THE ASTRONOMER Electronic Circular No 498       1991 Mar 24 16.00UT
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-LAWRENCE (1991l)
Eleanor F. Helin and Kenneth J. Lawrence report their discovery of
a comet, as follows:
     1991 UT             R.A. (1950) Decl.        m1    Observer
     Mar. 17.40191   13 32 10.92   + 8 52 13.4   15     Helin
          17.42483   13 32 08.94   + 8 52 15.7            "
          19.69248   13 29 19.55   + 8 56 41.2   15     McNaught
E. Helin, K. Lawrence, and P. Rose (Palomar).  0.46-m Schmidt tele-
  scope films.  Measured by Lawrence.  Comet image extremely dense,
  with a tail fanning to the north-northeast.
IAUC 5213
Preliminary parabolic elements from 10 observations Mar. 17-21:
     T = 1992 Feb. 19.166 ET          Peri. = 262.890
                                      Node  =   9.648   1950.0
     q = 1.88148 AU                   Incl. = 102.503
IAUC 5215
Ephemeris by Hurst using a program by N.James:
m =  4.5 + 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 Mar
  24.00  13 23.68   +9  4.3   3.255   4.199  158.8  13.3    50  275
  25.00  13 22.32   +9  5.9   3.241   4.190  159.6  13.3    51  275
  26.00  13 20.94   +9  7.5   3.228   4.182  160.5  13.3    51  274
  27.00  13 19.54   +9  9.0   3.216   4.173  161.2  13.2    52  274
  28.00  13 18.13   +9 10.4   3.204   4.164  162.0  13.2    53  274
  29.00  13 16.71   +9 11.8   3.192   4.155  162.6  13.2    53  274
  30.00  13 15.26   +9 13.1   3.180   4.146  163.2  13.2    54  273
  31.00  13 13.81   +9 14.3   3.169   4.137  163.7  13.2    54  273
1991 Apr
   1.00  13 12.34   +9 15.4   3.159   4.129  164.1  13.2    55  273
   2.00  13 10.85   +9 16.4   3.148   4.120  164.4  13.1    55  273
   3.00  13  9.36   +9 17.4   3.138   4.111  164.6  13.1    56  272
   4.00  13  7.85   +9 18.2   3.129   4.102  164.7  13.1    56  272
   5.00  13  6.33   +9 19.0   3.120   4.093  164.7  13.1    56  272
   6.00  13  4.80   +9 19.6   3.111   4.084  164.6  13.1    57  272
   7.00  13  3.26   +9 20.2   3.103   4.076  164.3  13.1    57  271
   8.00  13  1.71   +9 20.6   3.095   4.067  163.9  13.0    57  271
   9.00  13  0.16   +9 21.0   3.088   4.058  163.5  13.0    58  271
  10.00  12 58.59   +9 21.2   3.081   4.049  162.9  13.0    58  270
  11.00  12 57.03   +9 21.3   3.074   4.040  162.3  13.0    58  270
  12.00  12 55.45   +9 21.2   3.068   4.031  161.6  13.0    58  270
  13.00  12 53.88   +9 21.1   3.062   4.023  160.8  13.0    58  269
  14.00  12 52.30   +9 20.8   3.057   4.014  160.0  13.0    59  269
  15.00  12 50.71   +9 20.4   3.052   4.005  159.1  12.9    59  269
  16.00  12 49.13   +9 19.8   3.047   3.996  158.2  12.9    59  269
  17.00  12 47.55   +9 19.2   3.043   3.987  157.2  12.9    59  268
  18.00  12 45.96   +9 18.4   3.039   3.978  156.2  12.9    59  268

The comet could reach mag 8 in 1992 January when it will be located
in the southern sky.

E-INDEX
Roger Pickard has re-joined TELECOM GOLD. His mailbox is:
10074:MIK3229

Guy M Hurst