Circular No. 5826

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 HARTLEY 3 (1993m) J. V. Scotti, University of Arizona, reports his recovery of this comet

with the Spacewatch telescope at Kitt Peak. On June 23, the comet exhibited a coma of diameter 10′′ and a tail 0′.54 long in p.a. 255^{o}, and m_{2} = 22.1; the comet was close to a star of mag 14 on June 24 (measures slightly uncertain).

1993 UT  α_{2000}  δ_{2000}  m_{1}
June 23.43707  1^{h}40^{m}51.^{s}19  +21^{o}40′45′′.4
23.44496  1 40 51.79  +21 40 49.2  19.5
23.45118  1 40 52.21  +21 40 52.2  19.7
24.44795  1 42 02.95  +21 49 40.3
24.45394  1 42 03.37  +21 49 42.9
24.45990  1 42 03.89  +21 49 46.1

The comet’s position is off slightly from the prediction on MPC 18257, such that ΔT ∼ +0.49 day. The following orbital elements by the undersigned are from 27 observations, 1988-1993 (mean residual 0′′.7):

Epoch = 1994 May 8.0 TT

T = 1994 May 20.8684 TT  ω = 168.^{o}4583
e = 0.316911  Ω = 287.8791 }2000.0
q = 2.461681 AU  i = 11.6954
a = 3.603750 AU n^{o} = 0.1440695 P = 6.841 years
1993 TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
July 12 2^{h}01.^{m}93 +24^{o}20.^{′}2 3.182 3.049 73.^{o}3 18.^{o}6 19.3
22 2 12.34 +25 41.7 3.026 3.020  80.0 19.3 19.1
Aug. 1 2 21.82 +26 59.6 2.869 2.990  86.9 19.8 18.9
11 2 30.15 +28 13.1 2.711 2.961  94.1 20.0 18.7
21 2 37.05 +29 21.3 2.556 2.933 101.6 19.7 18.5
31 2 42.18 +30 23.0 2.406 2.904 109.6 19.1 18.4
Sept. 10 2 45.27 +31 16.5 2.264 2.876 117.9 18.0 18.2
20 2 45.99 +31 59.3 2.132 2.849 126.7 16.4 18.0
30 2 44.18 +32 28.4 2.015 2.822 136.0 14.3 17.8
Oct. 10 2 39.90 +32 40.3 1.915 2.795 145.4 11.7 17.6
20 2 33.46 +32 31.7 1.837 2.769 154.5  8.9 17.5
30 2 25.61 +32 01.0 1.784 2.744 161.6  6.5 17.3
Nov. 9 2 17.38 +31 09.6 1.757 2.720 163.1  6.1 17.2

1993 June 29 Daniel W. E. Green