Update for (479) Caprera - August 11/12, 1999

Jan Manek's update

                      IOTA/IOTA-ES occultation update for
          (479) Caprera / HIP 95942 event on 1999, August 11/12
          visible from Tunisia, Lybia, Mauretania, Western Sahara,
                                Brasil and Peru


Summary 

On the night August 11/12, 1999 will be occulted 7.3 mag star by a 77 km asteroid (479) Caprera. This update is based on USNO/Flagstaff and TMO astrometry for asteroid and HIPPARCOS star position.

This update shows large ~0.7" south shift and time ~1.5 minutes later compared to Goffin's nominal prediction. This is mainly due to very large (more than 1" in total) positional offset of minor planet compared to the ephemeris.

Path runs over Tunisia, Lybia, Mauretania and Western Sahara in Africa and over Brasil and Peru in south America. No chance for european observers.

The event at one glimpse:
 * date and approx. UT time of event: August 3, 1999 @ 01:47 UT (Africa)
                                                       01:56 UT (S America)
 * magnitude of target star: 7.3
 * magnitude drop [mag]: 6.4
 * estimated maximum duration [s]: 7.7
 * path description: Path runs over Tunisia, Lybia, Mauretania and Western 
     Sahara in Africa and over Brasil and Peru. 
     No chance for european observers.

The occultation path:
 * approximate width [km]: 80
 * uncertainty [path widths]: 1.5
 * uncertainty in time [s]: 15
 * map: attached
 * remarks: Path uncertainities are given according to nominal star position 
    errors and expected asteroid positional accuracy. 
    !!!!!!!
    Circles along the path are OCCULT exactly calculated centerline points. 
    !!!!!!!

Data for the target star:
 * name: SAO 162699 = PPM 236094 = HIP 95942 = GSC 6302.3099
 * constellation: Sagittarius
 * J2000 position [h,m,s; o,',"]: 19h 30m 41.059s; -18o 19' 24.56"
 * position source: HIPPARCOS
 * estimated accuracy ["]: 0.01"  (0.01", 0.01")
 * Johnson V mag [mag]: 7.31
 * B-V [mag]: +1.09
 * remarks: 

Data for the minor planet:
 * general information:
     number, name: (479) Caprera
     approx. diameter [km]: 77
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
     number of used observations: 23 USNO, 5 TMO
     number of rejected observations: 0
     time covered by the observations: 1998 02 26 - 1999 07 25
     rms residuals ["] (RA,DE): 0.09", 0.09"
     estimated positional accuracy at epoch of event ["]: 0.09"
     remarks: 

Data for the event:
 * UT date and time of least geocentric approach: 01:55:24
 * approx. V mag of minor planet at event [mag]: 13.7
 * geocentric parallax of minor planet ["]: 4.883
 * magnitude drop [mag]: 6.4
 * estimated maximum duration [s]: 7.7
 * apparent motion of minor planet ["/h]: 27.72
 * angular distance to moon, phase of moon [deg,%]: 145, 0%
 * remarks: 

Calculator(s): Jan Manek








Path coordinates:
                                       Altitude
  E. Longitude    Latitude     U.T.    star  sun
   + 19 00 00   + 38 19 16    1 45 11    2   -23
   + 17 00 00   + 37 35 09    1 45 12    3   -24
   + 15 00 00   + 36 49 05    1 45 13    5   -26
   + 13 00 00   + 36 01 04    1 45 16    7   -28
   + 11 00 00   + 35 11 07    1 45 18    9   -29
   +  9 00 00   + 34 19 16    1 45 22   11   -31
   +  7 00 00   + 33 25 32    1 45 26   12   -33
   +  5 00 00   + 32 29 57    1 45 31   14   -34
   +  3 00 00   + 31 32 33    1 45 37   16   -36
   +  1 00 00   + 30 33 24    1 45 43   18   -38
   -  1 00 00   + 29 32 34    1 45 51   20   -40
   -  3 00 00   + 28 30 05    1 45 59   22   -41
   -  5 00 00   + 27 26 04    1 46 08   24   -43
   -  7 00 00   + 26 20 36    1 46 18   26   -45
   -  9 00 00   + 25 13 45    1 46 29   28   -47
   - 11 00 00   + 24 05 39    1 46 41   30   -48
   - 13 00 00   + 22 56 25    1 46 54   32   -50
   - 15 00 00   + 21 46 09    1 47 07   35   -52
   - 17 00 00   + 20 34 59    1 47 21   37   -53
   - 19 00 00   + 19 23 04    1 47 37   39   -55
   - 21 00 00   + 18 10 31    1 47 53   41   -56
   - 23 00 00   + 16 57 30    1 48 10   43   -58
   ......... shortened .........................
   - 45 00 00   +  3 44 06    1 51 56   66   -64
   - 47 00 00   +  2 36 25    1 52 19   67   -63
   - 49 00 00   +  1 29 59    1 52 43   69   -63
   - 51 00 00   +  0 24 55    1 53 06   71   -62
   - 53 00 00   -  0 38 43    1 53 30   72   -61
   - 55 00 00   -  1 40 49    1 53 53   73   -59
   - 57 00 00   -  2 41 20    1 54 17   74   -58
   - 59 00 00   -  3 40 10    1 54 40   75   -57
   - 61 00 00   -  4 37 17    1 55 04   75   -55
   - 63 00 00   -  5 32 36    1 55 27   76   -54
   - 65 00 00   -  6 26 06    1 55 50   75   -52
   - 67 00 00   -  7 17 43    1 56 13   75   -51
   - 69 00 00   -  8 07 26    1 56 36   74   -49
   - 71 00 00   -  8 55 12    1 56 58   73   -47
   - 73 00 00   -  9 41 00    1 57 20   72   -46
   - 75 00 00   - 10 24 49    1 57 42   71   -44
   - 77 00 00   - 11 06 37    1 58 04   69   -42
   - 79 00 00   - 11 46 24    1 58 25   68   -41
   - 81 00 00   - 12 24 09    1 58 46   66   -39
   - 83 00 00   - 12 59 50    1 59 06   65   -37
   ......... shortened .........................

----------------------------------------------------------------------------
Jan Manek
Stefanik Observatory                Private :
Petrin 205                          Werichova 950
118 46  Praha 1                     152 00  Praha 5 - Barrandov     |_|_|
Czech Republic                      Czech Republic                  /   \
Internet : jmanek@mbox.vol.cz                                      |-O-O-|
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