Periodic Comet d'Arrest (1976e)

A. Mrkos, Klet Observatory, provides the following positions: 1976 UT R. A. (1950) Decl. m2 June 24.97100 18 52 35.72 +21 42 22.3 14.8 24.98211 18 52 35.97 +21 42 30.9 30.97389 19 00 13.28 +22 04 26.0 14.6 30.98708 19 00 14.11 +22 04 29.7 July 2.99725 19 03 08.35 +22 04 03.2 14.6 3.00870 19 03 09.28 +22 04 04.9 3.94939 19 04 35.90 +22 02 19.6 14.4 3.96084 19 04 36.80 +22 02 17.3 H. U. Keller and Rh. Lust, Max Planck Institut fur Physik und Astrophysik, point out that the comet will occult the star HR 8054 = BD -1 4095 = HD 200340 (magnitude 6.3, spectrum B8) on Aug. 6. Calculations by the undersigned indicate that the geocentric separation will be 3" at 21h31m UT, with the substellar point in the extreme western Indian Ocean. The occultation track will run from west of western Europe (around 21h21m) to south of western Australia (21h41m). The comet, the geocentric parallax of which will be 56", will pass within 0'.5 of the star for most observers in Europe, Africa, southern Asia and western Australia. J. Bortle, Brooks Observatory, provides further visual magnitude estimates (32-cm reflector): July 15.09 UT, 10.1; 16.11, 9.8, 18.12, 9.4; 19.11, 9.4; 20.10, 9.5. The coma, of diameter 4'-6', was extremely diffuse in its outer regions, but strongly condensed within some 0'.5 of the center.