ’ s Object )

We report the results of monitoring of V4334 Sgr (Sakurai’s Object) at 450μm and 850μm with scuba on the James Clerk Maxwell Telescope. The flux density at both wavelengths has increased dramatically since 2001, and is consistent with continued cooling of the dust shell in which Sakurai’s Object is still enshrouded, and which still dominates the near-infrared emission. Assuming that the dust shell is optically thin at sub-millimetre wavelengths and optically thick in the near-infrared, the sub-millimetre data imply a mass-loss rate during 2003 of ∼3.4± 0.2× 10 M⊙ yr −1 for a gas-todust ratio of 75. This is consistent with the evidence from 1− 5μm observations that the mass-loss is steadily increasing.