IOTA/IOTA-ES occultation update for (1761) Edmondson / TYC 1895-01769-1 event on 2012 Oct 19, 16:17 UT Visible from E Australia Summary ------- On 2012 Oct 19 UT, the 22 km diameter asteroid (1761) Edmondson will occult a 9.3 mag star in the constellation Gemini for observers along a path across E Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.9 mag to 16.2 mag (the magnitude of the asteroid) for at most 1.6 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 24 * date and approx. time of event: 2012 Oct 19, 16:11 - 2012 Oct 19, 16:17 UT * geocentric midpoint of event [JD]: 2456220.17860833 * magnitude of target star: 9.3 * magnitude drop [mag]: 6.9 * estimated maximum duration [s]: 1.6 * Moon: 24 % sunlit, 159° distance * Sun: 101° distance * rough path description: E Australia The occultation path -------------------- * approximate projected width [km]: 30 * 1 sigma uncertainty interval [path widths]: +/- 2.76 * 1 sigma uncertainty interval [seconds]: +/- 5.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .054 +/- .039) * 1 sigma uncertainty ellipse (major, minor, PA): ( .054", .039", 93° ) * approx speed of asteroid's shadow [km/s]: 13.3642 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1895-01769-1 by 1761 Edmondson on 2012 Oct 19 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 125 0 0 -37 34 29 16 11 28 1 60 -41 -37 43 54 -37 25 6 -38 36 22 .. .. .. 126 0 0 -37 7 45 16 11 29 1 60 -41 -37 17 9 -36 58 24 -38 9 28 .. .. .. 127 0 0 -36 41 9 16 11 29 2 59 -41 -36 50 31 -36 31 49 -37 42 43 .. .. .. 128 0 0 -36 14 41 16 11 29 3 59 -42 -36 24 2 -36 5 23 -37 16 6 .. .. .. 129 0 0 -35 48 23 16 11 30 4 58 -42 -35 57 42 -35 39 6 -36 49 38 .. .. .. 130 0 0 -35 22 15 16 11 31 5 57 -42 -35 31 33 -35 13 0 -36 23 20 -34 22 19 131 0 0 -34 56 19 16 11 32 6 57 -42 -35 5 35 -34 47 4 -35 57 13 -33 56 32 132 0 0 -34 30 34 16 11 33 7 56 -42 -34 39 48 -34 21 21 -35 31 19 -33 30 57 133 0 0 -34 5 2 16 11 35 8 56 -42 -34 14 15 -33 55 51 -35 5 36 -33 5 35 134 0 0 -33 39 44 16 11 36 9 55 -42 -33 48 55 -33 30 34 -34 40 8 -32 40 26 135 0 0 -33 14 40 16 11 38 10 54 -42 -33 23 50 -33 5 31 -34 14 54 -32 15 32 136 0 0 -32 49 51 16 11 40 11 54 -42 -32 58 59 -32 40 44 -33 49 55 -31 50 53 137 0 0 -32 25 18 16 11 42 12 53 -42 -32 34 25 -32 16 13 -33 25 12 -31 26 30 138 0 0 -32 1 2 16 11 44 13 53 -42 -32 10 8 -31 51 59 -33 0 45 -31 2 23 139 0 0 -31 37 4 16 11 47 13 52 -41 -31 46 7 -31 28 1 -32 36 36 -30 38 35 140 0 0 -31 13 23 16 11 49 14 52 -41 -31 22 25 -31 4 23 -32 12 46 -30 15 4 141 0 0 -30 50 2 16 11 52 15 51 -41 -30 59 2 -30 41 3 -31 49 14 -29 51 52 142 0 0 -30 27 0 16 11 55 16 50 -41 -30 35 59 -30 18 2 -31 26 2 -29 29 0 143 0 0 -30 4 18 16 11 58 17 50 -41 -30 13 16 -29 55 22 -31 3 10 -29 6 28 144 0 0 -29 41 57 16 12 1 18 49 -40 -29 50 53 -29 33 3 -30 40 39 -28 44 17 145 0 0 -29 19 58 16 12 5 19 49 -40 -29 28 53 -29 11 5 -30 18 29 -28 22 27 146 0 0 -28 58 21 16 12 9 20 48 -40 -29 7 14 -28 49 29 -29 56 42 -28 1 0 147 0 0 -28 37 7 16 12 12 21 47 -39 -28 45 58 -28 28 17 -29 35 18 -27 39 55 148 0 0 -28 16 16 16 12 16 22 47 -39 -28 25 6 -28 7 27 -29 14 18 -27 19 13 149 0 0 -27 55 49 16 12 21 23 46 -38 -28 4 38 -27 47 2 -28 53 41 -26 58 56 150 0 0 -27 35 47 16 12 25 23 45 -38 -27 44 34 -27 27 1 -28 33 29 -26 39 2 151 0 0 -27 16 9 16 12 29 24 45 -38 -27 24 55 -27 7 25 -28 13 42 -26 19 34 152 0 0 -26 56 58 16 12 34 25 44 -37 -27 5 42 -26 48 15 -27 54 21 -26 0 31 153 0 0 -26 38 12 16 12 39 26 43 -37 -26 46 55 -26 29 30 -27 35 27 -25 41 54 154 0 0 -26 19 53 16 12 44 27 43 -36 -26 28 35 -26 11 13 -27 16 59 -25 23 43 155 0 0 -26 2 1 16 12 49 28 42 -35 -26 10 41 -25 53 22 -26 58 58 -25 5 59 156 0 0 -25 44 36 16 12 54 29 41 -35 -25 53 15 -25 35 58 -26 41 25 -24 48 43 157 0 0 -25 27 39 16 13 0 29 41 -34 -25 36 17 -25 19 3 -26 24 19 -24 31 54 158 0 0 -25 11 11 16 13 5 30 40 -34 -25 19 48 -25 2 36 -26 7 43 -24 15 34 159 0 0 -24 55 11 16 13 11 31 39 -33 -25 3 47 -24 46 37 -25 51 35 -23 59 41 160 0 0 -24 39 41 16 13 16 32 38 -32 -24 48 15 -24 31 8 -25 35 57 -23 44 18 161 0 0 -24 24 39 16 13 22 32 38 -32 -24 33 12 -24 16 8 -25 20 48 -23 29 24 162 0 0 -24 10 8 16 13 28 33 37 -31 -24 18 40 -24 1 37 -25 6 9 -23 15 0 163 0 0 -23 56 7 16 13 35 34 36 -30 -24 4 38 -23 47 37 -24 52 1 -23 1 5 164 0 0 -23 42 36 16 13 41 35 35 -30 -23 51 6 -23 34 7 -24 38 23 -22 47 41 165 0 0 -23 29 36 16 13 47 35 34 -29 -23 38 5 -23 21 8 -24 25 17 -22 34 47 166 0 0 -23 17 7 16 13 54 36 33 -28 -23 25 35 -23 8 40 -24 12 41 -22 22 24 167 0 0 -23 5 9 16 14 0 37 32 -27 -23 13 36 -22 56 43 -24 0 37 -22 10 32 168 0 0 -22 53 43 16 14 7 37 32 -27 -23 2 9 -22 45 18 -23 49 5 -21 59 12 169 0 0 -22 42 48 16 14 14 38 31 -26 -22 51 14 -22 34 24 -23 38 5 -21 48 23 170 0 0 -22 32 26 16 14 21 39 30 -25 -22 40 51 -22 24 3 -23 27 38 -21 38 5 171 0 0 -22 22 36 16 14 28 39 29 -24 -22 31 0 -22 14 13 -23 17 43 -21 28 20 172 0 0 -22 13 18 16 14 35 40 28 -23 -22 21 41 -22 4 57 -23 8 20 -21 19 7 173 0 0 -22 4 33 16 14 42 40 27 -23 -22 12 56 -21 56 12 -22 59 31 -21 10 26 174 0 0 -21 56 21 16 14 50 41 25 -22 -22 4 43 -21 48 1 -22 51 14 -21 2 18 175 0 0 -21 48 42 16 14 57 42 24 -21 -21 57 3 -21 40 22 -22 43 31 -20 54 43 176 0 0 -21 41 36 16 15 4 42 23 -20 -21 49 57 -21 33 17 -22 36 21 -20 47 40 177 0 0 -21 35 3 16 15 12 43 22 -19 -21 43 23 -21 26 44 -22 29 45 -20 41 11 178 0 0 -21 29 4 16 15 19 43 21 -18 -21 37 23 -21 20 45 -22 23 43 -20 35 14 179 0 0 -21 23 38 16 15 27 43 20 -17 -21 31 57 -21 15 20 -22 18 14 -20 29 51 180 0 0 -21 18 46 16 15 35 44 19 -16 -21 27 5 -21 10 28 -22 13 19 -20 25 1 -179 0 0 -21 14 27 16 15 42 44 17 -16 -21 22 46 -21 6 10 -22 8 59 -20 20 45 -178 0 0 -21 10 43 16 15 50 44 16 -15 -21 19 1 -21 2 26 -22 5 12 -20 17 2 -177 0 0 -21 7 32 16 15 58 45 15 -14 -21 15 50 -20 59 15 -22 2 0 -20 13 53 -176 0 0 -21 4 55 16 16 6 45 13 -13 -21 13 13 -20 56 39 -21 59 22 -20 11 18 -175 0 0 -21 2 52 16 16 14 45 12 -12 -21 11 10 -20 54 36 -21 57 18 -20 9 16 -174 0 0 -21 1 24 16 16 22 46 11 -11 -21 9 41 -20 53 7 -21 55 49 -20 7 48 -173 0 0 -21 0 29 16 16 30 46 10 -10 -21 8 47 -20 52 13 -21 54 54 -20 6 53 -172 0 0 -21 0 9 16 16 38 46 8 -9 -21 8 26 -20 51 52 -21 54 33 -20 6 33 -171 0 0 -21 0 22 16 16 46 46 7 -8 -21 8 40 -20 52 6 -21 54 47 -20 6 47 -170 0 0 -21 1 10 16 16 54 46 5 -7 -21 9 28 -20 52 54 -21 55 35 -20 7 34 -169 0 0 -21 2 32 16 17 2 46 4 -6 -21 10 50 -20 54 16 -21 56 58 -20 8 55 -168 0 0 -21 4 28 16 17 10 46 3 -5 -21 12 46 -20 56 11 -21 58 55 -20 10 50 -167 0 0 -21 6 58 16 17 18 46 1 -4 -21 15 16 -20 58 41 -22 1 26 -20 13 19 -166 0 0 -21 10 2 16 17 26 46 360 -4 -21 18 21 -21 1 45 -22 4 32 -20 16 21 -165 0 0 -21 13 41 16 17 34 46 359 -3 -21 21 59 -21 5 23 -22 8 13 -20 19 58 -164 0 0 -21 17 53 16 17 42 46 357 -2 -21 26 12 -21 9 35 -22 12 27 -20 24 8 -163 0 0 -21 22 39 16 17 50 46 356 -1 -21 30 58 -21 14 20 -22 17 16 -20 28 51 Uncertainty in time = +/- 6 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 1895-01769-1 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 06 35.3706 DE: +22 51 40.378 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .025 ) * V mag [mag]: 9.3 * B mag [mag]: 10.3 * Apparent position with proper motion RA(deg): 106.8453153168 DE(deg): 22.8388465244 * Equation of equinoxes (radians) : 0.000060057875545 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1761) Edmondson approx. diameter [km]: 22 approx. diameter ["]: .014 distance from Earth [AU]: 2.18300 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1210 number of rejected observations: 25 time covered by the observations: 1950 Dec 12 - 2012 Feb 02 1 sigma uncertainty ellipse (major, minor, PA): 0.050, 0.029, 94° remarks: * orbital elements for (1761) Edmondson : Mean anomaly = 332.61592777 deg Arg. of pericenter = 49.66717564 deg Long. of node = 77.00434066 deg Inclination = 2.46478430 deg Eccentricity = 0.23374050 Semimajor axis = 3.17629353 AU Perihelion dist = 2.43386509 AU Mag: H = 11.67, G = 0.15 Epoch of elements : MJD 56219.67800000 TDT (2012 Oct 19.678) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 19 1761 Edmondson 16h 17.2m UT 9.3 7 6 35.371 22 51 40.38TYC 1895-01769-1 10.4 16.2 22 1.6 2.183 2.196 -1.25 -166.1924 22.861 -68.08 -10.29 16.2866 -0.02882 -0.69159 7.53677 -0.30973 -0.00559 0.00063 2000 330.93089420121010.00000 49.667176 77.004341 2.4647840.23374050 3.1762935 2.433865111.4 5.00.15 RATE 1.7410970 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.054 0.039 93 3.76 0.039 0 0-4-2 056165.0020121019_1769-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 26, 04:42 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org