THE ASTRONOMER Electronic Circular No 537      1991 July 07 11.01UT
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 MACHHOLZ
This comet was found by Don Machholz on 1986 May 12 and designated
Comet (1986e) [IAUC 4214]. Subsequently S.Nakano produced elements
on IAUC 4223 confirming that it was of short-period. According to
the International Comet Quarterly 1991 Handbook this comet, which
has not so far been recovered in 1991, could reach mag 2 although
at an elongation of about 4 degrees! However there remains a
possibility that this comet might be recovered during July or
August, and perhaps even VISUALLY. The following elements have
been downloaded from the IAU Computer:
T  1991 July 22.0127 E.T.    w  14.52911 )
e  0.95836920                O  93.82273 ) 1950.0
q  0.1255478 A.U.            i  60.14704 )
Source: MPC14748    Positions are geocentric
m = 13.0 + 5.0 log R + 12.0 log r
Ephemeris by Hurst using a program by N.James. The magnitude
predictions are very uncertain:
  Date    R.A. (1950) Dec.     R       r     Elong  Mag.    Motion
          h  m       o  '     (AU)    (AU)     o          "/hr P.A.
1991 July
   7.00   5 53.24   -5 38.0   0.924   0.554   32.7   9.7   346   49
   8.00   6  0.24   -4  6.8   0.932   0.527   31.0   9.5   347   49
   9.00   6  7.19   -2 34.3   0.941   0.499   29.2   9.2   349   48
  10.00   6 14.10   -1  0.3   0.952   0.470   27.4   9.0   351   48
  11.00   6 20.99   +0 35.3   0.964   0.441   25.6   8.7   353   47
  12.00   6 27.88   +2 12.6   0.977   0.411   23.7   8.3   356   46
  13.00   6 34.79   +3 51.9   0.991   0.381   21.8   7.9   361   46
  14.00   6 41.76   +5 33.6   1.006   0.349   19.9   7.5   367   45
  15.00   6 48.84   +7 18.3   1.023   0.317   17.9   7.1   376   45
  16.00   6 56.11   +9  6.7   1.041   0.285   15.9   6.5   388   45
  17.00   7  3.66  +10 59.8   1.060   0.252   13.7   5.9   405   45
  18.00   7 11.65  +12 59.1   1.079   0.218   11.5   5.2   430   45
  19.00   7 20.33  +15  6.2   1.099   0.186    9.1   4.4   464   45
  20.00   7 30.05  +17 22.5   1.117   0.157    6.5   3.6   510   46
  21.00   7 41.28  +19 47.1   1.130   0.134    3.8   2.8   561   49
  22.00   7 54.31  +22 11.7   1.134   0.126    2.3   2.5   593   54
  23.00   8  8.70  +24 19.7   1.126   0.134    4.1   2.8   581   60
  24.00   8 23.50  +25 59.9   1.109   0.156    6.7   3.5   544   66
  25.00   8 38.15  +27 12.9   1.088   0.185    9.3   4.4   508   72
  26.00   8 52.49  +28  4.2   1.066   0.217   11.7   5.2   482   77
  27.00   9  6.56  +28 38.4   1.045   0.250   13.9   5.9   464   81
  28.00   9 20.39  +28 59.0   1.026   0.283   16.0   6.5   452   85
  29.00   9 34.03  +29  8.0   1.009   0.316   18.0   7.0   444   89
  30.00   9 47.48  +29  7.2   0.994   0.348   19.9   7.5   438   92
  31.00  10  0.74  +28 57.5   0.981   0.379   21.8   7.9   433   94
1991 Aug
   1.00  10 13.80  +28 40.0   0.970   0.410   23.7   8.3   429   97
   2.00  10 26.62  +28 15.3   0.960   0.440   25.5   8.6   426   99
   3.00  10 39.19  +27 44.3   0.953   0.469   27.3   8.9   422  102
   4.00  10 51.48  +27  7.4   0.948   0.498   29.1   9.2   417  104
   5.00  11  3.46  +26 25.5   0.944   0.526   30.9   9.5   413  105
   6.00  11 15.11  +25 39.0   0.943   0.553   32.6   9.8   407  107
   7.00  11 26.42  +24 48.6   0.943   0.580   34.2  10.0   401  109
   8.00  11 37.36  +23 55.0   0.944   0.606   35.8  10.3   394  110
   9.00  11 47.93  +22 58.6   0.948   0.632   37.4  10.5   387  112
  10.00  11 58.13  +22  0.1   0.952   0.657   38.9  10.7   379  113
  11.00  12  7.94  +20 60.0   0.958   0.682   40.4  10.9   370  114
  12.00  12 17.38  +19 58.6   0.966   0.707   41.8  11.1   361  115

Guy M Hurst