Update for (1266) Tone - February 20/21, 2002 - South Africa, South America

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
              (1266) Tone / TAC -07 06447 on February 20/21, 2002
   visible from middle South Africa, S Uruguay, middle Argentina and middle Chile

Summary 

In the night of February 20/21, 2002 a faint 11.8 mag star TAC 07 06447 will be occulted by a 76 km asteroid (1266) Tone. This update is based on USNO/Flagstaff astrometry for the asteroid and UCAC star position.

The updated path shows ~0.4" north shift with time ~2.7 minutes earlier compared to Edwin Goffin's nominal prediction.

Updated path runs over South Africa around ~02:58.5 UT with Kimberley in path. After passing over Atlantic ocean souther coast of Uruguay with Montevideo is in path at ~03:07 UT and few seconds later the capital of Argentina - Buenos Aires is hit by north limit. Santiago de Chile is about one path width north ~03:08.2 UT - well within uncertainty. Much larger area is covered taking uncertainty into consideration. Please check the path chart for details.

Good luck !

The event at one glimpse:
 * date and approx. UT time of event: February 21, 2002 @ 02:59 UT (South Africa)
                                                          03:08 UT (South America)
 * magnitude of target star: 11.8
 * magnitude drop [mag]: 2.7
 * estimated maximum duration [s]: 5.7
 * path description: given above
 * Goffin's original chart reference: A02_0248

The occultation path:
 * approximate ground width [km]: 85
 * uncertainty [path widths]: 3.0
 * uncertainty in time [s]: 20
 * map: below
 * remarks: Path uncertainties are given according to nominal star
    position errors and expected asteroid positional accuracy.

Data for the target star:
 * name: TAC -07 06447 = GSC 5508.0541
 * constellation: Crater
 * J2000 position [h,m,s; o,',"]: 11h 21m 18.9001s; -07o 42' 26.157"
 * position source: UCAC combined with AC 2000.2 positions
 * estimated accuracy ["]: 0.02" (0.015", 0.010")
 * B mag [mag]: 11.8
 * remarks:
    Recent UCAC position was provided by Marion and Norbert Zacharias.
    Target star is in northern Crater, rather far from really bright stars, about midway
    between 4.5 mag phi Leonis = SAO 138102 and 4.8 mag epsilon Crateris = SAO 156658.
    Target star is 1.2 degrees SE of 6.1 mag star SAO 138106 = variable SV Crt.

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: (1266) Tone
     approx. diameter [km]: 76
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone)
     number of used observations: 83 USNO
     number of rejected observations: 5 USNO
     time covered by the observations: 1998 07 04 - 2002 02 10
     rms residuals ["] (RA,DE): 0.09", 0.10"
     estimated positional accuracy at epoch of event ["]: 0.11", 0.11"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 03:03.6 UT
 * approx. V mag of minor planet at event [mag]: 14.4
 * geocentric parallax of minor planet ["]: 3.672
 * magnitude drop [mag]: 2.7
 * estimated maximum duration [s]: 5.7
 * apparent motion of minor planet ["/h]: 27.87
 * angular distance to moon, phase of moon [deg,%]: 104, 56%
 * 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  '  "
     38  0  0   -26 27  5    2 57 29    28    -5  -26  3 55  -26 50 21
     37  0  0   -26 36 11    2 57 33    29    -6  -26 13  0  -26 59 27
     36  0  0   -26 45 16    2 57 37    29    -7  -26 22  5  -27  8 31
     35  0  0   -26 54 20    2 57 41    30    -7  -26 31  9  -27 17 35
     34  0  0   -27  3 22    2 57 45    31    -8  -26 40 11  -27 26 37
     33  0  0   -27 12 23    2 57 49    32    -9  -26 49 12  -27 35 38
     32  0  0   -27 21 22    2 57 54    33   -10  -26 58 11  -27 44 37
     31  0  0   -27 30 19    2 57 58    34   -11  -27  7  8  -27 53 34
     30  0  0   -27 39 14    2 58  3    34   -11  -27 16  4  -28  2 29
     29  0  0   -27 48  7    2 58  7    35   -12  -27 24 57  -28 11 22
     28  0  0   -27 56 58    2 58 12    36   -13  -27 33 48  -28 20 13
     27  0  0   -28  5 47    2 58 17    37   -14  -27 42 37  -28 29  2
     26  0  0   -28 14 33    2 58 22    38   -14  -27 51 23  -28 37 48
     25  0  0   -28 23 16    2 58 27    39   -15  -28  0  6  -28 46 31
     24  0  0   -28 31 56    2 58 32    39   -16  -28  8 46  -28 55 11
     23  0  0   -28 40 34    2 58 37    40   -17  -28 17 24  -29  3 48
     22  0  0   -28 49  8    2 58 42    41   -17  -28 25 58  -29 12 22
     21  0  0   -28 57 39    2 58 47    42   -18  -28 34 29  -29 20 53
     20  0  0   -29  6  6    2 58 53    42   -19  -28 42 57  -29 29 20
     19  0  0   -29 14 30    2 58 58    43   -20  -28 51 21  -29 37 44
     18  0  0   -29 22 51    2 59  4    44   -20  -28 59 42  -29 46  4
     17  0  0   -29 31  7    2 59  9    45   -21  -29  7 58  -29 54 21
     16  0  0   -29 39 20    2 59 15    46   -22  -29 16 11  -30  2 33
     15  0  0   -29 47 28    2 59 20    46   -22  -29 24 20  -30 10 41
     14  0  0   -29 55 33    2 59 26    47   -23  -29 32 24  -30 18 45
     13  0  0   -30  3 32    2 59 32    48   -24  -29 40 24  -30 26 45
   ........................... shortened .............................
   - 50  0  0   -34 56 55    3  6 20    56   -44  -34 34  1  -35 19 52
   - 51  0  0   -34 57 32    3  6 26    55   -44  -34 34 39  -35 20 29
   - 52  0  0   -34 58  1    3  6 32    55   -44  -34 35  8  -35 20 58
   - 53  0  0   -34 58 22    3  6 38    54   -44  -34 35 29  -35 21 19
   - 54  0  0   -34 58 34    3  6 44    53   -43  -34 35 41  -35 21 32
   - 55  0  0   -34 58 38    3  6 50    53   -43  -34 35 45  -35 21 36
   - 56  0  0   -34 58 34    3  6 55    52   -43  -34 35 41  -35 21 32
   - 57  0  0   -34 58 22    3  7  1    51   -43  -34 35 29  -35 21 19
   - 58  0  0   -34 58  1    3  7  7    51   -42  -34 35  8  -35 20 58
   - 59  0  0   -34 57 32    3  7 13    50   -42  -34 34 39  -35 20 29
   - 60  0  0   -34 56 54    3  7 18    50   -42  -34 34  2  -35 19 52
   - 61  0  0   -34 56  9    3  7 24    49   -42  -34 33 16  -35 19  6
   - 62  0  0   -34 55 15    3  7 30    48   -41  -34 32 22  -35 18 12
   - 63  0  0   -34 54 12    3  7 35    48   -41  -34 31 19  -35 17 10
   - 64  0  0   -34 53  2    3  7 40    47   -41  -34 30  9  -35 15 59
   - 65  0  0   -34 51 43    3  7 46    46   -40  -34 28 49  -35 14 40
   - 66  0  0   -34 50 15    3  7 51    46   -40  -34 27 22  -35 13 13
   - 67  0  0   -34 48 40    3  7 56    45   -40  -34 25 46  -35 11 38
   - 68  0  0   -34 46 56    3  8  2    44   -39  -34 24  3  -35  9 54
   - 69  0  0   -34 45  4    3  8  7    43   -39  -34 22 10  -35  8  2
   - 70  0  0   -34 43  4    3  8 12    43   -38  -34 20 10  -35  6  2
   - 71  0  0   -34 40 55    3  8 17    42   -38  -34 18  1  -35  3 53
   - 72  0  0   -34 38 38    3  8 22    41   -37  -34 15 44  -35  1 37
   - 73  0  0   -34 36 13    3  8 27    41   -37  -34 13 19  -34 59 12
   - 74  0  0   -34 33 40    3  8 32    40   -37  -34 10 46  -34 56 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 : jan.manek@worldonline.cz                                |-O-O-|
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