The radio emission from Sakurai's Object (beyond 1 mm)

Observations of V4334 Sgr have been made with the JCMT, MERLIN, ATCA and the VLA. Searches with JCMT for CO in and around the PN associated with V4334 Sgr has provided upper limits for the peak emission of 20 mK and the line-flux of 0.17 K-kms^-1. This gives an upper limit on the CO mass of ∼ 3 × 10^-7 D² M_⊙ at D kpc. VLA observations have detected 2.7±0.1 mJy of emission from the PN, which appears to be clumpy and extends to a radius of ∼17 arcsec. This indicates an optically thick nebula, and suggests a range of distances of 1.83 to 4.96 kpc for a reasonable range of masses for optically thick PN. Comparison with estimated total Hβ emission gives E(B - V) 0.8±0.1. MERLIN observations do not detect the wind indicated to be present in IR observations prior to dust obscuration. The Australia Telescope Compact Array did not detect OH maser emission from either the main- or satellite-lines. Future VLA observations will increase integration times and uv-coverage to significantly improve the radio imaging. MERLIN target-of-opportunity time is retained in order to attempt to image any fast wind as it develops. An independent estimate of the PN mass would allow the use of the radio observations to determine the distance; conversely an independent distance measurement would lead to a PN mass estimate. The author urges the acquisition of an accurate measurement of the total Hβ emission from the PN.