On the variability of VEGA

The variability of Vega is investigated by direct telescopic (0.5-m) observation, and the results are compared with photometric studies. On two nights Vega was brighter than average by about 0.015 mag, and on one night by about 0.041 + or - 0.005 mag. Although there is evidence suggesting that Vega has occasionally shown definite radial pulsation, the brightening observed is nevertheless attributed to a variability similar to the Delta Scuti-type. Observations made simultaneously on Epsilon (1) Lyr and Epsilon (2) Lyr indicate a constancy to within 0.003 mag.