Update for (814) Tauris - December 15, 1999

Jan Manek's update

                     IOTA/IOTA-ES occultation update for
             (814) Tauris / HIP 9185 event on December 15, 1999
             visible from Canary Islands and western Ireland (?) 


Summary 

In the night December 15, 1999 a 8.8 mag star HIP 9185 = SAO 148132 will be occulted by a 116 km asteroid (814) Tauris. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and HIPPARCOS star position.

The updated path shows ~1.5 path width eastern shift with time essentially the same compared to Edwin Goffin's nominal prediction.

The path now runs over Canary Islands with Gran Canaria in the path and Teide Observatory on the western limit at ~21:56 UT. Later at ~21:58 UT the path grazes western coast of Ireland. Within errors is western half of Ireland and whole Hebrides.

The event at one glimpse:
 * date and approx. UT time of event: December 15, 1999 @ 21:57 UT
 * magnitude of target star: 8.8
 * magnitude drop [mag]: 3.7
 * estimated maximum duration [s]: 8.1
 * path description: given above

The occultation path:
 * approximate ground width [km]: 120
 * uncertainty [path widths]: 1.0
 * uncertainty in time [s]: 10
 * map: attached 
 * remarks: Path uncertainities are given according to nominal star 
    position errors and expected asteroid positional accuracy. 
    !!!!!!!
    Circles along the path are OCCULT exactly calculated centerline points. 
    !!!!!!!

Data for the target star:
 * name: HIP 9185 = SAO 148132 = PPM 210897 = GSC 5278.2269
 * constellation: Cetus
 * J2000 position [h,m,s; o,',"]: 01h 58m 15.095s; -10o 41' 40.32"
 * position source: HIPPARCOS
 * estimated accuracy ["]: 0.01" (0.01", 0.01")
 * V mag [mag]: 8.77
 * B-V [mag]: +0.99
 * remarks: 

     Target star is in middle Cetus, about 1.7 degrees east of 3.7 mag 
     star zeta Ceti. About 31' NW from target star is 6.4 mag star 
     SAO 148123 and 37' south of target is 6.5 mag star SAO 148139.
     
Data for the minor planet:
 * general information:
     number, name: (814) Tauris
     approx. diameter [km]: 116
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 45 USNO, 10 TMO
     number of rejected observations: 5 USNO, 2 TMO
     time covered by the observations: 1998 04 23 - 1999 12 05
     rms residuals ["] (RA,DE): 0.09", 0.10"
     estimated positional accuracy at epoch of event ["]: 0.09"
     remarks: 

Data for the event:
 * UT date and time of least geocentric approach: 21:51:16 UT
 * approx. V mag of minor planet at event [mag]: 12.5
 * geocentric parallax of minor planet ["]: 5.634
 * magnitude drop [mag]: 3.7
 * estimated maximum duration [s]: 8.1
 * apparent motion of minor planet ["/h]: 45.46
 * angular distance to moon, phase of moon [deg,%]: 37, 47%
 * remarks: 

Calculator(s): Jan Manek





Path coordinates:
                                       Altitude
  E. Longitude    Latitude     U.T.    star  sun
   ........ shortened ..........................
   - 19 00 00   - 18 18 08   21 50 20   82   -26
   - 17 00 00   + 16 12 45   21 54 40   62   -45
   - 15 00 00   + 33 31 08   21 56 28   45   -50
   - 13 00 00   + 43 54 50   21 57 21   35   -50
   - 11 00 00   + 50 57 40   21 57 50   27   -48
   -  9 00 00   + 56 05 05   21 58 07   22   -47
   -  7 00 00   + 59 59 06   21 58 18   18   -45
   +  5 00 00   + 71 56 44   21 58 38    5   -39
   +  7 00 00   + 73 00 52   21 58 38    4   -39
   ........ shortened ..........................

----------------------------------------------------------------------------
Jan Manek
Stefanik Observatory                Private :
Petrin 205                          Werichova 950
118 46  Praha 1                     152 00  Praha 5 - Barrandov     |_|_|
Czech Republic                      Czech Republic                  /   \
Internet : jmanek@mbox.vol.cz                                      |-O-O-|
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