IOTA/IOTA-ES occultation update for (161) Athor / TYC 7346-00610-1 event on 2012 Oct 02, 09:29 UT Visible from E Australia Summary ------- On 2012 Oct 02 UT, the 41 km diameter asteroid (161) Athor will occult a 11.0 mag star in the constellation Scorpius 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 2.9 mag to 13.8 mag (the magnitude of the asteroid) for at most 1.3 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, 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: 42 * date and approx. time of event: 2012 Oct 02, 09:30 - 2012 Oct 02, 09:32 UT * geocentric midpoint of event [JD]: 2456202.89534583 * magnitude of target star: 11.0 * magnitude drop [mag]: 2.9 * estimated maximum duration [s]: 1.3 * Moon: 95 % sunlit, 141° distance * Sun: 64° distance * rough path description: E Australia The occultation path -------------------- * approximate projected width [km]: 41 * 1 sigma uncertainty interval [path widths]: +/- 1.55 * 1 sigma uncertainty interval [seconds]: +/- 3.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .069 +/- .037) * 1 sigma uncertainty ellipse (major, minor, PA): ( .069", .037", 90° ) * approx speed of asteroid's shadow [km/s]: 32.4278 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 7346-00610-1 by 161 Athor on 2012 Oct 2 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 127 0 0 -31 51 11 9 30 43 64 265 0 -32 2 30 -31 39 52 -32 37 36 -31 4 48 128 0 0 -31 40 59 9 30 45 63 264 -1 -31 52 19 -31 29 39 -32 27 28 -30 54 31 129 0 0 -31 30 17 9 30 48 62 263 -2 -31 41 39 -31 18 56 -32 16 52 -30 43 44 130 0 0 -31 19 8 9 30 51 62 263 -3 -31 30 30 -31 7 45 -32 5 47 -30 32 29 131 0 0 -31 7 29 9 30 53 61 262 -4 -31 18 53 -30 56 5 -31 54 14 -30 20 45 132 0 0 -30 55 21 9 30 56 60 261 -4 -31 6 47 -30 43 56 -31 42 12 -30 8 32 133 0 0 -30 42 44 9 30 59 59 261 -5 -30 54 11 -30 31 18 -31 29 41 -29 55 49 134 0 0 -30 29 39 9 31 1 58 260 -6 -30 41 7 -30 18 11 -31 16 42 -29 42 38 135 0 0 -30 16 4 9 31 4 57 260 -7 -30 27 34 -30 4 34 -31 3 13 -29 28 57 136 0 0 -30 2 0 9 31 6 56 259 -8 -30 13 31 -29 50 29 -30 49 15 -29 14 46 137 0 0 -29 47 27 9 31 9 55 258 -9 -29 58 59 -29 35 54 -30 34 48 -29 0 7 138 0 0 -29 32 24 9 31 12 54 258 -10 -29 43 58 -29 20 49 -30 19 52 -28 44 57 139 0 0 -29 16 52 9 31 14 53 257 -11 -29 28 28 -29 5 16 -30 4 27 -28 29 18 140 0 0 -29 0 50 9 31 17 53 257 -12 -29 12 28 -28 49 12 -29 48 32 -28 13 10 141 0 0 -28 44 19 9 31 19 52 256 -13 -28 55 59 -28 32 40 -29 32 8 -27 56 32 142 0 0 -28 27 18 9 31 22 51 256 -13 -28 39 0 -28 15 37 -29 15 15 -27 39 24 143 0 0 -28 9 48 9 31 24 50 255 -14 -28 21 31 -27 58 5 -28 57 52 -27 21 46 144 0 0 -27 51 48 9 31 27 49 254 -15 -28 3 33 -27 40 3 -28 39 59 -27 3 39 145 0 0 -27 33 18 9 31 29 48 254 -16 -27 45 5 -27 21 32 -28 21 37 -26 45 2 146 0 0 -27 14 19 9 31 31 47 253 -17 -27 26 8 -27 2 31 -28 2 45 -26 25 55 147 0 0 -26 54 50 9 31 34 46 253 -18 -27 6 41 -26 43 0 -27 43 24 -26 6 18 148 0 0 -26 34 52 9 31 36 45 252 -19 -26 46 44 -26 22 59 -27 23 34 -25 46 12 149 0 0 -26 14 23 9 31 39 44 252 -20 -26 26 18 -26 2 29 -27 3 13 -25 25 36 150 0 0 -25 53 26 9 31 41 43 251 -21 -26 5 22 -25 41 29 -26 42 23 -25 4 30 151 0 0 -25 31 58 9 31 43 42 251 -22 -25 43 57 -25 20 0 -26 21 4 -24 42 55 152 0 0 -25 10 2 9 31 45 41 251 -23 -25 22 2 -24 58 2 -25 59 16 -24 20 50 153 0 0 -24 47 36 9 31 48 40 250 -24 -24 59 38 -24 35 34 -25 36 58 -23 58 16 154 0 0 -24 24 40 9 31 50 39 250 -25 -24 36 45 -24 12 36 -25 14 11 -23 35 12 155 0 0 -24 1 16 9 31 52 38 249 -26 -24 13 22 -23 49 10 -24 50 54 -23 11 40 156 0 0 -23 37 23 9 31 54 37 249 -27 -23 49 31 -23 25 15 -24 27 9 -22 47 38 157 0 0 -23 13 1 9 31 56 36 248 -28 -23 25 11 -23 0 51 -24 2 55 -22 23 8 158 0 0 -22 48 10 9 31 58 35 248 -29 -23 0 22 -22 35 58 -23 38 13 -21 58 9 159 0 0 -22 22 51 9 32 0 34 247 -30 -22 35 5 -22 10 37 -23 13 2 -21 32 42 160 0 0 -21 57 4 9 32 2 33 247 -31 -22 9 20 -21 44 48 -22 47 23 -21 6 47 161 0 0 -21 30 49 9 32 4 32 247 -32 -21 43 7 -21 18 31 -22 21 17 -20 40 24 162 0 0 -21 4 7 9 32 6 31 246 -33 -21 16 27 -20 51 47 -21 54 42 -20 13 34 163 0 0 -20 36 58 9 32 8 30 246 -34 -20 49 20 -20 24 36 -21 27 41 -19 46 17 164 0 0 -20 9 21 9 32 9 29 246 -35 -20 21 45 -19 56 58 -21 0 12 -19 18 33 165 0 0 -19 41 19 9 32 11 28 245 -36 -19 53 44 -19 28 53 -20 32 17 -18 50 22 166 0 0 -19 12 50 9 32 13 27 245 -37 -19 25 17 -19 0 22 -20 3 56 -18 21 46 167 0 0 -18 43 56 9 32 14 26 245 -38 -18 56 25 -18 31 26 -19 35 9 -17 52 44 168 0 0 -18 14 36 9 32 16 25 244 -39 -18 27 7 -18 2 5 -19 5 57 -17 23 17 169 0 0 -17 44 52 9 32 18 24 244 -40 -17 57 25 -17 32 19 -18 36 21 -16 53 26 170 0 0 -17 14 44 9 32 19 23 244 -42 -17 27 19 -17 2 10 -18 6 20 -16 23 11 171 0 0 -16 44 13 9 32 20 21 243 -43 -16 56 49 -16 31 37 -17 35 55 -15 52 33 172 0 0 -16 13 18 9 32 22 20 243 -44 -16 25 57 -16 0 41 -17 5 8 -15 21 32 173 0 0 -15 42 2 9 32 23 19 243 -45 -15 54 42 -15 29 22 -16 33 58 -14 50 9 174 0 0 -15 10 24 9 32 24 18 242 -46 -15 23 5 -14 57 43 -16 2 26 -14 18 25 175 0 0 -14 38 25 9 32 25 17 242 -47 -14 51 8 -14 25 43 -15 30 33 -13 46 20 176 0 0 -14 6 6 9 32 27 16 242 -48 -14 18 50 -13 53 22 -14 58 20 -13 13 55 177 0 0 -13 33 28 9 32 28 15 242 -49 -13 46 13 -13 20 42 -14 25 47 -12 41 11 178 0 0 -13 0 31 9 32 28 14 241 -50 -13 13 17 -12 47 44 -13 52 55 -12 8 9 179 0 0 -12 27 16 9 32 29 13 241 -51 -12 40 4 -12 14 28 -13 19 46 -11 34 49 180 0 0 -11 53 45 9 32 30 11 241 -53 -12 6 34 -11 40 56 -12 46 19 -11 1 13 -179 0 0 -11 19 57 9 32 31 10 241 -54 -11 32 47 -11 7 7 -12 12 36 -10 27 21 -178 0 0 -10 45 55 9 32 32 9 241 -55 -10 58 46 -10 33 4 -11 38 38 - 9 53 14 -177 0 0 -10 11 38 9 32 32 8 240 -56 -10 24 30 - 9 58 46 -11 4 25 - 9 18 54 -176 0 0 - 9 37 8 9 32 33 7 240 -57 - 9 50 1 - 9 24 15 -10 29 59 - 8 44 20 -175 0 0 - 9 2 26 9 32 33 6 240 -58 - 9 15 20 - 8 49 33 - 9 55 20 - 8 9 35 -174 0 0 - 8 27 33 9 32 33 5 240 -59 - 8 40 28 - 8 14 39 - 9 20 30 - 7 34 39 -173 0 0 - 7 52 30 9 32 34 3 240 -60 - 8 5 25 - 7 39 35 - 8 45 29 - 6 59 33 -172 0 0 - 7 17 17 9 32 34 2 240 -62 - 7 30 13 - 7 4 22 - 8 10 19 - 6 24 18 -171 0 0 - 6 41 57 9 32 34 1 240 -63 - 6 54 53 - 6 29 1 - 7 35 0 - 5 48 56 Uncertainty in time = +/- 4 secs Prediction of 2012 Aug 6.0 Data for the target star ------------------------ * name: TYC 7346-00610-1 * constellation : Scorpius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 16 43 25.1899 DE: -30 22 48.106 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .068, .036 ) * V mag [mag]: 11.0 * B mag [mag]: 12.3 * Apparent position with proper motion RA(deg): 251.0593181443 DE(deg): -30.4029567134 * Equation of equinoxes (radians) : 0.000062586814564 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (161) Athor approx. diameter [km]: 41 approx. diameter ["]: .024 distance from Earth [AU]: 2.32600 * orbital information: orbit source: Preston date of fit: 2012 Jul 09 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 966 number of rejected observations: 120 time covered by the observations: 1917 Aug 08 - 2012 Jun 28 1 sigma uncertainty ellipse (major, minor, PA): 0.012, 0.008, 103° remarks: * orbital elements for (161) Athor : Mean anomaly = 334.39948381 deg Arg. of pericenter = 294.13389738 deg Long. of node = 18.73358966 deg Inclination = 9.05469144 deg Eccentricity = 0.13717995 Semimajor axis = 2.37950787 AU Perihelion dist = 2.05308709 AU Mag: H = 9.02, G = 0.13 Epoch of elements : MJD 56202.39500000 TDT (2012 Oct 02.395) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 2 161 Athor 9h 29.3m UT 11.0 16 43 25.190-30 22 48.11TYC 7346-00610-1 12.3 13.8 41 1.3 2.326 5.333 -5.15 97.0233 -30.379 34.99 -3.80 9.4883 -0.00240 -0.04832 18.25225 -1.36448 0.00471 -0.00096 2000 333.7563832012 930.00000294.133897 18.733590 9.0546910.13717995 2.3795079 2.0530871 9.2 5.00.13 RATE 2.6851800 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.069 0.037 90 2.55 0.037 0 0-1 4 056145.0020121002_0610-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 17:07 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org