Update for (346) Hermentaria - October 20/21, 2003

Jan Manek's update

                   IOTA/IOTA-ES occultation update for
           (346) Hermentaria / GSC 6865-01922 on October 20/21, 2003
             visible from S Portugal, Spain, SE France and N Italy


Summary 

In the night of October 20/21, 2003 a faint 11.7 mag star GSC 6865-01922 will be occulted by a 110 km asteroid (346) Hermentaria. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and UCAC2 star position.

The updated path shows only very small shifts compared to Eric Frappa's nominal prediction.

Path runs over S Portugal ~18:58.1 UT, Spain ~18:58.3 UT, SE France ~18:58.5 and N Italy ~18:58.7 UT. Please check the path chart for details.

Short event at low and very altitudes at the end of path. Video highly recommended for sure event observation. Clear sky and good luck !!!

The event at one glimpse:
 * date and approx. UT time of event: October 20, 2003 @ 18:58 UT (Europe)
 * magnitude of target star: 11.7
 * magnitude drop [mag]: 1.3
 * estimated maximum duration [s]: 4.1
 * path description: given above
 * Goffin's original chart reference: non-Goffin event; found by Eric Frappa

The occultation path:
 * approximate ground width [km]: 210
 * uncertainty [path widths]: 1.2
 * uncertainty in time [s]: 5
 * map: below
 * remarks: Path uncertainties are given according to nominal star
    position errors and expected asteroid positional accuracy.

Data for the target star:
 * name: GSC 6865-01922
 * constellation: Sagittarius
 * J2000 position [h,m,s; o,',"]: 18h 33m 10.1774s; -26o 46' 49.193"
 * position source: UCAC2
 * estimated accuracy ["]: 0.03" (0.02", 0.02")
 * V mag [mag]: 11.7
 * B-V [mag]: +0.00 ?
 * remarks:
    Target star is in middle Sagittarius, about 1.8 degrees southwest of 2.8 mag star lambda Sagittarius = SAO 186841.
    !!! 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 chart shows 30' blowup to show correctly the star in field.










Data for the minor planet:
 * general information:
     number, name: (346) Hermentaria
     approx. diameter [km]: 110
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 137 USNO, 10 TMO
     number of rejected observations: 26 USNO, 1 TMO
     time covered by the observations: 1998 03 22 - 2003 08 31
     rms residuals ["] (RA,DE): 0.06", 0.07"
     estimated positional accuracy at epoch of event ["]: 0.05", 0.06"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 18:56.6 UT
 * approx. V mag of minor planet at event [mag]: 12.6
 * geocentric parallax of minor planet ["]: 3.027
 * magnitude drop [mag]: 1.3
 * estimated maximum duration [s]: 4.1
 * apparent motion of minor planet ["/h]: 45.80
 * angular distance to moon, phase of moon [deg,%]: 134, 28%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2003 Oct 20
  346  Hermentaria
18h 56.6m UT
  11.7   18 33 10.177-26 46 49.19GSC 6865-01922        11.7
12.6    110    4.1   2.905     3.393      0.71
  -34.675 -26.780  -107.93  -10.40
 18.9429  -.01330   .84662 15.00902  0.23229  0.00548  0.00019
2000    286.43100820031018.00000290.19224892.180430 8.760279  0.102916642.795795002.508061197.135   0.15
RATE 2.1083660 .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
    ...................................... shortened .............................................
                                                         Latitude   Latitude   Latitude   Latitude
      o  '  "     o  '  "    h  m  s     o     o     o    o  '  "    o  '  "    o  '  "    o  '  "
   - 15  0  0    34 22 17   18 57 45    26   200    -8   33 23 45   35 22 32   31  6 10   37 59 23
   - 14  0  0    34 39 34   18 57 48    26   201    -9   33 40 45   35 40  9   31 22 34   38 17 54
   - 13  0  0    34 57 38   18 57 51    25   202   -10   33 58 31   35 58 32   31 39 42   38 37 14
   - 12  0  0    35 16 27   18 57 54    24   203   -11   34 17  1   36 17 41   31 57 32   38 57 24
   - 11  0  0    35 36  2   18 57 57    24   203   -12   34 36 16   36 37 37   32 16  6   39 18 23
   - 10  0  0    35 56 21   18 58  0    23   204   -13   34 56 16   36 58 20   32 35 21   39 40 12
   -  9  0  0    36 17 26   18 58  2    22   205   -14   35 16 59   37 19 48   32 55 19   40  2 50
   -  8  0  0    36 39 16   18 58  5    22   206   -14   35 38 27   37 42  2   33 15 59   40 26 16
   -  7  0  0    37  1 50   18 58  8    21   207   -15   36  0 37   38  5  2   33 37 21   40 50 32
   -  6  0  0    37 25  8   18 58 10    20   208   -16   36 23 31   38 28 46   33 59 23   41 15 36
   -  5  0  0    37 49 10   18 58 13    20   208   -17   36 47  8   38 53 16   34 22  7   41 41 28
   -  4  0  0    38 13 55   18 58 15    19   209   -18   37 11 27   39 18 30   34 45 31   42  8  9
   -  3  0  0    38 39 23   18 58 17    18   210   -18   37 36 28   39 44 28   35  9 35   42 35 37
   -  2  0  0    39  5 33   18 58 19    17   211   -19   38  2 11   40 11  9   35 34 19   43  3 53
   -  1  0  0    39 32 26   18 58 21    17   211   -20   38 28 34   40 38 34   35 59 42   43 32 56
      0  0  0    40  0  0   18 58 23    16   212   -21   38 55 38   41  6 42   36 25 43   44  2 45
      1  0  0    40 28 16   18 58 25    15   213   -21   39 23 23   41 35 32   36 52 23   44 33 21
      2  0  0    40 57 11   18 58 27    14   214   -22   39 51 46   42  5  4   37 19 39   45  4 43
      3  0  0    41 26 47   18 58 29    13   215   -23   40 20 49   42 35 16   37 47 33   45 36 51
      4  0  0    41 57  2   18 58 30    12   215   -24   40 50 29   43  6 10   38 16  3   46  9 43
      5  0  0    42 27 55   18 58 32    12   216   -24   41 20 47   43 37 43   38 45  8   46 43 20
      6  0  0    42 59 27   18 58 33    11   217   -25   41 51 42   44  9 55   39 14 48   47 17 41
      7  0  0    43 31 35   18 58 34    10   217   -25   42 23 13   44 42 46   39 45  2   47 52 46
      8  0  0    44  4 19   18 58 36     9   218   -26   42 55 19   45 16 14   40 15 49   48 28 33
      9  0  0    44 37 39   18 58 37     8   219   -27   43 27 59   45 50 19   40 47  8   49  5  1
     10  0  0    45 11 33   18 58 38     7   220   -27   44  1 12   46 24 59   41 18 58   49 42 12
     11  0  0    45 46  1   18 58 38     6   220   -28   44 34 57   47  0 15   41 51 19   50 20  2
     12  0  0    46 21  1   18 58 39     5   221   -28   45  9 14   47 36  4   42 24  9   50 58 32
     13  0  0    46 56 32   18 58 40     5   222   -29   45 44  1   48 12 26   42 57 27   51 37 41
     14  0  0    47 32 33   18 58 40     4   223   -29   46 19 17   48 49 20   43 31 12   52 17 27
     15  0  0    48  9  4   18 58 41     3   223   -30   46 55  1   49 26 44   44  5 24   .. .. ..
     16  0  0    48 46  1   18 58 41     2   224   -30   47 31 11   50  4 37   44 40  0   .. .. ..
     17  0  0    49 23 26   18 58 41     1   225   -31   48  7 47   50 42 58   45 15  0   .. .. ..
     18  0  0    50  1 15   18 58 41     0   226   -31   48 44 46   .. .. ..   45 50 22   .. .. ..
     19  0  0    .. .. ..   .. .. ..    ..    ..    ..   49 22  8   .. .. ..   46 26  4   .. .. ..
     20  0  0    .. .. ..   .. .. ..    ..    ..    ..   .. .. ..   .. .. ..   47  2  6   .. .. ..
     21  0  0    .. .. ..   .. .. ..    ..    ..    ..   .. .. ..   .. .. ..   47 38 27   .. .. ..
    ...................................... 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-|
--------------------------------------------------------------------U---U---