SIMBAD references

The observed gas and dust disk around the main sequence star βPictoris suggests that neutral hydrogen clouds could surround the star. We present an observational attempt to detect such a cloud through its 21cm line emission. No HI emission was detected. Upper limits on the column density of a HI cloud around βPictoris with synthesized beams of sizes between 27 and 90 arcsecs are given. The 3σ upper limit is less than 0.5% of the mass of Jupiter for a wide range of possible distributions of that mass. The inferred gas to dust ratio is less than 10 and indicates that most of the original gas present in the protoplanetary nebulae has been processed or expelled.