IOTA/IOTA-ES occultation update for (82) Alkmene / UCAC2 20957938 event on 2009 Jul 02, 12:12 UT Visible from Japan 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 Japan. 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, 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: Japan The occultation path -------------------- * approximate projected width [km]: 115 * 1 sigma uncertainty interval [path widths]: +/- 1.38 * 1 sigma uncertainty interval [seconds]: +/- 5.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .054 +/- .052) * 1 sigma uncertainty ellipse (major, minor, PA): ( .054", .052", 90° ) * 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 1 8 53 0 0 12 8 32 0 221 -3 -134 11 10 ... .. .. -137 29 24 ... .. .. -134 28 22 52 0 0 12 8 32 2 220 -5 -135 37 58 -133 19 38 -138 55 12 ... .. .. -135 56 53 51 0 0 12 8 33 3 218 -6 -137 6 12 -134 48 30 -140 22 52 ... .. .. -137 26 55 50 0 0 12 8 34 4 217 -8 -138 36 4 -136 18 43 -141 52 36 ... .. .. -138 58 38 49 0 0 12 8 36 6 216 -9 -140 7 48 -137 50 30 -143 24 38 ... .. .. -140 32 18 48 0 0 12 8 39 7 215 -10 -141 41 37 -139 24 4 -144 59 15 ... .. .. -142 8 9 47 0 0 12 8 42 9 214 -12 -143 17 47 -140 59 40 -146 36 44 ... .. .. -143 46 28 46 0 0 12 8 45 10 212 -13 -144 56 36 -142 37 34 -148 17 29 -139 33 9 -145 27 35 45 0 0 12 8 49 12 211 -15 -146 38 26 -144 18 4 -150 1 53 -141 12 22 -147 11 52 44 0 0 12 8 54 13 210 -16 -148 23 40 -146 1 31 -151 50 28 -142 54 2 -148 59 45 43 0 0 12 9 0 15 208 -18 -150 12 46 -147 48 19 -153 43 50 -144 38 28 -150 51 45 42 0 0 12 9 7 16 207 -19 -152 6 19 -149 38 58 -155 42 45 -146 26 4 -152 48 31 41 0 0 12 9 14 18 205 -21 -154 5 0 -151 34 0 -157 48 11 -148 17 17 -154 50 48 40 0 0 12 9 23 19 204 -22 -156 9 42 -153 34 10 -160 1 25 -150 12 39 Latitude Latitude Latitude Latitude -156 0 0 39 27 22 12 9 28 20 203 -23 40 4 33 38 50 54 41 51 33 37 13 48 -157 0 0 38 59 50 12 9 32 21 202 -24 39 36 42 38 23 41 41 22 39 36 47 21 -158 0 0 38 33 1 12 9 37 21 201 -25 39 9 34 37 57 11 40 54 31 36 21 36 -159 0 0 38 6 56 12 9 42 22 200 -26 38 43 11 37 31 23 40 27 11 35 56 31 -160 0 0 37 41 35 12 9 47 23 200 -26 38 17 32 37 6 19 40 0 37 35 32 9 -161 0 0 37 16 58 12 9 52 23 199 -27 37 52 38 36 41 58 39 34 50 35 8 28 -162 0 0 36 53 5 12 9 57 24 198 -28 37 28 28 36 18 20 39 9 51 34 45 29 -163 0 0 36 29 56 12 10 2 25 197 -28 37 5 4 35 55 26 38 45 38 34 23 12 -164 0 0 36 7 32 12 10 8 25 196 -29 36 42 24 35 33 16 38 22 13 34 1 37 -165 0 0 35 45 52 12 10 13 26 195 -29 36 20 30 35 11 49 37 59 34 33 40 45 -166 0 0 35 24 56 12 10 19 26 194 -30 35 59 21 34 51 7 37 37 43 33 20 35 -167 0 0 35 4 46 12 10 24 27 193 -30 35 38 58 34 31 9 37 16 40 33 1 9 -168 0 0 34 45 20 12 10 30 27 193 -31 35 19 19 34 11 55 36 56 23 32 42 25 -169 0 0 34 26 39 12 10 36 28 192 -31 35 0 26 33 53 25 36 36 54 32 24 23 -170 0 0 34 8 43 12 10 42 28 191 -32 34 42 19 33 35 40 36 18 11 32 7 5 -171 0 0 33 51 32 12 10 48 29 190 -32 34 24 57 33 18 39 36 0 17 31 50 30 -172 0 0 33 35 5 12 10 54 29 189 -33 34 8 20 33 2 22 35 43 9 31 34 38 -173 0 0 33 19 24 12 11 0 29 188 -33 33 52 29 32 46 50 35 26 48 31 19 29 -174 0 0 33 4 27 12 11 6 30 187 -34 33 37 24 32 32 3 35 11 15 31 5 4 -175 0 0 32 50 16 12 11 13 30 186 -34 33 23 4 32 17 59 34 56 28 30 51 21 -176 0 0 32 36 50 12 11 19 30 185 -34 33 9 29 32 4 41 34 42 29 30 38 22 -177 0 0 32 24 8 12 11 25 31 184 -35 32 56 40 31 52 6 34 29 17 30 26 7 -178 0 0 32 12 11 12 11 32 31 183 -35 32 44 36 31 40 17 34 16 52 30 14 34 -179 0 0 32 1 0 12 11 38 31 182 -35 32 33 18 31 29 11 34 5 13 30 3 45 -180 0 0 31 50 33 12 11 45 31 181 -35 32 22 45 31 18 51 33 54 22 29 53 39 179 0 0 31 40 52 12 11 51 32 180 -35 32 12 58 31 9 15 33 44 17 29 44 17 178 0 0 31 31 55 12 11 58 32 179 -36 32 3 56 31 0 23 33 35 0 29 35 38 177 0 0 31 23 43 12 12 4 32 178 -36 31 55 40 30 52 16 33 26 29 29 27 42 176 0 0 31 16 17 12 12 11 32 177 -36 31 48 9 30 44 53 33 18 45 29 20 30 175 0 0 31 9 35 12 12 17 32 176 -36 31 41 23 30 38 15 33 11 48 29 14 2 174 0 0 31 3 38 12 12 24 32 175 -36 31 35 23 30 32 22 33 5 37 29 8 16 173 0 0 30 58 26 12 12 30 32 174 -36 31 30 8 30 27 13 33 0 14 29 3 14 172 0 0 30 54 0 12 12 37 32 173 -36 31 25 39 30 22 48 32 55 37 28 58 56 171 0 0 30 50 18 12 12 43 32 172 -36 31 21 55 30 19 8 32 51 47 28 55 21 170 0 0 30 47 21 12 12 50 32 171 -36 31 18 56 30 16 13 32 48 44 28 52 29 169 0 0 30 45 9 12 12 56 32 170 -36 31 16 43 30 14 2 32 46 27 28 50 21 168 0 0 30 43 42 12 13 3 32 169 -36 31 15 16 30 12 36 32 44 57 28 48 57 167 0 0 30 43 0 12 13 9 31 168 -35 31 14 33 30 11 54 32 44 14 28 48 16 166 0 0 30 43 3 12 13 16 31 167 -35 31 14 37 30 11 57 32 44 18 28 48 19 165 0 0 30 43 51 12 13 22 31 166 -35 31 15 25 30 12 44 32 45 8 28 49 5 164 0 0 30 45 24 12 13 29 31 165 -35 31 17 0 30 14 17 32 46 46 28 50 34 163 0 0 30 47 43 12 13 35 30 164 -35 31 19 19 30 16 34 32 49 10 28 52 48 162 0 0 30 50 46 12 13 41 30 163 -34 31 22 25 30 19 35 32 52 21 28 55 45 161 0 0 30 54 35 12 13 47 30 162 -34 31 26 16 30 23 21 32 56 19 28 59 25 160 0 0 30 59 8 12 13 53 30 161 -34 31 30 52 30 27 53 33 1 4 29 3 49 159 0 0 31 4 27 12 13 59 29 160 -33 31 36 14 30 33 8 33 6 36 29 8 57 158 0 0 31 10 32 12 14 5 29 159 -33 31 42 22 30 39 9 33 12 55 29 14 49 157 0 0 31 17 21 12 14 11 28 158 -32 31 49 16 30 45 55 33 20 1 29 21 24 156 0 0 31 24 56 12 14 17 28 157 -32 31 56 55 30 53 25 33 27 55 29 28 43 155 0 0 31 33 16 12 14 23 27 156 -31 32 5 21 31 1 40 33 36 36 29 36 46 154 0 0 31 42 22 12 14 29 27 155 -31 32 14 32 31 10 41 33 46 4 29 45 33 153 0 0 31 52 13 12 14 34 26 155 -31 32 24 29 31 20 26 33 56 19 29 55 4 152 0 0 32 2 49 12 14 40 26 154 -30 32 35 12 31 30 56 34 7 22 30 5 18 151 0 0 32 14 11 12 14 45 25 153 -29 32 46 41 31 42 12 34 19 12 30 16 16 150 0 0 32 26 19 12 14 51 25 152 -29 32 58 56 31 54 12 34 31 50 30 27 59 149 0 0 32 39 12 12 14 56 24 151 -28 33 11 58 32 6 58 34 45 16 30 40 25 148 0 0 32 52 51 12 15 1 24 150 -28 33 25 45 32 20 28 34 59 29 30 53 35 147 0 0 33 7 16 12 15 6 23 150 -27 33 40 19 32 34 44 35 14 30 31 7 29 146 0 0 33 22 26 12 15 11 22 149 -26 33 55 39 32 49 45 35 30 20 31 22 7 145 0 0 33 38 22 12 15 16 22 148 -26 34 11 45 33 5 32 35 46 57 31 37 29 144 0 0 33 55 4 12 15 20 21 147 -25 34 28 37 33 22 3 36 4 22 31 53 34 143 0 0 34 12 31 12 15 25 20 147 -24 34 46 16 33 39 20 36 22 35 32 10 24 142 0 0 34 30 45 12 15 29 20 146 -24 35 4 41 33 57 22 36 41 36 32 27 58 141 0 0 34 49 44 12 15 33 19 145 -23 35 23 52 34 16 9 37 1 25 32 46 15 140 0 0 35 9 28 12 15 38 18 144 -22 35 43 50 34 35 42 37 22 3 33 5 16 139 0 0 35 29 59 12 15 41 18 144 -21 36 4 34 34 55 59 37 43 29 33 25 1 138 0 0 35 51 15 12 15 45 17 143 -21 36 26 4 35 17 2 38 5 43 33 45 29 137 0 0 36 13 16 12 15 49 16 142 -20 36 48 21 35 38 49 38 28 46 34 6 41 136 0 0 36 36 3 12 15 52 15 142 -19 37 11 24 36 1 21 38 52 36 34 28 37 135 0 0 36 59 36 12 15 56 14 141 -18 37 35 13 36 24 39 39 17 15 34 51 15 134 0 0 37 23 54 12 15 59 14 140 -17 37 59 47 36 48 40 39 42 42 35 14 37 133 0 0 37 48 57 12 16 2 13 140 -17 38 25 8 37 13 27 40 8 58 35 38 42 132 0 0 38 14 45 12 16 5 12 139 -16 38 51 15 37 38 58 40 36 2 36 3 29 131 0 0 38 41 18 12 16 7 11 138 -15 39 18 7 38 5 12 41 3 53 36 28 59 130 0 0 39 8 35 12 16 10 10 138 -14 39 45 44 38 32 11 41 32 33 36 55 11 129 0 0 39 36 37 12 16 12 9 137 -13 40 14 7 38 59 54 42 2 0 37 22 5 128 0 0 40 5 24 12 16 14 9 136 -12 40 43 14 39 28 20 42 32 15 37 49 41 127 0 0 40 34 54 12 16 16 8 136 -11 41 13 7 39 57 29 43 3 17 38 17 58 126 0 0 41 5 7 12 16 17 7 135 -11 41 43 43 40 27 20 43 35 7 38 46 56 125 0 0 41 36 3 12 16 19 6 134 -10 42 15 4 40 57 54 44 7 43 .. .. .. 124 0 0 42 7 43 12 16 20 5 134 -9 42 47 8 41 29 10 44 41 6 .. .. .. 123 0 0 42 40 4 12 16 21 4 133 -8 43 19 55 42 1 8 45 15 16 .. .. .. 122 0 0 43 13 7 12 16 22 3 132 -7 43 53 25 42 33 46 45 50 11 .. .. .. 121 0 0 43 46 51 12 16 23 2 131 -6 44 27 37 43 7 4 46 25 51 .. .. .. 120 0 0 44 21 16 12 16 23 1 131 -5 45 2 30 43 41 2 .. .. .. .. .. .. 119 0 0 44 56 21 12 16 23 0 130 -4 .. .. .. 44 15 39 .. .. .. .. .. .. Uncertainty in time = +/- 6 secs Prediction of 2009 Jun 25.0 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: 2009 Jun 24 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1135 number of rejected observations: 127 time covered by the observations: 1905 Nov 06 - 2009 Jun 07 1 sigma uncertainty ellipse (major, minor, PA): 0.017, 0.012, 85° remarks: * orbital elements for (82) Alkmene : Mean anomaly = 128.03356534 deg Arg. of pericenter = 110.48865200 deg Long. of node = 25.60885336 deg Inclination = 2.83252175 deg Eccentricity = 0.22361235 Semimajor axis = 2.76051795 AU Perihelion dist = 2.14323203 AU Mag: H = 8.22, 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 12.5m UT 11.9 18 50 35.914-26 57 28.58UCAC2 20957938 0.0 12.8 61 4.3 2.196 -2.401 -3.16 178.8666 -26.956 -2.09 23.00 12.2076 -0.08311 0.84352 -8.01603 -0.79002 -0.00007 0.00039 2000 127.0646222009 628.00000110.488652 25.608853 2.8325220.22361235 2.7605180 2.1432320 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 90 2.38 0.053 0 55007.0020090702_957938 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2009 Jun 24, 17:08 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org