Eric George Bowman Hintz

ROTATIONAL VELOCITY DETERMINATIONS FOR 118 δ SCUTI VARIABLES

A calibration method is presented for the determination of projected rotational velocities of 118 δ Scuti variables from FWHM measurements of metal lines near 4500 A. The calibration relation used was derived from measurements of 29 stars. Of the 44 stars brighter than 8th magnitude and north of –1° declination which did not have values in the Rodriguez catalog (Rodriguez, E., Lopez Gonzalez, M. J., & Lopez de Coca, P. 2000, A&AS, 144, 469) we present values for 38. In addition, we present new projected rotational velocity, vsin i, values for 10 stars south of –1° or fainter than 8th magnitude for a total of 48 vsin i values for stars with no previously published values.

TIME-SERIES ENSEMBLE PHOTOMETRY OF SX PHOENICIS STARS. II. AE URSAE MAJORIS

We have examined the short period, double-mode variable star AE Ursae Majoris. Using time series ensemble photometry we have determined six new times of maximum light. We also applied a Fourier decomposition to the data to determine the component frequencies of the light curve. Using our data, along with archival data, we find that the period of AE UMa is continually decreasing at a rate of -1.14x 10-10 d d-1 . However, from the Fourier decomposition we find that the period ratio P1/P0 has remained constant at 0.773. We also find that AE UMa is incorrectly classified as a SX Phoenicis star.