Update for (1143) Odysseus - April 17, 2002 - South Africa

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
       (1143) Odysseus/ HIP 54541 = SAO 118693 on April 17, 2002
        visible from Madagascar, N Mozambique, Malawi and Zambia


Summary 

In the evening of April 17, 2002 a 7.7 mag star HIP 54541 = SAO 118693 will be occulted by a 135 km asteroid (1143) Odysseus. This update is based on USNO/Flagstaff astrometry for the asteroid and Hipparcos star position.

The updated path shows no path shift with time 3.5 minutes later compared to Edwin Goffin's nominal prediction.

Updated path runs over middle Madagascar, south of capital Antananarivo ~16:20 UT. Follows north Mozambique ~16:21.6 UT, Malawi ~16:22 UT and Zambia in twilight ~16:22.7 UT. Within uncertainties is somewhat larger area, but probably without any observer. please check the path chart for details.

There is only one complication - there are probably no observers at the current path location.
Clear sky and good luck !!!

The event at one glimpse:
 * date and approx. UT time of event: April 17, 2002 @ 16:21 UT
 * magnitude of target star: 7.7
 * magnitude drop [mag]: 7.5
 * estimated maximum duration [s]: 13.8
 * path description: given above
 * Goffin's original chart reference: A02_0448

The occultation path:
 * approximate ground width [km]: 165
 * uncertainty [path widths]: 2.8
 * uncertainty in time [s]: 35
 * map: below
 * remarks: Path uncertainties are given according to nominal star
    position errors and expected asteroid positional accuracy.

Data for the target star:
 * name: HIP 54541 = SAO 118693 = PPM 157569 = TYC 0262-00070-1
 * constellation: Leo
 * J2000 position [h,m,s; o,',"]: 11h 09m 40.1765s; +02o 27' 22.599"
 * position source: Hipparcos
 * estimated accuracy ["]: 0.01" (0.012", 0.009")
 * V mag [mag]: 7.69
 * B-V [mag]: +0.78
 * remarks:
    Target star is in south Leo, rather far from familiar constellation shapes.
    About 10 degrees east of target is 3.6 mag star beta Virginis.
    Purple stars in identification chart are so called 'non-star' objects in GSC; in dense fields
    the 'non-stars' are often real stars or blends of close pairs. Be careful.

Close finding chart (prepared in GUIDE7):
 * occulted star is in center - labeled with cross
 * field is 3.0x3.0 degrees
 * limiting magnitude is 13.0
 * labeled stars have indicated SAO numbers
 * remarks:





Data for the minor planet:
 * general information:
     number, name: (1143) Odysseus
     approx. diameter [km]: 135
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone)
     number of used observations: 89 USNO
     number of rejected observations: 9 USNO
     time covered by the observations: 1998 09 28 - 2002 04 12
     rms residuals ["] (RA,DE): 0.13", 0.13"
     estimated positional accuracy at epoch of event ["]: 0.10", 0.11"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 16:17.6 UT
 * approx. V mag of minor planet at event [mag]: 15.2
 * geocentric parallax of minor planet ["]: 2.045
 * magnitude drop [mag]: 7.5
 * estimated maximum duration [s]: 13.8
 * apparent motion of minor planet ["/h]: 11.30
 * angular distance to moon, phase of moon [deg,%]: 85, 21%
 * remarks:

Calculator(s): Jan Manek





Path coordinates:
                                                   Latitude   Latitude
                  Center               Altitude       Path Limits
  E. Longitude   Latitude      U.T.   star   sun   Limit 1    Limit 2
   ........................... shortened .............................
      o  '  "     o  '  "    h  m  s     o     o    o  '  "    o  '  "
     62  0  0   -29 15 18   16 16 56    55   -37  -28 21 40  -30  9 41
     60  0  0   -28  3 24   16 17 20    55   -35  -27 10  6  -28 57 24
     58  0  0   -26 52  8   16 17 43    55   -34  -25 59 12  -27 45 46
     56  0  0   -25 41 39   16 18  7    55   -32  -24 49  5  -26 34 53
     54  0  0   -24 32  5   16 18 30    55   -30  -23 39 54  -25 24 56
     52  0  0   -23 23 35   16 18 54    54   -29  -22 31 47  -24 16  2
     50  0  0   -22 16 16   16 19 17    54   -27  -21 24 51  -23  8 18
     48  0  0   -21 10 15   16 19 40    53   -25  -20 19 14  -22  1 53
     46  0  0   -20  5 40   16 20  3    52   -23  -19 15  2  -20 56 53
     44  0  0   -19  2 36   16 20 26    51   -21  -18 12 22  -19 53 25
     42  0  0   -18  1  9   16 20 48    50   -20  -17 11 18  -18 51 35
     40  0  0   -17  1 26   16 21 10    49   -18  -16 11 57  -17 51 27
     38  0  0   -16  3 30   16 21 31    48   -16  -15 14 24  -16 53  8
     36  0  0   -15  7 26   16 21 52    46   -14  -14 18 43  -15 56 42
     34  0  0   -14 13 20   16 22 12    45   -12  -13 24 57  -15  2 13
     32  0  0   -13 21 14   16 22 32    43   -10  -12 33 12  -14  9 46
     30  0  0   -12 31 12   16 22 51    42    -8  -11 43 30  -13 19 23
     28  0  0   -11 43 17   16 23 10    40    -6  -10 55 55  -12 31  8
     26  0  0   -10 57 32   16 23 28    39    -4  -10 10 28  -11 45  4
   ........................... shortened .............................

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