From: awootten@polaris.cv.nrao.edu (Al Wootten)
Subject: Re: Any Swift -Tuttle Observations ??
Organization: National Radio Astronomy Observatory
Date: Thu, 12 Nov 1992 20:51:15 GMT

In article <BxLzxy.H2q@cs.dal.ca> andromed@cs.dal.ca (Mike Boschat) writes:
    Hi;

    we've been overcast for awhile and I was wondering if anyone saw
   the comet yet and is it following the predicted RA and DEC ?
   Thanks in advance..

						   Clear skies

						   Mike Boschat

From the new elements on MPC 21081 I calculate that the positions for today
are within roughly 30" of those calculated with the elements on IAU5636--
important for millimeter telescopes with beams of this size or smaller.

The Calculations:

1                                   TWO BODY COMET EPHEMERIS GENERATOR - NO. 2 OPTION
0                                    OBSERVATORY COORDINATES AND E.T.-U.T.C. 
                     EAST LONGITUDE     RHO*COS(GEOCENTRIC LAT.)     RHO*SIN(GEOCENTRIC LAT.)     ET MINUS UTC 
0                    -111.61500000          .8471000000                  .5248600000                 58.00000
0                                             MATRIX OF ORBITAL ELEMENTS
                       YR  MN DY  HR       J.D.           Q           E       SOMEGA     LOMEGA        I
0                     1992 12 12  7.8  2448968.82300   .9581200   .9635900  153.00013  138.74518  113.43090
1                           TWO BODY EPHEMERIS FOR COMET Swift-Tuttle   EPOCH Dec 4.0  ORBIT MPC 21081                             

  YR  MN DY  HR   J.D.(UT)    R.A. 1950.0 DEC.      R.A.  DATA  DEC.    DELTA  DELTAD    R    RDOT   TMAG  NMAG  THETA   BETA
New Position:
 1992 11 12   .0  2448938.5 17 43.562  +28 41.60  17 45.228  +28 40.81  1.1739   7.06 1.0887 -13.71  4.94   .00  59.70  51.71
Old Position, orbit from IAU Circular 
 1992 11 12   .0  2448938.5 17 43.592  +28 41.55  17 45.258  +28 40.76  1.1738   6.87 1.0887 -13.71   .60   .00  59.70  51.71

 
0                       THE ABOVE EPHEMERIS IS BASED ON THE FOLLOWING ECLIPTIC (1950.0) ORBITAL ELEMENTS.
                        YR  MN DY  HR       J.D.           Q          E        SOMEGA     LOMEGA        I
0                      1992 12 12  7.8  2448968.82300   .9581200   .9635900  153.00013  138.74518  113.43090
0EXPLANATION OF SYMBOLS

 J.D.= JULIAN DATE(UNIVERSAL TIME)
 R.A. AND DEC. - 1950.0 = TOPOCENTRIC RIGHT ASCENSION AND DECLINATION REFERRED TO THE MEAN EQUATOR AND EQUINOX OF 1950.0
 R.A. AND DEC. - DATE = TOPOCENTRIC RIGHT ASCENSION AND DECLINATION REFERRED TO THE APPARENT EQUATOR AND EQUINOX OF DATE,
                        R.A. IN HOURS AND TIME MINUTES, DEC. IN DEGREES AND ARC MINUTES
 DELTA= TOPOCENTRIC DISTANCE OF OBJECT IN A.U.
 DELTAD = D(DELTA)/DT, IN KM/SEC
 R= HELIOCENTRIC DISTANCE OF OBJECT IN A.U.
 RDOT = D(R)/DT, IN KM/SEC
 TMAG= TOTAL   MAGNITUDE =  4.5 +  5.00*DLOG10(DELTA) +  2.50*DLOG10(R)
 NMAG= NUCLEAR MAGNITUDE =   .0 +   .00*DLOG10(DELTA) +   .00*DLOG10(R) +  .00*BETA
 THETA= SUN-EARTH-OBJECT ANGLE IN DEGREES
 BETA= SUN-OBJECT-EARTH ANGLE IN DEGREES







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