Chinese Acad Sci, Inst High Energy Phys, Lab Cosm Ray & High Energy Astrophys, Beijing 100039, Peoples R China
; Nanjing Univ, Dept Astron, Nanjing 210008, Peoples R China
We point out that in the polar cap model, the visible part is only part of the cap and this fact should be taken into account when calculating the pulsar luminosity. When this is done, the calculated luminosities are in basic agreement with the observed values. Based on our calculations we give a list of 12 possible gamma-ray candidates.