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

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
               (8) Flora / TYC 6272-00706-1 on April 2/3, 2003
                            visible from Brasil

Summary 

In the morning of night of April 2/3, 2003 a bright 8.6 mag star TYC 6272-00706-1 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 Brasil with Curitiba in path ~2:58.6 UT. Later path runs off the South African coast ~3:05 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 northernmost and brightest star in a triangle. The easternmost star in triangle will be occulted for observers in north Africa few minutes later. Clear sky and good luck !!!

The event at one glimpse:
 * date and approx. UT time of event: April 3, 2003 @ 02:59 UT (Brasil)
 * magnitude of target star: 8.6
 * magnitude drop [mag]: 2.5
 * estimated maximum duration [s]: 11.5
 * path description: given above
 * Goffin's original chart reference: A03_0401

The occultation path:
 * approximate ground width [km]: 150
 * uncertainty [path widths]: 0.5
 * uncertainty in time [s]: 6
 * 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 6272-00706-1
 * constellation: Sagittarius
 * J2000 position [h,m,s; o,',"]: 18h 13m 46.2977s; -18o 48' 36.442"
 * position source: Tycho-2
 * estimated accuracy ["]: 0.04" (0.03", 0.03")
 * V mag [mag]: 8.60
 * B-V [mag]: +0.33
 * 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 northernmost and brightest star in a triangle. The easternmost star in triangle will be occulted
    for observers in north Africa few minutes later.
    !!! 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: 03:06.7 UT
 * approx. V mag of minor planet at event [mag]: 11.0
 * geocentric parallax of minor planet ["]: 4.192
 * magnitude drop [mag]: 2.5
 * 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  6.7m UT
72-00706-1   8.6   18 13 46.298-18 48 36.44TYC 6272-00706-1
11.0    141   11.5   2.098     2.048      1.75
   35.720 -18.811  -225.80    5.12
  3.1119   .02026  -.32657  6.93814  0.41681 -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  '  "
   - 58  0  0   -22  2 13    2 58 34     2   -68  -22 45 37  -21 19  1
   - 56  0  0   -22 43 19    2 58 35     4   -69  -23 26 42  -22  0  8
   - 54  0  0   -23 24  4    2 58 36     6   -69  -24  7 26  -22 40 55
   - 52  0  0   -24  4 25    2 58 38     8   -70  -24 47 45  -23 21 18
   - 50  0  0   -24 44 19    2 58 41    10   -70  -25 27 36  -24  1 14
   - 48  0  0   -25 23 42    2 58 45    12   -69  -26  6 56  -24 40 40
   - 46  0  0   -26  2 30    2 58 49    13   -69  -26 45 40  -25 19 31
   - 44  0  0   -26 40 40    2 58 53    15   -68  -27 23 47  -25 57 45
   - 42  0  0   -27 18 10    2 58 58    17   -68  -28  1 13  -26 35 19
   - 40  0  0   -27 54 56    2 59  4    19   -67  -28 37 55  -27 12 10
  ............................. shortened ..................................
     14  0  0   -38  5  7    3  3 56    63   -27  -38 45 42  -37 24 41
     16  0  0   -38 11 31    3  4 10    64   -26  -38 52  3  -37 31  8
     18  0  0   -38 16 42    3  4 24    65   -24  -38 57 13  -37 36 21
     20  0  0   -38 20 41    3  4 38    66   -22  -39  1 10  -37 40 21
     22  0  0   -38 23 27    3  4 52    67   -21  -39  3 55  -37 43  8
     24  0  0   -38 25  0    3  5  7    68   -19  -39  5 28  -37 44 42
     26  0  0   -38 25 21    3  5 21    68   -18  -39  5 48  -37 45  3
     28  0  0   -38 24 29    3  5 35    69   -16  -39  4 56  -37 44 10
     30  0  0   -38 22 24    3  5 50    70   -14  -39  2 52  -37 42  5
     32  0  0   -38 19  6    3  6  4    70   -13  -38 59 35  -37 38 46
  ............................. 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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