Circular No. 5893

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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)

PERIODIC COMET SHOEMAKER-LEVY 9 (1993e) The new orbit computations (IAUC 5892) demonstrate that it is abso-

lutely certain that all of the individual nuclei observed by Spacewatch will pass ∼ 0.0002 AU from the center of Jupiter (the radius of which is 0.0005 AU) in July 1994, the computed collision times being as follows: nucleus 17, July 18.7 UT; 15, 19.1; 14, 19.6; 12, 20.2; 11, 20.9; 7, 21.6; 6, 22.1; 5, 22.7; 1, 23.2. On July 17.0 this portion of the train will extend 14′ in p.a. 61^{o}-241^{o}. The ephemeris below is for nucleus 7, but the magnitude is a guess for the total comet. Now that the basic dynamical history of the comet has been established, observers are requested to provide astrometric measurements (preferably using CCDs) only of the individual nuclei, not of the “center of the train”; separations between nuclei can be quoted with precision better than 0′′.1 if circumstances allow.

1993 /94 α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Nov. 29 13^{h}58.^{m}25 −12^{o}58.^{′}8 6.185 5.405 34.^{o}8 6.^{o}0 14.3
Dec. 9 14 05.83 −13 38.6 6.081 5.403  43.0  7.1 14.2
19 14 12.99 −14 15.2 5.960 5.400  51.3  8.2 14.2
29 14 19.59 −14 48.1 5.825 5.398  59.8  9.1 14.1
Jan. 8 14 25.52 −15 16.8 5.678 5.396  68.5  9.8 14.1
18 14 30.67 −15 40.9 5.522 5.394  77.4 10.3 14.0
28 14 34.90 −16 00.0 5.361 5.392  86.5 10.5 14.0
Feb. 7 14 38.11 −16 13.7 5.199 5.390  95.8 10.5 13.9
17 14 40.19 −16 21.7 5.040 5.388 105.4 10.2 13.8
27 14 41.07 −16 23.8 4.889 5.387 115.3  9.6 13.8
Mar. 9 14 40.74 −16 19.7 4.749 5.386 125.4  8.6 13.7
19 14 39.22 −16 09.7 4.626 5.385 135.8  7.4 13.6
29 14 36.62 −15 53.8 4.524 5.384 146.4  5.9 13.6
Apr. 8 14 33.13 −15 32.9 4.447 5.383 157.1  4.1 13.5
18 14 29.00 −15 07.9 4.397 5.383 168.0  2.2 13.5
28 14 24.54 −14 40.3 4.377 5.383 178.9  0.2 13.5
May 8 14 20.11 −14 11.7 4.387 5.384 170.2  1.8 13.5
18 14 16.04 −13 44.0 4.426 5.385 159.4  3.8 13.5
28 14 12.64 −13 18.8 4.493 5.386 148.9  5.6 13.6
June 7 14 10.13 −12 57.6 4.585 5.389 138.6  7.1 13.6
17 14 08.70 −12 41.2 4.698 5.392 128.7  8.5 13.7
27 14 08.47 −12 30.2 4.829 5.396 119.0  9.5 13.7
July 7 14 09.51 −12 24.3 4.973 5.401 109.7 10.2 13.8
17 14 11.96 −12 22.0 5.128 5.410 100.7 10.6 13.9

1993 November 22 Brian G. Marsden