Spectroscopic observations of 27 Canis Majoris from 0.14 to 4.7 microns.

Results are presented for visual spectroscopy, uvby photometry, HKLM infrared photometry, and satellite UV observations of the Be star 27 CMa over the wavelength range from 0.14 to 4.7 microns. The visual spectrum between 3650 and 6800 A is found to consist mainly of the Balmer lines from H-alpha to H14 with complicated asymmetric profiles as well as He I lines exhibiting the same asymmetry as the Balmer lines. A model-atmospheres analysis indicates that the atmosphere of the central star can be represented by a model with an effective temperature of 20,000 K and a surface gravity of 6300 cm/sec per sec; a spectral type of B3 IV is suggested. Variations in the visual and UV regions are discussed, and the star is shown to exhibit an IR excess similar to that of other Be stars. A shell with a radius of approximately 17 solar radii, an electron density of no more than 590 billion per cu cm, and an electron temperature of 14,400 K is inferred.