The AG Carinae nebula revisited.

We report new Cassegrain observation of the AG Car nebula, as well as long slit Coude spectra and imagery at H-alpha. From our data we derive an expansion velocity of 66 km/s for the nebula and a minimal mass of 2.7 solar mass. Long slit data show H-alpha emission up to 45 arcsec from the star, indicating a diffuse nebulosity surrounding the main nebula. We also find that nitrogen is overabundant by one order of magnitude and oxygen is deficient at least by a factor of 6 in the nebula. These results are consistent with the surface abundances of a 60 solar mass star aged at 3.7 x 10 exp 6 yr just beginning its LBV phase.