IOTA/IOTA-ES occultation update for (639) Latona / 2UCAC 30778594 event on 2012 Nov 17, 21:36 UT Visible from Japan, China Summary ------- On 2012 Nov 17 UT, the 80 km diameter asteroid (639) Latona will occult a 11.5 mag star in the constellation Aquarius for observers along a path across Japan, China. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.1 mag to 13.4 mag (the magnitude of the asteroid) for at most 5.0 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: 83 * date and approx. time of event: 2012 Nov 17, 12:30 - 2012 Nov 17, 12:36 UT * geocentric midpoint of event [JD]: 2456249.02176667 * magnitude of target star: 11.5 * magnitude drop [mag]: 2.1 * estimated maximum duration [s]: 5.0 * Moon: 18 % sunlit, 44° distance * Sun: 94° distance * rough path description: Japan, China The occultation path -------------------- * approximate projected width [km]: 98 * 1 sigma uncertainty interval [path widths]: +/- 0.63 * 1 sigma uncertainty interval [seconds]: +/- 3.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .032 +/- .029) * 1 sigma uncertainty ellipse (major, minor, PA): ( .032", .028", 81° ) * approx speed of asteroid's shadow [km/s]: 16.0806 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 30778594 by 639 Latona on 2012 Nov 17 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 68 0 0 29 41 33 12 30 25 54 152 -1 29 14 35 30 8 39 28 40 49 30 43 2 69 0 0 29 52 18 12 30 31 54 154 -1 29 25 20 30 19 25 28 51 33 30 53 49 70 0 0 30 3 9 12 30 37 54 155 -2 29 36 11 30 30 17 29 2 23 31 4 42 71 0 0 30 14 7 12 30 44 54 157 -3 29 47 8 30 41 16 29 13 20 31 15 41 72 0 0 30 25 10 12 30 50 55 159 -4 29 58 10 30 52 20 29 24 22 31 26 46 73 0 0 30 36 19 12 30 56 55 161 -5 30 9 19 31 3 29 29 35 29 31 37 56 74 0 0 30 47 34 12 31 2 55 163 -6 30 20 32 31 14 44 29 46 42 31 49 12 75 0 0 30 58 53 12 31 9 55 164 -7 30 31 51 31 26 4 29 58 0 32 0 32 76 0 0 31 10 17 12 31 15 55 166 -8 30 43 14 31 37 28 30 9 23 32 11 57 77 0 0 31 21 45 12 31 21 55 168 -9 30 54 42 31 48 57 30 20 50 32 23 27 78 0 0 31 33 18 12 31 27 55 170 -9 31 6 14 32 0 30 30 32 22 32 35 1 79 0 0 31 44 54 12 31 33 55 172 -10 31 17 50 32 12 7 30 43 57 32 46 38 80 0 0 31 56 34 12 31 40 55 173 -11 31 29 30 32 23 48 30 55 36 32 58 19 81 0 0 32 8 18 12 31 46 55 175 -12 31 41 13 32 35 32 31 7 19 33 10 4 82 0 0 32 20 5 12 31 52 55 177 -13 31 52 59 32 47 19 31 19 5 33 21 51 83 0 0 32 31 54 12 31 58 54 179 -14 32 4 48 32 59 8 31 30 53 33 33 42 84 0 0 32 43 46 12 32 4 54 181 -15 32 16 40 33 11 1 31 42 44 33 45 34 85 0 0 32 55 40 12 32 10 54 182 -16 32 28 34 33 22 55 31 54 38 33 57 29 86 0 0 33 7 36 12 32 16 54 184 -17 32 40 30 33 34 52 32 6 33 34 9 26 87 0 0 33 19 34 12 32 22 53 186 -17 32 52 27 33 46 50 32 18 31 34 21 24 88 0 0 33 31 33 12 32 28 53 187 -18 33 4 26 33 58 49 32 30 29 34 33 24 89 0 0 33 43 34 12 32 34 53 189 -19 33 16 27 34 10 50 32 42 29 34 45 25 90 0 0 33 55 35 12 32 40 52 191 -20 33 28 28 34 22 51 32 54 30 34 57 27 91 0 0 34 7 37 12 32 46 52 192 -21 33 40 30 34 34 54 33 6 32 35 9 29 92 0 0 34 19 39 12 32 52 52 194 -22 33 52 32 34 46 56 33 18 34 35 21 32 93 0 0 34 31 42 12 32 57 51 195 -23 34 4 34 34 58 58 33 30 36 35 33 34 94 0 0 34 43 44 12 33 3 51 197 -24 34 16 36 35 11 1 33 42 38 35 45 36 95 0 0 34 55 46 12 33 9 50 198 -24 34 28 38 35 23 2 33 54 40 35 57 38 96 0 0 35 7 47 12 33 14 50 200 -25 34 40 39 35 35 3 34 6 41 36 9 39 97 0 0 35 19 47 12 33 20 50 201 -26 34 52 39 35 47 3 34 18 41 36 21 39 98 0 0 35 31 45 12 33 25 49 203 -27 35 4 38 35 59 2 34 30 40 36 33 38 99 0 0 35 43 43 12 33 31 49 204 -28 35 16 35 36 10 59 34 42 37 36 45 35 100 0 0 35 55 38 12 33 36 48 206 -29 35 28 31 36 22 55 34 54 33 36 57 30 101 0 0 36 7 32 12 33 41 47 207 -30 35 40 25 36 34 48 35 6 27 37 9 23 102 0 0 36 19 23 12 33 47 47 208 -30 35 52 16 36 46 39 35 18 19 37 21 14 103 0 0 36 31 12 12 33 52 46 209 -31 36 4 5 36 58 28 35 30 8 37 33 3 104 0 0 36 42 58 12 33 57 46 211 -32 36 15 51 37 10 14 35 41 55 37 44 48 105 0 0 36 54 41 12 34 2 45 212 -33 36 27 35 37 21 56 35 53 39 37 56 31 106 0 0 37 6 21 12 34 7 45 213 -34 36 39 15 37 33 36 36 5 19 38 8 10 107 0 0 37 17 58 12 34 12 44 214 -34 36 50 52 37 45 12 36 16 56 38 19 46 108 0 0 37 29 30 12 34 17 43 215 -35 37 2 25 37 56 45 36 28 30 38 31 18 109 0 0 37 41 0 12 34 22 43 217 -36 37 13 55 38 8 14 36 40 0 38 42 46 110 0 0 37 52 24 12 34 26 42 218 -37 37 25 20 38 19 38 36 51 26 38 54 10 111 0 0 38 3 45 12 34 31 41 219 -38 37 36 41 38 30 58 37 2 47 39 5 30 112 0 0 38 15 1 12 34 36 41 220 -38 37 47 58 38 42 14 37 14 5 39 16 45 113 0 0 38 26 13 12 34 40 40 221 -39 37 59 10 38 53 25 37 25 17 39 27 55 114 0 0 38 37 19 12 34 45 39 222 -40 38 10 17 39 4 31 37 36 25 39 39 0 115 0 0 38 48 21 12 34 49 39 223 -41 38 21 19 39 15 32 37 47 27 39 50 1 116 0 0 38 59 17 12 34 53 38 224 -41 38 32 15 39 26 27 37 58 25 40 0 56 117 0 0 39 10 7 12 34 57 37 225 -42 38 43 6 39 37 18 38 9 17 40 11 45 118 0 0 39 20 52 12 35 2 37 226 -43 38 53 52 39 48 2 38 20 3 40 22 28 119 0 0 39 31 32 12 35 6 36 227 -44 39 4 32 39 58 40 38 30 43 40 33 6 120 0 0 39 42 5 12 35 10 35 228 -44 39 15 5 40 9 13 38 41 18 40 43 38 121 0 0 39 52 32 12 35 13 35 229 -45 39 25 33 40 19 39 38 51 46 40 54 3 122 0 0 40 2 52 12 35 17 34 230 -46 39 35 54 40 29 59 39 2 8 41 4 22 123 0 0 40 13 6 12 35 21 33 230 -47 39 46 9 40 40 12 39 12 24 41 14 35 124 0 0 40 23 14 12 35 25 33 231 -47 39 56 17 40 50 19 39 22 33 41 24 41 125 0 0 40 33 14 12 35 28 32 232 -48 40 6 18 41 0 19 39 32 35 41 34 40 126 0 0 40 43 8 12 35 32 31 233 -49 40 16 13 41 10 12 39 42 30 41 44 32 127 0 0 40 52 54 12 35 35 30 234 -49 40 26 0 41 19 58 39 52 18 41 54 16 128 0 0 41 2 33 12 35 38 30 235 -50 40 35 40 41 29 36 40 1 59 42 3 54 129 0 0 41 12 5 12 35 42 29 236 -51 40 45 12 41 39 7 40 11 33 42 13 24 130 0 0 41 21 30 12 35 45 28 236 -51 40 54 37 41 48 31 40 20 59 42 22 46 131 0 0 41 30 46 12 35 48 27 237 -52 41 3 55 41 57 47 40 30 17 42 32 1 132 0 0 41 39 55 12 35 51 27 238 -53 41 13 5 42 6 55 40 39 28 42 41 8 133 0 0 41 48 56 12 35 54 26 239 -53 41 22 6 42 15 55 40 48 30 42 50 8 134 0 0 41 57 49 12 35 56 25 240 -54 41 31 0 42 24 47 40 57 25 42 58 59 135 0 0 42 6 34 12 35 59 25 240 -54 41 39 46 42 33 31 41 6 12 43 7 42 136 0 0 42 15 11 12 36 2 24 241 -55 41 48 23 42 42 7 41 14 50 43 16 17 137 0 0 42 23 39 12 36 4 23 242 -55 41 56 53 42 50 35 41 23 20 43 24 43 138 0 0 42 31 59 12 36 7 22 243 -56 42 5 13 42 58 54 41 31 42 43 33 1 139 0 0 42 40 11 12 36 9 22 244 -57 42 13 26 43 7 4 41 39 55 43 41 11 140 0 0 42 48 13 12 36 12 21 244 -57 42 21 29 43 15 6 41 48 0 43 49 12 141 0 0 42 56 8 12 36 14 20 245 -58 42 29 24 43 23 0 41 55 56 43 57 4 142 0 0 43 3 53 12 36 16 20 246 -58 42 37 10 43 30 44 42 3 43 44 4 48 143 0 0 43 11 30 12 36 18 19 247 -58 42 44 48 43 38 20 42 11 22 44 12 22 144 0 0 43 18 57 12 36 20 18 247 -59 42 52 16 43 45 47 42 18 51 44 19 48 145 0 0 43 26 16 12 36 22 17 248 -59 42 59 36 43 53 5 42 26 11 44 27 5 146 0 0 43 33 25 12 36 24 17 249 -60 43 6 46 44 0 14 42 33 23 44 34 13 147 0 0 43 40 26 12 36 26 16 250 -60 43 13 47 44 7 13 42 40 25 44 41 11 148 0 0 43 47 17 12 36 27 15 250 -61 43 20 39 44 14 4 42 47 18 44 48 1 149 0 0 43 53 59 12 36 29 14 251 -61 43 27 22 44 20 45 42 54 1 44 54 41 150 0 0 44 0 32 12 36 30 14 252 -61 43 33 55 44 27 17 43 0 36 45 1 12 151 0 0 44 6 55 12 36 32 13 252 -62 43 40 19 44 33 39 43 7 1 45 7 33 152 0 0 44 13 9 12 36 33 12 253 -62 43 46 34 44 39 52 43 13 16 45 13 46 153 0 0 44 19 13 12 36 34 12 254 -62 43 52 39 44 45 56 43 19 22 45 19 48 154 0 0 44 25 8 12 36 36 11 255 -62 43 58 34 44 51 50 43 25 18 45 25 41 155 0 0 44 30 53 12 36 37 10 255 -63 44 4 20 44 57 34 43 31 5 45 31 25 156 0 0 44 36 29 12 36 38 9 256 -63 44 9 57 45 3 9 43 36 42 45 36 59 157 0 0 44 41 55 12 36 39 9 257 -63 44 15 23 45 8 35 43 42 10 45 42 24 158 0 0 44 47 11 12 36 40 8 257 -63 44 20 40 45 13 50 43 47 28 45 47 38 159 0 0 44 52 18 12 36 40 7 258 -63 44 25 47 45 18 56 43 52 36 45 52 43 160 0 0 44 57 14 12 36 41 7 259 -64 44 30 45 45 23 53 43 57 34 45 57 39 161 0 0 45 2 1 12 36 42 6 260 -64 44 35 32 45 28 39 44 2 22 46 2 25 162 0 0 45 6 39 12 36 42 5 260 -64 44 40 10 45 33 16 44 7 1 46 7 0 163 0 0 45 11 6 12 36 43 4 261 -64 44 44 38 45 37 42 44 11 29 46 11 26 164 0 0 45 15 24 12 36 43 4 262 -64 44 48 56 45 41 59 44 15 48 46 15 43 165 0 0 45 19 31 12 36 44 3 262 -64 44 53 4 45 46 6 44 19 57 46 19 49 166 0 0 45 23 29 12 36 44 2 263 -64 44 57 3 45 50 4 44 23 56 46 23 46 167 0 0 45 27 17 12 36 44 2 264 -64 45 0 51 45 53 51 44 27 45 46 27 32 168 0 0 45 30 54 12 36 44 1 265 -64 45 4 29 45 57 28 44 31 23 46 31 9 169 0 0 45 34 22 12 36 44 0 265 -64 45 7 57 46 0 56 .. .. .. 46 34 36 Uncertainty in time = +/- 4 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: 2UCAC 30778594 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 53 51.2985 DE: -03 14 12.692 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .026, .027 ) * V mag [mag]: 11.5 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (639) Latona approx. diameter [km]: 80 approx. diameter ["]: .045 distance from Earth [AU]: 2.45200 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 858 number of rejected observations: 104 time covered by the observations: 1907 Jul 20 - 2012 Oct 01 1 sigma uncertainty ellipse (major, minor, PA): 0.019, 0.010, 63° remarks: * orbital elements for (639) Latona : Mean anomaly = 2.17890703 deg Arg. of pericenter = 68.61234616 deg Long. of node = 280.05088826 deg Inclination = 8.57739006 deg Eccentricity = 0.10244299 Semimajor axis = 3.01676096 AU Perihelion dist = 2.70771494 AU Mag: H = 8.17, G = 0.15 Epoch of elements : MJD 56248.90000000 TDT (2012 Nov 17.900) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 17 639 Latona 12h 31.3m UT 11.5 21 53 51.299- 3 14 12.692UCAC 30778594 0.0 13.4 80 5.0 2.452 2.138 5.92 83.6572 -3.238 -11.57 -19.15 12.5224 -0.10240 0.56346 8.92501 1.65049 0.00554 0.00196 2000 0.504802201211 9.00000 68.612346280.050888 8.5773900.10244299 3.0167610 2.7077149 8.2 5.00.15 RATE 1.8810170 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.032 0.028 81 1.63 0.028 0 0-5-2 056208.0020121117_778594 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 20:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org