Charles L. Perry

SPECTROSCOPIC STUDIES OF SOUTHERN GALACTIC CLUSTERS, I. IC 2391

Radial velocities and MK spectral types are presented for twenty stars in the vicinity of the southern galactic cluster IC 2391. Two new single-line spectroscopic binaries (HD 75029 and HD 75105) and two suspected variable- velocity stars (HD 74340 and HD 75202) are noted. The question of cluster membership is reviewed on the basis of multicolor photometry, proper motions, radial velocities, and MK spectral types with the result that, of the fo -two stars in the photometric observing program, only nineteen stars were se ected as certain cluster members.

RADIAL VELOCITIES AND SPECTRAL CLASSIFICATION OF A-TYPE STARS NEAR THE SOUTH GALACTIC POLE

Radial velocities and spectral types are listed for over 100 A-type stars in the region of the south galactic pole (SGP). Comparison of published photometry with intrinsic color indices derived from the spectral types yields a small but significant interstellar reddening at the SGP of E(B-V) = . Key words: galactic poles - radial velocities - spectral types - interstellar reddening

Four-color and H-beta photometry near SA 57

Stromgren uvby and H-beta photometry has been obtained for 37 stars in and near the region of SA 57, the Selected Area nearest the north galactic pole. These stars can serve as secondary standards for photometric work in this region. Comparisons with previous photometry shows reasonable agreement. The data are analyzed to determine interstellar reddening, metal abundances of the F-type stars, and distances. On the average, the stars are somewhat weak lined, compared to the sun. The reddening is close to zero.

RADIAL VELOCITIES OF A-TYPE STARS NEAR THE NORTH GALACTIC POLE

Some time ago, a study of early A-type stars in the vicinity of the North Galactic Pole was initiated by one of us (W.P.B.). The spectrograms were taken with the G//2 Cassegrain spectrograph attached to the McDonald 82-inch reflector, at a dispersion of 76 Â/mm at Hy. The radial velocities derived have been reduced to the system defined by R. E. Wilsons General Catalogue of Stellar Radial Velocities. The pertinent data are given in Table I.