IOTA/IOTA-ES occultation update for (590) Tomyris / TYC 6955-00767-1 event on 2012 Sep 10, 13:58 UT Visible from Japan, China, India Summary ------- On 2012 Sep 10 UT, the 37 km diameter asteroid (590) Tomyris will occult a 12.0 mag star in the constellation Aquarius for observers along a path across Japan, China, India. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.6 mag to 14.5 mag (the magnitude of the asteroid) for at most 3.3 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: 29 * date and approx. time of event: 2012 Sep 10, 13:56 - 2012 Sep 10, 14:07 UT * geocentric midpoint of event [JD]: 2456181.08450833 * magnitude of target star: 12.0 * magnitude drop [mag]: 2.6 * estimated maximum duration [s]: 3.3 * Moon: 32 % sunlit, 130° distance * Sun: 156° distance * rough path description: Japan, China, India The occultation path -------------------- * approximate projected width [km]: 61 * 1 sigma uncertainty interval [path widths]: +/- 2.29 * 1 sigma uncertainty interval [seconds]: +/- 5.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .045 +/- .056) * 1 sigma uncertainty ellipse (major, minor, PA): ( .056", .045", 359° ) * approx speed of asteroid's shadow [km/s]: 11.2471 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6955-00767-1 by 590 Tomyris on 2012 Sep 10 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 166 46 11 63 0 0 13 56 0 0 209 -21 166 4 19 ... .. .. 162 51 0 ... .. .. 165 35 25 62 0 0 13 56 0 1 208 -22 164 54 43 166 16 1 161 46 43 ... .. .. 164 25 30 61 0 0 13 56 0 2 207 -24 163 45 52 165 5 1 160 42 43 ... .. .. 163 16 15 60 0 0 13 56 1 3 206 -25 162 37 35 163 54 47 159 38 52 ... .. .. 162 7 30 59 0 0 13 56 3 5 205 -26 161 29 44 162 45 8 158 35 4 ... .. .. 160 59 7 58 0 0 13 56 4 6 204 -27 160 22 10 161 35 57 157 31 11 ... .. .. 159 50 59 57 0 0 13 56 6 7 203 -28 159 14 46 160 27 4 156 27 10 ... .. .. 158 42 58 56 0 0 13 56 9 8 202 -29 158 7 26 159 18 22 155 22 53 161 58 58 157 34 57 55 0 0 13 56 12 9 201 -30 157 0 2 158 9 44 154 18 16 160 47 27 156 26 50 54 0 0 13 56 15 10 200 -31 155 52 28 157 1 3 153 13 13 159 36 10 155 18 30 53 0 0 13 56 19 12 199 -32 154 44 39 155 52 13 152 7 40 158 24 58 154 9 52 52 0 0 13 56 23 13 198 -33 153 36 28 154 43 8 151 1 31 157 13 45 153 0 50 51 0 0 13 56 27 14 197 -34 152 27 50 153 33 41 149 54 41 156 2 23 151 51 18 50 0 0 13 56 32 15 196 -35 151 18 40 152 23 48 148 47 5 154 50 48 150 41 11 49 0 0 13 56 38 16 195 -36 150 8 51 151 13 22 147 38 38 153 38 52 149 30 22 48 0 0 13 56 44 17 194 -37 148 58 18 150 2 16 146 29 14 152 26 29 148 18 45 47 0 0 13 56 50 19 193 -38 147 46 55 148 50 26 145 18 48 151 13 33 147 6 15 46 0 0 13 56 57 20 192 -39 146 34 35 147 37 45 144 7 12 149 59 57 145 52 45 45 0 0 13 57 4 21 191 -40 145 21 13 146 24 6 142 54 22 148 45 35 144 38 8 44 0 0 13 57 12 22 190 -41 144 6 42 145 9 24 141 40 9 147 30 21 143 22 18 43 0 0 13 57 21 23 188 -42 142 50 54 143 53 30 140 24 27 146 14 8 142 5 6 42 0 0 13 57 29 24 187 -43 141 33 41 142 36 18 139 7 6 144 56 48 140 46 24 41 0 0 13 57 39 25 186 -44 140 14 56 141 17 38 137 47 58 143 38 13 139 26 3 40 0 0 13 57 49 26 185 -44 138 54 30 139 57 24 136 26 53 142 18 16 138 3 54 39 0 0 13 57 59 27 183 -45 137 32 11 138 35 24 135 3 39 140 56 48 136 39 46 38 0 0 13 58 11 28 182 -46 136 7 49 137 11 27 133 38 4 139 33 39 135 13 25 37 0 0 13 58 22 30 181 -46 134 41 11 135 45 23 132 9 53 138 8 38 133 44 39 36 0 0 13 58 35 31 179 -47 133 12 4 134 16 58 130 38 49 136 41 33 132 13 12 35 0 0 13 58 48 31 177 -47 131 40 9 132 45 56 129 4 32 135 12 12 130 38 44 34 0 0 13 59 2 32 176 -48 130 5 9 131 11 59 127 26 40 133 40 18 129 0 55 33 0 0 13 59 16 33 174 -48 128 26 41 129 34 47 125 44 44 132 5 35 127 19 19 32 0 0 13 59 32 34 172 -48 126 44 17 127 53 55 123 58 11 130 27 42 125 33 25 31 0 0 13 59 48 35 170 -48 124 57 27 126 8 55 122 6 18 128 46 16 123 42 35 30 0 0 14 0 5 36 168 -48 123 5 29 124 19 10 120 8 12 127 0 48 121 46 3 29 0 0 14 0 23 36 166 -47 121 7 34 122 23 57 118 2 45 125 10 44 119 42 49 28 0 0 14 0 43 37 163 -47 119 2 38 120 22 19 115 48 23 123 15 22 Latitude Latitude Latitude Latitude 118 0 0 27 12 40 14 0 59 37 161 -46 27 31 19 26 54 10 28 58 44 25 31 14 117 0 0 26 46 11 14 1 8 37 160 -46 27 4 42 26 27 50 28 31 26 25 5 28 116 0 0 26 20 33 14 1 18 37 159 -46 26 38 56 26 2 19 28 5 1 24 40 31 115 0 0 25 55 46 14 1 27 37 158 -45 26 14 1 25 37 39 27 39 29 24 16 23 114 0 0 25 31 49 14 1 37 37 157 -45 25 49 56 25 13 49 27 14 49 23 53 3 113 0 0 25 8 42 14 1 46 37 156 -44 25 26 43 24 50 49 26 51 1 23 30 33 112 0 0 24 46 26 14 1 55 37 155 -44 25 4 20 24 28 40 26 28 6 23 8 51 111 0 0 24 25 0 14 2 5 37 153 -43 24 42 48 24 7 20 26 6 3 22 47 58 110 0 0 24 4 25 14 2 14 37 152 -43 24 22 7 23 46 51 25 44 53 22 27 54 109 0 0 23 44 40 14 2 23 37 151 -42 24 2 16 23 27 11 25 24 34 22 8 38 108 0 0 23 25 45 14 2 32 37 150 -42 23 43 16 23 8 21 25 5 8 21 50 11 107 0 0 23 7 40 14 2 42 37 149 -41 23 25 6 22 50 22 24 46 33 21 32 33 106 0 0 22 50 25 14 2 51 36 148 -40 23 7 46 22 33 12 24 28 50 21 15 44 105 0 0 22 34 1 14 3 0 36 147 -40 22 51 17 22 16 51 24 11 58 20 59 43 104 0 0 22 18 26 14 3 9 36 146 -39 22 35 38 22 1 21 23 55 58 20 44 31 103 0 0 22 3 41 14 3 17 36 145 -38 22 20 49 21 46 40 23 40 50 20 30 7 102 0 0 21 49 46 14 3 26 35 144 -38 22 6 51 21 32 49 23 26 33 20 16 32 101 0 0 21 36 41 14 3 35 35 143 -37 21 53 42 21 19 47 23 13 8 20 3 45 100 0 0 21 24 26 14 3 43 35 142 -36 21 41 24 21 7 35 23 0 33 19 51 47 99 0 0 21 13 1 14 3 52 34 141 -35 21 29 55 20 56 13 22 48 50 19 40 37 98 0 0 21 2 25 14 4 0 34 140 -35 21 19 17 20 45 40 22 37 59 19 30 16 97 0 0 20 52 39 14 4 8 33 140 -34 21 9 28 20 35 56 22 27 58 19 20 43 96 0 0 20 43 43 14 4 17 33 139 -33 21 0 30 20 27 2 22 18 49 19 11 59 95 0 0 20 35 36 14 4 25 32 138 -32 20 52 21 20 18 58 22 10 31 19 4 3 94 0 0 20 28 20 14 4 32 32 137 -31 20 45 3 20 11 43 22 3 3 18 56 55 93 0 0 20 21 53 14 4 40 31 136 -31 20 38 34 20 5 17 21 56 28 18 50 36 92 0 0 20 16 15 14 4 48 31 136 -30 20 32 56 19 59 41 21 50 43 18 45 6 91 0 0 20 11 28 14 4 55 30 135 -29 20 28 7 19 54 55 21 45 49 18 40 24 90 0 0 20 7 30 14 5 3 29 134 -28 20 24 9 19 50 58 21 41 47 18 36 30 89 0 0 20 4 23 14 5 10 29 133 -27 20 21 0 19 47 51 21 38 36 18 33 26 88 0 0 20 2 5 14 5 17 28 133 -26 20 18 42 19 45 33 21 36 16 18 31 10 87 0 0 20 0 37 14 5 24 28 132 -25 20 17 14 19 44 6 21 34 47 18 29 42 86 0 0 19 59 59 14 5 31 27 131 -25 20 16 37 19 43 28 21 34 11 18 29 4 85 0 0 20 0 12 14 5 38 26 131 -24 20 16 50 19 43 40 21 34 25 18 29 15 84 0 0 20 1 15 14 5 44 25 130 -23 20 17 53 19 44 43 21 35 32 18 30 14 83 0 0 20 3 8 14 5 50 25 130 -22 20 19 48 19 46 35 21 37 30 18 32 3 82 0 0 20 5 52 14 5 57 24 129 -21 20 22 32 19 49 18 21 40 20 18 34 41 81 0 0 20 9 26 14 6 3 23 128 -20 20 26 8 19 52 51 21 44 2 18 38 9 80 0 0 20 13 52 14 6 8 22 128 -19 20 30 35 19 57 15 21 48 37 18 42 26 79 0 0 20 19 8 14 6 14 22 127 -18 20 35 53 20 2 29 21 54 4 18 47 33 78 0 0 20 25 16 14 6 20 21 127 -17 20 42 3 20 8 35 22 0 23 18 53 30 77 0 0 20 32 14 14 6 25 20 126 -16 20 49 4 20 15 31 22 7 36 19 0 16 76 0 0 20 40 5 14 6 30 19 126 -15 20 56 57 20 23 19 22 15 41 19 7 53 75 0 0 20 48 47 14 6 35 18 125 -15 21 5 42 20 31 58 22 24 40 19 16 20 74 0 0 20 58 21 14 6 40 18 125 -14 21 15 19 20 41 29 22 34 32 19 25 38 73 0 0 21 8 47 14 6 44 17 124 -13 21 25 48 20 51 52 22 45 17 19 35 46 72 0 0 21 20 5 14 6 48 16 124 -12 21 37 10 21 3 7 22 56 57 19 46 45 71 0 0 21 32 16 14 6 52 15 123 -11 21 49 25 21 15 14 23 9 31 19 58 36 70 0 0 21 45 20 14 6 56 14 123 -10 22 2 33 21 28 13 23 22 59 20 11 18 69 0 0 21 59 16 14 7 0 13 123 -9 22 16 34 21 42 6 23 37 22 20 24 51 68 0 0 22 14 7 14 7 3 12 122 -8 22 31 29 21 56 51 23 52 40 20 39 16 67 0 0 22 29 50 14 7 6 11 122 -7 22 47 18 22 12 30 24 8 54 20 54 34 66 0 0 22 46 28 14 7 9 11 121 -6 23 4 1 22 29 2 24 26 3 21 10 43 65 0 0 23 3 59 14 7 12 10 121 -5 23 21 38 22 46 28 24 44 8 21 27 45 64 0 0 23 22 25 14 7 15 9 120 -4 23 40 10 23 4 48 25 3 9 21 45 40 63 0 0 23 41 46 14 7 17 8 120 -3 23 59 37 23 24 3 25 23 7 22 4 28 62 0 0 24 2 1 14 7 19 7 120 -2 24 19 59 23 44 12 25 44 1 .. .. .. 61 0 0 24 23 12 14 7 20 6 119 -1 24 41 17 24 5 16 26 5 53 .. .. .. 60 0 0 24 45 18 14 7 22 5 119 0 25 3 30 24 27 14 26 28 43 .. .. .. Uncertainty in time = +/- 8 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 6955-00767-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 22 16 37.4281 DE: -23 41 58.068 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .034, .054 ) * V mag [mag]: 12.0 * B mag [mag]: 12.6 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (590) Tomyris approx. diameter [km]: 37 approx. diameter ["]: .024 distance from Earth [AU]: 2.12500 * orbital information: orbit source: Preston date of fit: 2012 Aug 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 837 number of rejected observations: 44 time covered by the observations: 1906 Mar 05 - 2012 Aug 06 1 sigma uncertainty ellipse (major, minor, PA): 0.030, 0.017, 78° remarks: * orbital elements for (590) Tomyris : Mean anomaly = 255.68765461 deg Arg. of pericenter = 341.32966119 deg Long. of node = 106.20111732 deg Inclination = 11.18042577 deg Eccentricity = 0.07893791 Semimajor axis = 2.99811260 AU Perihelion dist = 2.76144785 AU Mag: H = 9.93, G = 0.15 Epoch of elements : MJD 56180.58200000 TDT (2012 Sep 10.582) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 10 590 Tomyris 14h 1.7m UT 12.0 22 16 37.428-23 41 58.07TYC 6955-00767-1 12.6 14.5 37 3.3 2.125 -1.754 -10.42 133.7232 -23.696 -31.22 4.64 14.0282 -0.31566 0.72930 -5.82593 -2.52154 0.00144 0.00179 2000 255.5771572012 910.00000341.329661106.201117 11.1804260.07893791 2.9981126 2.7614479 9.9 5.00.15 RATE 1.8985940 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.056 0.045 359 3.29 0.055 0 0 1 2 056165.0020120910_0767-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 25, 22:39 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org