Possible Identification of X Persei with an X-ray Source

Abstract

COMPARISON of the Yale catalogue1 with a recent catalogue of 116 X-ray sources observed with the Uhuru satellite (private communication from R. Giacconi, H. Gursky, E. Kellogg, S. Murray, E. Schreier and H. Tananbaum) shows that the position of the irregular variable star X Persei (see Table 1) coincides with that of the X-ray source 2ASE 0352 + 30. The total number of chance coincidences of bright stars to within 0.5 arc min in α and 0°.1 in δ of the Uhuru X-ray source positions is estimated to be ∼ 1—the exact number of chance coincidences is difficult to evaluate because both the bright stars and the X-ray sources have a non-random distribution on the sky—but the very unusual nature of X Persei lends some support to the speculation that the positional agreement of this star with an X-ray source may not be a chance coincidence. The spectrum of X Persei is classified as O pe, and is peculiar because it is strongly veiled.