Circular No. 5373 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN 1991 TF3 C. S. Shoemaker has discovered another fast-moving asteroidal object. The following precise positions are available: 1991 UT R.A. (1950) Decl. Mag. Observer Oct. 2.34600 0 22 18.00 + 6 36 23.0 16.7 Shoemaker 2.37517 0 22 13.89 + 6 38 57.2 " 7.27482 0 14 55.56 +12 25 16.6 17 " 7.31545 0 14 51.87 +12 27 31.3 " 12.28941 0 10 13.72 +16 13 04.2 17.0 Lawrence 12.31233 0 10 12.38 +16 13 55.2 " C. S. Shoemaker, E. M. Shoemaker and D. H. Levy (Palomar). 0.46-m Schmidt telescope. Measurer C. S. Shoemaker. K. Lawrence, P. Rose and R. Bambery (Palomar). 0.46-m Schmidt telescope. Measurer J. Alu. Communicated by E. Helin. Preliminary orbital elements from the above observations by B. G. Marsden, Center for Astrophysics: T = 1991 Aug. 11.993 ET Peri. = 303.234 e = 0.53106 Node = 6.030 1950.0 q = 0.95736 AU Incl. = 14.048 a = 2.04153 AU n = 0.337886 P = 2.92 years 1991 ET R.A. (1950) Decl. Delta r V Oct. 11 0 11.21 +15 23.6 0.215 1.208 16.8 21 0 06.82 +20 01.7 31 0 08.11 +22 11.6 0.403 1.352 18.8 Nov. 10 0 13.41 +23 16.9 20 0 21.81 +23 55.2 0.634 1.503 20.1 MWC 560 Visual magnitude estimates (cf. IAUC} 5137): Jan. 7.97 UT, 9.7 (P. Schmeer, Bischmisheim, Germany); Mar. 3.98, 9.7 (Schmeer); Apr. 1.90, 9.6 (A. Pereira, Cabo da Roca, Portugal); May 13.88, 9.5 (Pereira); Sept. 17.21, 9.6 (Pereira); Oct. 5.18, 9.8 (Schmeer); 11.18, 9.9 (Schmeer); 16.18, 10.3 (Pereira); 18.16, 10.5 (Schmeer). 1991 October 24 Daniel W. E. Green