Circular No. 5417
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN
 
 
OCCULTATION BY P/SCHWASSMANN-WACHMANN 1
     Predictions by D. W. Dunham, Computer Sciences Corporation;
D. Mink, Harvard-Smithsonian Center for Astrophysics; and L.
Wasserman, Lowell Observatory, indicate that the path of the
comet's occultation of a star on 1992 Jan. 1 (Dunham 1992, Sky
Tel. 83, 72) is still very uncertain, to the extent that the event
might begin anywhere from eastern Canada to southern Mexico and end
between central Australia and New Zealand, although the recent
measures seem more to favor a Mexico-New Zealand track.  A. R.
Klemola, Lick Observatory, gives the star's position as R.A. =
3 07 10.56, Decl. = +28 07 41.6 (equinox 1950.0, epoch 1991.94).
The occultation should begin around 7h40m UT in North America and end
around 8h00m UT in the southwestern Pacific region.  The star
appears to be brighter than the mag 13.2 previously indicated, the
Guide Star Catalogue giving the magnitude as V = 10.47.
 
 
1991 VB
     Precise positions measured by P. Rose from films taken by E. Helin,
K. Lawrence and himself with the 0.46-m Palomar Schmidt:
 
     1991 UT             R.A. (2000) Decl.        B
     Dec.  7.20590    2 29 17.92   +19 12 11.1   17.0
           7.23021    2 29 19.85   +19 11 53.6
 
     Orbital elements from 10 observations Nov. 1-Dec. 7:
 
     T = 1991 Oct. 23.5054 TT         Peri. = 134.0216
     e = 0.408984                     Node  = 256.8218  2000.0
     q = 1.319919 AU                  Incl. =   6.3823
       a =  2.233305 AU    n = 0.2953126    P =   3.338 years
 
1991/92     R. A. (2000) Decl.     Delta      r    Elong. Phase      V
Dec. 20     2 49.16    +17 28.2    0.537    1.427  137.4   27.8     17.2
     30     3 06.24    +16 46.7    0.616    1.463  130.9   30.5     17.6
Jan.  9     3 24.36    +16 32.4    0.707    1.504  124.8   32.5     18.0
     19     3 43.35    +16 37.0    0.808    1.547  119.1   33.8     18.4
     29     4 02.96    +16 53.3    0.919    1.593  113.6   34.5     18.8
Feb.  8     4 23.06    +17 15.3    1.039    1.641  108.2   34.8     19.1
     18     4 43.54    +17 38.3    1.167    1.691  103.0   34.7     19.4
 
 
1991 December 27                                   Brian G. Marsden