Update for (1031) Arctica - January 17, 2002

Jan Manek's update

                     IOTA/IOTA-ES occultation update for
            (1031) Arctica / TYC 0131-00050-1 on January 17, 2002
     visible from Asia, middle East, north Africa, S Spain and S Portugal


Summary 

In the night of January 17, 2002 a 10.9 mag star TYC 0131-00050-1 will be occulted by a 78 km asteroid (1031) Arctica. This update is based on USNO/Flagstaff, TMO and Gnosca astrometry for the asteroid and UCAC star position.

The updated path shows ~0.6" south shift with time ~2.2 minutes earlier compared to Edwin Goffin's nominal prediction.

Updated path runs over Asia, middle East and north Africa. European continent is hit at S Spain ~19:58.3 UT and runs also over south coast of Portugal ~19:58.8 UT. Please check the path chart for details.

The event at one glimpse:
 * date and approx. UT time of event: January 17, 2002 @ 19:58 UT (Euro)
 * magnitude of target star: 10.9
 * magnitude drop [mag]: 3.3
 * estimated maximum duration [s]: 7.3
 * path description: given above
 * Goffin's original chart reference: A02_0153

The occultation path:
 * approximate ground width [km]: 90
 * uncertainty [path widths]: 2.1
 * uncertainty in time [s]: 15
 * 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 0131-00050-1
 * constellation: Orion
 * J2000 position [h,m,s; o,',"]: 06h 14m 36.8727s; +00o 36' 25.795"
 * position source: UCAC + Tycho-2 proper motion
 * estimated accuracy ["]: 0.02" (0.015", 0.020")
 * V mag [mag]: 10.90
 * B-V [mag]: +0.84
 * remarks:
     Recent UCAC position was provided by Marion and Norbert Zacharias.
     Target star is in east Orion. GSC flags this as non-star object, due to
     faint companions just east and west of star.

Close finding chart (prepared in GUIDE7):
 * occulted star is in center - labeled with cross
 * field is 1.5x1.5 degrees
 * limiting magnitude is 13.0
 * labeled stars have indicated SAO numbers





Data for the minor planet:
 * general information:
     number, name: (1031) Arctica
     approx. diameter [km]: 78
 * orbital information
     orbit source: calculation Manek
     source of used astrometry: USNO/Flagstaff (Ron Stone),
                                TMO (Bill Owen),
                                Gnosca (Stefano Sposetti)
     number of used observations: 78 USNO, 4 TMO, 10(2)
     number of rejected observations: 10 USNO
     time covered by the observations: 1998 03 02 - 2002 01 09
     rms residuals ["] (RA,DE): 0.09", 0.09"
     estimated positional accuracy at epoch of event ["]: 0.09", 0.09"
     remarks: Gnosca frames were reduced by Raoul Behrend.

Data for the event:
 * UT date and time of least geocentric approach: 19:52.4 UT
 * approx. V mag of minor planet at event [mag]: 14.1
 * geocentric parallax of minor planet ["]: 4.275
 * magnitude drop [mag]: 3.3
 * estimated maximum duration [s]: 7.3
 * apparent motion of minor planet ["/h]: 25.92
 * angular distance to moon, phase of moon [deg,%]: 105, 16%
 * 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  '  "
      4  0  0    35 44 14   19 57 33    43   -36   36  9  3   35 19 32
      3  0  0    35 50 13   19 57 39    43   -36   36 15  1   35 25 31
      2  0  0    35 56  6   19 57 46    42   -35   36 20 54   35 31 24
      1  0  0    36  1 54   19 57 52    41   -34   36 26 41   35 37 12
      0  0  0    36  7 36   19 57 59    41   -33   36 32 23   35 42 55
   -  1  0  0    36 13 13   19 58  5    40   -33   36 38  0   35 48 32
   -  2  0  0    36 18 45   19 58 11    39   -32   36 43 31   35 54  4
   -  3  0  0    36 24 11   19 58 17    39   -31   36 48 57   35 59 30
   -  4  0  0    36 29 31   19 58 23    38   -30   36 54 17   36  4 51
   -  5  0  0    36 34 45   19 58 28    37   -29   36 59 31   36 10  6
   -  6  0  0    36 39 54   19 58 34    36   -29   37  4 39   36 15 14
   -  7  0  0    36 44 56   19 58 40    36   -28   37  9 41   36 20 17
   -  8  0  0    36 49 53   19 58 45    35   -27   37 14 37   36 25 14
   -  9  0  0    36 54 43   19 58 51    34   -26   37 19 28   36 30  5
   - 10  0  0    36 59 28   19 58 56    34   -26   37 24 12   36 34 50
   - 11  0  0    37  4  6   19 59  1    33   -25   37 28 50   36 39 28
   ........................... 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-|
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