IOTA/IOTA-ES occultation update for (1403) Idelsonia / TYC 6285-03410-1 event on 2012 Sep 25, 13:04 UT Visible from E Russia Summary ------- On 2012 Sep 25 UT, the 26 km diameter asteroid (1403) Idelsonia will occult a 10.6 mag star in the constellation Sagittarius for observers along a path across E Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.8 mag to 14.4 mag (the magnitude of the asteroid) for at most 1.8 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: UCAC. The event at a glimpse ---------------------- * Rank: 45 * date and approx. time of event: 2012 Sep 25, 13:01 - 2012 Sep 25, 13:06 UT * geocentric midpoint of event [JD]: 2456196.04455417 * magnitude of target star: 10.6 * magnitude drop [mag]: 3.8 * estimated maximum duration [s]: 1.8 * Moon: 79 % sunlit, 25° distance * Sun: 100° distance * rough path description: E Russia The occultation path -------------------- * approximate projected width [km]: 73 * 1 sigma uncertainty interval [path widths]: +/- 1.44 * 1 sigma uncertainty interval [seconds]: +/- 3.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .041 +/- .033) * 1 sigma uncertainty ellipse (major, minor, PA): ( .041", .033", 93° ) * approx speed of asteroid's shadow [km/s]: 14.6691 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6285-03410-1 by 1403 Idelsonia on 2012 Sep 25 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 70 31 40 72 0 0 13 1 39 0 167 0 69 25 32 71 38 36 ... .. .. 74 56 35 71 19 25 71 0 0 13 1 40 1 168 -1 70 16 7 72 23 30 ... .. .. 75 32 56 72 11 31 70 0 0 13 1 40 2 169 -1 71 10 41 73 13 7 ... .. .. 76 15 8 73 7 35 69 0 0 13 1 41 3 170 -1 72 8 53 74 7 0 ... .. .. 77 2 36 74 7 19 68 0 0 13 1 43 4 171 -2 73 10 29 75 4 52 70 30 21 77 54 54 75 10 32 67 0 0 13 1 45 6 172 -2 74 15 19 76 6 27 71 39 47 78 51 42 76 17 6 66 0 0 13 1 48 7 173 -3 75 23 16 77 11 36 72 51 44 79 52 46 77 26 56 65 0 0 13 1 51 8 174 -3 76 34 18 78 20 14 74 6 11 80 57 58 78 40 1 64 0 0 13 1 54 9 175 -4 77 48 22 79 32 20 75 23 9 82 7 14 79 56 23 63 0 0 13 1 58 10 176 -4 79 5 33 80 47 54 76 42 43 83 20 33 81 16 7 62 0 0 13 2 3 11 178 -5 80 25 56 82 7 1 78 5 0 84 38 1 82 39 22 61 0 0 13 2 8 12 179 -6 81 49 38 83 29 50 79 30 7 85 59 44 84 6 19 60 0 0 13 2 13 13 181 -7 83 16 51 84 56 33 80 58 17 87 25 58 85 37 14 59 0 0 13 2 20 14 182 -8 84 47 51 86 27 26 82 29 42 88 57 1 87 12 28 58 0 0 13 2 27 15 184 -9 86 22 56 88 2 50 84 4 41 90 33 19 88 52 26 57 0 0 13 2 35 16 185 -10 88 2 34 89 43 15 85 43 35 92 15 25 90 37 44 56 0 0 13 2 43 17 187 -11 89 47 14 91 29 16 87 26 52 94 4 7 92 29 6 55 0 0 13 2 52 17 189 -12 91 37 38 93 21 42 89 15 5 96 0 27 94 27 30 54 0 0 13 3 3 18 191 -14 93 34 41 95 21 37 91 8 58 98 5 49 96 34 15 53 0 0 13 3 14 19 193 -15 95 39 35 97 30 27 93 9 28 100 22 16 Latitude Latitude Latitude Latitude 97 0 0 52 48 20 13 3 16 19 194 -16 52 23 32 53 13 46 51 15 7 54 30 54 98 0 0 52 21 51 13 3 22 19 195 -16 51 57 25 52 46 53 50 49 56 54 2 41 99 0 0 51 56 19 13 3 27 20 196 -17 51 32 13 52 20 58 50 25 38 53 35 31 100 0 0 51 31 44 13 3 33 20 197 -18 51 7 58 51 56 2 50 2 12 53 9 25 101 0 0 51 8 5 13 3 38 20 198 -19 50 44 37 51 32 4 49 39 38 52 44 22 102 0 0 50 45 22 13 3 44 20 199 -19 50 22 11 51 9 2 49 17 57 52 20 20 103 0 0 50 23 35 13 3 49 20 200 -20 50 0 40 50 46 58 48 57 7 51 57 19 104 0 0 50 2 43 13 3 55 20 201 -21 49 40 4 50 25 50 48 37 10 51 35 18 105 0 0 49 42 47 13 4 1 20 202 -22 49 20 22 50 5 39 48 18 5 51 14 17 106 0 0 49 23 46 13 4 6 20 203 -22 49 1 34 49 46 24 47 59 51 50 54 16 107 0 0 49 5 39 13 4 12 20 204 -23 48 43 40 49 28 4 47 42 30 50 35 13 108 0 0 48 48 27 13 4 17 20 205 -24 48 26 40 49 10 40 47 26 0 50 17 9 109 0 0 48 32 10 13 4 23 20 207 -25 48 10 33 48 54 11 47 10 22 50 0 3 110 0 0 48 16 47 13 4 28 20 208 -25 47 55 20 48 38 37 46 55 35 49 43 55 111 0 0 48 2 18 13 4 34 20 209 -26 47 41 1 48 23 58 46 41 40 49 28 44 112 0 0 47 48 43 13 4 39 20 210 -27 47 27 34 48 10 14 46 28 37 49 14 30 113 0 0 47 36 1 13 4 45 20 211 -27 47 15 1 47 57 24 46 16 25 49 1 12 114 0 0 47 24 14 13 4 50 20 212 -28 47 3 21 47 45 28 46 5 4 48 48 51 115 0 0 47 13 19 13 4 55 19 213 -29 46 52 33 47 34 27 45 54 35 48 37 27 116 0 0 47 3 18 13 5 0 19 214 -29 46 42 39 47 24 19 45 44 57 48 26 58 117 0 0 46 54 11 13 5 5 19 215 -30 46 33 37 47 15 5 45 36 9 48 17 25 118 0 0 46 45 56 13 5 10 19 216 -31 46 25 27 47 6 45 45 28 13 48 8 48 119 0 0 46 38 34 13 5 15 18 216 -31 46 18 10 46 59 18 45 21 8 48 1 5 120 0 0 46 32 5 13 5 20 18 217 -32 46 11 45 46 52 45 45 14 54 47 54 19 121 0 0 46 26 29 13 5 25 18 218 -33 46 6 12 46 47 5 45 9 31 47 48 27 122 0 0 46 21 45 13 5 29 17 219 -33 46 1 31 46 42 18 45 4 58 47 43 30 123 0 0 46 17 54 13 5 34 17 220 -34 45 57 43 46 38 24 45 1 16 47 39 27 124 0 0 46 14 55 13 5 38 16 221 -34 45 54 46 46 35 23 44 58 24 47 36 20 125 0 0 46 12 48 13 5 43 16 222 -35 45 52 41 46 33 15 44 56 23 47 34 6 126 0 0 46 11 34 13 5 47 16 223 -35 45 51 27 46 31 59 44 55 13 47 32 47 127 0 0 46 11 11 13 5 51 15 224 -36 45 51 5 46 31 36 44 54 52 47 32 23 128 0 0 46 11 41 13 5 55 15 225 -36 45 51 35 46 32 6 44 55 22 47 32 52 129 0 0 46 13 3 13 5 58 14 225 -37 45 52 56 46 33 28 44 56 42 47 34 16 130 0 0 46 15 16 13 6 2 14 226 -37 45 55 9 46 35 43 44 58 53 47 36 33 131 0 0 46 18 21 13 6 6 13 227 -38 45 58 13 46 38 49 45 1 53 47 39 44 132 0 0 46 22 18 13 6 9 12 228 -38 46 2 8 46 42 48 45 5 43 47 43 50 133 0 0 46 27 7 13 6 12 12 229 -38 46 6 54 46 47 39 45 10 23 47 48 49 134 0 0 46 32 47 13 6 15 11 230 -39 46 12 31 46 53 23 45 15 53 47 54 42 135 0 0 46 39 19 13 6 18 11 230 -39 46 19 0 46 59 58 45 22 12 48 1 29 136 0 0 46 46 42 13 6 21 10 231 -39 46 26 19 47 7 25 45 29 21 48 9 9 137 0 0 46 54 57 13 6 23 9 232 -40 46 34 30 47 15 45 45 37 20 48 17 44 138 0 0 47 4 3 13 6 26 9 233 -40 46 43 31 47 24 56 45 46 8 48 27 12 139 0 0 47 14 1 13 6 28 8 234 -40 46 53 23 47 35 0 45 55 46 48 37 34 140 0 0 47 24 50 13 6 30 7 234 -40 47 4 6 47 45 55 46 6 13 48 48 50 141 0 0 47 36 30 13 6 32 7 235 -40 47 15 39 47 57 43 46 17 29 49 1 0 142 0 0 47 49 2 13 6 34 6 236 -41 47 28 4 48 10 22 46 29 34 49 14 4 143 0 0 48 2 25 13 6 35 5 237 -41 47 41 19 48 23 53 46 42 29 49 28 2 144 0 0 48 16 39 13 6 37 5 237 -41 47 55 25 48 38 17 46 56 12 49 42 54 145 0 0 48 31 45 13 6 38 4 238 -41 48 10 22 48 53 32 .. .. .. 49 58 41 146 0 0 48 47 42 13 6 39 3 239 -41 48 26 9 49 9 40 .. .. .. 50 15 23 147 0 0 49 4 31 13 6 40 3 240 -41 48 42 47 49 26 40 .. .. .. 50 32 59 148 0 0 49 22 11 13 6 40 2 240 -41 49 0 16 49 44 32 .. .. .. 50 51 30 149 0 0 49 40 43 13 6 41 1 241 -40 49 18 36 50 3 17 .. .. .. 51 10 57 150 0 0 50 0 7 13 6 41 0 242 -40 49 37 46 50 22 54 .. .. .. .. .. .. Uncertainty in time = +/- 3 secs Prediction of 2012 Sep 8.0 Data for the target star ------------------------ * name: TYC 6285-03410-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 54 49.3774 DE: -17 21 13.667 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .030, .026 ) * V mag [mag]: 10.6 * B mag [mag]: 12.4 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1403) Idelsonia approx. diameter [km]: 26 approx. diameter ["]: .023 distance from Earth [AU]: 1.58600 * orbital information: orbit source: Preston date of fit: 2012 Sep 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1054 number of rejected observations: 21 time covered by the observations: 1936 Aug 17 - 2012 Aug 30 1 sigma uncertainty ellipse (major, minor, PA): 0.028, 0.020, 97° remarks: * orbital elements for (1403) Idelsonia : Mean anomaly = 339.75685147 deg Arg. of pericenter = 192.16400355 deg Long. of node = 157.10589714 deg Inclination = 10.14478309 deg Eccentricity = 0.29006431 Semimajor axis = 2.72027280 AU Perihelion dist = 1.93121874 AU Mag: H = 11.51, G = 0.15 Epoch of elements : MJD 56195.54500000 TDT (2012 Sep 25.545) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 25 1403 Idelsonia 13h 4.2m UT 10.6 18 54 49.377-17 21 13.67TYC 6285-03410-1 12.4 14.4 26 1.8 1.586 3.080 -12.79 82.9118 -17.349 -18.16 -1.14 13.0693 0.26079 0.89819 7.95146 -2.30801 0.00515 0.00040 2000 338.5387402012 920.00000192.164004157.105897 10.1447830.29006431 2.7202728 1.931218710.6 5.00.15 RATE 2.1967740 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.041 0.033 93 2.44 0.032 0 0 4 3 056178.0020120925_3410-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Sep 07, 23:09 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org