Update for (8) Flora - April 2/3, 2003

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
               (8) Flora / TYC 6272-00706-2 on April 2/3, 2003
          visible from S Morocco, S Algeria, S Libya and middle Egypt

Summary 

In the morning of night of April 2/3, 2003 a bright 9.4 mag star TYC 6272-00706-2 will be occulted by a 141 km asteroid (8) Flora. This update is based on USNO/Flagstaff, TMO and Bordeaux-Floirac astrometry for the asteroid and Tycho-2 star position.

The updated path shows ~1 path width north shift with time 0.1 minutes later compared to Edwin Goffin's nominal prediction.

Updated path runs over S Morocco 3:15.0 UT, S Algeria around 3:16 UT, S Libya around 3:18 UT and middle Egypt around 3:19.5 UT. Canary Islands are now 1 path width south of south limit ~3:14.4 UT. Please check the path chart for details.

There is no UCAC position for target star, so we must rely on Tycho-2 position. It is the easternmost star in a triangle. The brightest star in triangle will be occulted for observers in South America few minutes earlier. Clear sky and good luck !!!

The event at one glimpse:
 * date and approx. UT time of event: April 3, 2003 @ 03:15 UT (NW Africa)
 * magnitude of target star: 9.4
 * magnitude drop [mag]: 1.8
 * estimated maximum duration [s]: 11.5
 * path description: given above
 * Goffin's original chart reference: A03_0402

The occultation path:
 * approximate ground width [km]: 200
 * uncertainty [path widths]: 0.6
 * uncertainty in time [s]: 7
 * 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 6272-00706-2
 * constellation: Sagittarius
 * J2000 position [h,m,s; o,',"]: 18h 13m 46.7653s; -18o 48' 40.376"
 * position source: Tycho-2
 * estimated accuracy ["]: 0.05" (0.03", 0.03")
 * V mag [mag]: 9.40
 * B-V [mag]: +0.20
 * remarks:
    Target star is in NW Sagittarius, about 2.3 degrees north of 3.8 mag star mu Sagittarii = SAO 186497.
    There is no UCAC position for target star, so we must rely on Tycho-2 position.
    It is the easternmost star in a triangle. The brightest star in triangle will be occulted
    for observers in South America few minutes earlier.
    !!! IMPORTANT !!!
    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 GUIDE8):
 * occulted star is in center - labeled with cross
 * field is 3.0x3.0 degrees
 * limiting magnitude is 12.0
 * labeled stars have indicated SAO numbers
 * remarks: Second and mainly third chart is blowup to show correctly the target star in the field.














Data for the minor planet:
 * general information:
     number, name: (8) Flora
     approx. diameter [km]: 141
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen), Bordeaux-Floirac
     number of used observations: 128 USNO, 29 TMO, 2 Bordeaux-Floirac
     number of rejected observations: 12 USNO, 6 TMO
     time covered by the observations: 1993 03 30 - 2002 04 28
     rms residuals ["] (RA,DE): 0.06", 0.07"
     estimated positional accuracy at epoch of event ["]: 0.04", 0.04"
     remarks: No recent opposition astrometry.

Data for the event:
 * UT date and time of least geocentric approach: 03:19.9 UT
 * approx. V mag of minor planet at event [mag]: 11.0
 * geocentric parallax of minor planet ["]: 4.192
 * magnitude drop [mag]: 1.8
 * estimated maximum duration [s]: 11.5
 * apparent motion of minor planet ["/h]: 29.14
 * angular distance to moon, phase of moon [deg,%]: 114, 2%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2003 Apr 03
8 Flora
 3h 19.9m UT
72-00706-2   9.4   18 13 46.765-18 48 40.38TYC 6272-00706-2
11.0    141   11.5   2.098     2.047      1.75
   32.421 -18.811  -229.09    5.12
  3.3313  -.04096   .70315  6.93613  0.41654 -0.00557 -0.00021
2000    223.8083262003 4 1.00000285.010819111.0361475.887300  0.156589972.201208841.856521626.495   0.28
RATE 3.0179510 .0000000 .0000000 .0000000 .00000000 .00000000 .00000000
============ cut here ===========================================

Calculator(s): Jan Manek








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