IOTA/IOTA-ES occultation update for (2259) Sofievka / HIP 40113 event on 2008 May 12, 12:58 UT Visible from W Australia Summary ------- On 2008 May 12 UT, the 21 km diameter asteroid (2259) Sofievka will occult a 8.6 mag star in the constellation Cancer for observers along a path across W Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 9.4 mag to 18.0 mag (the magnitude of the asteroid) for at most 0.8 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: . The event at a glimpse ---------------------- * Rank: 21 * date and approx. time of event: 2008 May 12, 13:00 - 2008 May 12, 13:02 UT * midpoint of event [JD]: 2454599.04079167 * magnitude of target star: 8.6 * magnitude drop [mag]: 9.4 * estimated maximum duration [s]: 0.8 * Moon: 54 % sunlit, 26° distance * Sun: 69° distance * rough path description: W Australia The occultation path -------------------- * approximate projected width [km]: 24 * 1 sigma uncertainty interval [path widths]: +/- 3.18 * 1 sigma uncertainty interval [seconds]: +/- 3.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .039 +/- .032) * 1 sigma uncertainty ellipse (major, minor, PA): ( .040", .032", 102° ) * approx speed of asteroid's shadow [km/s]: 25.0319 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 40113 by 2259 Sofievka on 2008 May 12 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 69 0 0 -16 49 17 13 0 2 54 341 -1 -16 56 11 -16 42 23 -17 40 15 -15 58 45 70 0 0 -17 8 20 13 0 7 54 339 -2 -17 15 15 -17 1 26 -17 59 24 -16 17 44 71 0 0 -17 27 41 13 0 11 53 338 -3 -17 34 36 -17 20 46 -18 18 49 -16 37 0 72 0 0 -17 47 19 13 0 15 52 337 -4 -17 54 15 -17 40 23 -18 38 32 -16 56 33 73 0 0 -18 7 13 13 0 19 52 335 -5 -18 14 9 -18 0 17 -18 58 31 -17 16 22 74 0 0 -18 27 23 13 0 23 51 334 -6 -18 34 20 -18 20 26 -19 18 46 -17 36 27 75 0 0 -18 47 48 13 0 27 50 333 -7 -18 54 46 -18 40 51 -19 39 16 -17 56 48 76 0 0 -19 8 28 13 0 31 50 332 -8 -19 15 27 -19 1 30 -20 0 1 -18 17 23 77 0 0 -19 29 23 13 0 35 49 331 -9 -19 36 22 -19 22 24 -20 21 0 -18 38 13 78 0 0 -19 50 31 13 0 39 48 329 -10 -19 57 31 -19 43 32 -20 42 13 -18 59 17 79 0 0 -20 11 52 13 0 43 47 328 -11 -20 18 53 -20 4 52 -21 3 39 -19 20 34 80 0 0 -20 33 26 13 0 47 46 327 -12 -20 40 27 -20 26 26 -21 25 17 -19 42 4 81 0 0 -20 55 13 13 0 50 46 326 -13 -21 2 14 -20 48 12 -21 47 8 -20 3 46 82 0 0 -21 17 11 13 0 54 45 325 -14 -21 24 13 -21 10 9 -22 9 10 -20 25 39 83 0 0 -21 39 20 13 0 58 44 325 -15 -21 46 22 -21 32 17 -22 31 23 -20 47 44 84 0 0 -22 1 39 13 1 1 43 324 -16 -22 8 42 -21 54 36 -22 53 47 -21 9 59 85 0 0 -22 24 8 13 1 5 42 323 -17 -22 31 12 -22 17 4 -23 16 20 -21 32 24 86 0 0 -22 46 46 13 1 8 41 322 -18 -22 53 50 -22 39 42 -23 39 2 -21 54 59 87 0 0 -23 9 33 13 1 12 40 321 -19 -23 16 37 -23 2 28 -24 1 52 -22 17 42 88 0 0 -23 32 27 13 1 15 40 320 -20 -23 39 33 -23 25 22 -24 24 50 -22 40 33 89 0 0 -23 55 29 13 1 18 39 320 -21 -24 2 35 -23 48 24 -24 47 56 -23 3 31 90 0 0 -24 18 38 13 1 21 38 319 -22 -24 25 44 -24 11 32 -25 11 8 -23 26 37 91 0 0 -24 41 52 13 1 24 37 318 -23 -24 48 59 -24 34 46 -25 34 26 -23 49 48 92 0 0 -25 5 13 13 1 27 36 317 -24 -25 12 20 -24 58 6 -25 57 49 -24 13 5 93 0 0 -25 28 37 13 1 30 35 317 -25 -25 35 45 -25 21 30 -26 21 17 -24 36 27 94 0 0 -25 52 6 13 1 33 34 316 -26 -25 59 14 -25 44 59 -26 44 48 -24 59 54 95 0 0 -26 15 39 13 1 36 33 315 -27 -26 22 47 -26 8 31 -27 8 23 -25 23 24 96 0 0 -26 39 14 13 1 39 32 314 -28 -26 46 23 -26 32 6 -27 32 1 -25 46 57 97 0 0 -27 2 52 13 1 41 31 314 -28 -27 10 0 -26 55 43 -27 55 41 -26 10 32 98 0 0 -27 26 31 13 1 44 30 313 -29 -27 33 40 -27 19 22 -28 19 22 -26 34 9 99 0 0 -27 50 11 13 1 47 30 313 -30 -27 57 20 -27 43 2 -28 43 4 -26 57 47 100 0 0 -28 13 51 13 1 49 29 312 -31 -28 21 0 -28 6 42 -29 6 46 -27 21 26 101 0 0 -28 37 31 13 1 51 28 311 -32 -28 44 40 -28 30 21 -29 30 27 -27 45 4 102 0 0 -29 1 10 13 1 54 27 311 -33 -29 8 20 -28 54 0 -29 54 7 -28 8 42 103 0 0 -29 24 47 13 1 56 26 310 -34 -29 31 57 -29 17 37 -30 17 46 -28 32 18 104 0 0 -29 48 22 13 1 58 25 309 -35 -29 55 32 -29 41 12 -30 41 22 -28 55 52 105 0 0 -30 11 54 13 2 0 24 309 -36 -30 19 5 -30 4 45 -31 4 55 -29 19 24 106 0 0 -30 35 23 13 2 2 23 308 -37 -30 42 34 -30 28 14 -31 28 25 -29 42 52 107 0 0 -30 58 48 13 2 4 22 308 -38 -31 5 59 -30 51 38 -31 51 50 -30 6 17 108 0 0 -31 22 9 13 2 5 21 307 -38 -31 29 19 -31 14 59 -32 15 10 -30 29 37 109 0 0 -31 45 24 13 2 7 20 306 -39 -31 52 34 -31 38 14 -32 38 26 -30 52 52 110 0 0 -32 8 33 13 2 9 19 306 -40 -32 15 44 -32 1 23 -33 1 35 -31 16 2 111 0 0 -32 31 37 13 2 10 18 305 -41 -32 38 47 -32 24 27 -33 24 38 -31 39 5 112 0 0 -32 54 33 13 2 12 18 305 -42 -33 1 43 -32 47 23 -33 47 34 -32 2 2 113 0 0 -33 17 22 13 2 13 17 304 -43 -33 24 32 -33 10 12 -34 10 22 -32 24 52 114 0 0 -33 40 3 13 2 14 16 303 -43 -33 47 13 -33 32 54 -34 33 2 -32 47 34 115 0 0 -34 2 36 13 2 16 15 303 -44 -34 9 46 -33 55 27 -34 55 34 -33 10 8 116 0 0 -34 25 0 13 2 17 14 302 -45 -34 32 10 -34 17 51 -35 17 56 -33 32 34 117 0 0 -34 47 15 13 2 18 13 302 -46 -34 54 24 -34 40 6 -35 40 9 -33 54 50 118 0 0 -35 9 20 13 2 19 12 301 -46 -35 16 29 -35 2 11 -36 2 13 -34 16 57 119 0 0 -35 31 14 13 2 20 11 300 -47 -35 38 23 -35 24 6 -36 24 5 -34 38 53 120 0 0 -35 52 58 13 2 21 10 300 -48 -36 0 7 -35 45 50 -36 45 47 -35 0 39 121 0 0 -36 14 31 13 2 21 9 299 -49 -36 21 40 -36 7 23 -37 7 18 -35 22 14 122 0 0 -36 35 53 13 2 22 9 299 -49 -36 43 1 -36 28 45 -37 28 37 -35 43 38 123 0 0 -36 57 2 13 2 23 8 298 -50 -37 4 10 -36 49 55 -37 49 44 -36 4 50 124 0 0 -37 18 0 13 2 23 7 297 -51 -37 25 7 -37 10 53 -38 10 38 -36 25 50 125 0 0 -37 38 44 13 2 24 6 297 -51 -37 45 51 -37 31 38 -38 31 20 -36 46 38 126 0 0 -37 59 16 13 2 24 5 296 -52 -38 6 23 -37 52 10 -38 51 49 -37 7 12 127 0 0 -38 19 34 13 2 25 4 295 -52 -38 26 40 -38 12 29 -39 12 4 -37 27 34 128 0 0 -38 39 39 13 2 25 3 295 -53 -38 46 45 -38 32 34 -39 32 5 .. .. .. 129 0 0 -38 59 30 13 2 25 3 294 -54 -39 6 35 -38 52 25 -39 51 53 .. .. .. 130 0 0 -39 19 7 13 2 25 2 294 -54 -39 26 11 -39 12 2 -40 11 26 .. .. .. 131 0 0 -39 38 29 13 2 25 1 293 -55 -39 45 33 -39 31 25 -40 30 44 .. .. .. 132 0 0 -39 57 36 13 2 25 0 292 -55 .. .. .. -39 50 33 .. .. .. .. .. .. Uncertainty in time = +/- 3 secs [Prediction of 2008 Mar 31.0] Data for the target star ------------------------ * name: HIP 40113 * constellation : Cancer * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 08 11 35.2416 DE: +16 59 52.402 * position source: mpos:HIP pm:HIP plx:HIP * standard error: RA,DE ["]: ( .022, .015 ) * V mag [mag]: 8.6 * B mag [mag]: 9.7 * Apparent position with proper motion RA(deg): 123.0168355058 DE(deg): 16.9738547936 * Equation of equinoxes (radians) : 0.000041193838476 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2259) Sofievka approx. diameter [km]: 21 approx. diameter ["]: .010 distance from Earth [AU]: 2.82100 * orbital information: orbit source: Preston date of fit: 2008 Mar 28 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 822 number of rejected observations: 18 time covered by the observations: 1929 May 12 - 2008 Jan 19 1 sigma uncertainty ellipse (major, minor, PA): 0.033, 0.028, 107° remarks: * orbital elements for (2259) Sofievka : Mean anomaly = 222.36481586 deg Arg. of pericenter = 11.84583756 deg Long. of node = 280.41728348 deg Inclination = 4.68789912 deg Eccentricity = 0.18632001 Semimajor axis = 2.29374909 AU Perihelion dist = 1.86637773 AU Mag: H = 12.42, G = 0.15 Epoch of elements : MJD 54598.54100000 TDT (2008 May 12.541) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 12 2259 Sofievka 12h 58.7m UT 8.6 8 11 35.242 16 59 52.40HIP 40113 9.7 18.0 21 0.8 2.821 3.001 -9.36 57.5415 17.000 -15.59 18.31 12.9790 -0.10516 -0.48383 13.80640 -3.00063 0.00505 -0.00122 2000 219.9415902008 5 4.00000 11.845838280.417283 4.6878990.18632001 2.2937491 1.866377712.6 5.00.15 RATE 2.8371690 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.040 0.032 102 4.18 0.032 0 54556.5020080512__40113 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 31, 04:42 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org