TA e-circular

<title>TA e-circular</title>
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THE ASTRONOMER Electronic Circular No 589       1991 Dec 22 16.39UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England. Telephone/FAX(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 KOWAL 2 (1991f1)
H. Kosai and T. Hirayama, National Astronomical Observatory, Tokyo,
report that Masao Ishikawa has discovered a comet, and they provide
the following precise positions:
     1991 UT             R.A. (1950) Decl.        m1    Observer
     Dec. 12.70336    8 32 29.59   - 0 30 54.6   14.0   Ishikawa
          12.80011    8 32 29.28   - 0 32 48.8            "
          13.72775    8 32 42.18   - 0 56 07.9            "
          13.76373    8 32 42.29   - 0 57 04.4            "
          13.79457    8 32 42.64   - 0 57 48.1            "
          15.79330    8 32 59.91   - 1 47 08.1            "
          16.72291    8 33 06.03   - 2 09 38.7   14.0   Kushida
          16.74930    8 33 06.05   - 2 10 13.9            "
          16.79861    8 33 06.41   - 2 11 34.1            "
M. Ishikawa (Fukaya, Saitama).  0.16-m hyperboloid astrograph.
   Tech-Pan film without filter.  Image diffuse without
condensation.
   Measurer S. Hayakawa.
Y. Kushida (Yatsugatake South Base Observatory).  0.20-m f/4 hyper-
   boloid reflector.  Comet images diffuse and difficult to
measure,
   especially in right ascension.
B. G. Marsden (Harvard-Smithsonian Center for Astrophysics) and
T. Kobayashi (Oizumi, Gunma, Japan) have identified the comet with
P/Kowal 2 (1979 II), the prediction for which on MPC 13046 requires
correction by Delta(T) = -54 days.  Marsden provides the following
improved orbital elements, which satisfy 16 observations 1979-1991
with mean residual 1".2:
                    Epoch = 1979 Jan.  7.0 ET
     T = 1979 Jan. 13.6774 ET         Peri. = 189.3294
     e = 0.560490                     Node  = 247.2065  1950.0
     q = 1.519722 AU                  Incl. =  15.8032
       a =  3.457766 AU    n = 0.1532889    P =   6.430 years

                    Epoch = 1991 Oct. 31.0 ET
     T = 1991 Nov.  4.3598 ET         Peri. = 189.5235
     e = 0.564287                     Node  = 247.0738  1950.0
     q = 1.499650 AU                  Incl. =  15.8359
       a =  3.441834 AU    n = 0.1543544    P =   6.385 years
IAUC 5406
Ephemeris by G.Hurst using a program by N.James:
m = 12.0 + 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 Dec
  20.00   8 33.07   -3 26.2   0.739   1.574  131.4  14.3    57  183
  25.00   8 32.13   -5 14.8   0.736   1.590  134.8  14.4    53  192
  30.00   8 30.20   -6 51.4   0.736   1.608  138.2  14.4    48  201
1992 Jan
   4.00   8 27.41   -8 14.0   0.739   1.627  141.3  14.5    44  212
   9.00   8 23.96   -9 21.4   0.747   1.648  144.1  14.6    40  223
  14.00   8 20.08  -10 12.8   0.758   1.669  146.5  14.7    37  234
  19.00   8 16.01  -10 48.1   0.774   1.692  148.3  14.9    33  245
  24.00   8 11.98  -11  7.9   0.794   1.715  149.2  15.0    30  258
  29.00   8  8.22  -11 13.1   0.818   1.740  149.4  15.2    26  272
1992 Feb
   3.00   8  4.92  -11  5.4   0.847   1.765  148.7  15.3    23  287

Guy M Hurst
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