IOTA/IOTA-ES occultation update for (82) Alkmene / UCAC2 20957938 event on 2009 Jul 02, 12:12 UT Visible from Summary ------- On 2009 Jul 02 UT, the 61 km diameter asteroid (82) Alkmene will occult a 11.9 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 1.3 mag to 12.8 mag (the magnitude of the asteroid) for at most 4.3 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: 47 * date and approx. time of event: 2009 Jul 02, 12:08 - 2009 Jul 02, 12:16 UT * magnitude of target star: 11.9 * magnitude drop [mag]: 1.3 * estimated maximum duration [s]: 4.3 * Moon: 79 % sunlit, 55° distance * Sun: 176° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 115 * 1 sigma uncertainty interval [path widths]: +/- 1.38 * 1 sigma uncertainty interval [seconds]: +/- 5.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .054 +/- .052) * 1 sigma uncertainty ellipse (major, minor, PA): ( .054", .052", 89° ) * approx speed of asteroid's shadow [km/s]: 14.2709 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 20957938 by 82 Alkmene on 2009 Jul 2 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 ' " Longitude Longitude Longitude Longitude -133 7 51 53 0 0 12 8 31 0 221 -4 -134 17 59 ... .. .. -137 36 29 ... .. .. -134 35 2 52 0 0 12 8 31 2 219 -5 -135 44 44 -133 26 13 -139 2 16 ... .. .. -136 3 32 51 0 0 12 8 32 3 218 -6 -137 12 56 -134 55 3 -140 29 55 ... .. .. -137 33 32 50 0 0 12 8 33 4 217 -8 -138 42 48 -136 25 15 -141 59 39 ... .. .. -139 5 15 49 0 0 12 8 35 6 216 -9 -140 14 31 -137 57 1 -143 31 42 ... .. .. -140 38 56 48 0 0 12 8 38 7 215 -10 -141 48 21 -139 30 36 -145 6 21 ... .. .. -142 14 48 47 0 0 12 8 41 9 214 -12 -143 24 34 -141 6 13 -146 43 55 ... .. .. -143 53 10 46 0 0 12 8 44 10 212 -13 -145 3 27 -142 44 9 -148 24 44 -139 39 26 -145 34 21 45 0 0 12 8 48 12 211 -15 -146 45 21 -144 24 42 -150 9 15 -141 18 42 -147 18 44 44 0 0 12 8 53 13 210 -16 -148 30 41 -146 8 14 -151 57 59 -143 0 25 -149 6 44 43 0 0 12 8 59 15 208 -18 -150 19 55 -147 55 9 -153 51 32 -144 44 55 -150 58 53 42 0 0 12 9 6 16 207 -19 -152 13 38 -149 45 55 -155 50 41 -146 32 37 -152 55 49 41 0 0 12 9 13 18 205 -21 -154 12 31 -151 41 7 -157 56 25 -148 23 57 -154 58 21 40 0 0 12 9 22 19 204 -23 -156 17 29 -153 41 29 -160 10 2 -150 19 28 Latitude Latitude Latitude Latitude -156 0 0 39 30 56 12 9 26 20 203 -23 40 8 12 38 54 24 41 55 26 37 17 7 -157 0 0 39 3 22 12 9 31 21 202 -24 39 40 19 38 27 10 41 26 30 36 50 39 -158 0 0 38 36 32 12 9 35 21 201 -25 39 13 9 38 0 38 40 58 21 36 24 52 -159 0 0 38 10 26 12 9 40 22 200 -25 38 46 44 37 34 49 40 30 58 35 59 47 -160 0 0 37 45 3 12 9 45 23 200 -26 38 21 4 37 9 43 40 4 22 35 35 23 -161 0 0 37 20 24 12 9 50 23 199 -27 37 56 8 36 45 20 39 38 34 35 11 41 -162 0 0 36 56 30 12 9 55 24 198 -27 37 31 57 36 21 41 39 13 32 34 48 41 -163 0 0 36 33 20 12 10 1 25 197 -28 37 8 31 35 58 46 38 49 18 34 26 23 -164 0 0 36 10 54 12 10 6 25 196 -29 36 45 51 35 36 35 38 25 51 34 4 47 -165 0 0 35 49 13 12 10 12 26 195 -29 36 23 55 35 15 7 38 3 11 33 43 54 -166 0 0 35 28 17 12 10 17 26 194 -30 36 2 45 34 54 24 37 41 19 33 23 43 -167 0 0 35 8 5 12 10 23 27 193 -30 35 42 20 34 34 25 37 20 13 33 4 16 -168 0 0 34 48 38 12 10 29 27 193 -31 35 22 41 34 15 10 36 59 56 32 45 31 -169 0 0 34 29 56 12 10 35 28 192 -31 35 3 47 33 56 39 36 40 25 32 27 29 -170 0 0 34 11 59 12 10 41 28 191 -32 34 45 39 33 38 53 36 21 42 32 10 10 -171 0 0 33 54 47 12 10 47 29 190 -32 34 28 16 33 21 51 36 3 46 31 53 34 -172 0 0 33 38 20 12 10 53 29 189 -33 34 11 38 33 5 34 35 46 37 31 37 42 -173 0 0 33 22 38 12 10 59 29 188 -33 33 55 46 32 50 1 35 30 15 31 22 32 -174 0 0 33 7 41 12 11 5 30 187 -34 33 40 40 32 35 13 35 14 41 31 8 6 -175 0 0 32 53 29 12 11 11 30 186 -34 33 26 19 32 21 9 34 59 54 30 54 23 -176 0 0 32 40 2 12 11 18 30 185 -34 33 12 44 32 7 50 34 45 54 30 41 24 -177 0 0 32 27 19 12 11 24 31 184 -34 32 59 54 31 55 15 34 32 41 30 29 8 -178 0 0 32 15 22 12 11 30 31 183 -35 32 47 50 31 43 25 34 20 15 30 17 35 -179 0 0 32 4 10 12 11 37 31 182 -35 32 36 32 31 32 19 34 8 36 30 6 45 -180 0 0 31 53 44 12 11 43 31 181 -35 32 25 58 31 21 58 33 57 44 29 56 39 179 0 0 31 44 2 12 11 50 31 180 -35 32 16 11 31 12 22 33 47 39 29 47 17 178 0 0 31 35 5 12 11 56 32 179 -36 32 7 9 31 3 30 33 38 21 29 38 38 177 0 0 31 26 53 12 12 3 32 178 -36 31 58 52 30 55 22 33 29 50 29 30 42 176 0 0 31 19 26 12 12 9 32 177 -36 31 51 21 30 47 59 33 22 6 29 23 30 175 0 0 31 12 44 12 12 16 32 176 -36 31 44 35 30 41 21 33 15 9 29 17 1 174 0 0 31 6 47 12 12 22 32 175 -36 31 38 35 30 35 28 33 8 58 29 11 15 173 0 0 31 1 35 12 12 29 32 174 -36 31 33 20 30 30 19 33 3 34 29 6 13 172 0 0 30 57 8 12 12 35 32 173 -36 31 28 50 30 25 54 32 58 58 29 1 55 171 0 0 30 53 26 12 12 42 32 172 -36 31 25 7 30 22 14 32 55 7 28 58 20 170 0 0 30 50 30 12 12 49 32 171 -36 31 22 8 30 19 19 32 52 4 28 55 29 169 0 0 30 48 18 12 12 55 32 170 -36 31 19 55 30 17 8 32 49 48 28 53 21 168 0 0 30 46 51 12 13 1 31 169 -36 31 18 28 30 15 42 32 48 18 28 51 56 167 0 0 30 46 9 12 13 8 31 168 -35 31 17 46 30 15 1 32 47 35 28 51 16 166 0 0 30 46 13 12 13 14 31 167 -35 31 17 49 30 15 4 32 47 39 28 51 18 165 0 0 30 47 1 12 13 21 31 166 -35 31 18 38 30 15 52 32 48 30 28 52 5 164 0 0 30 48 35 12 13 27 31 165 -35 31 20 13 30 17 24 32 50 8 28 53 35 163 0 0 30 50 53 12 13 33 30 164 -34 31 22 33 30 19 41 32 52 32 28 55 48 162 0 0 30 53 57 12 13 40 30 163 -34 31 25 39 30 22 43 32 55 44 28 58 46 161 0 0 30 57 46 12 13 46 30 162 -34 31 29 30 30 26 30 32 59 42 29 2 27 160 0 0 31 2 20 12 13 52 29 161 -34 31 34 7 30 31 2 33 4 28 29 6 51 159 0 0 31 7 40 12 13 58 29 160 -33 31 39 30 30 36 18 33 10 1 29 12 0 158 0 0 31 13 45 12 14 4 29 159 -33 31 45 38 30 42 19 33 16 20 29 17 52 157 0 0 31 20 35 12 14 10 28 158 -32 31 52 33 30 49 5 33 23 27 29 24 28 156 0 0 31 28 10 12 14 16 28 157 -32 32 0 13 30 56 36 33 31 22 29 31 48 155 0 0 31 36 31 12 14 22 27 156 -31 32 8 39 31 4 52 33 40 3 29 39 51 154 0 0 31 45 38 12 14 27 27 155 -31 32 17 51 31 13 53 33 49 32 29 48 38 153 0 0 31 55 29 12 14 33 26 155 -30 32 27 49 31 23 40 33 59 48 29 58 10 152 0 0 32 6 7 12 14 38 26 154 -30 32 38 33 31 34 11 34 10 52 30 8 25 151 0 0 32 17 30 12 14 44 25 153 -29 32 50 3 31 45 27 34 22 44 30 19 24 150 0 0 32 29 39 12 14 49 25 152 -29 33 2 19 31 57 28 34 35 23 30 31 7 149 0 0 32 42 33 12 14 54 24 151 -28 33 15 21 32 10 15 34 48 50 30 43 34 148 0 0 32 56 13 12 14 59 24 150 -28 33 29 10 32 23 47 35 3 4 30 56 45 147 0 0 33 10 38 12 15 4 23 150 -27 33 43 45 32 38 4 35 18 7 31 10 40 146 0 0 33 25 50 12 15 9 22 149 -26 33 59 6 32 53 6 35 33 57 31 25 19 145 0 0 33 41 47 12 15 14 22 148 -26 34 15 13 33 8 54 35 50 36 31 40 42 144 0 0 33 58 30 12 15 19 21 147 -25 34 32 7 33 25 26 36 8 2 31 56 49 143 0 0 34 15 59 12 15 23 20 147 -24 34 49 47 33 42 44 36 26 17 32 13 40 142 0 0 34 34 14 12 15 28 20 146 -24 35 8 14 34 0 48 36 45 20 32 31 15 141 0 0 34 53 14 12 15 32 19 145 -23 35 27 27 34 19 36 37 5 11 32 49 33 140 0 0 35 13 0 12 15 36 18 144 -22 35 47 26 34 39 10 37 25 51 33 8 36 139 0 0 35 33 32 12 15 40 17 144 -21 36 8 12 34 59 29 37 47 18 33 28 22 138 0 0 35 54 50 12 15 44 17 143 -21 36 29 44 35 20 33 38 9 35 33 48 52 137 0 0 36 16 53 12 15 47 16 142 -20 36 52 2 35 42 22 38 32 39 34 10 5 136 0 0 36 39 42 12 15 51 15 142 -19 37 15 7 36 4 56 38 56 32 34 32 2 135 0 0 37 3 16 12 15 54 14 141 -18 37 38 57 36 28 15 39 21 13 34 54 42 134 0 0 37 27 36 12 15 57 14 140 -17 38 3 34 36 52 19 39 46 43 35 18 5 133 0 0 37 52 41 12 16 0 13 140 -17 38 28 57 37 17 7 40 13 1 35 42 12 132 0 0 38 18 31 12 16 3 12 139 -16 38 55 6 37 42 40 40 40 7 36 7 1 131 0 0 38 45 6 12 16 6 11 138 -15 39 22 0 38 8 57 41 8 1 36 32 32 130 0 0 39 12 26 12 16 8 10 138 -14 39 49 40 38 35 57 41 36 43 36 58 46 129 0 0 39 40 30 12 16 10 9 137 -13 40 18 5 39 3 42 42 6 13 37 25 42 128 0 0 40 9 19 12 16 12 8 136 -12 40 47 15 39 32 10 42 36 31 37 53 20 127 0 0 40 38 51 12 16 14 8 136 -11 41 17 10 40 1 21 43 7 37 38 21 39 126 0 0 41 9 7 12 16 16 7 135 -10 41 47 49 40 31 15 43 39 29 38 50 39 125 0 0 41 40 6 12 16 17 6 134 -10 42 19 12 41 1 52 44 12 9 .. .. .. 124 0 0 42 11 48 12 16 18 5 134 -9 42 51 19 41 33 10 44 45 36 .. .. .. 123 0 0 42 44 12 12 16 19 4 133 -8 43 24 9 42 5 10 45 19 49 .. .. .. 122 0 0 43 17 18 12 16 20 3 132 -7 43 57 42 42 37 51 45 54 48 .. .. .. 121 0 0 43 51 5 12 16 21 2 131 -6 44 31 57 43 11 12 46 30 32 .. .. .. 120 0 0 44 25 33 12 16 21 1 131 -5 45 6 54 43 45 13 .. .. .. .. .. .. 119 0 0 45 0 40 12 16 21 0 130 -4 .. .. .. 44 19 53 .. .. .. .. .. .. Uncertainty in time = +/- 6 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: UCAC2 20957938 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 50 35.9144 DE: -26 57 28.576 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .051, .051 ) * V mag [mag]: 11.9 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (82) Alkmene approx. diameter [km]: 61 approx. diameter ["]: .038 distance from Earth [AU]: 2.19600 * orbital information: orbit source: Preston date of fit: 2008 Mar 20 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): 0.019, 0.012, 85° remarks: * orbital elements for (82) Alkmene : Mean anomaly = 128.03356106 deg Arg. of pericenter = 110.48862654 deg Long. of node = 25.60887941 deg Inclination = 2.83252220 deg Eccentricity = 0.22361232 Semimajor axis = 2.76051795 AU Perihelion dist = 2.14323212 AU Mag: H = 8.21, G = 0.28 Epoch of elements : MJD 55014.50900000 TDT (2009 Jul 02.509) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Jul 2 82 Alkmene 12h 12.4m UT 11.9 18 50 35.914-26 57 28.58UCAC2 20957938 0.0 12.8 61 4.3 2.196 -2.401 -3.16 178.8716 -26.956 -2.08 23.00 12.2072 -0.08315 0.84400 -8.01603 -0.79002 -0.00007 0.00039 2000 127.0646182009 628.00000110.488627 25.608879 2.8325220.22361232 2.7605180 2.1432321 8.4 5.00.28 RATE 2.1489090 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.054 0.052 89 2.38 0.053 0 54545.5020090702_957938 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 10:10 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org