Update for (361) Bononia - January 30/31, 2002

Jan Manek's update

                       IOTA/IOTA-ES occultation update for
           (361) Bononia / TYC 2495-00265-1 on January 30/31, 2002
          visible from middle East, Spain and N Portugal in Europe
                   and USA from NE to SW plus north Mexico

Summary 

In the night of night January 30/31, 2002 a faint 11.5 mag star TYC 2495-00265-1 will be occulted by a 149 km asteroid (361) Bononia. This update is based on USNO/Flagstaff, TMO and OFXB astrometry for the asteroid and Tycho-2 star position.

The updated path shows ~3 path width south shift with time ~4.5 minutes later compared to Edwin Goffin's nominal prediction.

Updated path runs over middle East, mid-north Spain around 1:35 UT and very north Portugal ~1:35.6 UT. Later path runs over USA from NE to SW and north Mexico. Much larger area is covered taking uncertainty into consideration. Please check the path chart for details.

Good luck !

The event at one glimpse:
 * date and approx. UT time of event: January 31, 2002 @ 01:35 UT (Euro)
                                                         01:43 UT (USA)
 * magnitude of target star: 11.5
 * magnitude drop [mag]: 1.7
 * estimated maximum duration [s]: 11.9
 * path description: given above
 * Goffin's original chart reference: A02_0127

The occultation path:
 * approximate ground width [km]: 150
 * uncertainty [path widths]: 2.7
 * uncertainty in time [s]: 30
 * map: below
 * remarks: Path uncertainities are given according to nominal star
    position errors and expected asteroid positional accuracy.

Data for the target star:
 * name: TYC 2495-00265-1
 * constellation: Lynx
 * J2000 position [h,m,s; o,',"]: 09h 00m 12.1206s; +34o 45' 36.846"
 * position source: Tycho-2
 * estimated accuracy ["]: 0.17" (0.10", 0.13")
 * V mag [mag]: 11.48
 * B-V [mag]: +0.49
 * remarks:
    Target star is in SE Lynx, 4.4 degrees west of 3.1 mag star alpha Lynxis =
    = SAO 61414.

Close finding chart (prepared in GUIDE7):
 * occulted star is in center - labeled with cross
 * field is 2.5x2.5 degrees
 * limiting magnitude is 13.0
 * labeled stars have indicated SAO numbers





Data for the minor planet:
 * general information:
     number, name: (361) Bononia
     approx. diameter [km]: 149
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen),
                                OFXB (Yves Revaz and Nicolas Waelchli)
     number of used observations: 97 USNO, 3 TMO, 5(1) OFXB
     number of rejected observations: 14 USNO
     time covered by the observations: 1998 06 08 - 2002 01 22
     rms residuals ["] (RA,DE): 0.10", 0.11"
     estimated positional accuracy at epoch of event ["]: 0.11", 0.11"
     remarks: From 5 OFXB positions was formed one mean position; these frames were reduced by Raoul Behrend.

Data for the event:
 * UT date and time of least geocentric approach: 01:36.6 UT
 * approx. V mag of minor planet at event [mag]: 13.0
 * geocentric parallax of minor planet ["]: 3.828
 * magnitude drop [mag]: 1.7
 * estimated maximum duration [s]: 11.9
 * apparent motion of minor planet ["/h]: 27.02
 * angular distance to moon, phase of moon [deg,%]: 35, 93%
 * remarks:

Calculator(s): Jan Manek








Path coordinates:
                                                   Latitude   Latitude
                  Centre               Altitude       Path Limits
  E. Longitude   Latitude      U.T.   star   sun   Limit 1    Limit 2
   ........................... shortened .............................
      o  '  "     o  '  "    h  m  s     o     o    o  '  "    o  '  "
     42  0  0    22 13 36    1 29 54    37   -33   23  2 53   21 24 27
     40  0  0    23 28  1    1 30  6    39   -35   24 17  4   22 39  6
     38  0  0    24 40 32    1 30 19    41   -36   25 29 19   23 51 52
     36  0  0    25 51  2    1 30 32    43   -38   26 39 33   25  2 39
     34  0  0    26 59 30    1 30 45    45   -40   27 47 43   26 11 24
     32  0  0    28  5 49    1 30 58    47   -42   28 53 45   27 18  1
     30  0  0    29  9 59    1 31 12    49   -43   29 57 36   28 22 29
     28  0  0    30 11 57    1 31 25    51   -45   30 59 16   29 24 46
     26  0  0    31 11 42    1 31 39    53   -47   31 58 41   30 24 50
     24  0  0    32  9 12    1 31 53    55   -48   32 55 52   31 22 39
     22  0  0    33  4 27    1 32  7    57   -50   33 50 47   32 18 13
     20  0  0    33 57 27    1 32 21    59   -51   34 43 28   33 11 33
     18  0  0    34 48 13    1 32 35    60   -52   35 33 55   34  2 38
     16  0  0    35 36 45    1 32 50    62   -53   36 22  8   34 51 29
     14  0  0    36 23  5    1 33  4    64   -55   37  8  8   35 38  7
     12  0  0    37  7 13    1 33 18    65   -56   37 51 58   36 22 34
     10  0  0    37 49 11    1 33 32    67   -57   38 33 38   37  4 50
      8  0  0    38 29  1    1 33 46    68   -58   39 13 10   37 44 58
      6  0  0    39  6 44    1 33 59    70   -59   39 50 36   38 22 58
      4  0  0    39 42 23    1 34 13    71   -59   40 25 58   38 58 53
      2  0  0    40 15 59    1 34 27    73   -60   40 59 18   39 32 45
      0  0  0    40 47 34    1 34 40    74   -61   41 30 37   40  4 35
   -  2  0  0    41 17  9    1 34 54    75   -61   41 59 58   40 34 26
   -  4  0  0    41 44 48    1 35  7    76   -62   42 27 23   41  2 18
   -  6  0  0    42 10 31    1 35 21    77   -62   42 52 53   41 28 15
   -  8  0  0    42 34 21    1 35 34    78   -63   43 16 31   41 52 17
   - 10  0  0    42 56 19    1 35 47    79   -63   43 38 17   42 14 26
   - 12  0  0    43 16 27    1 36 00    80   -63   43 58 15   42 34 45
   - 14  0  0    43 34 47    1 36 13    80   -63   44 16 24   42 53 14
   ........................... shortened .............................
   - 66  0  0    41 27 60    1 41 22    54   -45   42 10 43   40 45 22
   - 68  0  0    40 59  0    1 41 34    52   -44   41 41 58   40 16  8
   - 70  0  0    40 28  1    1 41 45    51   -43   41 11 14   39 44 53
   - 72  0  0    39 54 59    1 41 56    49   -42   40 38 29   39 11 35
   - 74  0  0    39 19 53    1 42  7    48   -40   40  3 39   38 36 13
   - 76  0  0    38 42 41    1 42 17    46   -39   39 26 44   37 58 43
   - 78  0  0    38  3 20    1 42 28    44   -37   38 47 41   37 19  4
   - 80  0  0    37 21 48    1 42 39    43   -36   38  6 28   36 37 14
   - 82  0  0    36 38  4    1 42 49    41   -34   37 23  3   35 53 10
   - 84  0  0    35 52  5    1 42 59    39   -33   36 37 24   35  6 53
   - 86  0  0    35  3 51    1 43  9    37   -31   35 49 29   34 18 18
   - 88  0  0    34 13 19    1 43 19    36   -30   34 59 17   33 27 27
   - 90  0  0    33 20 29    1 43 29    34   -28   34  6 47   32 34 17
   - 92  0  0    32 25 19    1 43 38    32   -26   33 11 58   31 38 47
   - 94  0  0    31 27 51    1 43 47    30   -25   32 14 50   30 40 58
   - 96  0  0    30 28  2    1 43 56    28   -23   31 15 22   29 40 49
   - 98  0  0    29 25 55    1 44  4    26   -21   30 13 34   28 38 22
   -100  0  0    28 21 30    1 44 12    24   -19   29  9 29   27 33 38
   -102  0  0    27 14 48    1 44 19    22   -17   28  3  7   26 26 37
   -104  0  0    26  5 54    1 44 26    20   -15   26 54 30   25 17 24
   -106  0  0    24 54 48    1 44 32    18   -13   25 43 43   24  6  1
   -108  0  0    23 41 37    1 44 38    16   -11   24 30 48   22 52 33
   -110  0  0    22 26 24    1 44 43    13    -9   23 15 51   21 37  4
   -112  0  0    21  9 15    1 44 47    11    -7   21 58 57   20 19 40
   -114  0  0    19 50 17    1 44 51     9    -5   20 40 13   19  0 29
   ........................... 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---