Photoelectric rocket spectra at 10 Å resolution

Abstract

Spectral scans of a number of early-type stars have been made with a three-channel spectrophotometer attached to a 32 cm telescope. The telescope was pointed at the individual program stars with an accuracy of at least 20 sec of arc. The spectral resolution was 10 Å over the range 1150 Å to 4000 Å. The data were recorded in digital form and processed in a computer.

The profile of hydrogen Ly-α, as smeared by the exit slit, was obtained for α Lyr, α CMA, β Ori, and β Tau. For the earlier-type stars observed the Ly-α line of the star is masked by interstellar hydrogen absorption. For ζ Oph and ζ Per the Ly-α absorption is considerably larger than for the other early-type stars. The identification of lines is relatively simple for the light elements but becomes more difficult with the heavier ions since there are many more weaker lines and 10 Å is then insufficient resolution. Extreme P Cygni profiles are present in the earliest stars and are interpreted as mass loss at high velocity.

A full description appears in Astrophys. J.159, Feb. 1970.