Update for (794) Irenaea - August 6/7, 2003

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
         (794) Irenaea / TYC 5802-01289-1 on August 6/7, 2003
         visible from W Russia, Ukraine, Moldavia, E Romania,
     W Bulgaria, S Albania, very SE Sicilia, Malta and S Tunisia

Summary 

In the night of August 6/7, 2003 a faint 10.9 mag star TYC 5802-01289-1 will be occulted by a 41 km asteroid (794) Irenaea. This update is based on USNO/Flagstaff and La Silla astrometry for the asteroid and UCAC2-beta star position.

The updated path shows ~1.2" SE shift with time ~0.9 minutes later compared to Edwin Goffin's nominal prediction.

Updated path runs due to south-east shift over W Russia ~0:14.5 UT, Ukraine ~0:15.2 UT, Moldavia ~0:15.7 UT, E Romania ~0:16.1 UT with Bucharest in path, W Bulgaria ~0:16.7 UT with Sofia in path, S Albania ~0:17.4 UT, very SE Sicilia ~0:18.6 UT, Malta ~0:18.8 UT and S Tunisia ~0:20.0 UT. 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 7, 2003 @ 00:17 UT
 * magnitude of target star: 10.9
 * magnitude drop [mag]: 3.1
 * estimated maximum duration [s]: 5.8
 * path description: given above
 * Goffin's original chart reference: A03_0841

The occultation path:
 * approximate ground width [km]: 50
 * uncertainty [path widths]: 1.8
 * uncertainty in time [s]: 11
 * 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 5802-01289-1
 * constellation: Aquarius
 * J2000 position [h,m,s; o,',"]: 22h 03m 18.1833s; -08o 49' 01.310"
 * position source: recent UCAC2 beta
 * estimated accuracy ["]: 0.03" (0.02", 0.02")
 * V mag [mag]: 10.89
 * B-V [mag]: +1.34
 * remarks:
    Target star is in middle Aquarius, about 3.5 degrees west of 4.1 mag star theta Aquarii = SAO 145991.
    !!! 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 4.0x4.0 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: (794) Irenaea
     approx. diameter [km]: 41
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), La Silla (Raoul Behrend)
     number of used observations: 60 USNO, 3 La Silla
     number of rejected observations: 14 USNO
     time covered by the observations: 1998 08 26 - 2003 07 10
     rms residuals ["] (RA,DE): 0.19", 0.19"
     estimated positional accuracy at epoch of event ["]: 0.09", 0.06"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 00:25.4 UT
 * approx. V mag of minor planet at event [mag]: 13.9
 * geocentric parallax of minor planet ["]: 6.860
 * magnitude drop [mag]: 3.1
 * estimated maximum duration [s]: 5.8
 * apparent motion of minor planet ["/h]: 27.15
 * angular distance to moon, phase of moon [deg,%]: 83, 69%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2003 Aug 07
794 Irenaea
 0h 25.4m UT
02-01289-1  10.9   22  3 18.183- 8 49  1.31TYC 5802-01289-1
13.9     41    5.8   1.282    -1.498    -15.64
    9.349  -8.812  -184.88   16.59
  0.4234  -.31525   .44826 -3.23615 -2.27897 -0.00123 -0.00073
2000    14.57316492003 730.00000132.085142160.5034105.414379  0.295823243.130046262.2041058311.15   0.15
RATE 1.7798276 .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  '  "
     51  0  0    58 24 58    0 13 29    16   220    -4   58 42 11   58  7 48   59 44 50   57  6 38
     50  0  0    57 59 17    0 13 33    17   219    -4   58 16 36   57 42  2   59 19 36   56 40 33
     49  0  0    57 32 57    0 13 36    17   218    -5   57 50 22   57 15 37   58 53 43   56 13 48
     48  0  0    57  5 58    0 13 40    18   217    -6   57 23 29   56 48 33   58 27  9   55 46 25
     47  0  0    56 38 20    0 13 45    19   216    -6   56 55 55   56 20 49   57 59 56   55 18 23
     46  0  0    56 10  1    0 13 49    19   216    -7   56 27 42   55 52 25   57 32  2   54 49 42
     45  0  0    55 41  3    0 13 54    20   215    -8   55 58 48   55 23 22   57  3 27   54 20 21
     44  0  0    55 11 24    0 13 59    21   214    -8   55 29 15   54 53 38   56 34 11   53 50 21
     43  0  0    54 41  5    0 14  4    22   213    -9   54 59  0   54 23 15   56  4 15   53 19 41
     42  0  0    54 10  6    0 14  9    22   212   -10   54 28  6   53 52 11   55 33 37   52 48 23
     41  0  0    53 38 27    0 14 15    23   211   -11   53 56 31   53 20 28   55  2 18   52 16 24
     40  0  0    53  6  7    0 14 21    24   210   -12   53 24 15   52 48  4   54 30 18   51 43 47
     39  0  0    52 33  8    0 14 27    25   209   -12   52 51 20   52 15  1   53 57 37   51 10 32
     38  0  0    51 59 30    0 14 34    25   209   -13   52 17 45   51 41 19   53 24 15   50 36 37
     37  0  0    51 25 12    0 14 41    26   208   -14   51 43 31   51  6 58   52 50 13   50  2  5
     36  0  0    50 50 16    0 14 48    27   207   -15   51  8 38   50 31 59   52 15 31   49 26 55
     35  0  0    50 14 41    0 14 55    28   206   -16   50 33  6   49 56 22   51 40 10   48 51  9
     34  0  0    49 38 29    0 15  3    29   205   -17   49 56 56   49 20  8   51  4 10   48 14 46
     33  0  0    49  1 41    0 15 11    29   204   -17   49 20 10   48 43 17   50 27 32   47 37 48
     32  0  0    48 24 16    0 15 20    30   203   -18   48 42 47   48  5 50   49 50 16   47  0 15
     31  0  0    47 46 16    0 15 28    31   202   -19   48  4 49   47 27 49   49 12 24   46 22  8
     30  0  0    47  7 42    0 15 37    32   201   -20   47 26 16   46 49 14   48 33 56   45 43 29
     29  0  0    46 28 35    0 15 47    33   200   -21   46 47 10   46 10  6   47 54 53   45  4 18
     28  0  0    45 48 56    0 15 56    34   199   -22   46  7 32   45 30 26   47 15 17   44 24 37
     27  0  0    45  8 47    0 16  7    34   198   -23   45 27 23   44 50 17   46 35  9   43 44 26
     26  0  0    44 28  8    0 16 17    35   197   -24   44 46 44   44  9 38   45 54 30   43  3 47
     25  0  0    43 47  1    0 16 28    36   196   -25   44  5 36   43 28 31   45 13 22   42 22 41
     24  0  0    43  5 27    0 16 39    37   195   -26   43 24  2   42 46 58   44 31 45   41 41 11
     23  0  0    42 23 28    0 16 50    38   194   -27   42 42  2   42  5  0   43 49 42   40 59 16
     22  0  0    41 41  6    0 17  2    39   193   -28   41 59 39   41 22 39   43  7 13   40 16 59
     21  0  0    40 58 21    0 17 14    40   192   -28   41 16 53   40 39 56   42 24 22   39 34 22
     20  0  0    40 15 17    0 17 26    40   191   -29   40 33 46   39 56 53   41 41  8   38 51 25
     19  0  0    39 31 53    0 17 39    41   190   -30   39 50 21   39 13 32   40 57 35   38  8 11
     18  0  0    38 48 13    0 17 52    42   189   -31   39  6 38   38 29 54   40 13 43   37 24 42
     17  0  0    38  4 18    0 18  5    43   188   -32   38 22 40   37 46  1   39 29 35   36 40 58
     16  0  0    37 20  9    0 18 19    44   187   -33   37 38 28   37  1 56   38 45 13   35 57  2
     15  0  0    36 35 49    0 18 33    45   185   -34   36 54  5   36 17 39   38  0 38   35 12 56
     14  0  0    35 51 19    0 18 47    45   184   -35   36  9 32   35 33 12   37 15 52   34 28 41
     13  0  0    35  6 42    0 19  2    46   183   -36   35 24 51   34 48 38   36 30 57   33 44 19
     12  0  0    34 21 58    0 19 16    47   182   -37   34 40  3   34  3 58   35 45 55   32 59 53
     11  0  0    33 37 10    0 19 31    48   180   -38   33 55 11   33 19 14   35  0 48   32 15 22
     10  0  0    32 52 19    0 19 47    48   179   -39   33 10 16   32 34 28   34 15 38   31 30 50
      9  0  0    32  7 29    0 20  2    49   177   -40   32 25 21   31 49 41   33 30 27   30 46 18
      8  0  0    31 22 39    0 20 18    50   176   -41   31 40 27   31  4 56   32 45 15   30  1 49
      7  0  0    30 37 52    0 20 34    51   174   -42   30 55 35   30 20 13   32  0  7   29 17 22
      6  0  0    29 53 10    0 20 50    51   173   -43   30 10 48   29 35 36   31 15  2   28 33  1
      5  0  0    29  8 34    0 21  6    52   171   -44   29 26  8   28 51  5   30 30  3   27 48 47
      4  0  0    28 24  6    0 21 23    52   170   -44   28 41 35   28  6 42   29 45 12   27  4 41
      3  0  0    27 39 48    0 21 39    53   168   -45   27 57 12   27 22 29   29  0 30   26 20 46
      2  0  0    26 55 41    0 21 56    53   166   -46   27 13  0   26 38 27   28 15 58   25 37  2
      1  0  0    26 11 47    0 22 13    54   164   -47   26 29  1   25 54 39   27 31 40   24 53 31
      0  0  0    25 28  8    0 22 30    54   163   -48   25 45 16   25 11  4   26 47 35   24 10 15
    ...................................... 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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