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Session 38 - Disks and Bipolar Outflows from Hot Stars.
Display session, Tuesday, June 11
We present high resolution coronographic images of the nebula around HR Car and medium resolution spectra of the same nebula at several positions, obtained between May 1995 and January 1996. Our coronographic data confirm the overall bipolar structure already suggested by Hutsemékers amp; van Drom (1991) and the presence of a compact, bright, inner nebula from which filaments seem to depart, reported by Clampin et al. (1995). From our spectra we find that the inner shell expands at \sim 30 km/s, while the northern and southern arcs reach a maximum radial velocity of \sim 100 km/s. Within each arc the radial velocity varies by up to \sim 50 km/s. We find that the calculated electron density, assuming T_e= 10,000 K, increases from the outer region, where we measure N_e= 400 - 1000 cm^-3, to the inner region for which we determine N_e > 2000 cm^-3. For all the slit positions, we measure a very high N^+/S^+ ratio, which is indicative of a nitrogen enrichment similar to that found in other ejecta nebula around massive, evolved stars. Indeed, we calculate 12+log\,N/H \approx 8.4, which implies N is enhanced by a factor of 7 as has been observed in AG Car and M1--67 nebulae by Smith et al. (1996) and Esteban et al. (1991).
Program listing for Tuesday