IOTA/IOTA-ES occultation update for (584) Semiramis / TYC 1798-00731-1 event on 2008 Feb 03, 11:23 UT Visible from near Australia Summary ------- On 2008 Feb 03 UT, the 54 km diameter asteroid (584) Semiramis will occult a 9.5 mag star in the constellation Aries for observers along a path across near Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.2 mag to 12.6 mag (the magnitude of the asteroid) for at most 3.6 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: 96 * date and approx. time of event: 2008 Feb 03, 11:19 - 2008 Feb 03, 11:26 UT * midpoint of event [JD]: 2454499.97427917 * magnitude of target star: 9.5 * magnitude drop [mag]: 3.2 * estimated maximum duration [s]: 3.6 * Moon: 14 % sunlit, 146° distance * Sun: 102° distance * rough path description: near Australia The occultation path -------------------- * approximate projected width [km]: 98 * 1 sigma uncertainty interval [path widths]: +/- 0.42 * 1 sigma uncertainty interval [seconds]: +/- 1.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .022 +/- .018) * 1 sigma uncertainty ellipse (major, minor, PA): ( .022", .018", 86° ) * approx speed of asteroid's shadow [km/s]: 15.0410 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1798-00731-1 by 584 Semiramis on 2008 Feb 03 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 ' " Longitude Longitude Longitude Longitude ... .. .. -55 0 0 .. .. .. .. .. .. 158 17 44 ... .. .. 157 22 13 ... .. .. 157 36 20 -54 0 0 11 26 51 1 315 -14 156 31 28 158 40 39 155 36 33 ... .. .. 155 49 10 -53 0 0 11 26 50 3 317 -14 154 44 55 156 52 52 153 50 29 ... .. .. 154 1 37 -52 0 0 11 26 49 4 318 -14 152 57 50 155 4 48 152 3 45 ... .. .. 152 13 23 -51 0 0 11 26 47 6 320 -14 151 9 55 153 16 12 150 16 4 154 8 30 150 24 12 -50 0 0 11 26 45 7 321 -14 149 20 54 151 26 48 148 27 9 152 18 53 148 33 46 -49 0 0 11 26 42 9 323 -14 147 30 29 149 36 18 146 36 43 150 28 17 146 41 47 -48 0 0 11 26 39 10 324 -14 145 38 21 147 44 24 144 44 25 148 36 24 144 47 53 -47 0 0 11 26 34 12 326 -14 143 44 8 145 50 45 142 49 52 146 42 56 142 51 42 -46 0 0 11 26 29 14 327 -13 141 47 26 143 55 1 140 52 39 144 47 30 140 52 47 -45 0 0 11 26 24 15 329 -13 139 47 46 141 56 45 138 52 17 142 49 43 138 50 39 -44 0 0 11 26 17 17 330 -13 137 44 38 139 55 30 136 48 12 140 49 8 Latitude Latitude Latitude Latitude 137 0 0 -43 7 11 11 26 11 18 332 -12 -43 38 43 -42 36 10 -44 5 37 -42 10 29 136 0 0 -42 39 12 11 26 7 19 333 -12 -43 10 31 -42 8 23 -43 37 14 -41 42 52 135 0 0 -42 11 42 11 26 3 20 334 -11 -42 42 48 -41 41 4 -43 9 19 -41 15 43 134 0 0 -41 44 41 11 25 59 20 335 -11 -42 15 35 -41 14 15 -42 41 55 -40 49 3 133 0 0 -41 18 10 11 25 55 21 335 -11 -41 48 52 -40 47 56 -42 15 2 -40 22 53 132 0 0 -40 52 10 11 25 50 22 336 -10 -41 22 40 -40 22 7 -41 48 40 -39 57 14 131 0 0 -40 26 42 11 25 46 23 337 -10 -40 57 1 -39 56 51 -41 22 51 -39 32 5 130 0 0 -40 1 47 11 25 41 23 338 -9 -40 31 54 -39 32 6 -40 57 34 -39 7 29 129 0 0 -39 37 25 11 25 37 24 339 -9 -40 7 21 -39 7 54 -40 32 52 -38 43 26 128 0 0 -39 13 37 11 25 32 25 340 -8 -39 43 23 -38 44 16 -40 8 44 -38 19 56 127 0 0 -38 50 23 11 25 27 25 341 -8 -39 19 59 -38 21 12 -39 45 11 -37 57 1 126 0 0 -38 27 44 11 25 22 26 342 -7 -38 57 10 -37 58 43 -39 22 13 -37 34 39 125 0 0 -38 5 41 11 25 17 26 343 -7 -38 34 58 -37 36 50 -38 59 52 -37 12 53 124 0 0 -37 44 15 11 25 11 27 344 -6 -38 13 21 -37 15 32 -38 38 8 -36 51 43 123 0 0 -37 23 25 11 25 6 28 345 -6 -37 52 22 -36 54 51 -38 17 1 -36 31 8 122 0 0 -37 3 12 11 25 0 28 346 -5 -37 32 1 -36 34 46 -37 56 31 -36 11 11 121 0 0 -36 43 36 11 24 55 29 347 -4 -37 12 17 -36 15 19 -37 36 40 -35 51 50 120 0 0 -36 24 39 11 24 49 29 348 -4 -36 53 11 -35 56 30 -37 17 28 -35 33 7 119 0 0 -36 6 20 11 24 43 30 349 -3 -36 34 44 -35 38 18 -36 58 54 -35 15 2 118 0 0 -35 48 40 11 24 37 30 350 -3 -36 16 57 -35 20 46 -36 41 0 -34 57 35 117 0 0 -35 31 39 11 24 31 30 351 -2 -35 59 48 -35 3 52 -36 23 45 -34 40 47 116 0 0 -35 15 18 11 24 25 31 352 -1 -35 43 20 -34 47 37 -36 7 10 -34 24 37 115 0 0 -34 59 36 11 24 19 31 353 -1 -35 27 32 -34 32 1 -35 51 16 -34 9 7 114 0 0 -34 44 34 11 24 13 32 354 0 -35 12 23 -34 17 6 -35 36 3 -33 54 17 113 0 0 -34 30 13 11 24 7 32 355 1 -34 57 56 -34 2 50 -35 21 30 -33 40 6 112 0 0 -34 16 32 11 24 1 32 356 2 -34 44 9 -33 49 15 -35 7 38 -33 26 35 111 0 0 -34 3 32 11 23 55 32 357 2 -34 31 4 -33 36 20 -34 54 28 -33 13 45 110 0 0 -33 51 13 11 23 48 33 358 3 -34 18 40 -33 24 6 -34 41 59 -33 1 35 109 0 0 -33 39 35 11 23 42 33 359 4 -34 6 57 -33 12 33 -34 30 12 -32 50 5 108 0 0 -33 28 38 11 23 36 33 1 5 -33 55 56 -33 1 41 -34 19 7 -32 39 17 107 0 0 -33 18 23 11 23 29 33 2 5 -33 45 36 -32 51 30 -34 8 44 -32 29 9 106 0 0 -33 8 50 11 23 23 33 3 6 -33 35 59 -32 42 1 -33 59 3 -32 19 43 105 0 0 -32 59 58 11 23 16 33 4 7 -33 27 4 -32 33 13 -33 50 4 -32 10 58 104 0 0 -32 51 49 11 23 10 33 5 8 -33 18 50 -32 25 6 -33 41 48 -32 2 54 103 0 0 -32 44 21 11 23 3 33 6 9 -33 11 20 -32 17 42 -33 34 15 -31 55 32 102 0 0 -32 37 35 11 22 57 34 7 9 -33 4 31 -32 10 59 -33 27 24 -31 48 52 101 0 0 -32 31 32 11 22 50 33 9 10 -32 58 25 -32 4 58 -33 21 15 -31 42 53 100 0 0 -32 26 11 11 22 44 33 10 11 -32 53 2 -31 59 39 -33 15 50 -31 37 36 99 0 0 -32 21 32 11 22 38 33 11 12 -32 48 21 -31 55 2 -33 11 8 -31 33 0 98 0 0 -32 17 36 11 22 31 33 12 13 -32 44 23 -31 51 7 -33 7 8 -31 29 7 97 0 0 -32 14 22 11 22 25 33 13 14 -32 41 7 -31 47 55 -33 3 51 -31 25 55 96 0 0 -32 11 50 11 22 18 33 14 14 -32 38 34 -31 45 24 -33 1 17 -31 23 26 95 0 0 -32 10 1 11 22 12 33 15 15 -32 36 44 -31 43 36 -32 59 26 -31 21 38 94 0 0 -32 8 54 11 22 6 33 16 16 -32 35 37 -31 42 29 -32 58 19 -31 20 32 93 0 0 -32 8 29 11 22 0 32 17 17 -32 35 12 -31 42 5 -32 57 54 -31 20 8 92 0 0 -32 8 47 11 21 53 32 18 18 -32 35 30 -31 42 23 -32 58 12 -31 20 26 91 0 0 -32 9 48 11 21 47 32 19 19 -32 36 31 -31 43 23 -32 59 12 -31 21 26 90 0 0 -32 11 30 11 21 41 31 20 20 -32 38 14 -31 45 5 -33 0 56 -31 23 8 89 0 0 -32 13 55 11 21 35 31 22 20 -32 40 40 -31 47 29 -33 3 23 -31 25 31 88 0 0 -32 17 2 11 21 29 31 23 21 -32 43 48 -31 50 35 -33 6 32 -31 28 36 87 0 0 -32 20 52 11 21 23 30 24 22 -32 47 39 -31 54 23 -33 10 24 -31 32 23 86 0 0 -32 25 23 11 21 17 30 25 23 -32 52 12 -31 58 53 -33 14 58 -31 36 51 85 0 0 -32 30 36 11 21 12 29 26 24 -32 57 27 -32 4 5 -33 20 15 -31 42 1 84 0 0 -32 36 32 11 21 6 29 26 25 -33 3 25 -32 9 58 -33 26 15 -31 47 53 83 0 0 -32 43 9 11 21 0 28 27 26 -33 10 4 -32 16 32 -33 32 57 -31 54 25 82 0 0 -32 50 28 11 20 55 28 28 26 -33 17 26 -32 23 48 -33 40 21 -32 1 39 81 0 0 -32 58 28 11 20 49 27 29 27 -33 25 29 -32 31 45 -33 48 27 -32 9 34 80 0 0 -33 7 9 11 20 44 27 30 28 -33 34 14 -32 40 24 -33 57 15 -32 18 9 79 0 0 -33 16 32 11 20 39 26 31 29 -33 43 41 -32 49 43 -34 6 45 -32 27 26 78 0 0 -33 26 36 11 20 34 26 32 30 -33 53 49 -32 59 43 -34 16 56 -32 37 23 77 0 0 -33 37 21 11 20 29 25 33 31 -34 4 38 -33 10 24 -34 27 49 -32 48 0 76 0 0 -33 48 46 11 20 24 24 34 32 -34 16 8 -33 21 45 -34 39 23 -32 59 18 75 0 0 -34 0 52 11 20 19 24 34 32 -34 28 19 -33 33 46 -34 51 38 -33 11 15 74 0 0 -34 13 39 11 20 14 23 35 33 -34 41 10 -33 46 27 -35 4 34 -33 23 52 73 0 0 -34 27 5 11 20 10 23 36 34 -34 54 42 -33 59 48 -35 18 10 -33 37 9 72 0 0 -34 41 11 11 20 5 22 37 35 -35 8 53 -34 13 49 -35 32 27 -33 51 5 71 0 0 -34 55 56 11 20 1 21 38 36 -35 23 45 -34 28 29 -35 47 24 -34 5 40 70 0 0 -35 11 21 11 19 57 20 38 37 -35 39 16 -34 43 47 -36 3 0 -34 20 54 69 0 0 -35 27 25 11 19 53 20 39 37 -35 55 26 -34 59 44 -36 19 16 -34 36 46 68 0 0 -35 44 7 11 19 49 19 40 38 -36 12 15 -35 16 20 -36 36 11 -34 53 16 67 0 0 -36 1 27 11 19 45 18 41 39 -36 29 43 -35 33 33 -36 53 45 -35 10 24 66 0 0 -36 19 25 11 19 42 17 41 40 -36 47 49 -35 51 25 -37 11 57 -35 28 9 65 0 0 -36 38 1 11 19 38 17 42 40 -37 6 32 -36 9 53 -37 30 48 -35 46 31 64 0 0 -36 57 14 11 19 35 16 43 41 -37 25 53 -36 28 58 -37 50 16 -36 5 30 63 0 0 -37 17 4 11 19 32 15 44 42 -37 45 51 -36 48 40 -38 10 21 -36 25 5 62 0 0 -37 37 30 11 19 29 14 44 43 -38 6 26 -37 8 57 -38 31 3 -36 45 16 61 0 0 -37 58 31 11 19 26 13 45 43 -38 27 36 -37 29 50 -38 52 22 -37 6 2 60 0 0 -38 20 8 11 19 24 13 46 44 -38 49 23 -37 51 18 -39 14 16 -37 27 23 59 0 0 -38 42 20 11 19 21 12 46 45 -39 11 44 -38 13 21 -39 36 46 -37 49 18 58 0 0 -39 5 6 11 19 19 11 47 45 -39 34 40 -38 35 57 -39 59 50 -38 11 47 57 0 0 -39 28 25 11 19 17 10 48 46 -39 58 9 -38 59 7 -40 23 29 -38 34 49 56 0 0 -39 52 18 11 19 15 9 48 47 -40 22 12 -39 22 50 -40 47 41 -38 58 23 55 0 0 -40 16 43 11 19 13 8 49 47 -40 46 48 -39 47 4 -41 12 26 -39 22 30 54 0 0 -40 41 40 11 19 11 8 50 48 -41 11 56 -40 11 51 -41 37 44 -39 47 8 53 0 0 -41 7 8 11 19 10 7 50 48 -41 37 35 -40 37 8 -42 3 33 -40 12 16 52 0 0 -41 33 6 11 19 9 6 51 49 -42 3 45 -41 2 55 -42 29 53 -40 37 55 51 0 0 -41 59 34 11 19 7 5 52 49 -42 30 25 -41 29 12 -42 56 43 -41 4 2 50 0 0 -42 26 31 11 19 7 4 52 50 -42 57 34 -41 55 57 -43 24 3 -41 30 38 49 0 0 -42 53 56 11 19 6 3 53 50 -43 25 12 -42 23 10 -43 51 51 .. .. .. 48 0 0 -43 21 48 11 19 5 2 54 51 -43 53 17 -42 50 50 -44 20 8 .. .. .. 47 0 0 -43 50 7 11 19 5 2 55 51 -44 21 48 -43 18 57 -44 48 50 .. .. .. 46 0 0 -44 18 51 11 19 5 1 55 51 -44 50 45 -43 47 28 -45 17 59 .. .. .. 45 0 0 .. .. .. .. .. .. .. .. .. .. .. .. -44 16 24 .. .. .. .. .. .. Data for the target star ------------------------ * name: TYC 1798-00731-1 * constellation : Aries * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 29 20.8546 DE: +23 36 31.527 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .013, .014 ) * V mag [mag]: 9.5 * B mag [mag]: 10.0 * Apparent position with proper motion RA(deg): 52.4597771214 DE(deg): 23.6393551044 * Equation of equinoxes (radians) : 0.000045318900192 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (584) Semiramis approx. diameter [km]: 54 approx. diameter ["]: .044 distance from Earth [AU]: 1.68500 * orbital information: orbit source: Preston date of fit: 2008 Jan 02 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 643 number of rejected observations: 74 time covered by the observations: 1906 Jan 15 - 2007 Dec 12 1 sigma uncertainty ellipse (major, minor, PA): 0.017, 0.012, 84° remarks: * orbital elements for (584) Semiramis : Mean anomaly = 50.89709735 deg Arg. of pericenter = 84.87540032 deg Long. of node = 282.29724348 deg Inclination = 10.72776699 deg Eccentricity = 0.23304457 Semimajor axis = 2.37401664 AU Perihelion dist = 1.82076494 AU Mag: H = 8.52, G = 0.24 Epoch of elements : MJD 54499.47400000 TDT (2008 Feb 03.474) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Feb 03 584 Semiramis 11h 23.0m UT 9.5 3 29 20.855 23 36 31.53TYC 1798-00731-1 10.0 12.6 54 3.6 1.685 3.202 -5.06 -251.427 23.609 12.70 -16.63 11.3827 -.09640 -.82704 8.43390 -0.97076 0.00533 0.00125 2000 48.34432622008 125.00000 84.875400282.297243 10.7277670.233044572.374016641.820764948.715 0.24 RATE 2.6945015 .0000000 .0000000 .0000000 .00000000 .00000000 .00000000 Meas 0.022 0.018 86.3 1.420 0.019 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Jan 04, 01:14 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org