THE ASTRONOMER Electronic Circular No 541 1991 July 14 08.58UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke,
Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074
Telex: 9312111261 Answerback: TA G JANET BOXES:
GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER
TELECOM GOLD: 10074:MIK2885 PRESTEL 256471074
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PERIODIC COMET WIRTANEN (1991s)
S. Nakano, Sumoto, Japan, reports that T. Seki, Geisei, has
recovered this comet as shown below. The object is diffuse with
condensation, and the indicated correction to the prediction on MPC
13046 (ephemeris on MPC 18148) is delta T = -0.05 day.
1991 UT R.A. (1950) Decl. m1
July 8.76666 3 12 02.7 + 8 03 58 17
9.77743 3 15 32.12 + 8 19 56.5 17
9.78333 3 15 33.57 + 8 20 03.8
IAUC 5303
PERIODIC COMET HARTLEY 2 (1991t)
G. R. Kastel', Institute for Theoretical Astronomy, reports the
following rough positions of a comet discovered by T. V. Kryachko
at Majdanak. The object was diffuse and condensed with a coma 15'
across.
1991 UT R.A. (1950) Decl. m1
July 9.854 1 01.5 +20 15 11
9.938 1 02.0 +20 05
10.875 1 06.2 +20 40 11
S. Nakano, Sumoto, Japan, has suggested that this is P/Hartley 2,
a correction of delta T = -5.6 days being necessary to his
prediction on MPC 13046. As a result, R. E. McCrosky and C.-Y. Shao
were able to confirm the comet and its identification with the
1.5-m reflector at Oak Ridge Observatory, as follows:
1991 UT R.A. (1950) Decl.
July 12.31995 1 12 48.80 +21 21 05.9
12.33093 1 12 51.82 +21 21 23.9
Orbital elements by Brian Marsden from 20 observations 1986-1991:
Epoch = 1991 Sept. 21.0 ET
T = 1991 Sept. 11.6515 ET Peri. = 174.9274
e = 0.719504 Node = 226.0600 1950.0
q = 0.953226 AU Incl. = 9.2552
a = 3.398363 AU n = 0.1573256 P = 6.265 years
IAUC 5304
Ephemeris by Hurst using a program by N.James:
m = 10.5 + 5.0 log R + 15.0 log r
Date R.A. (1950) Dec. R r Elong Mag. Motion
h m o ' (AU) (AU) o "/hr P.A.
1991 July
14.00 1 20.91 +22 6.4 0.900 1.281 83.6 11.9 183 69
15.00 1 25.86 +22 33.1 0.891 1.272 83.3 11.8 185 69
16.00 1 30.89 +22 59.5 0.883 1.263 83.0 11.8 187 69
17.00 1 36.01 +23 25.6 0.875 1.254 82.7 11.7 189 70
18.00 1 41.22 +23 51.3 0.868 1.245 82.4 11.6 191 70
19.00 1 46.53 +24 16.6 0.860 1.237 82.0 11.6 193 71
20.00 1 51.92 +24 41.5 0.853 1.228 81.6 11.5 195 72
21.00 1 57.40 +25 5.8 0.846 1.220 81.3 11.4 197 72
22.00 2 2.98 +25 29.7 0.840 1.211 80.9 11.4 199 73
23.00 2 8.64 +25 52.9 0.834 1.203 80.5 11.3 201 73
24.00 2 14.39 +26 15.5 0.828 1.195 80.1 11.2 202 74
25.00 2 20.23 +26 37.4 0.822 1.186 79.7 11.2 204 75
26.00 2 26.15 +26 58.5 0.817 1.178 79.2 11.1 206 75
27.00 2 32.15 +27 18.8 0.812 1.170 78.8 11.1 207 76
28.00 2 38.23 +27 38.3 0.807 1.162 78.3 11.0 209 77
29.00 2 44.39 +27 56.9 0.802 1.154 77.9 11.0 210 78
30.00 2 50.62 +28 14.6 0.798 1.146 77.4 10.9 211 78
31.00 2 56.93 +28 31.2 0.794 1.139 76.9 10.8 213 79
Guy M Hurst