Update for (407) Arachne - April 17/18, 2003

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
           (407) Arachne / TYC 1368-01752-1 on April 17/18, 2003
 visible from S Norway, S Sweden, NE Poland, SW Belarus, Ukraine and S Russia

Summary 

In the night of April 17/18, 2003 a faint 10.6 mag star TYC 1368-01752-1 will be occulted by a 98 km asteroid (407) Arachne. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and recent UCAC star position.

The updated path shows no path shift with time 0.4 minutes earlier compared to Edwin Goffin's nominal prediction.

Updated path runs over S Norway ~21:18.4 UT with Oslo on north limit, S Sweden ~21:18.8 UT, NE Poland around 21:19.3 UT with Warsaw close to south limit, SW Belarus ~21:19.4 UT, Ukraine around 21:19.7 UT with Dnepropetrovsk on north limit and S Russia ~21:20.1 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: April 17, 2003 @ 21:19 UT (Europe)
 * magnitude of target star: 10.6
 * magnitude drop [mag]: 3.6
 * estimated maximum duration [s]: 5.2
 * path description: given above
 * Goffin's original chart reference: A03_0438

The occultation path:
 * approximate ground width [km]: 170
 * uncertainty [path widths]: 0.8
 * 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: TYC 1368-01752-1
 * constellation: Gemini
 * J2000 position [h,m,s; o,',"]: 07h 34m 57.1592s; +19o 00' 42.374"
 * position source: recent UCAC position combined with derived proper motion
 * estimated accuracy ["]: 0.04" (0.03", 0.02")
 * V mag [mag]: 10.56
 * B-V [mag]: +0.50
 * remarks:
    Recent UCAC position was provided by Marion and Norbert Zacharias.
    Target star is in southeast Gemini, about 4.6 degrres SE of 3.5 mag star delta Geminorum = SAO 79294.
    !!! 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 12.5
 * labeled stars have indicated SAO numbers
 * remarks: Second chart is 30' blowup to show correctly the target star in the field.











Data for the minor planet:
 * general information:
     number, name: (407) Arachne
     approx. diameter [km]: 98
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 108 USNO, 27 TMO
     number of rejected observations: 16 USNO, 5 TMO
     time covered by the observations: 1998 11 16 - 2003 03 12
     rms residuals ["] (RA,DE): 0.06", 0.07"
     estimated positional accuracy at epoch of event ["]: 0.04", 0.04"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 21:17.0 UT
 * approx. V mag of minor planet at event [mag]: 14.2
 * geocentric parallax of minor planet ["]: 3.389
 * magnitude drop [mag]: 3.6
 * estimated maximum duration [s]: 5.2
 * apparent motion of minor planet ["/h]: 36.27
 * angular distance to moon, phase of moon [deg,%]: 110, 98%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2003 Apr 17
407 Arachne
21h 17.0m UT
68-01752-1  10.6    7 34 57.159 19  0 42.37TYC 1368-01752-1
14.2     98    5.2   2.595     2.495     -8.01
  -51.109  19.015  -139.36   10.57
 21.2838   .17729   .78856 10.43995 -2.36312  0.00554 -0.00092
2000    108.5795802003 411.0000082.027680 294.9043907.540664  0.069226622.626316632.444505608.885   0.15
RATE 2.3157070 .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  '  "
   -  4  0  0    64 47 42   21 17 49    35   238    -8   63 48 24   65 48 55   62 20 25   67 27 29
   -  3  0  0    64 24 58   21 17 52    34   239    -8   63 25 34   65 26 19   61 57 25   67  5  5
   -  2  0  0    64  1 50   21 17 55    34   240    -9   63  2 19   65  3 17   61 34  1   66 42 15
   -  1  0  0    63 38 17   21 17 59    34   242    -9   62 38 41   64 39 50   61 10 16   66 18 58
      0  0  0    63 14 20   21 18  2    34   243   -10   62 14 39   64 15 58   60 46  8   65 55 15
      1  0  0    62 50  0   21 18  6    34   244   -11   61 50 15   63 51 42   60 21 39   65 31  6
      2  0  0    62 25 16   21 18  9    33   245   -11   61 25 29   63 27  1   59 56 49   65  6 31
      3  0  0    62  0 11   21 18 12    33   247   -12   61  0 21   63  1 58   59 31 39   64 41 31
      4  0  0    61 34 43   21 18 16    33   248   -13   60 34 53   62 36 31   59  6  9   64 16  7
      5  0  0    61  8 54   21 18 19    32   249   -13   60  9  4   62 10 43   58 40 19   63 50 18
      6  0  0    60 42 45   21 18 23    32   250   -14   59 42 55   61 44 33   58 14 12   63 24  7
      7  0  0    60 16 16   21 18 27    32   252   -14   59 16 27   61 18  2   57 47 46   62 57 33
      8  0  0    59 49 28   21 18 30    32   253   -15   58 49 42   60 51 11   57 21  4   62 30 38
      9  0  0    59 22 21   21 18 34    31   254   -16   58 22 39   60 24  1   56 54  5   62  3 22
     10  0  0    58 54 58   21 18 37    31   255   -16   57 55 19   59 56 33   56 26 52   61 35 46
     11  0  0    58 27 18   21 18 41    30   257   -17   57 27 45   59 28 48   55 59 24   61  7 51
     12  0  0    57 59 23   21 18 45    30   258   -18   56 59 55   59  0 47   55 31 42   60 39 38
     13  0  0    57 31 14   21 18 48    30   259   -18   56 31 52   58 32 30   55  3 48   60 11  9
     14  0  0    57  2 51   21 18 52    29   260   -19   56  3 37   58  3 59   54 35 43   59 42 24
     15  0  0    56 34 16   21 18 55    29   261   -20   55 35 10   57 35 16   54  7 27   59 13 25
     16  0  0    56  5 30   21 18 59    28   262   -20   55  6 33   57  6 20   53 39  2   58 44 12
     17  0  0    55 36 34   21 19  2    28   264   -21   54 37 46   56 37 14   53 10 29   58 14 48
     18  0  0    55  7 29   21 19  6    27   265   -22   54  8 52   56  7 58   52 41 48   57 45 12
     19  0  0    54 38 17   21 19  9    27   266   -23   53 39 50   55 38 34   52 13  2   57 15 27
     20  0  0    54  8 58   21 19 13    26   267   -23   53 10 43   55  9  3   51 44 10   56 45 34
     21  0  0    53 39 35   21 19 16    25   268   -24   52 41 31   54 39 26   51 15 15   56 15 35
     22  0  0    53 10  7   21 19 19    25   269   -25   52 12 16   54  9 44   50 46 17   55 45 29
     23  0  0    52 40 36   21 19 23    24   270   -25   51 42 59   53 39 59   50 17 18   55 15 20
     24  0  0    52 11  4   21 19 26    24   271   -26   51 13 40   53 10 13   49 48 18   54 45  7
     25  0  0    51 41 32   21 19 29    23   272   -27   50 44 22   52 40 25   49 19 19   54 14 54
     26  0  0    51 12  1   21 19 32    22   273   -27   50 15  5   52 10 39   48 50 22   53 44 40
     27  0  0    50 42 32   21 19 35    22   274   -28   49 45 51   51 40 54   48 21 29   53 14 27
     28  0  0    50 13  7   21 19 38    21   275   -28   49 16 41   51 11 12   47 52 39   52 44 17
     29  0  0    49 43 46   21 19 41    20   276   -29   48 47 35   50 41 35   47 23 55   52 14 11
     30  0  0    49 14 32   21 19 44    20   277   -30   48 18 36   50 12  3   46 55 18   51 44 10
     31  0  0    48 45 24   21 19 46    19   278   -30   47 49 44   49 42 39   46 26 48   51 14 16
     32  0  0    48 16 25   21 19 49    18   279   -31   47 21  1   49 13 22   45 58 27   50 44 29
     33  0  0    47 47 35   21 19 52    17   279   -31   46 52 27   48 44 15   45 30 16   50 14 52
     34  0  0    47 18 55   21 19 54    17   280   -32   46 24  4   48 15 18   45  2 15   49 45 24
     35  0  0    46 50 28   21 19 56    16   281   -33   45 55 53   47 46 32   44 34 27   49 16  9
     36  0  0    46 22 13   21 19 59    15   282   -33   45 27 54   47 17 59   44  6 51   48 47  5
     37  0  0    45 54 12   21 20  1    14   283   -34   45  0 10   46 49 41   43 39 30   48 18 16
     38  0  0    45 26 25   21 20  3    13   283   -34   44 32 40   46 21 36   43 12 23   47 49 41
     39  0  0    44 58 55   21 20  5    13   284   -35   44  5 26   45 53 48   42 45 32   47 21 23
     40  0  0    44 31 41   21 20  7    12   285   -35   43 38 28   45 26 17   42 18 58   46 53 21
     41  0  0    44  4 45   21 20  8    11   286   -35   43 11 49   44 59  3   41 52 41   46 25 37
     42  0  0    43 38  8   21 20 10    10   287   -36   42 45 28   44 32  9   41 26 43   45 58 13
     43  0  0    43 11 50   21 20 11     9   287   -36   42 19 26   44  5 33   41  1  5   45 31  8
     44  0  0    42 45 53   21 20 13     9   288   -37   41 53 45   43 39 19   40 35 46   45  4 24
     45  0  0    42 20 17   21 20 14     8   289   -37   41 28 25   43 13 26   40 10 48   44 38  2
     46  0  0    41 55  3   21 20 15     7   289   -37   41  3 26   42 47 55   39 46 12   44 12  2
     47  0  0    41 30 11   21 20 16     6   290   -38   40 38 50   42 22 47   39 21 58   43 46 26
     48  0  0    41  5 43   21 20 17     5   291   -38   40 14 38   41 58  2   38 58  7   43 21 13
     49  0  0    40 41 40   21 20 18     4   291   -38   39 50 49   41 33 42   38 34 40   42 56 26
     50  0  0    40 18  1   21 20 18     3   292   -38   39 27 25   41  9 47   38 11 37   42 32  4
   ........................................ 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---