Circular No. 4209 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444 COMET SINGER BREWSTER (1986d) A comet has been discovered by Stephen Singer-Brewster on two films exposed by D. Schneeberger, E. Burr and himself with the 0.46-m Schmidt telescope at Palomar in the course of the International Near-Earth Asteroid Survey under the direction of E. F. Helin. The comet was subsequently identified on an exposure obtained the following night by C. S. and E. M. Shoemaker with the same telescope. The object is diffuse and only slightly condensed, maybe with a faint tail to the northeast on May 4. 1986 UT R.A. (1950.0) Decl. m1 Observer May 3.4 14 50.1 - 6 34 15 Singer-Brewster 4.32777 14 49.8 - 6 17 Shoemaker PERIODIC COMET HALLEY (1982i) Several observers have remarked on further tail disconnection events, particularly during Mar. 9-16 and Apr. 10-11. Further to the note on IAUC 4205, naked-eye tail-length estimates by G. Thompson and R. Bouma in Queensland showed a general increase from almost 15 deg on Apr. 13 to 25 deg on Apr. 19 and possibly 35 deg during the Apr. 24 total lunar eclipse, when T. Lovejoy reported a 43 deg tail. Exposures by G. Emerson with a 0.30-m f/1.8 Schmidt telescope near Boulder, CO, during Apr. 30-May 2 showed a 20' antitail and two 3 deg dust tails over a 10 deg range of position angle. Further selected total visual magnitude estimates (naked eye unless otherwise stated): Apr. 17.06 UT, 2.5 (V. F. de Assis Neto, Sao Francisco de Oliveira, Brazil); 19.18, 2.7 (de Assis Neto); 21.35, 3.4 (D. W. E. Green, Queenstown, N.Z.); 24.53, 3.6 (Green, near Lake Tekapo, N.Z.; during total lunar eclipse); 25.82, 4.3 (R. Fleet, Harare, Zimbabwe; moonlight); 27.86, 4.9 (G. M. Hurst, Basingstoke, England, 10 x 50 binoculars; low altitude); 29.81, 4.4 (Fleet, Pretoria, R.S.A.); May 3.12, 4.6 (Green, Harvard, MA). VY AQUARII S. Lubbock, Bridge End, Wales; and R. H. McNaught, Coonabarabran, N.S.W., have reported (apparently independently) an outburst of this presumed dwarf nova (cf. IAUC 3896, etc.): Apr. 27.80 UT, [14.1 (McNaught); May 1.14, 11.7 (Lubbock); 3.82, 10.8 (McNaught); 4.66, 10.7 (McNaught). 1986 May 5 (4209) Brian G. Marsden
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