Update for (954) Li - April 12/13, 2003

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
             (954) Li / TYC 4940-00154-1 on April 12/13, 2003
     visible from Saudi Arabia, NE Egypt, Sicilia, Sardegna and S France

Summary 

In the night of April 12/13, 2003 a faint 10.7 mag star TYC 4940-00154-1 will be occulted by a 60 km asteroid (954) Li. This update is based on USNO/Flagstaff astrometry for the asteroid and recent UCAC star position.

The updated path shows ~10 path width south shift with time 1.1 minutes later compared to Edwin Goffin's nominal prediction.

Updated path runs over Saudi Arabia around 23:25 UT, NE Egypt ~23:27.2 UT, Sicily ~23:29.4 UT with Palermo in path, Sardinia ~23:30.0 UT and S France around 23:30.9 UT with Toulouse and Bordeaux in path. 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 12, 2003 @ 23:30 UT (Europe)
 * magnitude of target star: 10.1
 * magnitude drop [mag]: 4.8
 * estimated maximum duration [s]: 4.5
 * path description: given above
 * Goffin's original chart reference: A03_0459

The occultation path:
 * approximate ground width [km]: 85
 * uncertainty [path widths]: 1.8
 * 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 4940-00154-1
 * constellation: Virgo
 * J2000 position [h,m,s; o,',"]: 12h 18m 09.3542s; -01o 10' 02.289"
 * position source: recent UCAC position combined with Tycho-2 proper motion
 * estimated accuracy ["]: 0.02" (0.01", 0.02")
 * V mag [mag]: 10.09
 * B-V [mag]: +0.48
 * remarks:
    Target star is in mid-west Virgo, about 40' SW of 3.9 mag star eta Virginis = SAO 138721
    and should be easy to find.
    !!! 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 13.0
 * 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: (954) Li
     approx. diameter [km]: 60
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone)
     number of used observations: 109 USNO
     number of rejected observations: 30 USNO
     time covered by the observations: 1998 03 04 - 2003 03 25
     rms residuals ["] (RA,DE): 0.09", 0.10"
     estimated positional accuracy at epoch of event ["]: 0.04", 0.06"
     remarks:

Data for the event:
 * UT date and time of least geocentric approach: 23:29.5 UT
 * approx. V mag of minor planet at event [mag]: 14.9
 * geocentric parallax of minor planet ["]: 3.646
 * magnitude drop [mag]: 4.8
 * estimated maximum duration [s]: 4.5
 * apparent motion of minor planet ["/h]: 27.34
 * angular distance to moon, phase of moon [deg,%]: 35, 80%
 * remarks:

Elements for WinOccult:
============ cut here ===========================================
 2003 Apr 12
954 Li
23h 29.5m UT
40-00154-1  10.1   12 18  9.354- 1 10  2.29TYC 4940-00154-1
14.9     60    4.5   2.412    -1.662     11.20
   -8.577  -1.170  -172.17    8.81
 23.4909   .28435   .63377 -6.83989  3.07414  0.00164 -0.00079
2000    250.2281232003 411.00000152.677805163.2026761.165069  0.166248983.136280072.614876719.945   0.15
RATE 1.7745240 .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  '  "
     38  0  0    27 49  4   23 26 23    37   -44   28 13 27   27 24 52
     37  0  0    28 10 35   23 26 30    38   -44   28 35  2   27 46 18
     36  0  0    28 32 28   23 26 37    39   -44   28 57  0   28  8  7
     35  0  0    28 54 45   23 26 43    39   -45   29 19 21   28 30 19
     34  0  0    29 17 24   23 26 50    40   -45   29 42  5   28 52 54
     33  0  0    29 40 25   23 26 57    40   -45   30  5 11   29 15 50
     32  0  0    30  3 47   23 27  4    41   -45   30 28 38   29 39  7
     31  0  0    30 27 29   23 27 11    41   -45   30 52 25   30  2 45
     30  0  0    30 51 32   23 27 19    42   -45   31 16 33   30 26 43
     29  0  0    31 15 55   23 27 26    42   -45   31 41  1   30 51  1
     28  0  0    31 40 36   23 27 33    43   -45   32  5 47   31 15 37
     27  0  0    32  5 36   23 27 40    43   -45   32 30 52   31 40 32
     26  0  0    32 30 53   23 27 48    43   -45   32 56 14   32  5 44
     25  0  0    32 56 27   23 27 55    44   -45   33 21 54   32 31 13
     24  0  0    33 22 18   23 28  3    44   -45   33 47 49   32 56 59
     23  0  0    33 48 24   23 28 10    44   -45   34 14  0   33 22 60
     22  0  0    34 14 45   23 28 18    45   -45   34 40 26   33 49 16
     21  0  0    34 41 20   23 28 25    45   -45   35  7  6   34 15 46
     20  0  0    35  8  8   23 28 33    45   -45   35 33 60   34 42 29
     19  0  0    35 35  9   23 28 40    45   -45   36  1  6   35  9 25
     18  0  0    36  2 22   23 28 48    45   -44   36 28 24   35 36 33
     17  0  0    36 29 46   23 28 55    46   -44   36 55 52   36  3 52
     16  0  0    36 57 20   23 29  3    46   -44   37 23 31   36 31 21
     15  0  0    37 25  3   23 29 10    46   -43   37 51 19   36 58 60
     14  0  0    37 52 55   23 29 18    46   -43   38 19 16   37 26 47
     13  0  0    38 20 54   23 29 25    46   -43   38 47 20   37 54 42
     12  0  0    38 49  1   23 29 33    46   -42   39 15 31   38 22 44
     11  0  0    39 17 13   23 29 40    46   -42   39 43 48   38 50 52
     10  0  0    39 45 31   23 29 48    46   -42   40 12 10   39 19  5
      9  0  0    40 13 53   23 29 55    46   -41   40 40 37   39 47 23
      8  0  0    40 42 18   23 30  2    46   -41   41  9  6   40 15 44
      7  0  0    41 10 46   23 30  9    45   -40   41 37 38   40 44  8
      6  0  0    41 39 15   23 30 17    45   -40   42  6 11   41 12 33
      5  0  0    42  7 45   23 30 24    45   -39   42 34 45   41 40 59
      4  0  0    42 36 15   23 30 31    45   -39   43  3 18   42  9 26
      3  0  0    43  4 43   23 30 38    45   -38   43 31 50   42 37 51
      2  0  0    43 33 10   23 30 45    44   -38   44  0 21   43  6 14
      1  0  0    44  1 34   23 30 52    44   -37   44 28 48   43 34 35
      0  0  0    44 29 54   23 30 59    44   -36   44 57 11   44  2 52
   -  1  0  0    44 58 10   23 31  5    43   -36   45 25 29   44 31  5
   -  2  0  0    45 26 20   23 31 12    43   -35   45 53 42   44 59 13
   -  3  0  0    45 54 23   23 31 19    43   -35   46 21 48   45 27 14
   -  4  0  0    46 22 20   23 31 25    42   -34   46 49 47   45 55  9
   -  5  0  0    46 50  9   23 31 31    42   -33   47 17 38   46 22 55
   -  6  0  0    47 17 49   23 31 38    42   -33   47 45 19   46 50 34
   -  7  0  0    47 45 19   23 31 44    41   -32   48 12 51   47 18  2
   -  8  0  0    48 12 39   23 31 50    41   -32   48 40 13   47 45 21
   -  9  0  0    48 39 48   23 31 56    40   -31   49  7 23   48 12 29
   - 10  0  0    49  6 45   23 32  2    40   -30   49 34 21   48 39 25
  ............................. 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---