Update for (336) Lacadeira - September 20/21, 2000

Jan Manek's update

                    IOTA/IOTA-ES occultation update for
        (336) Lacadeira / TYC 0572-00380-1 on September 20/21, 2000
 visible from Romania, frm.Yugoslavia, N Italy, Spain, S Portugal in Europe
     and Trinidad&Tobago, Venezuela, Columbia and Ecuador in S.America


Summary 

In the night of September 20/21, 2000 a 9.3 mag star TYC 0572-00380-1 = SAO 127862 will be occulted by a 72 km asteroid (336)Lacadeira. This update is based on USNO/Flagstaff astrometry for the asteroid and Tycho-2 star position.

The updated path shows no significant path shift with time ~0.1 minutes later compared to Edwin Goffin's nominal prediction.

The path of this occultation runs over S Ukraina at low altitudes ~1:56 UT, central Romania ~1:56.5 UT, frm.Yugoslavia ~1:56.7 UT, mid-north Italy ~1:57 UT, grazes coast of France close to Toulon ~1:57.5 UT, runs over Spain from NE to SW with Barcelona on S limit ~1:57.7 UT and Madrid on N limit ~1:58.4 UT, south Portugal with Lisbon close to N limit ~1:59 UT.

After crossing Atlantic ocean path runs over south of Trinidad&Tobago ~2:08.5 UT, Venezuela ~2:09-2:10 UT, Columbia ~2:11-2:12 UT and Ecuador at ~2:12.5 UT.

Good event with high chances.

The event at one glimpse:
 * date and approx. UT time of event: September 21, 2000 @ 01:58 UT (Europe)
                                                           02:11 UT (S.Am.)
 * magnitude of target star: 9.3
 * magnitude drop [mag]: 3.2
 * estimated maximum duration [s]: 8.0
 * path description: given above
 * Goffin's original chart reference: A00_0915

The occultation path:
 * approximate ground width [km]: 80
 * uncertainty [path widths]: 1.3
 * uncertainty in time [s]: 15
 * map: below
 * remarks: Path uncertainities are given according to nominal star
    position errors and expected asteroid positional accuracy.
    !!!!!!!
    Circles along path indicates the centerline for this event.
    They are more accurate than the path limit lines.
    !!!!!!!

Data for the target star:
 * name: SAO 127862 = PPM 173593 = TYC 0572-00380-1
 * constellation: Pisces
 * J2000 position [h,m,s; o,',"]: 22h 57m 42.246s; +03o 13' 39.24"
 * position source: Tycho-2
 * estimated accuracy ["]: 0.03" (0.02", 0.02")
 * V mag [mag]: 9.27
 * B-V [mag]: +0.45
 * remarks: 
     Target star is in very west part of Pisces, only 1.6 degrees SW of
     4.5 mag star beta Piscium and is easy to find. Target star is brighter 
     star in a pair; fainter 10.7 mag star is only 1.2' south of target. 

Close finding chart (prepared in GUIDE7):
 * 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





Data for the minor planet:
 * general information:
     number, name: (336) Lacadeira
     approx. diameter [km]: 72
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone)
     number of used observations: 30 USNO
     number of rejected observations: 2 USNO
     time covered by the observations: 1998 12 13 - 2000 09 12
     rms residuals ["] (RA,DE): 0.09", 0.07"
     estimated positional accuracy at epoch of event ["]: 0.08"
     remarks: 

Data for the event:
 * UT date and time of least geocentric approach: 02:07.4 UT
 * approx. V mag of minor planet at event [mag]: 12.4
 * geocentric parallax of minor planet ["]: 7.138
 * magnitude drop [mag]: 3.2
 * estimated maximum duration [s]: 8.0
 * apparent motion of minor planet ["/h]: 36.31
 * angular distance to moon, phase of moon [deg,%]: 102, 50%
 * remarks: 

Calculator(s): Jan Manek








Path coordinates:
                                       Altitude
  E. Longitude    Latitude     U.T.    star  sun
   ........ shortened ..........................
      o  '  "      o  '  "    h  m  s    o     o
     24 56 18    46  0  0    1 56 21    16   -23
     17 25 10    45  0  0    1 56 43    22   -28
     11 52 21    44  0  0    1 57  3    26   -31
      7 17 22    43  0  0    1 57 23    29   -35
      3 18 29    42  0  0    1 57 43    32   -37
   -  0 15  5    41  0  0    1 58  2    35   -40
   -  3 29 43    40  0  0    1 58 21    37   -42
   -  6 29 29    39  0  0    1 58 41    40   -44
   -  9 17 14    38  0  0    1 59  0    42   -46
   - 11 55  3    37  0  0    1 59 20    44   -48
   - 14 24 30    36  0  0    1 59 39    46   -50
   - 16 46 47    35  0  0    1 59 59    48   -52
   - 19  2 53    34  0  0    2  0 19    50   -53
   ........ shortened ..........................
   - 57 18 27    12  0  0    2  7 57    77   -63
   - 58 51  1    11  0  0    2  8 18    77   -63
   - 60 23 39    10  0  0    2  8 40    76   -62
   - 61 56 27     9  0  0    2  9  1    75   -61
   - 63 29 32     8  0  0    2  9 22    74   -59
   - 65  3  1     7  0  0    2  9 44    73   -58
   - 66 36 60     6  0  0    2 10  5    72   -57
   - 68 11 37     5  0  0    2 10 26    70   -56
   - 69 46 60     4  0  0    2 10 48    69   -54
   - 71 23 16     3  0  0    2 11  9    67   -53
   - 73  0 34     2  0  0    2 11 30    66   -52
   - 74 39  3     1  0  0    2 11 51    64   -50
   - 76 18 52     0  0  0    2 12 12    62   -48
   - 78  0 12   - 1  0  0    2 12 33    61   -47
   - 79 43 15   - 2  0  0    2 12 54    59   -45
   - 81 28 13   - 3  0  0    2 13 15    57   -44
   - 83 15 20   - 4  0  0    2 13 36    55   -42
   - 85  4 52   - 5  0  0    2 13 56    53   -40
   - 86 57  7   - 6  0  0    2 14 17    51   -38
   ........ 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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