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Session 58 - Stellar Modelling/Abundances.
Display session, Wednesday, June 12
Great Hall,

[58.02] Extreme Ultraviolet Spectrum of \epsilon Canis Majoris between 600-920Å

E. Wilkinson, J. C. Green, R. McLean (ARL, U. Colorado), B. Welsh (Experimental Astrophysics Group, UC, Berkeley)

We present the spectrum the brightest known extreme ultraviolet source, \epsilon Canis Majoris, between 600 and 920Å\epsilon Canis Majoris (B2 II) was discovered to be the brightest EUV source in the sky during the Extreme Ultraviolet Explorer (EUVE) all-sky survey. Subsequent spectroscopic observations found an anomolously low neutral hydrogen column density, allowing for the first time the observation of a B star between 500 and 730ÅUnexpectedly, the spectrum is still increasing at 730ÅBy observing \epsilonCMa between 600 and 920Åthe spectrum of \epsilonCMa is now complete from the x-ray thru to the infrared. This provides a unique opportunity for studying the atmospheres of B stars and refining the current atmospheric models, which cannot currently model the stellar flux from \epsilonCMa.

\epsilonCMa was observed on March 4, 1996 from White Sands Missile Range using a sounding rocket borne spectrograph. The spectrum has a resolution ranging between 1000 at 735Å\ to 450 at 900ÅTwo data sets were acquired during the flight; one with a tin filter, to block out potential scattered light longward of 920Åand one without the filter. We will present the spectrum \epsilonCMa and discuss and the current state of our analysis.

Program listing for Wednesday