EXO 063111+1801.9

G. F. Bignami, P. A. Caraveo and L. Salotti, Institute of Cosmic Physics, Milan; and G. G. C. Palumbo, National Research Council, Bologna, telex: "The EXOSAT channel-multiplier array position of the source EXO 063111+1801.9 is R.A. = 6h31m11s49, Decl. = +18deg01'52"5 (equinox 1950.0), and the 0.5-2-keV flux is a few times 10**-16 J m**-2 s**-1. The source had been serendipitously discovered in an Einstein image-proportional-counter field and suggested to have a soft spectrum, but there was no possibility of high-resolution-imager follow up. The improved position allows us to propose a tentative optical counterpart R.A. = 6h31m10s82, Decl. = +18deg01'54"2 (equinox 1950.0), some 10" away. The object appears stellar on the Palomar Sky Survey at V ~ 17, implying comparable optical and x-ray luminosity. No radio counterpart is seen in the 21-cm Westerbork map of Spoelstra and Hermsen (1984, A.Ap. 135, 135), or in the 6-cm and 20-cm Bonn maps of Sieber and Schlikeiser (1982, A.Ap. 113, 314). Accurate spectrophotometry of the object is needed."