IOTA/IOTA-ES occultation update for (206) Hersilia / TYC 1386-01569-1 event on 2008 May 07, 11:26 UT Visible from Australia Summary ------- On 2008 May 07 UT, the 95 km diameter asteroid (206) Hersilia will occult a 10.9 mag star in the constellation Cancer for observers along a path across Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.2 mag to 14.0 mag (the magnitude of the asteroid) for at most 4.0 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: 97 * date and approx. time of event: 2008 May 07, 11:27 - 2008 May 07, 11:30 UT * magnitude of target star: 10.9 * magnitude drop [mag]: 3.2 * estimated maximum duration [s]: 4.0 * Moon: 6 % sunlit, 48° distance * Sun: 76° distance * rough path description: Australia The occultation path -------------------- * approximate projected width [km]: 119 * 1 sigma uncertainty interval [path widths]: +/- 0.40 * 1 sigma uncertainty interval [seconds]: +/- 1.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .021 +/- .019) * 1 sigma uncertainty ellipse (major, minor, PA): ( .021", .019", 94° ) * approx speed of asteroid's shadow [km/s]: 23.9945 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1386-01569-1 by 206 Hersilia on 2008 May 7 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 92 0 0 -19 28 36 11 27 47 51 354 -1 -20 2 10 -18 55 17 -20 29 12 -18 28 48 93 0 0 -19 44 7 11 27 52 51 353 -2 -20 17 45 -19 10 44 -20 44 51 -18 44 12 94 0 0 -20 0 3 11 27 56 50 351 -3 -20 33 45 -19 26 36 -21 0 54 -19 0 2 95 0 0 -20 16 24 11 28 1 50 350 -4 -20 50 10 -19 42 53 -21 17 22 -19 16 16 96 0 0 -20 33 9 11 28 5 49 348 -5 -21 6 59 -19 59 35 -21 34 15 -19 32 54 97 0 0 -20 50 18 11 28 9 49 347 -6 -21 24 13 -20 16 40 -21 51 32 -19 49 56 98 0 0 -21 7 51 11 28 14 48 346 -7 -21 41 50 -20 34 9 -22 9 12 -20 7 22 99 0 0 -21 25 47 11 28 18 48 344 -8 -21 59 50 -20 52 1 -22 27 16 -20 25 10 100 0 0 -21 44 6 11 28 22 47 343 -9 -22 18 13 -21 10 15 -22 45 42 -20 43 21 101 0 0 -22 2 47 11 28 26 47 342 -10 -22 36 58 -21 28 52 -23 4 31 -21 1 55 102 0 0 -22 21 50 11 28 31 46 341 -11 -22 56 6 -21 47 51 -23 23 42 -21 20 51 103 0 0 -22 41 15 11 28 35 46 339 -12 -23 15 35 -22 7 11 -23 43 15 -21 40 7 104 0 0 -23 1 0 11 28 39 45 338 -13 -23 35 25 -22 26 52 -24 3 8 -21 59 45 105 0 0 -23 21 6 11 28 43 44 337 -14 -23 55 35 -22 46 54 -24 23 22 -22 19 43 106 0 0 -23 41 32 11 28 47 44 336 -15 -24 16 5 -23 7 15 -24 43 56 -22 40 2 107 0 0 -24 2 17 11 28 51 43 335 -16 -24 36 55 -23 27 56 -25 4 50 -23 0 39 108 0 0 -24 23 22 11 28 55 42 334 -17 -24 58 4 -23 48 56 -25 26 2 -23 21 36 109 0 0 -24 44 44 11 28 59 41 333 -18 -25 19 31 -24 10 15 -25 47 33 -23 42 51 110 0 0 -25 6 25 11 29 2 41 332 -19 -25 41 16 -24 31 51 -26 9 21 -24 4 23 111 0 0 -25 28 22 11 29 6 40 331 -20 -26 3 18 -24 53 44 -26 31 27 -24 26 13 112 0 0 -25 50 37 11 29 10 39 330 -21 -26 25 36 -25 15 54 -26 53 49 -24 48 20 113 0 0 -26 13 7 11 29 13 38 329 -22 -26 48 11 -25 38 20 -27 16 27 -25 10 42 114 0 0 -26 35 52 11 29 17 38 328 -23 -27 11 1 -26 1 1 -27 39 21 -25 33 20 115 0 0 -26 58 53 11 29 20 37 327 -23 -27 34 5 -26 23 57 -28 2 29 -25 56 13 116 0 0 -27 22 7 11 29 24 36 326 -24 -27 57 24 -26 47 7 -28 25 51 -26 19 20 117 0 0 -27 45 35 11 29 27 35 326 -25 -28 20 56 -27 10 31 -28 49 26 -26 42 41 118 0 0 -28 9 15 11 29 30 34 325 -26 -28 44 41 -27 34 8 -29 13 14 -27 6 14 119 0 0 -28 33 8 11 29 33 33 324 -27 -29 8 37 -27 57 56 -29 37 14 -27 29 59 120 0 0 -28 57 12 11 29 37 33 323 -28 -29 32 45 -28 21 56 -30 1 25 -27 53 56 121 0 0 -29 21 26 11 29 40 32 322 -29 -29 57 4 -28 46 7 -30 25 47 -28 18 4 122 0 0 -29 45 51 11 29 42 31 322 -30 -30 21 32 -29 10 28 -30 50 18 -28 42 22 123 0 0 -30 10 24 11 29 45 30 321 -31 -30 46 9 -29 34 58 -31 14 59 -29 6 49 124 0 0 -30 35 7 11 29 48 29 320 -32 -31 10 55 -29 59 36 -31 39 48 -29 31 25 125 0 0 -30 59 56 11 29 51 28 319 -33 -31 35 49 -30 24 23 -32 4 44 -29 56 9 126 0 0 -31 24 53 11 29 53 27 319 -33 -32 0 49 -30 49 16 -32 29 47 -30 21 0 127 0 0 -31 49 56 11 29 56 27 318 -34 -32 25 55 -31 14 16 -32 54 56 -30 45 57 128 0 0 -32 15 5 11 29 58 26 317 -35 -32 51 7 -31 39 22 -33 20 11 -31 11 0 129 0 0 -32 40 18 11 30 1 25 317 -36 -33 16 24 -32 4 32 -33 45 30 -31 36 8 130 0 0 -33 5 36 11 30 3 24 316 -37 -33 41 44 -32 29 47 -34 10 52 -32 1 20 131 0 0 -33 30 56 11 30 5 23 315 -38 -34 7 7 -32 55 5 -34 36 18 -32 26 36 132 0 0 -33 56 20 11 30 7 22 314 -38 -34 32 33 -33 20 25 -35 1 46 -32 51 55 133 0 0 -34 21 44 11 30 9 21 314 -39 -34 58 0 -33 45 47 -35 27 15 -33 17 15 134 0 0 -34 47 10 11 30 11 20 313 -40 -35 23 29 -34 11 11 -35 52 45 -33 42 37 135 0 0 -35 12 36 11 30 13 19 312 -41 -35 48 57 -34 36 35 -36 18 16 -34 7 59 136 0 0 -35 38 2 11 30 15 18 312 -42 -36 14 24 -35 1 58 -36 43 45 -34 33 21 137 0 0 -36 3 26 11 30 16 18 311 -42 -36 39 51 -35 27 21 -37 9 13 -34 58 42 138 0 0 -36 28 48 11 30 18 17 311 -43 -37 5 15 -35 52 42 -37 34 38 -35 24 2 139 0 0 -36 54 8 11 30 19 16 310 -44 -37 30 36 -36 18 0 -38 0 0 -35 49 19 140 0 0 -37 19 24 11 30 21 15 309 -44 -37 55 53 -36 43 15 -38 25 19 -36 14 33 141 0 0 -37 44 37 11 30 22 14 309 -45 -38 21 7 -37 8 26 -38 50 34 -36 39 43 142 0 0 -38 9 44 11 30 23 13 308 -46 -38 46 15 -37 33 32 -39 15 43 -37 4 49 143 0 0 -38 34 46 11 30 24 12 307 -46 -39 11 18 -37 58 34 -39 40 46 -37 29 49 144 0 0 -38 59 42 11 30 25 11 307 -47 -39 36 15 -38 23 29 -40 5 43 -37 54 44 145 0 0 -39 24 31 11 30 26 11 306 -48 -40 1 4 -38 48 17 -40 30 33 -38 19 32 146 0 0 -39 49 13 11 30 27 10 305 -48 -40 25 46 -39 12 59 -40 55 15 -38 44 13 147 0 0 -40 13 46 11 30 28 9 305 -49 -40 50 20 -39 37 32 -41 19 49 -39 8 47 148 0 0 -40 38 11 11 30 29 8 304 -49 -41 14 45 -40 1 57 -41 44 14 -39 33 12 149 0 0 -41 2 27 11 30 29 7 303 -50 -41 39 0 -40 26 13 -42 8 29 -39 57 28 150 0 0 -41 26 33 11 30 30 6 303 -50 -42 3 6 -40 50 20 -42 32 35 -40 21 35 151 0 0 -41 50 29 11 30 31 5 302 -51 -42 27 1 -41 14 16 -42 56 29 -40 45 32 152 0 0 -42 14 13 11 30 31 5 301 -51 -42 50 45 -41 38 2 -43 20 12 -41 9 18 153 0 0 -42 37 47 11 30 31 4 301 -52 -43 14 17 -42 1 36 -43 43 44 -41 32 53 154 0 0 -43 1 8 11 30 32 3 300 -52 -43 37 37 -42 24 59 -44 7 3 -41 56 17 155 0 0 -43 24 17 11 30 32 2 299 -52 -44 0 45 -42 48 9 -44 30 10 -42 19 28 156 0 0 -43 47 14 11 30 32 1 299 -53 -44 23 40 -43 11 7 -44 53 3 -42 42 27 157 0 0 -44 9 57 11 30 32 0 298 -53 -44 46 21 -43 33 51 .. .. .. -43 5 13 Uncertainty in time = +/- 2 secs [Prediction of 2008 Apr 23.0] Data for the target star ------------------------ * name: TYC 1386-01569-1 * constellation : Cancer * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 08 22 35.0731 DE: +19 22 43.347 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .016, .017 ) * V mag [mag]: 10.9 * B mag [mag]: 11.2 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (206) Hersilia approx. diameter [km]: 95 approx. diameter ["]: .048 distance from Earth [AU]: 2.73300 * orbital information: orbit source: Preston date of fit: 2008 Apr 22 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 851 number of rejected observations: 141 time covered by the observations: 1902 Nov 21 - 2008 Apr 17 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.009, 99° remarks: * orbital elements for (206) Hersilia : Mean anomaly = 54.11589583 deg Arg. of pericenter = 301.53404928 deg Long. of node = 145.26702093 deg Inclination = 3.78064223 deg Eccentricity = 0.04081776 Semimajor axis = 2.74047831 AU Perihelion dist = 2.62861814 AU Mag: H = 8.64, G = 0.15 Epoch of elements : MJD 54593.47700000 TDT (2008 May 07.477) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 7 206 Hersilia 11h 27.0m UT 10.9 8 22 35.073 19 22 43.35TYC 1386-01569-1 11.2 14.0 95 4.0 2.733 3.029 -7.93 88.2178 19.380 7.39 16.99 11.4500 -0.11094 -0.59216 13.31719 -2.46383 0.00532 -0.00127 2000 53.3605102008 5 4.00000301.534049145.267021 3.7806420.04081776 2.7404783 2.6286181 8.7 5.00.15 RATE 2.1725230 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.021 0.019 94 1.40 0.019 0 54579.5020080507_1569-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 23, 04:05 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org