IOTA/IOTA-ES occultation update for (691) Lehigh / 2UCAC 18779176 event on 2012 Aug 31, 14:52 UT Visible from Antarctica Summary ------- On 2012 Aug 31 UT, the 86 km diameter asteroid (691) Lehigh will occult a 12.3 mag star in the constellation Sagittarius for observers along a path across Antarctica. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 14.3 mag (the magnitude of the asteroid) for at most 144.0 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: 51 * date and approx. time of event: 2012 Aug 31, 12:32 - 2012 Aug 31, 17:11 UT * geocentric midpoint of event [JD]: 2456171.12345 * magnitude of target star: 12.3 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 144.0 * Moon: 100 % sunlit, 58° distance * Sun: 123° distance * rough path description: Antarctica The occultation path -------------------- * approximate projected width [km]: 101 * 1 sigma uncertainty interval [path widths]: +/- 1.24 * 1 sigma uncertainty interval [seconds]: +/- 165.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .064 +/- .062) * 1 sigma uncertainty ellipse (major, minor, PA): ( .064", .062", 91° ) * approx speed of asteroid's shadow [km/s]: 0.6000 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 18779176 by 691 Lehigh on 2012 Aug 31 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude -168 27 48 10 16 3 12 32 51 6 236 -63 -166 29 28 11 9 13 -169 57 50 9 40 35 ... .. .. .. .. .. -172 52 1 8 43 40 -174 34 11 6 0 7 12 36 39 13 236 -70 -173 36 49 6 15 0 -175 28 7 5 47 28 -170 52 51 7 5 44 -177 30 33 5 23 24 -178 38 33 3 2 28 12 40 28 17 236 -74 -177 52 21 3 10 10 -179 23 7 2 55 51 -175 49 6 3 34 58 178 52 20 2 43 25 178 0 30 0 33 28 12 44 17 21 236 -77 178 41 29 0 37 45 177 20 34 0 29 55 -179 31 36 0 51 52 175 45 34 0 23 51 175 3 48 - 1 39 10 12 48 6 24 236 -80 175 41 42 - 1 36 59 174 26 40 - 1 40 48 177 19 28 - 1 29 1 172 57 40 - 1 42 44 172 23 0 - 3 40 50 12 51 55 26 237 -83 172 58 52 - 3 40 5 171 47 46 - 3 41 8 174 30 45 - 3 36 13 170 22 52 - 3 40 7 169 53 39 - 5 34 29 12 55 44 28 237 -85 170 28 4 - 5 34 48 169 19 45 - 5 33 46 171 55 52 - 5 33 53 167 57 49 - 5 30 32 167 32 57 - 7 21 56 12 59 32 31 238 -87 168 6 19 - 7 23 5 167 0 3 - 7 20 27 169 31 9 - 7 24 27 165 40 19 - 7 15 26 165 19 7 - 9 4 26 13 3 21 32 238 -89 165 51 41 - 9 6 15 164 46 58 - 9 2 19 167 14 19 - 9 9 26 163 28 54 - 8 55 52 163 10 51 -10 42 51 13 7 10 34 239 -88 163 42 49 -10 45 13 162 39 16 -10 40 12 165 3 46 -10 49 53 161 22 29 -10 32 32 161 7 13 -12 17 50 13 10 59 36 240 -86 161 38 42 -12 20 41 160 36 4 -12 14 44 162 58 23 -12 26 36 159 20 14 -12 6 2 159 7 29 -13 49 53 13 14 48 38 241 -84 159 38 37 -13 53 8 158 36 39 -13 46 24 160 57 19 -14 0 8 157 21 34 -13 36 48 157 11 5 -15 19 25 13 18 36 39 242 -82 157 41 58 -15 23 1 156 40 31 -15 15 35 158 59 57 -15 30 57 155 25 57 -15 5 11 155 17 36 -16 46 44 13 22 25 41 243 -81 155 48 18 -16 50 39 154 47 12 -16 42 36 157 5 46 -16 59 25 153 33 1 -16 31 29 153 26 40 -18 12 6 13 26 14 42 244 -79 153 57 14 -18 16 18 152 56 22 -18 7 41 155 14 21 -18 25 48 151 42 25 -17 55 55 151 37 57 -19 35 44 13 30 3 43 245 -77 152 8 28 -19 40 12 151 7 43 -19 31 5 153 25 23 -19 50 23 149 53 53 -19 18 43 149 51 15 -20 57 50 13 33 52 45 246 -76 150 21 44 -21 2 32 149 21 1 -20 52 57 151 38 34 -21 13 20 148 7 11 -20 40 3 148 6 18 -22 18 34 13 37 41 46 247 -74 148 36 49 -22 23 29 147 36 3 -22 13 28 149 53 41 -22 34 51 146 22 8 -22 0 3 146 22 58 -23 38 4 13 41 29 47 248 -73 146 53 33 -23 43 11 145 52 38 -23 32 46 148 10 33 -23 55 5 144 38 32 -23 18 52 144 41 3 -24 56 27 13 45 18 48 250 -71 145 11 44 -25 1 46 144 10 38 -24 50 58 146 28 58 -25 14 9 142 56 16 -24 36 37 143 0 26 -26 13 50 13 49 7 49 251 -70 143 31 15 -26 19 20 142 29 53 -26 8 10 144 48 49 -26 32 11 141 15 11 -25 53 23 141 21 0 -27 30 19 13 52 56 50 253 -68 141 51 59 -27 35 59 140 50 17 -27 24 28 143 9 57 -27 49 17 139 35 10 -27 9 17 139 42 38 -28 45 59 13 56 45 51 254 -67 140 13 49 -28 51 49 139 11 43 -28 39 59 141 32 16 -29 5 33 137 56 7 -28 24 23 138 5 14 -30 0 55 14 0 34 52 256 -66 138 36 38 -30 6 55 137 34 5 -29 54 45 139 55 40 -30 21 3 136 17 56 -29 38 46 136 28 43 -31 15 11 14 4 22 53 258 -64 137 0 23 -31 21 21 135 57 19 -31 8 52 138 20 3 -31 35 52 134 40 33 -30 52 31 134 53 0 -32 28 52 14 8 11 54 260 -63 135 24 57 -32 35 11 134 21 19 -32 22 24 136 45 21 -32 50 5 133 3 51 -32 5 40 133 18 1 -33 42 1 14 12 0 54 261 -62 133 50 17 -33 48 29 132 46 1 -33 35 24 135 11 29 -34 3 46 131 27 48 -33 18 19 131 43 42 -34 54 42 14 15 49 55 263 -60 132 16 19 -35 1 18 131 11 22 -34 47 56 133 38 24 -35 16 57 129 52 19 -34 30 29 130 9 59 -36 6 58 14 19 38 56 265 -59 130 42 58 -36 13 43 129 37 16 -36 0 3 132 6 1 -36 29 43 128 17 19 -35 42 15 128 36 48 -37 18 52 14 23 27 56 267 -58 129 10 12 -37 25 45 128 3 41 -37 11 49 130 34 18 -37 42 7 126 42 46 -36 53 39 127 4 7 -38 30 27 14 27 15 57 270 -57 127 37 58 -38 37 29 126 30 34 -38 23 15 129 3 11 -38 54 12 125 8 36 -38 4 44 125 31 52 -39 41 46 14 31 4 57 272 -55 126 6 11 -39 48 56 124 57 51 -39 34 25 127 32 38 -40 6 1 123 34 46 -39 15 33 124 0 1 -40 52 51 14 34 53 57 274 -54 124 34 50 -41 0 11 123 25 29 -40 45 22 126 2 35 -41 17 36 122 1 11 -40 26 8 122 28 29 -42 3 46 14 38 42 58 276 -53 123 3 52 -42 11 14 121 53 25 -41 56 8 124 33 2 -42 29 1 120 27 50 -41 36 32 120 57 15 -43 14 33 14 42 31 58 279 -52 121 33 14 -43 22 9 120 21 37 -43 6 46 123 3 55 -43 40 17 118 54 38 -42 46 47 119 26 16 -44 25 14 14 46 20 58 281 -50 120 2 53 -44 32 59 118 50 1 -44 17 18 121 35 12 -44 51 29 117 21 32 -43 56 57 117 55 29 -45 35 52 14 50 8 58 283 -49 118 32 47 -45 43 46 117 18 34 -45 27 47 120 6 51 -46 2 38 115 48 30 -45 7 2 116 24 52 -46 46 28 14 53 57 58 286 -48 117 2 53 -46 54 32 115 47 13 -46 38 14 118 38 50 -47 13 46 114 15 27 -46 17 6 114 54 21 -47 57 7 14 57 46 58 288 -47 115 33 9 -48 5 20 114 15 56 -47 48 43 117 11 7 -48 24 57 112 42 20 -47 27 11 113 23 53 -49 7 50 15 1 35 58 291 -46 114 3 32 -49 16 13 112 44 39 -48 59 16 115 43 40 -49 36 12 111 9 6 -48 37 19 111 53 26 -50 18 39 15 5 24 58 293 -44 112 34 0 -50 27 12 111 13 19 -50 9 55 114 16 29 -50 47 35 109 35 40 -49 47 32 110 22 57 -51 29 37 15 9 13 58 295 -43 111 4 29 -51 38 20 109 41 53 -51 20 43 112 49 29 -51 59 8 108 1 58 -50 57 53 108 52 22 -52 40 47 15 13 1 58 298 -42 109 34 57 -52 49 40 108 10 16 -52 31 42 111 22 41 -53 10 53 106 27 56 -52 8 23 107 21 38 -53 52 10 15 16 50 57 300 -41 108 5 21 -54 1 15 106 38 26 -53 42 54 109 56 3 -54 22 54 104 53 29 -53 19 7 105 50 40 -55 3 51 15 20 39 57 302 -40 106 35 37 -55 13 7 105 6 16 -54 54 23 108 29 31 -55 35 12 103 18 30 -54 30 5 104 19 25 -56 15 50 15 24 28 57 305 -38 105 5 42 -56 25 18 103 33 44 -56 6 10 107 3 6 -56 47 52 101 42 55 -55 41 21 102 47 48 -57 28 12 15 28 17 56 307 -37 103 35 33 -57 37 53 102 0 42 -57 18 19 105 36 44 -58 0 56 100 6 35 -56 52 57 101 15 44 -58 41 0 15 32 6 56 309 -36 102 5 3 -58 50 53 100 27 6 -58 30 53 104 10 24 -59 14 26 98 29 23 -58 4 55 99 43 6 -59 54 15 15 35 54 55 311 -35 100 34 9 -60 4 22 98 52 47 -59 43 54 102 44 4 -60 28 27 96 51 9 -59 17 20 98 9 47 -61 8 2 15 39 43 55 313 -34 99 2 45 -61 18 24 97 17 38 -60 57 26 101 17 42 -61 43 2 95 11 44 -60 30 12 96 35 40 -62 22 24 15 43 32 54 316 -32 97 30 45 -62 33 1 95 41 29 -62 11 32 99 51 15 -62 58 15 93 30 53 -61 43 36 95 0 35 -63 37 24 15 47 21 53 318 -31 95 57 59 -63 48 18 94 4 9 -63 26 16 98 24 42 -64 14 9 91 48 22 -62 57 35 93 24 19 -64 53 8 15 51 10 52 320 -30 94 24 19 -65 4 19 92 25 24 -64 41 41 96 57 58 -65 30 50 90 3 54 -64 12 12 91 46 39 -66 9 37 15 54 59 52 321 -29 92 49 34 -66 21 7 90 44 57 -65 57 51 95 31 2 -66 48 21 88 17 5 -65 27 31 90 7 16 -67 26 58 15 58 47 51 323 -28 91 13 29 -67 38 49 89 2 26 -67 14 51 94 3 49 -68 6 47 86 27 27 -66 43 35 88 25 49 -68 45 16 16 2 36 50 325 -26 89 35 47 -68 57 28 87 17 27 -68 32 45 92 36 15 -69 26 15 84 34 28 -68 0 28 86 41 49 -70 4 34 16 6 25 49 327 -25 87 56 4 -70 17 10 85 29 24 -69 51 39 91 8 16 -70 46 50 82 37 22 -69 18 15 84 54 38 -71 25 0 16 10 14 48 329 -24 86 13 51 -71 38 2 83 37 33 -71 11 37 89 39 44 -72 8 40 80 35 12 -70 37 0 83 3 26 -72 46 39 16 14 3 47 331 -23 84 28 27 -73 0 10 81 40 55 -72 32 45 88 10 32 -73 31 51 78 26 42 -71 56 46 81 7 1 -74 9 39 16 17 52 46 333 -21 82 38 56 -74 23 42 79 38 8 -73 55 11 86 40 29 -74 56 32 76 10 9 -73 17 39 79 3 44 -75 34 6 16 21 40 45 335 -20 80 43 57 -75 48 46 77 27 15 -75 18 59 85 9 20 -76 22 53 73 43 9 -74 39 43 76 51 6 -77 0 8 16 25 29 43 337 -19 78 41 30 -77 15 30 75 5 23 -76 44 16 83 36 45 -77 51 4 71 2 14 -76 3 0 74 25 14 -78 27 54 16 29 18 42 339 -17 76 28 25 -78 44 5 72 28 10 -78 11 9 82 2 10 -79 21 19 68 2 16 -77 27 32 71 39 45 -79 57 31 16 33 7 41 341 -16 73 59 23 -80 14 40 69 28 26 -79 39 42 80 24 41 -80 53 52 64 35 12 -78 53 16 68 23 22 -81 29 3 16 36 56 40 344 -15 71 4 49 -81 47 25 65 53 48 -81 9 56 78 42 37 -82 29 0 60 27 55 -80 20 3 64 13 54 -83 2 28 16 40 45 38 348 -13 67 25 15 -83 22 26 61 20 48 -82 41 41 76 52 20 -84 7 3 55 17 28 -81 47 26 58 21 46 -84 37 22 16 44 33 37 354 -12 62 14 37 -84 59 34 54 59 46 -84 14 16 74 44 9 -85 48 27 48 20 52 -83 14 22 48 32 33 -86 11 59 16 48 22 35 3 -10 53 13 58 -86 37 37 44 48 27 -85 45 32 71 39 33 -87 33 37 38 11 37 -84 38 12 27 1 11 -87 38 18 16 52 11 33 24 -9 30 7 2 -88 9 13 24 58 17 -87 7 29 59 17 36 -89 22 31 21 52 55 -85 52 6 - 25 32 40 -88 15 16 16 56 0 32 76 -7 - 40 28 19 -88 36 41 - 16 17 24 -87 49 27 -101 2 58 -88 40 38 - 4 49 50 -86 38 49 - 70 49 46 -87 12 31 16 59 49 30 121 -6 - 82 9 45 -87 11 4 - 59 54 23 -87 7 17 -106 46 28 -86 39 28 - 38 20 47 -86 31 27 - 88 35 33 -85 24 34 17 3 37 28 138 -4 - 95 15 38 -85 13 50 - 81 35 31 -85 30 53 -109 29 22 -84 30 11 - 64 13 47 -85 27 26 - 97 23 4 -83 19 5 17 7 26 26 146 -2 -101 53 15 -83 3 11 - 92 36 48 -83 31 44 -111 41 28 -82 10 52 - 80 2 51 -83 48 31 -103 1 51 -80 59 45 17 11 15 23 151 0 -106 22 0 -80 39 37 - 99 30 23 -81 17 9 -113 45 40 -79 38 23 - 90 6 3 -81 48 14 Uncertainty in time = +/- 179 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: 2UCAC 18779176 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 55 00.7604 DE: -31 26 07.021 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .061, .061 ) * V mag [mag]: 12.3 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (691) Lehigh approx. diameter [km]: 86 approx. diameter ["]: .051 distance from Earth [AU]: 2.31700 * orbital information: orbit source: Preston date of fit: 2012 Aug 25 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 892 number of rejected observations: 52 time covered by the observations: 1914 Nov 21 - 2012 Aug 14 1 sigma uncertainty ellipse (major, minor, PA): 0.020, 0.013, 101° remarks: * orbital elements for (691) Lehigh : Mean anomaly = 280.58895621 deg Arg. of pericenter = 303.83500582 deg Long. of node = 88.18756236 deg Inclination = 13.02715106 deg Eccentricity = 0.11887106 Semimajor axis = 3.01256890 AU Perihelion dist = 2.65446165 AU Mag: H = 9.16, G = 0.15 Epoch of elements : MJD 56170.62000000 TDT (2012 Aug 31.620) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Aug 31 691 Lehigh 14h 57.8m UT 12.3 18 55 0.760-31 26 7.022UCAC 18779176 0.0 14.3 86 144.0 2.317 -0.065 -0.97 79.1193 -31.435 -44.40 8.34 14.9628 0.39035 -0.34615 -0.22226 -0.25550 0.00465 0.00091 2000 280.4720892012 831.00000303.835006 88.187562 13.0271510.11887106 3.0125689 2.6544616 9.2 5.00.15 RATE 1.8849450 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.064 0.062 91 2.24 0.063 0 0 4-1 056165.0020120831_779176 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 25, 22:17 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org