THE ASTRONOMER Electronic Circular No 542 1991 July 16 19.10UT
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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COMET HELIN-ALU (1991r)
Improved parabolic orbital elements from 16 observations June 13-
July 13:
T = 1992 Feb. 17.467 ET Peri. = 30.319
Node = 252.946 1950.0
q = 4.87351 AU Incl. = 49.539
The comet is fading below m1=16.
IAUC 5305
PERIODIC COMET LEVY (1991q)
Orbital computations show that this comet has a revolution period
of some 35-60 years and that when perihelion passage is in
September a close approach to the earth is possible. S. Nakano and
D. W. E. Green have independently suggested identity with comet
1499, but the number of intervening revolutions is uncertain.
T = 1991 July 8.185 ET Peri. = 41.472
e = 0.92728 Node = 328.693 1950.0
q = 0.98217 AU Incl. = 19.182
a = 13.50559 AU n = 0.019858 P = 49.63 years
IAUC 5306
Ephemeris by Hurst using a program by N.James (cf E536):
m = 7.5 + 5.0 log R + 10.0 log r
Date R.A. (1950) Dec. R r Elong Mag. Motion
h m o ' (AU) (AU) o "/hr P.A.
1991 July
18.00 4 25.87 +32 53.6 1.398 0.996 45.4 8.2 166 72
19.00 4 30.89 +33 13.2 1.405 0.999 45.3 8.2 164 73
20.00 4 35.90 +33 31.9 1.413 1.002 45.1 8.3 163 74
21.00 4 40.88 +33 49.6 1.420 1.005 45.0 8.3 161 74
22.00 4 45.85 +34 6.3 1.428 1.009 45.0 8.3 159 75
23.00 4 50.80 +34 22.2 1.435 1.013 44.9 8.3 158 76
24.00 4 55.73 +34 37.1 1.443 1.017 44.8 8.4 156 77
25.00 5 0.63 +34 51.2 1.451 1.021 44.7 8.4 154 77
26.00 5 5.51 +35 4.3 1.459 1.026 44.7 8.4 153 78
27.00 5 10.36 +35 16.6 1.467 1.031 44.6 8.5 151 79
28.00 5 15.18 +35 28.1 1.475 1.036 44.6 8.5 149 79
29.00 5 19.96 +35 38.7 1.483 1.041 44.6 8.5 148 80
30.00 5 24.72 +35 48.5 1.491 1.047 44.6 8.6 146 81
31.00 5 29.43 +35 57.5 1.499 1.053 44.5 8.6 144 81
1991 Aug
1.00 5 34.11 +36 5.8 1.507 1.059 44.5 8.6 143 82
2.00 5 38.75 +36 13.3 1.515 1.065 44.6 8.7 141 83
3.00 5 43.36 +36 20.0 1.523 1.071 44.6 8.7 139 83
4.00 5 47.92 +36 26.1 1.531 1.078 44.6 8.8 138 84
5.00 5 52.43 +36 31.4 1.539 1.085 44.7 8.8 136 85
6.00 5 56.91 +36 36.1 1.547 1.092 44.7 8.8 135 85
7.00 6 1.33 +36 40.2 1.555 1.099 44.8 8.9 133 86
8.00 6 5.72 +36 43.6 1.563 1.106 44.8 8.9 131 87
9.00 6 10.05 +36 46.5 1.571 1.114 44.9 8.9 130 87
10.00 6 14.34 +36 48.7 1.579 1.121 45.0 9.0 128 88
11.00 6 18.57 +36 50.4 1.587 1.129 45.1 9.0 127 88
12.00 6 22.76 +36 51.6 1.595 1.137 45.2 9.1 125 89
13.00 6 26.90 +36 52.2 1.603 1.145 45.3 9.1 123 90
14.00 6 30.98 +36 52.3 1.611 1.154 45.4 9.2 122 90
15.00 6 35.02 +36 52.0 1.619 1.162 45.6 9.2 120 91
16.00 6 39.00 +36 51.2 1.627 1.171 45.7 9.2 119 91
Guy M Hurst