Update for (85) Io - September 26/27, 2003

Jan Manek's update

                   IOTA/IOTA-ES occultation update for
           (85) Io / TYC 5184-01124-1 on September 26/27, 2003
       visible from S Norway, N Denmark, S Sweden, Poland, Slovakia,
             E Hungary, Romania, Bulgaria, Turkey and Cyprus


Summary 

In the night of September 26/27, 2003 a faint 11.3 mag star TYC 5184-01124-1 will be occulted by a 178 km asteroid (85) Io. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and UCAC2 star position.

The updated path shows ~0.8 path width west shift with time ~0.2 minutes later compared to Edwin Goffin's nominal prediction.

Updated path runs due to west shift over S Norway ~18:21.5 UT, N Denmark ~18:21.9 UT, S Sweden ~18:22.3 UT, Poland ~18:23.0 UT, Slovakia ~18:23.5 UT, E Hungary ~18:23.7 UT, Romania ~18:24.2 UT, Bulgaria ~18:24.8 UT, Turkey ~18:25.7 UT and Cyprus ~18:26.8 UT. Please check the path chart for details.

Keep in mind the only 0.7 mag brightness drop ! Clear sky and good luck !!!

The event at one glimpse:
 * date and approx. UT time of event: September 26, 2003 @ 18:23 UT (Europe)
 * magnitude of target star: 11.3
 * magnitude drop [mag]: 0.7
 * estimated maximum duration [s]: 23.1
 * path description: given above
 * Goffin's original chart reference: A03_0923

The occultation path:
 * approximate ground width [km]: 205
 * uncertainty [path widths]: 0.3
 * uncertainty in time [s]: 8
 * 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 5184-01124-1
 * constellation: Aquila
 * J2000 position [h,m,s; o,',"]: 20h 31m 07.8365s; -03o 59' 34.183"
 * position source: UCAC2
 * estimated accuracy ["]: 0.03" (0.02", 0.02")
 * V mag [mag]: 11.28
 * B-V [mag]: +1.69
 * remarks:
    Target star is in east Aquila, about 5.9 degrees east of 3.2 mag star theta Aquilae = SAO 144150.
    !!! 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 3.5x3.5 degrees
 * limiting magnitude is 13.0
 * labeled stars have indicated SAO numbers
 * remarks: Second chart shows 30' blowup to show correctly the star in field.










Data for the minor planet:
 * general information:
     number, name: (85) Io
     approx. diameter [km]: 178
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 108 USNO, 20 TMO
     number of rejected observations: 14 USNO, 3 TMO
     time covered by the observations: 1998 02 26 - 2003 09 18
     rms residuals ["] (RA,DE): 0.06", 0.07"
     estimated positional accuracy at epoch of event ["]: 0.05", 0.05"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 18:32.3 UT
 * approx. V mag of minor planet at event [mag]: 11.1
 * geocentric parallax of minor planet ["]: 6.246
 * magnitude drop [mag]: 0.7
 * estimated maximum duration [s]: 23.1
 * apparent motion of minor planet ["/h]: 27.21
 * angular distance to moon, phase of moon [deg,%]: 115, 1%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2003 Sep 26
   85  Io
18h 32.3m UT
  11.3   20 31  7.836- 3 59 34.18TYC 5184-01124-1      13.0
11.1    178   23.1   1.408     1.229    -20.08
   24.563  -3.987  -100.22   -1.30
 18.5378   .35469   .32514  2.94025 -3.21589  0.00445  0.00034
2000    1.472647552003 918.00000122.442840203.44415511.965339 0.192916832.653380902.141499077.615   0.15
RATE 2.2803666 .0000000 .0000000 .0000000 .00000000 .00000000 .00000000
============ cut here ===========================================

Calculator(s): Jan Manek








Path coordinates:
                  Centre              Star  Star   Sun      Path Limits           Error Limits
  E. Longitude   Latitude      U.T.    Alt    Az   Alt    Limit 1    Limit 2    Limit 3    Limit 4
                                                         Latitude   Latitude   Latitude   Latitude
    ...................................... shortened .............................................
      o  '  "     o  '  "    h  m  s     o     o     o    o  '  "    o  '  "    o  '  "    o  '  "
      1  0  0    64 28 20   18 21  6    19   152    -5   63  1 52   65 56 40   62  7 27   66 54 17
      2  0  0    63 54 59   18 21 10    20   153    -5   62 27 29   65 24 25   61 32 25   66 22 46
      3  0  0    63 20 16   18 21 14    20   154    -6   61 51 44   64 50 48   60 56  2   65 49 54
      4  0  0    62 44  9   18 21 19    21   155    -6   61 14 35   64 15 48   60 18 15   65 15 38
      5  0  0    62  6 35   18 21 23    22   156    -7   60 35 58   63 39 20   59 39  0   64 39 55
      6  0  0    61 27 31   18 21 28    23   157    -8   59 55 52   63  1 22   58 58 16   64  2 42
      7  0  0    60 46 53   18 21 34    23   158    -8   59 14 13   62 21 50   58 15 59   63 23 55
      8  0  0    60  4 40   18 21 40    24   159    -9   58 30 59   61 40 42   57 32  8   62 43 30
      9  0  0    59 20 48   18 21 46    25   160   -10   57 46  6   60 57 54   56 46 39   62  1 26
     10  0  0    58 35 14   18 21 52    26   161   -10   56 59 34   60 13 23   55 59 31   61 17 38
     11  0  0    57 47 57   18 21 59    27   162   -11   56 11 19   59 27  7   55 10 41   60 32  3
     12  0  0    56 58 53   18 22  7    28   163   -12   55 21 20   58 39  3   54 20  8   59 44 40
     13  0  0    56  8  1   18 22 15    29   164   -12   54 29 35   57 49  8   53 27 50   58 55 24
     14  0  0    55 15 20   18 22 23    30   165   -13   53 36  1   56 57 21   52 33 46   58  4 15
     15  0  0    54 20 46   18 22 32    31   166   -14   52 40 39   56  3 40   51 37 54   57 11  9
     16  0  0    53 24 21   18 22 42    32   167   -15   51 43 28   55  8  4   50 40 15   56 16  6
     17  0  0    52 26  2   18 22 52    33   168   -16   50 44 27   54 10 30   49 40 48   55 19  4
     18  0  0    51 25 50   18 23  3    34   169   -17   49 43 36   53 11  0   48 39 34   54 20  2
     19  0  0    50 23 46   18 23 15    35   170   -18   48 40 57   52  9 33   47 36 33   53 19  0
     20  0  0    49 19 49   18 23 27    36   172   -19   47 36 29   51  6 10   46 31 47   52 15 59
     21  0  0    48 14  3   18 23 40    38   173   -20   46 30 17   50  0 52   45 25 18   51 11  1
     22  0  0    47  6 29   18 23 53    39   174   -21   45 22 21   48 53 41   44 17  9   50  4  6
     23  0  0    45 57 10   18 24  7    40   175   -22   44 12 45   47 44 40   43  7 23   48 55 17
     24  0  0    44 46 10   18 24 22    41   177   -23   43  1 33   46 33 53   41 56  4   47 44 38
     25  0  0    43 33 33   18 24 38    43   178   -24   41 48 50   45 21 23   40 43 17   46 32 12
     26  0  0    42 19 25   18 24 54    44   179   -26   40 34 40   44  7 16   39 29  6   45 18  6
     27  0  0    41  3 51   18 25 12    45   181   -27   39 19 11   42 51 37   38 13 39   44  2 24
     28  0  0    39 46 57   18 25 30    46   182   -28   38  2 27   41 34 33   36 57  1   42 45 13
     29  0  0    38 28 52   18 25 48    48   184   -29   36 44 37   40 16 11   35 39 20   41 26 39
     30  0  0    37  9 42   18 26  7    49   186   -31   35 25 47   38 56 39   34 20 43   40  6 52
     31  0  0    35 49 36   18 26 27    50   188   -32   34  6  7   37 36  5   33  1 19   38 45 59
     32  0  0    34 28 42   18 26 48    51   190   -34   32 45 44   36 14 38   31 41 14   37 24  9
     33  0  0    33  7 10   18 27  9    52   192   -35   31 24 47   34 52 27   30 20 40   36  1 32
     34  0  0    31 45  8   18 27 30    54   194   -36   30  3 26   33 29 42   28 59 43   34 38 17
     35  0  0    30 22 46   18 27 52    55   196   -38   28 41 49   32  6 32   27 38 33   33 14 35
     36  0  0    29  0 14   18 28 15    56   199   -39   27 20  5   30 43  7   26 17 19   31 50 34
     37  0  0    27 37 40   18 28 38    57   201   -41   25 58 24   29 19 37   24 56 10   30 26 26
     38  0  0    26 15 14   18 29  1    57   204   -42   24 36 54   27 56 12   23 35 14   29  2 19
     39  0  0    24 53  5   18 29 24    58   207   -44   23 15 45   26 33  0   22 14 40   27 38 25
     40  0  0    23 31 22   18 29 48    59   210   -45   21 55  3   25 10 11   20 54 37   26 14 51
    ...................................... 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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