RY Leporis : a bright, high amplitude delta Scuti star.

Walraven VBLUW photometry is reported for the variable RY Leporis (also known as HD 38882, BV 425, and 0545-200 from its Epoch 1950 coordinates). It is shown that this star - until now considered to be an eclipsing binary - is actually a relatively bright high-amplitude delta Scuti star with a period of 0.2254 day and an amplitude of delta V-sub-J = 0.35 magnitude in the Johnson system. After an evaluation of the reddening suffered by Ry Leporis (0.038 plus or minus 0.01), the basic physical parameters of this variable are determined from a semi-theoretical calibration of the colors of the Walraven system. A comparison is made of the physical characteristics of RY Leporis with observational parameters of similar variables and with theoretical calculations. The results support the 'high-mass' interpretation of large-amplitude delta Scuti stars.