Microturbulent Velocities of Southern F-type Supergiants

Coudé spectra were obtained for a selection of giant and supergiant stars having spectral types in the range A9 to F2 to determine their atmospheric characteristics. The 12 members of Table 1 were compiled from The Catalogue of Bright Stars. This group of stars includes all known supergiants south of declination −15° and brighter than mv = 5.0 with spectral type between F5 and A5. Delta Canis Majoris (F81a) which has been the subject of many detailed investigations, was also observed to check for possible systematic errors in our equivalent widths. The spectra were obtained using the Coudé spectrograph of the 40 cm reflector at the University of Tasmania Observatory. Linear dispersions of 1.8Å mm−1 (0.12Å resolution) in the range 3600 to 4000Å and 2.4Åmm−1 (0.18Å resolution) in the range 4000 to 5000Å were used for stars brighter than third magnitude; 9Å mm−1 (0.4Å resolution) was used for stars fainter than third magnitude. The classification of 196 Car. was observed to be later (F8III) than the listed value and the spectrum of this star was not analysed further.