THE ASTRONOMER Electronic Circular No 532      1991 June 18 20.32UT
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 LEVY (1991q)
Preliminary parabolic orbital elements by S. Nakano, Sumoto, Japan,
from 6 observations, June 14-18:
     T = 1991 July  8.168 ET          Peri. =  41.311
                                      Node  = 329.824   1950.0
     q = 0.99533 AU                   Incl. =  19.361
Ephemeris by Hurst using a program developed by N.James:
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 June
  18.00   1 58.68  +16  7.0   1.295   1.054   52.6   8.3   198   56
  19.00   2  3.28  +16 50.9   1.295   1.048   52.3   8.3   198   57
  20.00   2  7.90  +17 34.5   1.296   1.043   51.9   8.2   198   57
  21.00   2 12.56  +18 17.5   1.296   1.038   51.6   8.2   198   57
  22.00   2 17.24  +19  0.1   1.297   1.033   51.3   8.2   197   58
  23.00   2 21.96  +19 42.1   1.299   1.029   51.0   8.2   197   58
  24.00   2 26.70  +20 23.6   1.300   1.025   50.7   8.2   196   58
  25.00   2 31.47  +21  4.5   1.302   1.021   50.4   8.2   196   59
  26.00   2 36.26  +21 44.7   1.305   1.017   50.1   8.2   195   59
  27.00   2 41.09  +22 24.2   1.307   1.014   49.8   8.1   194   60
  28.00   2 45.94  +23  3.1   1.310   1.011   49.5   8.1   193   60
  29.00   2 50.81  +23 41.2   1.313   1.008   49.3   8.1   193   61
  30.00   2 55.71  +24 18.6   1.317   1.005   49.0   8.1   192   61
1991 July
   1.00   3  0.63  +24 55.1   1.321   1.003   48.7   8.1   191   62
   2.00   3  5.57  +25 30.9   1.325   1.001   48.5   8.1   189   62
   3.00   3 10.53  +26  5.8   1.329   0.999   48.2   8.1   188   63
   4.00   3 15.51  +26 39.8   1.334   0.998   48.0   8.1   187   63
   5.00   3 20.50  +27 13.0   1.338   0.997   47.7   8.1   186   64
   6.00   3 25.51  +27 45.2   1.343   0.996   47.5   8.1   185   64
   7.00   3 30.53  +28 16.6   1.349   0.996   47.3   8.1   183   65
   8.00   3 35.57  +28 47.0   1.354   0.995   47.0   8.1   182   66
   9.00   3 40.61  +29 16.5   1.360   0.995   46.8   8.1   180   66
  10.00   3 45.66  +29 45.0   1.366   0.996   46.6   8.2   179   67
  11.00   3 50.71  +30 12.5   1.372   0.997   46.4   8.2   177   68
  12.00   3 55.77  +30 39.1   1.378   0.998   46.3   8.2   176   68
  13.00   4  0.83  +31  4.7   1.385   0.999   46.1   8.2   174   69
  14.00   4  5.89  +31 29.3   1.391   1.000   45.9   8.2   173   69
  15.00   4 10.94  +31 53.0   1.398   1.002   45.8   8.2   171   70
  16.00   4 15.99  +32 15.6   1.405   1.004   45.6   8.3   169   71
  17.00   4 21.03  +32 37.3   1.412   1.007   45.5   8.3   168   72
S. Larson, D. Levy, and T. Spahr, University of Arizona, report
that, when observed with the Catalina 1.5-m reflector on June 18.45
UT, the comet exhibited ion streamers, a dust fan, and one or
perhaps two dust envelopes.  A spectrum shows CN, C2, C3, H2O+, and
possibly NH2.
Total visual magnitude estimates:  June 16.46 UT, 8.7 (C. S.Morris,
Pine Mountain Club, CA, 20x80 binoculars); 16.83, 8.3 (D. A.
J. Seargent, The Entrance, N.S.W., 15x80 binoculars); 17.45, 7.6
(D.H. Levy, Tucson, AZ, 0.41-m reflector; 3' sunward fan); 17.86,
8.5 (A. Pearce, Scarborough, W.A., 20x80 binoculars).
IAUC 5293 (In part)

Guy M Hurst