Update for (476) Hedwig - November 7, 2000

  • Update computed by Martin Federspiel;   issued 30 Oct 2000 18:50:00 +0100 (CET)
  • Update computed by Jan Manek;   issued 31 Oct 2000 12:50:20 +0100 (CET)

  • Martin Federspiel's update

                         IOTA/IOTA-ES occultation update for 
                     (476) Hedwig/HIP 103334 event on 2000 Nov 07
      visible from northeastern France, Belgium, w.+n. Germany, northern Poland 
    
    
    Summary 

    In the evening (UT) of 2000 Nov 07 the about 120 km large asteroid (476) Hedwig will occult the 8.4 mag star HIP 103334 in Aquarius for observers in northern France, Belgium, western and northern Germany, northern Poland, the Baltic States and parts of Russia. The event is to be rated favourable because the target star is relatively bright, high up in the sky, and good astrometry exists for both the asteroid and the target star which allows a relatively precise prediction of the occultation path.

    The updated path runs 0.14" north of Edwin Goffin's nominal prediction, the updated times are 0.2 minutes earlier than Edwin's.

    
    The event at one glimpse:
     * date and approx. UT time of event: 2000 Nov 07 @19h 48m
     * magnitude of target star: V=8.41 ph=9.33
     * magnitude drop [mag]: 5.1
     * estimated maximum duration [s]: 6.4
     * rough path description: France (Bretagne), Belgium, Germany (Köln to Berlin)
       northern Poland, Baltic States, Russia
    
    The occultation path:
     * approximate widths [km]: 125
     * more detailed path description: France (s. Brest, Caen, s. Le Havre,
       n. Rouen, Amiens), Belgium (Charleroi, Maastricht, n. Liege), Germany
       (n. Köln, Wuppertal, Paderborn, n. Magdeburg, n. Berlin), northern 
       Poland, Baltic States, Russia  
     * uncertainty [path widths]: 1.2
     * map: below
     * remarks: 
    
    Data for the target star:
     * name: HIP 103334
     * constellation: western Aquarius
     * J2000 position [h,m,s; °,',"]: RA 20 56 7.060 DE -7 42 58.63
     * position source: Hipparcos
     * estimated accuracy ["]: 0.01
     * V mag [mag]: V=8.41, ph=9.33
     * remarks:
    
    Data for the minor planet:
     * general information:
         mumber, name: (746) Hedwig
         approx. diameter [km]: 120
     * orbital information
         orbit source: Federspiel
         source of used astrometry: USNO 1998-2000
         number of used observations: 44
         number of rejected observations: 3
         time covered by the observations: 1998-2000 Oct 21
         rms residuals ["] (RA,DE): 0.07",0.11"
         estimated positional accuracy at epoch of event ["]: 0.08
         remarks: 1998 positions show relatively large residuals in DE but were
         retained in the orbit calculation to have an orbit from three oppositions
    
    Data for the event:
     * UT date and time of least geocentric approach: 2000 11 7 @ 19h 45m 24s UT
     * least geocentric distance ["]: 2.77
     * uncertainty in time [s]: 7
     * approx. V mag of minor planet at event [mag]: 13.5
     * geocentric parallax of minor planet ["]: 3.76"
     * magnitude drop [mag]: 5.1
     * estimated maximum duration [s]: 6.4 s
     * apparent motion of minor planet ["/h]: 40.29"/h
     * angular distance to moon, phase of moon [°,%]: 43°,82%+
     * remarks: favourable event
    
    Calculator(s): Martin Federspiel
    
    

    Updated path location for (476) Hedwig November 7, 2000 Path coordinates: Lat. Long. hh:mm:ss UT StarAlt° StarAzi° SunAlt° SunAzi° 38.59 -40.63 19:45:27. ! 42.6 165.1 -2.6 250.8 39.12 -38.32 19:45:38. ! 42.5 168.4 -4.5 252.3 39.67 -35.99 19:45:50. ! 42.3 171.6 -6.4 253.8 40.24 -33.63 19:46: 1. ! 41.9 174.9 -8.3 255.3 40.84 -31.25 19:46:12. ! 41.5 178.1 -10.3 256.9 41.45 -28.82 19:46:23. ! 40.8 181.4 -12.2 258.6 42.10 -26.33 19:46:34. ! 40.1 184.6 -14.2 260.4 42.76 -23.79 19:46:46. ! 39.2 187.9 -16.2 262.2 43.46 -21.17 19:46:57. ! 38.2 191.2 -18.2 264.2 44.19 -18.46 19:47: 8. ! 37.1 194.5 -20.2 266.3 44.95 -15.65 19:47:19. ! 35.8 197.8 -22.3 268.5 45.76 -12.70 19:47:30. ! 34.3 201.1 -24.4 271.0 46.60 -9.59 19:47:42. ! 32.7 204.5 -26.6 273.7 47.50 -6.28 19:47:53. ! 30.9 208.0 -28.8 276.8 48.45 -2.72 19:48: 4. ! 28.9 211.6 -31.0 280.2 49.48 1.17 19:48:15. ! 26.6 215.4 -33.3 284.1 50.60 5.51 19:48:26. ! 24.0 219.5 -35.7 288.8 51.84 10.49 19:48:37. ! 21.0 224.0 -38.2 294.5 53.27 16.51 19:48:49. ! 17.3 229.4 -40.7 301.7 55.03 24.53 19:48:60. ! 12.5 236.3 -43.5 312.1 58.07 41.24 19:49:11. ! 3.1 250.5 -46.5 335.4 ------------------------------------------------------------------------- Dr. Martin Federspiel E-mail: martin@astro.unibas.ch oder: federspielm@ubaclu.unibas.ch privat: dienstlich: Planetarium Freiburg Benzhauser Str. 21 Friedrichstr. 51 D-79232 March-Holzhausen D-79098 Freiburg Tel./Fax: +49 (0)7665 932064 Tel.: +49 (0)761 2017946 -------------------------------------------------------------------------

    Jan Manek's update

                        IOTA/IOTA-ES occultation update for
                  (476) Hedwig / HIP 103334 on November 7, 2000
             visible from N France, Belgium, Netherlands, N Germany, 
                   N Poland, Lithuania, S Latvia and NW Russia
    
    
    Summary 

    In the evening of November 7, 2000 a bright 8.3 mag star HIP 103334 = SAO 144953 will be occulted by a 121 km asteroid (476) Hedwig. This update is based on USNO/Flagstaff and TMO astrometry for the asteroid and Hipparcos/Tycho-2 star position.

    The updated path shows ~2.5 path width north shift and time ~0.3 minutes earlier compared to Edwin Goffin's nominal prediction. Compared to Martin Federspiel's update this one is ~0.3 path width north of his one.

    The path of this occultation runs over NE coast of France with Le Havre close to south limit ~19:48.1 UT and later Lille in path, Belgium with Brussels ~19:48.3 UT, south Netherlands few seconds later, north Germany with Essen, Dortmund, Hannover in path ~19:48.6 UT, north Poland with Gdynia/Gdansk ~19:48.7 UT, Kaliningrad (Russia), Lithuania ~19:48.9 UT, south Latvia and Russia (here at low altitude).

    This event is very favourable, the star is bright, brightness drop large and convenient altitude of star at the moment of occultation for many places. Also path uncertainties are acceptably small.

    Good weather and good luck !

    
    The event at one glimpse:
     * date and approx. UT time of event: November 7, 2000 @ 19:48 UT (Euro)
     * magnitude of target star: 8.3
     * magnitude drop [mag]: 5.2
     * estimated maximum duration [s]: 6.4
     * path description: given above
     * Goffin's original chart reference: A00_1113
    
    The occultation path:
     * approximate ground width [km]: 180
     * uncertainty [path widths]: 1.2
     * uncertainty in time [s]: 10
     * 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: HIP 103334 = SAO 144953 = PPM 204626 = TYC 5757-00516-1
     * constellation: Aquarius
     * J2000 position [h,m,s; o,',"]: 20h 56m 07.060s; -07o 42' 58.64"
     * position source: Hipparcos/Tycho-2
     * estimated accuracy ["]: 0.01" (0.01", 0.01")
     * V mag [mag]: 8.27
     * B-V [mag]: +0.91
     * remarks: 
         Target star is in western Aquarius, about 2.8 degrees NE of 3.8 mag 
         star epsilon Aquarii = SAO 144810 or 1.5 degrees NE of 4.7 mag star 
         mu Aquarii = SAO 144895 (this one is within field of the finding 
         chart). 
    
    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
    
    

    Close finding chart Data for the minor planet: * general information: number, name: (476) Hedwig approx. diameter [km]: 121 * orbital information orbit source: calculation Manek source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen) number of used observations: 47 USNO, 3 TMO number of rejected observations: 4 USNO time covered by the observations: 1998 02 12 - 2000 10 21 rms residuals ["] (RA,DE): 0.06", 0.07" estimated positional accuracy at epoch of event ["]: 0.07" remarks: Data for the event: * UT date and time of least geocentric approach: 19:45.3 UT * approx. V mag of minor planet at event [mag]: 13.5 * geocentric parallax of minor planet ["]: 3.757 * magnitude drop [mag]: 5.2 * estimated maximum duration [s]: 6.4 * apparent motion of minor planet ["/h]: 40.30 * angular distance to moon, phase of moon [deg,%]: 41, 80% * remarks: Calculator(s): Jan Manek

    Updated path location for (476) Hedwig November 7, 2000 Path coordinates: Altitude E. Longitude Latitude U.T. star sun ........ shortened .......................... o ' " o ' " h m s o o - 11 0 0 46 52 25 19 47 32 33 -26 - 10 0 0 47 8 48 19 47 36 32 -26 - 9 0 0 47 25 10 19 47 39 32 -27 - 8 0 0 47 41 30 19 47 43 31 -28 - 7 0 0 47 57 48 19 47 46 31 -28 - 6 0 0 48 14 4 19 47 49 30 -29 - 5 0 0 48 30 16 19 47 52 30 -29 - 4 0 0 48 46 26 19 47 56 29 -30 - 3 0 0 49 2 32 19 47 59 29 -31 - 2 0 0 49 18 34 19 48 2 28 -31 - 1 0 0 49 34 31 19 48 4 27 -32 0 0 0 49 50 24 19 48 7 27 -32 1 0 0 50 6 12 19 48 10 26 -33 2 0 0 50 21 55 19 48 13 26 -34 3 0 0 50 37 31 19 48 15 25 -34 4 0 0 50 53 2 19 48 18 24 -35 5 0 0 51 8 27 19 48 20 24 -35 6 0 0 51 23 44 19 48 23 23 -36 7 0 0 51 38 55 19 48 25 23 -36 8 0 0 51 53 59 19 48 27 22 -37 9 0 0 52 8 55 19 48 29 21 -37 10 0 0 52 23 43 19 48 31 21 -38 11 0 0 52 38 24 19 48 33 20 -38 12 0 0 52 52 56 19 48 35 20 -39 13 0 0 53 7 20 19 48 37 19 -39 14 0 0 53 21 35 19 48 39 18 -39 15 0 0 53 35 41 19 48 41 18 -40 16 0 0 53 49 38 19 48 42 17 -40 17 0 0 54 3 26 19 48 44 17 -41 18 0 0 54 17 4 19 48 46 16 -41 19 0 0 54 30 33 19 48 47 15 -41 20 0 0 54 43 52 19 48 49 15 -42 21 0 0 54 57 0 19 48 50 14 -42 22 0 0 55 9 59 19 48 51 14 -42 23 0 0 55 22 47 19 48 52 13 -43 24 0 0 55 35 25 19 48 54 12 -43 25 0 0 55 47 53 19 48 55 12 -43 26 0 0 56 0 10 19 48 56 11 -43 27 0 0 56 12 16 19 48 57 11 -44 28 0 0 56 24 11 19 48 58 10 -44 29 0 0 56 35 55 19 48 59 10 -44 30 0 0 56 47 28 19 48 59 9 -44 31 0 0 56 58 50 19 49 0 8 -45 32 0 0 57 10 1 19 49 1 8 -45 34 0 0 57 31 49 19 49 2 7 -45 36 0 0 57 52 51 19 49 3 6 -45 38 0 0 58 13 7 19 49 4 4 -46 40 0 0 58 32 38 19 49 5 3 -46 ........ 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-| --------------------------------------------------------------------U---U---

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