Update for (1264) Letaba - August 10/11, 2002

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
           (1264) Letaba / TYC 2266-01555-1 on August 10/11, 2002
          visible from South Africa, NW Algeria, Spain and Ireland


Summary 

In the morning of night of August 10/11, 2002 a faint 11.8 mag star TYC 2266-01555-1 will be occulted by a 78 km asteroid (1264) Letaba. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and recent UCAC star position.

The updated path shows ~3 path widths east shift with time ~0.7 minutes earlier compared to Edwin Goffin's nominal prediction.

Updated path runs over west South Africa around 3:10 UT, follows whole Africa to north ending there in NW Algeria ~3:32 UT. Spain is in path from ~3:33 UT to 3:36 UT with Madrid in path at ~3:34.4 UT and finally path hits southwest Ireland ~3:39.5 UT. Within expected uncertainties is sloghtly larger area, so please check the path chart for details.

Clear sky and good luck !!!

The event at one glimpse:
 * date and approx. UT time of event: August 11, 2002 @ 03:10 UT (South Africa)
                                                        03:35 UT (Europe)
 * magnitude of target star: 11.8
 * magnitude drop [mag]: 2.4
 * estimated maximum duration [s]: 17.1
 * path description: given above
 * Goffin's original chart reference: A02_0850

The occultation path:
 * approximate ground width [km]: 80
 * uncertainty [path widths]: 1.5
 * uncertainty in time [s]: 30
 * map: below
 * remarks: Path uncertainties are given according to nominal star
    position errors and expected asteroid positional accuracy.

Data for the target star:
 * name: TYC 2266-01555-1
 * constellation: Andromeda
 * J2000 position [h,m,s; o,',"]: 00h 29m 52.2364s; +32o 24' 04.088"
 * position source: UCAC combined with Tycho-2 proper motion
 * estimated accuracy ["]: 0.02" (0.012", 0.012")
 * V mag [mag]: 11.84
 * B-V [mag]: +0.85
 * remarks:
    Recent UCAC position was provided by Marion and Norbert Zacharias.
    Target star is in SW Andromeda, about 2.0 degrees southwest of 4.4 mag star pi Andromedae = SAO 54033.
    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 about this.

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: (1264) Letaba
     approx. diameter [km]: 78
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 86 USNO, 7 TMO
     number of rejected observations: 10 USNO, 1 TMO
     time covered by the observations: 1998 09 20 - 2002 07 29
     rms residuals ["] (RA,DE): 0.11", 0.13"
     estimated positional accuracy at epoch of event ["]: 0.06", 0.06"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 03:31.6 UT
 * approx. V mag of minor planet at event [mag]: 14.1
 * geocentric parallax of minor planet ["]: 3.938
 * magnitude drop [mag]: 2.4
 * estimated maximum duration [s]: 17.1
 * apparent motion of minor planet ["/h]: 10.14
 * angular distance to moon, phase of moon [deg,%]: 137, 8%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2002 Aug 11
1264 Letaba
 3h 31.6m UT
66-01555-1  11.8    0 29 52.236 32 24  4.09TYC 2266-01555-1
14.1     78   17.1   2.233    -0.227      9.72
   -4.856  32.398   128.43   15.34
  3.5259   .06198   .01873 -0.72605  2.46973 -0.00394 -0.00325
2000    72.90320372002 8 4.0000030.195345 235.30489625.009922 0.157983682.862066962.409907099.105   0.15
RATE 2.0355622 .0000000 .0000000 .0000000 .00000000 .00000000 .00000000
============ cut here ===========================================


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  '  "
     32  0  0   -48 35 32    3  8 24     5   -19  -47 47 16  -49 23 47
     31  0  0   -47 10 53    3  8 28     6   -20  -46 21 19  -48  0 27
     30  0  0   -45 41  0    3  8 33     8   -21  -44 50  7  -46 31 55
     29  0  0   -44  5 38    3  8 39     9   -21  -43 13 24  -44 57 55
     28  0  0   -42 24 30    3  8 47    11   -22  -41 30 54  -43 18 10
     27  0  0   -40 37 22    3  8 57    13   -23  -39 42 24  -41 32 24
     26  0  0   -38 44  2    3  9  9    15   -23  -37 47 43  -39 40 25
     25  0  0   -36 44 19    3  9 23    17   -24  -35 46 41  -37 42  3
     24  0  0   -34 38  9    3  9 40    20   -25  -33 39 15  -35 37 10
     23  0  0   -32 25 29    3 10  0    22   -26  -31 25 22  -33 25 43
     22  0  0   -30  6 23    3 10 24    24   -26  -29  5  8  -31  7 47
     21  0  0   -27 41  1    3 10 50    27   -27  -26 38 42  -28 43 28
     20  0  0   -25  9 36    3 11 21    30   -27  -24  6 21  -26 13  1
     19  0  0   -22 32 30    3 11 55    32   -28  -21 28 25  -23 36 46
     18  0  0   -19 50  9    3 12 32    35   -28  -18 45 20  -20 55  8
     17  0  0   -17  3  4    3 13 14    38   -29  -15 57 37  -18  8 40
     16  0  0   -14 11 50    3 13 60    41   -29  -13  5 52  -15 17 56
     15  0  0   -11 17  5    3 14 49    44   -29  -10 10 42  -12 23 34
     14  0  0   - 8 19 29    3 15 42    47   -29  - 7 12 46  - 9 26 16
     13  0  0   - 5 19 43    3 16 38    50   -30  - 4 12 45  - 6 26 44
     12  0  0   - 2 18 29    3 17 37    53   -29  - 1 11 19  - 3 25 38
     11  0  0     0 43 33    3 18 39    56   -29    1 50 51  - 0 23 42
     10  0  0     3 45 44    3 19 43    59   -29    4 53  8    2 38 27
      9  0  0     6 47 26    3 20 49    62   -29    7 54 53    5 40  8
      8  0  0     9 48  2    3 21 57    65   -28   10 55 32    8 40 45
      7  0  0    12 46 59    3 23  5    68   -27   13 54 29   11 39 45
      6  0  0    15 43 44    3 24 14    71   -27   16 51 13   14 36 35
      5  0  0    18 37 47    3 25 24    74   -26   19 45 13   17 30 44
      4  0  0    21 28 39    3 26 33    77   -25   22 36  0   20 21 43
      3  0  0    24 15 52    3 27 41    80   -24   25 23  7   23  9  7
      2  0  0    26 59  3    3 28 48    82   -24   28  6  7   25 52 30
      1  0  0    29 37 47    3 29 54    84   -23   30 44 38   28 31 31
      0  0  0    32 11 45    3 30 58    85   -22   33 18 18   31  5 48
   -  1  0  0    34 40 37    3 32  0    85   -21   35 46 48   33 35  4
   -  2  0  0    37  4  8    3 33  0    84   -20   38  9 53   35 59  4
   -  3  0  0    39 22  6    3 33 58    82   -19   40 27 18   38 17 34
   -  4  0  0    41 34 20    3 34 53    80   -18   42 38 54   40 30 26
   -  5  0  0    43 40 44    3 35 46    78   -17   44 44 35   42 37 33
   -  6  0  0    45 41 14    3 36 35    77   -16   46 44 17   44 38 51
   -  7  0  0    47 35 51    3 37 22    75   -15   48 38  0   46 34 20
   -  8  0  0    49 24 36    3 38  7    73   -14   50 25 48   48 24  3
   -  9  0  0    51  7 37    3 38 49    71   -13   52  7 47   50  8  4
   - 10  0  0    52 45  0    3 39 28    69   -12   53 44  5   51 46 31
   - 11  0  0    54 16 56    3 40  5    68   -12   55 14 53   53 19 33
   - 12  0  0    55 43 37    3 40 39    66   -11   56 40 23   54 47 22
   - 13  0  0    57  5 16    3 41 11    65   -10   58  0 50   56 10 11
   - 14  0  0    58 22  6    3 41 41    64    -9   59 16 27   57 28 12
   - 15  0  0    59 34 22    3 42  9    62    -9   60 27 30   58 41 39
   - 16  0  0    60 42 19    3 42 36    61    -8   61 34 14   59 50 47
   - 17  0  0    61 46 11    3 43  0    60    -8   62 36 54   60 55 50
   - 18  0  0    62 46 14    3 43 23    59    -7   63 35 46   61 57  3
   ........................... shortened .............................

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