IOTA/IOTA-ES occultation update for (82) Alkmene / UCAC2 21646026 event on 2009 Apr 06, 18:30 UT Visible from Summary ------- On 2009 Apr 06 UT, the 61 km diameter asteroid (82) Alkmene will occult a 11.7 mag star in the constellation Sagittarius for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 2.4 mag to 14.0 mag (the magnitude of the asteroid) for at most 4.4 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 52 * date and approx. time of event: 2009 Apr 06, 18:23 - 2009 Apr 06, 18:30 UT * magnitude of target star: 11.7 * magnitude drop [mag]: 2.4 * estimated maximum duration [s]: 4.4 * Moon: 90 % sunlit, 125° distance * Sun: 91° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 63 * 1 sigma uncertainty interval [path widths]: +/- 1.23 * 1 sigma uncertainty interval [seconds]: +/- 3.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .026", 360° ) * approx speed of asteroid's shadow [km/s]: 13.9402 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 21646026 by 82 Alkmene on 2009 Apr 6 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 81 0 0 -13 55 54 18 23 15 1 116 -82 -14 14 57 -13 36 52 -15 1 59 -12 50 10 82 0 0 -14 24 21 18 23 15 2 115 -82 -14 43 25 -14 5 19 -15 30 28 -13 18 36 83 0 0 -14 52 48 18 23 15 3 115 -82 -15 11 52 -14 33 45 -15 58 56 -13 47 2 84 0 0 -15 21 13 18 23 16 4 115 -81 -15 40 18 -15 2 10 -16 27 22 -14 15 26 85 0 0 -15 49 37 18 23 17 5 115 -81 -16 8 42 -15 30 34 -16 55 46 -14 43 49 86 0 0 -16 17 57 18 23 17 6 114 -80 -16 37 2 -15 58 54 -17 24 7 -15 12 10 87 0 0 -16 46 15 18 23 19 7 114 -80 -17 5 20 -16 27 12 -17 52 24 -15 40 27 88 0 0 -17 14 28 18 23 20 8 114 -79 -17 33 32 -16 55 25 -18 20 37 -16 8 40 89 0 0 -17 42 35 18 23 21 9 114 -78 -18 1 40 -17 23 33 -18 48 44 -16 36 49 90 0 0 -18 10 37 18 23 22 10 113 -77 -18 29 42 -17 51 35 -19 16 45 -17 4 52 91 0 0 -18 38 33 18 23 24 11 113 -77 -18 57 37 -18 19 31 -19 44 39 -17 32 49 92 0 0 -19 6 21 18 23 26 12 113 -76 -19 25 25 -18 47 19 -20 12 26 -18 0 39 93 0 0 -19 34 1 18 23 28 13 112 -75 -19 53 4 -19 15 0 -20 40 4 -18 28 21 94 0 0 -20 1 33 18 23 30 14 112 -74 -20 20 35 -19 42 32 -21 7 33 -18 55 54 95 0 0 -20 28 55 18 23 32 16 111 -73 -20 47 56 -20 9 55 -21 34 52 -19 23 19 96 0 0 -20 56 7 18 23 35 17 111 -72 -21 15 7 -20 37 8 -22 2 1 -19 50 34 97 0 0 -21 23 8 18 23 37 18 111 -71 -21 42 7 -21 4 10 -22 28 59 -20 17 38 98 0 0 -21 49 57 18 23 40 19 110 -70 -22 8 56 -21 31 0 -22 55 46 -20 44 31 99 0 0 -22 16 35 18 23 43 20 110 -69 -22 35 33 -21 57 39 -23 22 19 -21 11 12 100 0 0 -22 43 0 18 23 46 21 109 -68 -23 1 56 -22 24 5 -23 48 40 -21 37 41 101 0 0 -23 9 11 18 23 49 22 109 -67 -23 28 7 -22 50 18 -24 14 47 -22 3 56 102 0 0 -23 35 9 18 23 52 23 109 -66 -23 54 3 -23 16 16 -24 40 40 -22 29 58 103 0 0 -24 0 52 18 23 55 24 108 -65 -24 19 44 -23 42 1 -25 6 19 -22 55 46 104 0 0 -24 26 20 18 23 59 25 108 -64 -24 45 11 -24 7 30 -25 31 41 -23 21 19 105 0 0 -24 51 32 18 24 2 26 107 -63 -25 10 22 -24 32 44 -25 56 49 -23 46 36 106 0 0 -25 16 28 18 24 6 27 107 -62 -25 35 16 -24 57 42 -26 21 39 -24 11 38 107 0 0 -25 41 8 18 24 10 28 106 -61 -25 59 54 -25 22 23 -26 46 13 -24 36 23 108 0 0 -26 5 30 18 24 14 29 106 -60 -26 24 15 -25 46 47 -27 10 30 -25 0 52 109 0 0 -26 29 35 18 24 18 30 105 -59 -26 48 18 -26 10 54 -27 34 29 -25 25 2 110 0 0 -26 53 22 18 24 22 31 105 -58 -27 12 3 -26 34 43 -27 58 9 -25 48 56 111 0 0 -27 16 51 18 24 26 32 104 -58 -27 35 30 -26 58 13 -28 21 31 -26 12 31 112 0 0 -27 40 0 18 24 30 33 104 -57 -27 58 38 -27 21 25 -28 44 34 -26 35 47 113 0 0 -28 2 51 18 24 35 34 103 -56 -28 21 26 -27 44 17 -29 7 18 -26 58 44 114 0 0 -28 25 22 18 24 39 35 102 -55 -28 43 55 -28 6 50 -29 29 42 -27 21 22 115 0 0 -28 47 33 18 24 44 36 102 -54 -29 6 4 -28 29 3 -29 51 46 -27 43 40 116 0 0 -29 9 24 18 24 48 36 101 -53 -29 27 53 -28 50 56 -30 13 29 -28 5 38 117 0 0 -29 30 54 18 24 53 37 100 -52 -29 49 21 -29 12 28 -30 34 52 -28 27 15 118 0 0 -29 52 4 18 24 58 38 100 -51 -30 10 29 -29 33 40 -30 55 54 -28 48 32 119 0 0 -30 12 52 18 25 3 39 99 -50 -30 31 15 -29 54 31 -31 16 35 -29 9 28 120 0 0 -30 33 19 18 25 8 40 98 -49 -30 51 40 -30 15 0 -31 36 55 -29 30 2 121 0 0 -30 53 25 18 25 13 41 98 -48 -31 11 43 -30 35 8 -31 56 53 -29 50 15 122 0 0 -31 13 9 18 25 18 42 97 -47 -31 31 25 -30 54 54 -32 16 29 -30 10 7 123 0 0 -31 32 30 18 25 23 43 96 -46 -31 50 45 -31 14 18 -32 35 43 -30 29 36 124 0 0 -31 51 30 18 25 29 44 96 -45 -32 9 42 -31 33 20 -32 54 35 -30 48 44 125 0 0 -32 10 8 18 25 34 45 95 -44 -32 28 17 -31 52 0 -33 13 5 -31 7 29 126 0 0 -32 28 23 18 25 39 46 94 -43 -32 46 30 -32 10 17 -33 31 12 -31 25 52 127 0 0 -32 46 15 18 25 45 46 93 -43 -33 4 20 -32 28 11 -33 48 57 -31 43 52 128 0 0 -33 3 45 18 25 50 47 92 -42 -33 21 48 -32 45 43 -34 6 19 -32 1 29 129 0 0 -33 20 52 18 25 56 48 92 -41 -33 38 53 -33 2 53 -34 23 18 -32 18 44 130 0 0 -33 37 36 18 26 1 49 91 -40 -33 55 35 -33 19 39 -34 39 54 -32 35 35 131 0 0 -33 53 57 18 26 7 50 90 -39 -34 11 54 -33 36 2 -34 56 8 -32 52 4 132 0 0 -34 9 55 18 26 12 51 89 -38 -34 27 49 -33 52 3 -35 11 58 -33 8 10 133 0 0 -34 25 30 18 26 18 52 88 -37 -34 43 22 -34 7 40 -35 27 26 -33 23 52 134 0 0 -34 40 42 18 26 24 52 87 -36 -34 58 32 -34 22 54 -35 42 30 -33 39 11 135 0 0 -34 55 30 18 26 30 53 86 -35 -35 13 18 -34 37 44 -35 57 11 -33 54 7 136 0 0 -35 9 56 18 26 35 54 85 -35 -35 27 41 -34 52 12 -36 11 29 -34 8 40 137 0 0 -35 23 58 18 26 41 55 84 -34 -35 41 41 -35 6 16 -36 25 24 -34 22 49 138 0 0 -35 37 37 18 26 47 56 83 -33 -35 55 18 -35 19 57 -36 38 56 -34 36 35 139 0 0 -35 50 52 18 26 53 56 82 -32 -36 8 32 -35 33 14 -36 52 4 -34 49 57 140 0 0 -36 3 44 18 26 59 57 81 -31 -36 21 22 -35 46 8 -37 4 50 -35 2 56 141 0 0 -36 16 13 18 27 5 58 80 -30 -36 33 49 -35 58 39 -37 17 12 -35 15 32 142 0 0 -36 28 19 18 27 11 59 79 -29 -36 45 53 -36 10 47 -37 29 11 -35 27 44 143 0 0 -36 40 1 18 27 17 60 77 -29 -36 57 33 -36 22 31 -37 40 47 -35 39 32 144 0 0 -36 51 20 18 27 23 60 76 -28 -37 8 50 -36 33 52 -37 51 59 -35 50 58 145 0 0 -37 2 16 18 27 29 61 75 -27 -37 19 45 -36 44 50 -38 2 49 -36 2 0 146 0 0 -37 12 49 18 27 35 62 73 -26 -37 30 16 -36 55 24 -38 13 16 -36 12 38 147 0 0 -37 22 59 18 27 41 63 72 -25 -37 40 23 -37 5 35 -38 23 20 -36 22 54 148 0 0 -37 32 45 18 27 47 63 71 -24 -37 50 8 -37 15 23 -38 33 0 -36 32 46 149 0 0 -37 42 8 18 27 53 64 69 -23 -37 59 30 -37 24 48 -38 42 18 -36 42 14 150 0 0 -37 51 8 18 27 59 65 68 -23 -38 8 28 -37 33 50 -38 51 13 -36 51 20 151 0 0 -37 59 46 18 28 6 65 66 -22 -38 17 4 -37 42 28 -38 59 45 -37 0 2 152 0 0 -38 8 0 18 28 12 66 64 -21 -38 25 17 -37 50 44 -39 7 54 -37 8 21 153 0 0 -38 15 51 18 28 18 67 63 -20 -38 33 7 -37 58 36 -39 15 41 -37 16 17 154 0 0 -38 23 19 18 28 24 67 61 -19 -38 40 34 -38 6 6 -39 23 4 -37 23 49 155 0 0 -38 30 24 18 28 30 68 59 -19 -38 47 38 -38 13 12 -39 30 5 -37 30 59 156 0 0 -38 37 7 18 28 37 69 57 -18 -38 54 19 -38 19 56 -39 36 44 -37 37 45 157 0 0 -38 43 27 18 28 43 69 55 -17 -39 0 38 -38 26 17 -39 43 0 -37 44 9 158 0 0 -38 49 23 18 28 49 70 53 -16 -39 6 33 -38 32 15 -39 48 53 -37 50 9 159 0 0 -38 54 58 18 28 55 70 51 -15 -39 12 7 -38 37 50 -39 54 24 -37 55 47 160 0 0 -39 0 9 18 29 2 71 48 -15 -39 17 17 -38 43 2 -39 59 32 -38 1 2 161 0 0 -39 4 58 18 29 8 71 46 -14 -39 22 5 -38 47 52 -40 4 18 -38 5 53 162 0 0 -39 9 24 18 29 14 72 43 -13 -39 26 30 -38 52 19 -40 8 41 -38 10 22 163 0 0 -39 13 28 18 29 20 72 41 -12 -39 30 33 -38 56 23 -40 12 42 -38 14 28 164 0 0 -39 17 9 18 29 27 73 38 -11 -39 34 13 -39 0 5 -40 16 20 -38 18 12 165 0 0 -39 20 27 18 29 33 73 35 -11 -39 37 31 -39 3 24 -40 19 37 -38 21 32 166 0 0 -39 23 23 18 29 39 74 32 -10 -39 40 27 -39 6 20 -40 22 31 -38 24 30 167 0 0 -39 25 56 18 29 45 74 29 -9 -39 42 59 -39 8 54 -40 25 3 -38 27 5 168 0 0 -39 28 7 18 29 52 74 26 -8 -39 45 10 -39 11 5 -40 27 12 -38 29 17 169 0 0 -39 29 55 18 29 58 75 22 -7 -39 46 58 -39 12 54 -40 28 59 -38 31 7 170 0 0 -39 31 21 18 30 4 75 19 -7 -39 48 24 -39 14 20 -40 30 24 -38 32 33 171 0 0 -39 32 25 18 30 11 75 15 -6 -39 49 27 -39 15 24 -40 31 27 -38 33 38 172 0 0 -39 33 6 18 30 17 75 12 -5 -39 50 8 -39 16 5 -40 32 8 -38 34 19 173 0 0 -39 33 24 18 30 23 75 8 -4 -39 50 26 -39 16 24 -40 32 26 -38 34 38 174 0 0 -39 33 20 18 30 30 75 4 -3 -39 50 22 -39 16 20 -40 32 22 -38 34 34 175 0 0 -39 32 54 18 30 36 75 0 -3 -39 49 56 -39 15 53 -40 31 56 -38 34 7 176 0 0 -39 32 5 18 30 42 75 357 -2 -39 49 8 -39 15 4 -40 31 8 -38 33 18 177 0 0 -39 30 54 18 30 49 75 353 -1 -39 47 57 -39 13 53 -40 29 57 -38 32 6 178 0 0 -39 29 20 18 30 55 75 349 0 -39 46 23 -39 12 19 -40 28 25 -38 30 31 Uncertainty in time = +/- 5 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: UCAC2 21646026 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 11 09.7814 DE: -25 05 51.393 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .034 ) * V mag [mag]: 11.7 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (82) Alkmene approx. diameter [km]: 61 approx. diameter ["]: .029 distance from Earth [AU]: 2.89100 * orbital information: orbit source: Preston date of fit: 2008 Mar 19 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 1083 number of rejected observations: 126 time covered by the observations: 1905 Nov 06 - 2008 Feb 10 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.009, 83° remarks: * orbital elements for (82) Alkmene : Mean anomaly = 109.43195745 deg Arg. of pericenter = 110.43136475 deg Long. of node = 25.61819035 deg Inclination = 2.83269681 deg Eccentricity = 0.22384497 Semimajor axis = 2.75983074 AU Perihelion dist = 2.14205651 AU Mag: H = 8.21, G = 0.28 Epoch of elements : MJD 54927.77100000 TDT (2009 Apr 06.771) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Apr 6 82 Alkmene 18h 30.6m UT 11.7 19 11 9.781-25 5 51.39UCAC2 21646026 0.0 14.0 61 4.4 2.891 1.761 0.32 174.9523 -25.098 -97.08 6.71 18.5108 0.00476 -0.24619 7.86753 0.10640 -0.00574 -0.00070 2000 107.7614152009 330.00000110.431365 25.618190 2.8326970.22384497 2.7598307 2.1420565 8.4 5.00.28 RATE 2.1497130 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.026 360 2.23 0.036 0 54545.5020090406_646026 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 06:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org