The continuing saga of Sakurai's object (V4334 Sgr): dust production and helium line emission

Abstract

We report further UKIRT spectroscopic observations of Sakurai's object (V4334 Sgr) made in 1999 April/May in the 1-4.75 µm range, and find that the emission is dominated by amorphous carbon at T[subscript d] ~ 600. The estimated maximum grain size is 0.6 µm, and the mass lower limit is 1.7 ± 0.2 x 10[superscript -8] M[subscript ¤] to 8.9 ± 0.6 x 10[superscript -7] M[subscript ¤] for distances of 1.1-8 kpc. For 3.8 kpc the mass is 2.0 ± 0.1 x 10[superscript -7] M[subscript ¤]. <P> We also report strong He i emission at 1.083 µm, in contrast to the strong absorption in this line in 1998. We conclude that the excitation is collisional, and is probably caused by a wind, consistent with the P Cygni profile observed by Eyres et al. in 1998. Show more