Update for (613) Ginevra - November 4, 2000

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
              (613) Ginevra / HIP 103218 on November 4, 2000
                visible from SE Europe, Ukraine and Russia


Summary 

In the evening of November 4, 2000 a bright 8.0 mag star HIP 108218 = SAO 189827 will be occulted by a 82 km asteroid (613) Ginevra. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and Hipparcos star position.

The updated path shows 0.85" north shift and time almost 20 minutes later compared to Edwin Goffin's nominal prediction. There is rather large error in this nominal prediction, probably because of old orbit (MPC 19476).

The path of this occultation runs over Sicily and very south Italy in strong twiligt ~16:23.3 UT, Albania ~16:23.6 UT, Macedonia ~16:23.7 UT, NW Bulgaria at ~16:23.9 UT, central Romania frow SW to NE ~16:24.2 UT, north Moldavia ~16:24.8 UT, central Ukraine ~16:24.5 UT and finally Russia with Moscow just south of path ~16:24.8 UT.

There are large uncertainties for this event - 3.5 path widths - so much more places are within these; please check the chart for details. Note also that 50% Moon is only 6 degrees far.

The event at one glimpse:
 * date and approx. UT time of event: November 4, 2000 @ 16:24 UT (Euro)
 * magnitude of target star: 8.0
 * magnitude drop [mag]: 7.2
 * estimated maximum duration [s]: 4.6
 * path description: given above
 * Goffin's original chart reference: A00_1118

The occultation path:
 * approximate ground width [km]: 140
 * uncertainty [path widths]: 3.5
 * uncertainty in time [s]: 20
 * map: below
 * remarks: Path uncertainities are given according to nominal star
    position errors and expected asteroid positional accuracy.
    !!!!!!!
    Circles along path indicates the centerline for this event.
    They are more accurate than the path limit lines.
    !!!!!!!

Data for the target star:
 * name: HIP 103218 = SAO 189827 = PPM 271792 = TYC 6356-01460-1
 * constellation: Capricornus
 * J2000 position [h,m,s; o,',"]: 20h 54m 43.623s; -20o 56' 57.54"
 * position source: Hipparcos
 * estimated accuracy ["]: 0.01" (0.01", 0.01")
 * V mag [mag]: 8.01
 * B-V [mag]: +0.21
 * remarks: 
     Target star is in middle Capricornus, about 2.5 degrees SW of 4.9 mag 
     star eta Capricorni = SAO 189986. Only 37' SW of target is 7.4 mag star
     SAO 189794.

Close finding chart (prepared in GUIDE7):
 * occulted star is in center - labeled with cross
 * field is 3.0x3.0 degrees
 * limiting magnitude is 12.5
 * labeled stars have indicated SAO numbers





Data for the minor planet:
 * general information:
     number, name: (613) Ginevra
     approx. diameter [km]: 82
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 53 USNO, 3 TMO
     number of rejected observations: 6 USNO
     time covered by the observations: 1998 03 02 - 2000 10 18
     rms residuals ["] (RA,DE): 0.11", 0.10"
     estimated positional accuracy at epoch of event ["]: 0.12"
     remarks: Large scatter in recent positions.

Data for the event:
 * UT date and time of least geocentric approach: 16:21.5 UT
 * approx. V mag of minor planet at event [mag]: 15.2
 * geocentric parallax of minor planet ["]: 3.159
 * magnitude drop [mag]: 7.2
 * estimated maximum duration [s]: 4.6
 * apparent motion of minor planet ["/h]: 31.99
 * angular distance to moon, phase of moon [deg,%]: 6, 53%
 * remarks: 

Calculator(s): Jan Manek





Path coordinates:
                                       Altitude
  E. Longitude    Latitude     U.T.    star  sun
   ........ shortened ..........................
      o  '  "     o  '  "    h  m  s     o     o
     15  0  0    36 41 34   16 23  8    32    -5
     16  0  0    37 28 13   16 23 14    31    -6
     17  0  0    38 15 51   16 23 20    31    -7
     18  0  0    39  4 25   16 23 26    30    -8
     19  0  0    39 53 56   16 23 32    29    -9
     20  0  0    40 44 21   16 23 38    28   -10
     21  0  0    41 35 39   16 23 43    28   -11
     22  0  0    42 27 50   16 23 49    27   -12
     23  0  0    43 20 50   16 23 54    26   -13
     24  0  0    44 14 40   16 23 59    25   -14
     25  0  0    45  9 16   16 24  4    24   -15
     26  0  0    46  4 36   16 24  9    23   -15
     27  0  0    47  0 39   16 24 14    22   -16
     28  0  0    47 57 22   16 24 18    21   -17
     29  0  0    48 54 43   16 24 22    20   -18
     30  0  0    49 52 37   16 24 26    19   -18
     31  0  0    50 51  4   16 24 30    18   -19
     32  0  0    51 49 59   16 24 34    17   -20
     33  0  0    52 49 19   16 24 37    16   -20
     34  0  0    53 48 60   16 24 40    15   -21
     35  0  0    54 48 58   16 24 43    14   -21
     36  0  0    55 49 10   16 24 46    13   -22
     37  0  0    56 49 30   16 24 49    12   -22
     38  0  0    57 49 54   16 24 51    10   -23
     39  0  0    58 50 17   16 24 53     9   -23
     40  0  0    59 50 34   16 24 55     8   -24
     41  0  0    60 50 40   16 24 56     7   -24
     42  0  0    61 50 27   16 24 57     6   -24
   ........ 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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