IOTA/IOTA-ES occultation update for (493) Griseldis / TYC 6947-00520-1 event on 2012 Sep 04, 23:43 UT Visible from Africa Summary ------- On 2012 Sep 04 UT, the 51 km diameter asteroid (493) Griseldis will occult a 10.5 mag star in the constellation Piscis Austrinus for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 4.3 mag to 14.8 mag (the magnitude of the asteroid) for at most 4.5 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: 46 * date and approx. time of event: 2012 Sep 04, 23:37 - 2012 Sep 04, 23:50 UT * geocentric midpoint of event [JD]: 2456175.48896667 * magnitude of target star: 10.5 * magnitude drop [mag]: 4.3 * estimated maximum duration [s]: 4.5 * Moon: 81 % sunlit, 78° distance * Sun: 151° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 70 * 1 sigma uncertainty interval [path widths]: +/- 1.41 * 1 sigma uncertainty interval [seconds]: +/- 7.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .064 +/- .046) * 1 sigma uncertainty ellipse (major, minor, PA): ( .066", .044", 74° ) * approx speed of asteroid's shadow [km/s]: 11.3163 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6947-00520-1 by 493 Griseldis on 2012 Sep 4 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 - 75 0 0 47 23 11 23 50 59 0 133 -4 .. .. .. 46 57 11 .. .. .. .. .. .. - 74 0 0 46 44 55 23 50 59 1 134 -5 47 11 6 46 18 59 .. .. .. .. .. .. - 73 0 0 46 6 26 23 50 59 2 135 -5 46 32 33 45 40 34 47 47 37 .. .. .. - 72 0 0 45 27 44 23 50 58 3 135 -6 45 53 47 45 1 57 47 8 37 .. .. .. - 71 0 0 44 48 53 23 50 57 4 136 -7 45 14 50 44 23 11 46 29 25 .. .. .. - 70 0 0 44 9 53 23 50 57 5 137 -8 44 35 45 43 44 16 45 50 4 42 33 16 - 69 0 0 43 30 46 23 50 55 6 137 -9 43 56 32 43 5 15 45 10 34 41 54 30 - 68 0 0 42 51 35 23 50 54 7 138 -10 43 17 15 42 26 9 44 30 59 41 15 40 - 67 0 0 42 12 20 23 50 52 8 139 -11 42 37 54 41 47 1 43 51 19 40 36 48 - 66 0 0 41 33 4 23 50 50 9 139 -12 41 58 31 41 7 51 43 11 36 39 57 56 - 65 0 0 40 53 48 23 50 48 10 140 -13 41 19 8 40 28 42 42 31 53 39 19 5 - 64 0 0 40 14 35 23 50 46 11 141 -14 40 39 47 39 49 35 41 52 11 38 40 17 - 63 0 0 39 35 25 23 50 43 12 141 -14 40 0 30 39 10 32 41 12 32 38 1 33 - 62 0 0 38 56 20 23 50 40 13 142 -15 39 21 18 38 31 35 40 32 58 37 22 55 - 61 0 0 38 17 23 23 50 37 14 143 -16 38 42 13 37 52 45 39 53 30 36 44 26 - 60 0 0 37 38 34 23 50 34 15 143 -17 38 3 16 37 14 4 39 14 10 36 6 5 - 59 0 0 36 59 55 23 50 30 16 144 -18 37 24 30 36 35 33 38 35 0 35 27 55 - 58 0 0 36 21 29 23 50 27 17 145 -19 36 45 55 35 57 14 37 56 2 34 49 57 - 57 0 0 35 43 15 23 50 23 18 145 -20 36 7 34 35 19 9 37 17 16 34 12 13 - 56 0 0 35 5 17 23 50 18 19 146 -21 35 29 27 34 41 18 36 38 45 33 34 44 - 55 0 0 34 27 34 23 50 14 20 147 -22 34 51 36 34 3 44 36 0 30 32 57 32 - 54 0 0 33 50 9 23 50 9 21 147 -23 34 14 3 33 26 27 35 22 32 32 20 37 - 53 0 0 33 13 3 23 50 4 22 148 -24 33 36 49 32 49 29 34 44 53 31 44 1 - 52 0 0 32 36 17 23 49 59 22 149 -25 32 59 54 32 12 52 34 7 34 31 7 45 - 51 0 0 31 59 53 23 49 54 23 150 -26 32 23 21 31 36 35 33 30 36 30 31 50 - 50 0 0 31 23 50 23 49 48 24 150 -27 31 47 11 31 0 41 32 54 1 29 56 18 - 49 0 0 30 48 12 23 49 43 25 151 -28 31 11 24 30 25 10 32 17 50 29 21 9 - 48 0 0 30 12 58 23 49 37 26 152 -29 30 36 2 29 50 4 31 42 3 28 46 25 - 47 0 0 29 38 9 23 49 31 27 152 -30 30 1 5 29 15 24 31 6 43 28 12 6 - 46 0 0 29 3 47 23 49 24 28 153 -31 29 26 35 28 41 10 30 31 49 27 38 14 - 45 0 0 28 29 53 23 49 18 29 154 -32 28 52 32 28 7 23 29 57 23 27 4 48 - 44 0 0 27 56 27 23 49 11 30 155 -33 28 18 58 27 34 5 29 23 25 26 31 51 - 43 0 0 27 23 30 23 49 4 31 155 -34 27 45 53 27 1 15 28 49 57 25 59 22 - 42 0 0 26 51 2 23 48 57 31 156 -35 27 13 19 26 28 56 28 16 59 25 27 23 - 41 0 0 26 19 6 23 48 50 32 157 -36 26 41 14 25 57 7 27 44 33 24 55 54 - 40 0 0 25 47 41 23 48 43 33 158 -38 26 9 42 25 25 49 27 12 38 24 24 57 - 39 0 0 25 16 47 23 48 35 34 159 -39 25 38 41 24 55 3 26 41 15 23 54 30 - 38 0 0 24 46 26 23 48 27 35 159 -40 25 8 13 24 24 49 26 10 26 23 24 36 - 37 0 0 24 16 39 23 48 20 35 160 -41 24 38 18 23 55 8 25 40 10 22 55 14 - 36 0 0 23 47 24 23 48 12 36 161 -42 24 8 56 23 26 1 25 10 28 22 26 26 - 35 0 0 23 18 44 23 48 4 37 162 -43 23 40 9 22 57 28 24 41 21 21 58 11 - 34 0 0 22 50 39 23 47 56 38 163 -44 23 11 57 22 29 29 24 12 48 21 30 30 - 33 0 0 22 23 8 23 47 47 38 164 -45 22 44 20 22 2 4 23 44 52 21 3 23 - 32 0 0 21 56 13 23 47 39 39 165 -46 22 17 18 21 35 15 23 17 31 20 36 51 - 31 0 0 21 29 53 23 47 30 40 166 -47 21 50 52 21 9 2 22 50 47 20 10 55 - 30 0 0 21 4 9 23 47 22 40 167 -47 21 25 2 20 43 24 22 24 39 19 45 33 - 29 0 0 20 39 2 23 47 13 41 168 -48 20 59 49 20 18 23 21 59 8 19 20 48 - 28 0 0 20 14 31 23 47 4 41 169 -49 20 35 12 19 53 58 21 34 14 18 56 39 - 27 0 0 19 50 38 23 46 56 42 170 -50 20 11 13 19 30 10 21 9 58 18 33 6 - 26 0 0 19 27 21 23 46 47 43 171 -51 19 47 51 19 6 58 20 46 19 18 10 9 - 25 0 0 19 4 41 23 46 38 43 172 -52 19 25 6 18 44 24 20 23 19 17 47 50 - 24 0 0 18 42 39 23 46 29 44 173 -53 19 2 58 18 22 27 20 0 56 17 26 7 - 23 0 0 18 21 15 23 46 20 44 174 -54 18 41 29 18 1 8 19 39 12 17 5 1 - 22 0 0 18 0 29 23 46 11 44 176 -55 18 20 38 17 40 27 19 18 6 16 44 33 - 21 0 0 17 40 20 23 46 1 45 177 -56 18 0 25 17 20 23 18 57 39 16 24 42 - 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6 0 0 13 55 18 23 43 41 47 195 -67 14 14 30 13 36 12 15 9 13 12 42 51 - 5 0 0 13 45 29 23 43 32 47 197 -68 14 4 39 13 26 25 14 59 15 12 33 10 - 4 0 0 13 36 19 23 43 23 47 198 -68 13 55 27 13 17 17 14 49 57 12 24 7 - 3 0 0 13 27 48 23 43 13 47 199 -69 13 46 54 13 8 48 14 41 18 12 15 43 - 2 0 0 13 19 56 23 43 4 46 200 -69 13 39 0 13 0 58 14 33 20 12 7 58 - 1 0 0 13 12 43 23 42 55 46 202 -70 13 31 46 12 53 46 14 26 1 12 0 51 0 0 0 13 6 10 23 42 46 46 203 -70 13 25 11 12 47 14 14 19 22 11 54 23 1 0 0 13 0 16 23 42 37 46 204 -70 13 19 16 12 41 21 14 13 23 11 48 33 2 0 0 12 55 1 23 42 28 45 205 -70 13 13 59 12 36 8 14 8 3 11 43 22 3 0 0 12 50 25 23 42 19 45 206 -70 13 9 23 12 31 33 14 3 24 11 38 50 4 0 0 12 46 28 23 42 10 45 207 -71 13 5 25 12 27 37 13 59 24 11 34 57 5 0 0 12 43 11 23 42 1 44 208 -71 13 2 8 12 24 21 13 56 5 11 31 42 6 0 0 12 40 33 23 41 52 44 209 -71 12 59 29 12 21 43 13 53 25 11 29 6 7 0 0 12 38 35 23 41 44 43 210 -70 12 57 31 12 19 45 13 51 25 11 27 9 8 0 0 12 37 16 23 41 35 43 211 -70 12 56 12 12 18 26 13 50 6 11 25 51 9 0 0 12 36 37 23 41 26 43 212 -70 12 55 32 12 17 47 13 49 26 11 25 11 10 0 0 12 36 37 23 41 18 42 213 -70 12 55 32 12 17 47 13 49 27 11 25 11 11 0 0 12 37 16 23 41 10 41 214 -70 12 56 12 12 18 26 13 50 7 11 25 49 12 0 0 12 38 35 23 41 1 41 215 -69 12 57 31 12 19 45 13 51 28 11 27 6 13 0 0 12 40 34 23 40 53 40 216 -69 12 59 31 12 21 43 13 53 29 11 29 3 14 0 0 12 43 12 23 40 45 40 217 -68 13 2 10 12 24 20 13 56 11 11 31 38 15 0 0 12 46 30 23 40 37 39 217 -68 13 5 29 12 27 38 13 59 32 11 34 53 16 0 0 12 50 28 23 40 29 39 218 -67 13 9 28 12 31 34 14 3 34 11 38 47 17 0 0 12 55 6 23 40 21 38 219 -67 13 14 7 12 36 11 14 8 17 11 43 20 18 0 0 13 0 24 23 40 13 37 220 -66 13 19 26 12 41 27 14 13 40 11 48 33 19 0 0 13 6 21 23 40 6 37 220 -66 13 25 25 12 47 23 14 19 44 11 54 24 20 0 0 13 12 59 23 39 58 36 221 -65 13 32 4 12 53 59 14 26 28 12 0 55 21 0 0 13 20 16 23 39 51 35 222 -64 13 39 24 13 1 15 14 33 53 12 8 6 22 0 0 13 28 14 23 39 43 34 222 -64 13 47 23 13 9 10 14 41 59 12 15 56 23 0 0 13 36 52 23 39 36 34 223 -63 13 56 3 13 17 46 14 50 45 12 24 26 24 0 0 13 46 10 23 39 29 33 224 -62 14 5 24 13 27 1 15 0 13 12 33 35 25 0 0 13 56 8 23 39 22 32 224 -61 14 15 25 13 36 57 15 10 21 12 43 24 26 0 0 14 6 47 23 39 16 31 225 -60 14 26 6 13 47 33 15 21 10 12 53 53 27 0 0 14 18 6 23 39 9 31 225 -60 14 37 28 13 58 49 15 32 40 13 5 1 28 0 0 14 30 5 23 39 2 30 226 -59 14 49 30 14 10 46 15 44 52 13 16 49 29 0 0 14 42 45 23 38 56 29 226 -58 15 2 14 14 23 22 15 57 44 13 29 17 30 0 0 14 56 5 23 38 50 28 227 -57 15 15 37 14 36 40 16 11 18 13 42 25 31 0 0 15 10 6 23 38 44 27 227 -56 15 29 42 14 50 37 16 25 33 13 56 13 32 0 0 15 24 48 23 38 38 26 228 -55 15 44 27 15 5 15 16 40 29 14 10 41 33 0 0 15 40 10 23 38 32 25 228 -54 15 59 53 15 20 33 16 56 6 14 25 49 34 0 0 15 56 13 23 38 27 25 229 -54 16 16 0 15 36 32 17 12 25 14 41 37 35 0 0 16 12 56 23 38 21 24 229 -53 16 32 48 15 53 11 17 29 25 14 58 4 36 0 0 16 30 20 23 38 16 23 230 -52 16 50 16 16 10 31 17 47 6 15 15 12 37 0 0 16 48 25 23 38 11 22 230 -51 17 8 25 16 28 31 18 5 29 15 33 0 38 0 0 17 7 10 23 38 6 21 231 -50 17 27 15 16 47 12 18 24 33 15 51 28 39 0 0 17 26 36 23 38 2 20 231 -49 17 46 46 17 6 33 18 44 18 16 10 36 40 0 0 17 46 42 23 37 57 19 231 -48 18 6 58 17 26 34 19 4 44 16 30 23 41 0 0 18 7 29 23 37 53 18 232 -47 18 27 50 17 47 16 19 25 52 16 50 51 42 0 0 18 28 56 23 37 49 17 232 -46 18 49 22 18 8 38 19 47 41 17 11 58 43 0 0 18 51 4 23 37 45 16 233 -45 19 11 36 18 30 40 20 10 10 17 33 45 44 0 0 19 13 52 23 37 41 15 233 -44 19 34 29 18 53 22 20 33 21 17 56 12 45 0 0 19 37 19 23 37 38 14 233 -43 19 58 3 19 16 44 20 57 12 18 19 18 46 0 0 20 1 27 23 37 35 13 234 -42 20 22 17 19 40 45 21 21 44 18 43 3 47 0 0 20 26 14 23 37 32 12 234 -41 20 47 10 20 5 26 21 46 56 19 7 27 48 0 0 20 51 41 23 37 29 11 235 -40 21 12 44 20 30 47 22 12 48 19 32 30 49 0 0 21 17 47 23 37 26 10 235 -39 21 38 56 20 56 46 22 39 20 19 58 12 50 0 0 21 44 32 23 37 24 9 235 -38 22 5 48 21 23 25 23 6 32 20 24 33 51 0 0 22 11 56 23 37 22 8 236 -37 22 33 19 21 50 42 23 34 23 20 51 31 52 0 0 22 39 58 23 37 20 7 236 -36 23 1 28 22 18 37 24 2 53 21 19 7 53 0 0 23 8 38 23 37 19 6 237 -35 23 30 15 22 47 10 24 32 2 21 47 21 54 0 0 23 37 56 23 37 17 5 237 -34 23 59 40 23 16 20 25 1 48 .. .. .. 55 0 0 24 7 51 23 37 16 4 237 -33 24 29 43 23 46 7 25 32 13 .. .. .. 56 0 0 24 38 22 23 37 15 3 238 -32 25 0 22 24 16 31 26 3 14 .. .. .. 57 0 0 25 9 29 23 37 15 2 238 -31 25 31 37 24 47 31 26 34 53 .. .. .. 58 0 0 25 41 12 23 37 14 1 239 -30 26 3 28 25 19 6 27 7 7 .. .. .. 59 0 0 26 13 30 23 37 14 0 239 -28 .. .. .. 25 51 16 .. .. .. .. .. .. Uncertainty in time = +/- 9 secs Prediction of 2012 Aug 7.0 Data for the target star ------------------------ * name: TYC 6947-00520-1 * constellation : Piscis Austrinus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 29 39.6641 DE: -27 36 08.405 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .044, .034 ) * V mag [mag]: 10.5 * B mag [mag]: 11.4 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (493) Griseldis approx. diameter [km]: 51 approx. diameter ["]: .035 distance from Earth [AU]: 2.02600 * orbital information: orbit source: Preston date of fit: 2012 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 852 number of rejected observations: 30 time covered by the observations: 1902 Sep 07 - 2012 Jul 27 1 sigma uncertainty ellipse (major, minor, PA): 0.050, 0.028, 61° remarks: * orbital elements for (493) Griseldis : Mean anomaly = 297.98452196 deg Arg. of pericenter = 47.48523500 deg Long. of node = 357.47583010 deg Inclination = 15.14971297 deg Eccentricity = 0.17216993 Semimajor axis = 3.11959261 AU Perihelion dist = 2.58249256 AU Mag: H = 10.82, G = 0.15 Epoch of elements : MJD 56174.98900000 TDT (2012 Sep 04.989) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 4 493 Griseldis 23h 44.1m UT 10.5 21 29 39.664-27 36 8.41TYC 6947-00520-1 11.4 14.8 51 4.5 2.026 -2.030 6.29 -18.1061 -27.603 -176.35 6.74 23.7352 0.15466 0.66160 -6.22082 1.44856 0.00205 0.00182 2000 297.0920992012 831.00000 47.485235357.475830 15.1497130.17216993 3.1195926 2.582492610.3 5.00.15 RATE 1.7887810 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.066 0.044 74 2.41 0.049 0 0 1 5 056146.0020120904_0520-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 20:11 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org