IOTA/IOTA-ES occultation update for (98) Ianthe / HIP 56646 event on 2008 Nov 23, 06:53 UT Visible from NE USA Summary ------- On 2008 Nov 23 UT, the 105 km diameter asteroid (98) Ianthe will occult a 8.4 mag star in the constellation Leo for observers along a path across NE USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.1 mag to 13.5 mag (the magnitude of the asteroid) for at most 3.6 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: . The event at a glimpse ---------------------- * Rank: 99 * date and approx. time of event: 2008 Nov 23, 06:50 - 2008 Nov 23, 06:52 UT * magnitude of target star: 8.4 * magnitude drop [mag]: 5.1 * estimated maximum duration [s]: 3.6 * Moon: 17 % sunlit, 25° distance * Sun: 71° distance * rough path description: NE USA The occultation path -------------------- * approximate projected width [km]: 107 * 1 sigma uncertainty interval [path widths]: +/- 0.24 * 1 sigma uncertainty interval [seconds]: +/- 1.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .019) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .015", 119° ) * approx speed of asteroid's shadow [km/s]: 28.9837 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 56646 by 98 Ianthe on 2008 Nov 23 Centre Star Star Sun Path Limits Error Limits E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " Latitude Latitude Latitude Latitude - 89 0 0 39 47 22 6 50 7 0 77 -66 39 17 36 40 17 11 39 3 20 40 31 31 - 88 0 0 39 58 8 6 50 7 1 77 -65 39 28 26 40 27 54 39 14 12 40 42 12 - 87 0 0 40 8 29 6 50 7 2 78 -64 39 38 50 40 38 11 39 24 37 40 52 27 - 86 0 0 40 18 23 6 50 7 3 79 -64 39 48 48 40 48 2 39 34 37 41 2 17 - 85 0 0 40 27 52 6 50 7 4 79 -63 39 58 20 40 57 28 39 44 10 41 11 41 - 84 0 0 40 36 55 6 50 8 4 80 -62 40 7 26 41 6 28 39 53 18 41 20 40 - 83 0 0 40 45 33 6 50 8 5 81 -62 40 16 7 41 15 2 40 2 0 41 29 13 - 82 0 0 40 53 45 6 50 8 6 81 -61 40 24 22 41 23 12 40 10 16 41 37 21 - 81 0 0 41 1 32 6 50 8 7 82 -60 40 32 11 41 30 56 40 18 7 41 45 4 - 80 0 0 41 8 54 6 50 9 7 83 -60 40 39 35 41 38 15 40 25 32 41 52 21 - 79 0 0 41 15 50 6 50 9 8 83 -59 40 46 34 41 45 9 40 32 32 41 59 14 - 78 0 0 41 22 21 6 50 10 9 84 -58 40 53 8 41 51 38 40 39 7 42 5 42 - 77 0 0 41 28 28 6 50 10 10 85 -58 40 59 16 41 57 42 40 45 16 42 11 45 - 76 0 0 41 34 9 6 50 11 10 85 -57 41 5 0 42 3 21 40 51 1 42 17 24 - 75 0 0 41 39 25 6 50 11 11 86 -56 41 10 18 42 8 36 40 56 20 42 22 37 - 74 0 0 41 44 17 6 50 12 12 87 -56 41 15 11 42 13 26 41 1 14 42 27 26 - 73 0 0 41 48 44 6 50 12 13 87 -55 41 19 40 42 17 51 41 5 44 42 31 51 - 72 0 0 41 52 47 6 50 13 13 88 -54 41 23 44 42 21 52 41 9 48 42 35 51 - 71 0 0 41 56 24 6 50 14 14 89 -54 41 27 23 42 25 29 41 13 28 42 39 27 - 70 0 0 41 59 37 6 50 15 15 89 -53 41 30 37 42 28 41 41 16 43 42 42 38 - 69 0 0 42 2 26 6 50 15 16 90 -52 41 33 27 42 31 28 41 19 33 42 45 25 - 68 0 0 42 4 50 6 50 16 16 91 -51 41 35 52 42 33 51 41 21 58 42 47 48 - 67 0 0 42 6 50 6 50 17 17 91 -51 41 37 52 42 35 50 41 23 59 42 49 47 - 66 0 0 42 8 25 6 50 18 18 92 -50 41 39 28 42 37 25 41 25 35 42 51 21 - 65 0 0 42 9 36 6 50 19 19 93 -49 41 40 39 42 38 35 41 26 47 42 52 31 - 64 0 0 42 10 22 6 50 20 19 93 -49 41 41 26 42 39 21 41 27 33 42 53 17 - 63 0 0 42 10 44 6 50 21 20 94 -48 41 41 48 42 39 43 41 27 56 42 53 38 - 62 0 0 42 10 41 6 50 22 21 95 -47 41 41 45 42 39 40 41 27 53 42 53 36 - 61 0 0 42 10 14 6 50 23 22 95 -46 41 41 18 42 39 13 41 27 26 42 53 9 - 60 0 0 42 9 23 6 50 24 22 96 -46 41 40 26 42 38 22 41 26 34 42 52 18 - 59 0 0 42 8 7 6 50 25 23 97 -45 41 39 10 42 37 6 41 25 17 42 51 3 - 58 0 0 42 6 26 6 50 26 24 98 -44 41 37 29 42 35 27 41 23 36 42 49 23 - 57 0 0 42 4 21 6 50 27 25 98 -44 41 35 23 42 33 22 41 21 30 42 47 19 - 56 0 0 42 1 52 6 50 29 25 99 -43 41 32 53 42 30 53 41 18 59 42 44 51 - 55 0 0 41 58 57 6 50 30 26 100 -42 41 29 57 42 28 0 41 16 3 42 41 58 - 54 0 0 41 55 38 6 50 31 27 100 -41 41 26 37 42 24 42 41 12 42 42 38 40 - 53 0 0 41 51 54 6 50 33 28 101 -41 41 22 52 42 21 0 41 8 57 42 34 59 - 52 0 0 41 47 46 6 50 34 28 102 -40 41 18 42 42 16 53 41 4 46 42 30 52 - 51 0 0 41 43 12 6 50 35 29 102 -39 41 14 7 42 12 21 41 0 10 42 26 21 - 50 0 0 41 38 14 6 50 37 30 103 -39 41 9 7 42 7 24 40 55 9 42 21 25 - 49 0 0 41 32 50 6 50 38 31 104 -38 41 3 41 42 2 2 40 49 42 42 16 4 - 48 0 0 41 27 1 6 50 40 31 105 -37 40 57 50 41 56 15 40 43 51 42 10 18 - 47 0 0 41 20 47 6 50 42 32 105 -36 40 51 34 41 50 3 40 37 33 42 4 7 - 46 0 0 41 14 8 6 50 43 33 106 -36 40 44 52 41 43 26 40 30 50 41 57 31 - 45 0 0 41 7 3 6 50 45 34 107 -35 40 37 45 41 36 24 40 23 42 41 50 30 - 44 0 0 40 59 32 6 50 46 34 108 -34 40 30 11 41 28 56 40 16 7 41 43 3 - 43 0 0 40 51 36 6 50 48 35 108 -33 40 22 12 41 21 2 40 8 7 41 35 11 - 42 0 0 40 43 14 6 50 50 36 109 -32 40 13 47 41 12 43 39 59 41 41 26 53 - 41 0 0 40 34 25 6 50 52 37 110 -32 40 4 56 41 3 58 39 50 48 41 18 9 - 40 0 0 40 25 11 6 50 54 38 111 -31 39 55 39 40 54 46 39 41 29 41 9 0 - 39 0 0 40 15 31 6 50 56 38 111 -30 39 45 55 40 45 9 39 31 44 40 59 24 - 38 0 0 40 5 24 6 50 57 39 112 -29 39 35 45 40 35 6 39 21 32 40 49 22 - 37 0 0 39 54 50 6 50 59 40 113 -29 39 25 8 40 24 36 39 10 54 40 38 54 - 36 0 0 39 43 50 6 51 1 41 114 -28 39 14 4 40 13 40 38 59 48 40 27 59 - 35 0 0 39 32 24 6 51 4 41 114 -27 39 2 34 40 2 16 38 48 16 40 16 38 - 34 0 0 39 20 30 6 51 6 42 115 -26 38 50 36 39 50 27 38 36 16 40 4 50 - 33 0 0 39 8 9 6 51 8 43 116 -25 38 38 11 39 38 10 38 23 49 39 52 35 - 32 0 0 38 55 21 6 51 10 44 117 -25 38 25 19 39 25 26 38 10 55 39 39 53 - 31 0 0 38 42 5 6 51 12 45 117 -24 38 11 59 39 12 14 37 57 33 39 26 44 - 30 0 0 38 28 22 6 51 14 45 118 -23 37 58 12 38 58 36 37 43 44 39 13 7 - 29 0 0 38 14 11 6 51 17 46 119 -22 37 43 56 38 44 29 37 29 26 38 59 3 - 28 0 0 37 59 33 6 51 19 47 120 -21 37 29 13 38 29 55 37 14 41 38 44 31 - 27 0 0 37 44 26 6 51 22 48 121 -21 37 14 2 38 14 53 36 59 28 38 29 32 - 26 0 0 37 28 51 6 51 24 49 121 -20 36 58 23 37 59 23 36 43 46 38 14 4 - 25 0 0 37 12 48 6 51 27 49 122 -19 36 42 15 37 43 25 36 27 36 37 58 8 - 24 0 0 36 56 17 6 51 29 50 123 -18 36 25 38 37 26 59 36 10 57 37 41 44 - 23 0 0 36 39 17 6 51 32 51 124 -17 36 8 33 37 10 4 35 53 50 37 24 52 - 22 0 0 36 21 48 6 51 34 52 125 -16 35 51 0 36 52 40 35 36 14 37 7 31 - 21 0 0 36 3 51 6 51 37 53 126 -15 35 32 57 36 34 48 35 18 9 36 49 41 - 20 0 0 35 45 25 6 51 40 54 127 -15 35 14 26 36 16 27 34 59 35 36 31 23 - 19 0 0 35 26 30 6 51 43 55 128 -14 34 55 26 35 57 38 34 40 32 36 12 35 - 18 0 0 35 7 6 6 51 45 55 129 -13 34 35 56 35 38 19 34 21 0 35 53 19 - 17 0 0 34 47 13 6 51 48 56 130 -12 34 15 58 35 18 31 34 0 59 35 33 34 - 16 0 0 34 26 50 6 51 51 57 131 -11 33 55 30 34 58 14 33 40 29 35 13 20 - 15 0 0 34 5 59 6 51 54 58 132 -10 33 34 33 34 37 28 33 19 29 34 52 37 - 14 0 0 33 44 38 6 51 57 59 133 -9 33 13 7 34 16 13 32 58 0 34 31 24 - 13 0 0 33 22 48 6 52 0 60 134 -8 32 51 11 33 54 29 32 36 2 34 9 42 - 12 0 0 33 0 29 6 52 4 61 135 -7 32 28 46 33 32 15 32 13 35 33 47 32 - 11 0 0 32 37 41 6 52 7 61 136 -6 32 5 52 33 9 32 31 50 38 33 24 51 - 10 0 0 32 14 23 6 52 10 62 137 -6 31 42 29 32 46 20 31 27 12 33 1 42 - 9 0 0 31 50 36 6 52 13 63 138 -5 31 18 37 32 22 39 31 3 17 32 38 4 - 8 0 0 31 26 20 6 52 17 64 140 -4 30 54 16 31 58 29 30 38 53 32 13 56 - 7 0 0 31 1 36 6 52 20 65 141 -3 30 29 25 31 33 50 30 14 0 31 49 20 - 6 0 0 30 36 22 6 52 24 66 143 -2 30 4 6 31 8 42 29 48 39 31 24 15 - 5 0 0 30 10 40 6 52 27 67 144 -1 29 38 19 30 43 5 29 22 48 30 58 41 Uncertainty in time = +/- 2 secs [Prediction of 2008 Nov 13.0] Data for the target star ------------------------ * name: HIP 56646 * constellation : Leo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 11 36 56.8054 DE: +10 30 37.790 * position source: Pos: HIP2, pm: HIP2, pi:HIP2 * standard error: RA,DE ["]: ( .016, .013 ) * V mag [mag]: 8.4 * B mag [mag]: 8.8 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (98) Ianthe approx. diameter [km]: 105 approx. diameter ["]: .063 distance from Earth [AU]: 2.29600 * orbital information: orbit source: Preston date of fit: 2008 Aug 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 732 number of rejected observations: 47 time covered by the observations: 1927 Aug 30 - 2008 Mar 24 1 sigma uncertainty ellipse (major, minor, PA): 0.024, 0.009, 131° remarks: * orbital elements for (98) Ianthe : Mean anomaly = 354.28852546 deg Arg. of pericenter = 158.46646789 deg Long. of node = 354.12257235 deg Inclination = 15.61033208 deg Eccentricity = 0.18920966 Semimajor axis = 2.68547352 AU Perihelion dist = 2.17735600 AU Mag: H = 8.75, G = 0.15 Epoch of elements : MJD 54793.28700000 TDT (2008 Nov 23.287) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Nov 23 98 Ianthe 6h 53.7m UT 8.4 11 36 56.805 10 30 37.79HIP 56646 8.8 13.5 105 3.6 2.296 3.722 -30.23 8.1878 10.519 73.19 -20.43 6.8951 0.09611 0.17370 14.33077 -7.88999 -0.00476 0.00234 2000 353.55236520081120.00000158.466468354.122572 15.6103320.18920966 2.6854735 2.1773560 8.8 5.00.15 RATE 2.2396110 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.015 119 1.24 0.015 0 54783.5020081123__56646 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Nov 13, 23:03 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org