Space Telescope Observations of the Hubble-Sandage Variables ( or LBV's) in M31 and M3 M33

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Session 34 -- Massive Hot Stars with the Hubble Space Telescope Part I
Oral presentation, Tuesday, 31, 1994, 8:30-12:30

[34.05] Space Telescope Observations of the Hubble-Sandage Variables ( or LBV's) in M31 and M3 M33

R. M. Humphreys (Univ. Minn.)

UV imaging and spectroscopy have been obtained for several of the luminous blue variables in M31 and M33. The stars originally included in the 1953 paper by Hubble and Sandage are now recognized as members of a group of highly unstable massive stars found in many spiral and irregular galaxies.

The UV observations are combined with groundbased spectra and photometry for a discussion of these stars temperatures, luminosities, and mass loss rates. These data are necessary to place them on the HR diagram and to understand their relation to other LBV's and masive star evolution in general.

The UV spectrum of AE And shows an unusually strong emission line of Fe II at 2507A. The only other star known with this line so prominent is eta Carinae. Its prominence is probably due to Lyman alpha flourescence. Furthermore, the spectra of AE And and AF And, both observed at minimum light show a veritable forest of Fe II and [Fe II] emission.this is in contrast to the quiescent spectra of some LBV's which resemble Of/WN stars at minimum, such as R127 and AG Car. We were fortunate to capture Var B in M33 during an eruption while Var C in M33 was observed during its decline from its recent maximum.

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