IOTA/IOTA-ES occultation update for (322) Phaeo / UCAC2 39470326 event on 2012 Oct 04, 16:44 UT Visible from E Australia Summary ------- On 2012 Oct 04 UT, the 72 km diameter asteroid (322) Phaeo will occult a 11.7 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 2.3 mag to 13.8 mag (the magnitude of the asteroid) for at most 4.3 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: 88 * date and approx. time of event: 2012 Oct 04, 16:40 - 2012 Oct 04, 16:45 UT * geocentric midpoint of event [JD]: 2456205.1977 * magnitude of target star: 11.7 * magnitude drop [mag]: 2.3 * estimated maximum duration [s]: 4.3 * Moon: 82 % sunlit, 41° distance * Sun: 89° distance * rough path description: E Australia The occultation path -------------------- * approximate projected width [km]: 121 * 1 sigma uncertainty interval [path widths]: +/- 0.56 * 1 sigma uncertainty interval [seconds]: +/- 2.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .026", .025", 97° ) * approx speed of asteroid's shadow [km/s]: 16.7291 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 39470326 by 322 Phaeo on 2012 Oct 4 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 Latitude Latitude Latitude Latitude -168 0 0 -32 28 58 16 45 31 35 8 -1 -33 5 14 -31 53 15 -33 46 34 -31 13 53 -169 0 0 -32 6 42 16 45 25 36 9 -2 -32 42 46 -31 31 10 -33 23 51 -30 52 0 -170 0 0 -31 45 7 16 45 18 36 11 -2 -32 21 0 -31 9 47 -33 1 52 -30 30 49 -171 0 0 -31 24 16 16 45 12 36 12 -3 -31 59 57 -30 49 6 -32 40 36 -30 10 19 -172 0 0 -31 4 7 16 45 6 36 13 -4 -31 39 38 -30 29 8 -32 20 4 -29 50 32 -173 0 0 -30 44 42 16 45 0 36 14 -5 -31 20 2 -30 9 52 -32 0 16 -29 31 27 -174 0 0 -30 26 0 16 44 54 36 15 -6 -31 1 10 -29 51 20 -31 41 12 -29 13 5 -175 0 0 -30 8 2 16 44 47 36 17 -7 -30 43 3 -29 33 31 -31 22 53 -28 55 25 -176 0 0 -29 50 48 16 44 41 36 18 -8 -30 25 39 -29 16 25 -31 5 19 -28 38 29 -177 0 0 -29 34 18 16 44 35 36 19 -9 -30 9 1 -29 0 4 -30 48 30 -28 22 17 -178 0 0 -29 18 32 16 44 29 36 20 -10 -29 53 7 -28 44 26 -30 32 27 -28 6 48 -179 0 0 -29 3 31 16 44 23 36 21 -11 -29 37 58 -28 29 33 -30 17 8 -27 52 2 -180 0 0 -28 49 14 16 44 16 36 23 -12 -29 23 34 -28 15 23 -30 2 36 -27 38 1 179 0 0 -28 35 43 16 44 10 36 24 -13 -29 9 55 -28 1 59 -29 48 49 -27 24 43 178 0 0 -28 22 56 16 44 4 36 25 -14 -28 57 1 -27 49 18 -29 35 47 -27 12 10 177 0 0 -28 10 54 16 43 58 36 26 -14 -28 44 53 -27 37 23 -29 23 32 -27 0 21 176 0 0 -27 59 38 16 43 52 35 27 -15 -28 33 31 -27 26 12 -29 12 2 -26 49 16 175 0 0 -27 49 6 16 43 46 35 28 -16 -28 22 54 -27 15 46 -29 1 19 -26 38 56 174 0 0 -27 39 20 16 43 40 35 29 -17 -28 13 3 -27 6 5 -28 51 21 -26 29 20 173 0 0 -27 30 19 16 43 34 34 30 -18 -28 3 57 -26 57 8 -28 42 10 -26 20 29 172 0 0 -27 22 4 16 43 29 34 31 -19 -27 55 37 -26 48 57 -28 33 45 -26 12 22 171 0 0 -27 14 34 16 43 23 34 32 -20 -27 48 3 -26 41 31 -28 26 6 -26 5 0 170 0 0 -27 7 49 16 43 17 33 33 -21 -27 41 14 -26 34 49 -28 19 13 -25 58 22 169 0 0 -27 1 49 16 43 12 33 34 -22 -27 35 12 -26 28 53 -28 13 7 -25 52 29 168 0 0 -26 56 35 16 43 6 32 35 -23 -27 29 55 -26 23 42 -28 7 47 -25 47 21 167 0 0 -26 52 7 16 43 1 32 36 -24 -27 25 24 -26 19 16 -28 3 12 -25 42 58 166 0 0 -26 48 23 16 42 55 31 37 -24 -27 21 38 -26 15 35 -27 59 24 -25 39 19 165 0 0 -26 45 25 16 42 50 31 38 -25 -27 18 38 -26 12 38 -27 56 23 -25 36 24 164 0 0 -26 43 13 16 42 45 30 39 -26 -27 16 24 -26 10 27 -27 54 7 -25 34 15 163 0 0 -26 41 46 16 42 39 30 40 -27 -27 14 56 -26 9 1 -27 52 37 -25 32 49 162 0 0 -26 41 3 16 42 34 29 41 -28 -27 14 13 -26 8 19 -27 51 54 -25 32 8 161 0 0 -26 41 7 16 42 29 29 42 -29 -27 14 16 -26 8 23 -27 51 56 -25 32 12 160 0 0 -26 41 55 16 42 25 28 42 -30 -27 15 4 -26 9 11 -27 52 45 -25 33 0 159 0 0 -26 43 28 16 42 20 27 43 -30 -27 16 38 -26 10 44 -27 54 19 -25 34 33 158 0 0 -26 45 46 16 42 15 27 44 -31 -27 18 57 -26 13 1 -27 56 39 -25 36 50 157 0 0 -26 48 50 16 42 11 26 45 -32 -27 22 2 -26 16 4 -27 59 45 -25 39 50 156 0 0 -26 52 38 16 42 6 25 46 -33 -27 25 51 -26 19 50 -28 3 36 -25 43 36 155 0 0 -26 57 11 16 42 2 25 46 -34 -27 30 26 -26 24 21 -28 8 14 -25 48 5 154 0 0 -27 2 29 16 41 58 24 47 -34 -27 35 46 -26 29 37 -28 13 36 -25 53 18 153 0 0 -27 8 31 16 41 54 23 48 -35 -27 41 51 -26 35 36 -28 19 44 -25 59 15 152 0 0 -27 15 17 16 41 50 23 48 -36 -27 48 41 -26 42 20 -28 26 37 -26 5 55 151 0 0 -27 22 48 16 41 46 22 49 -37 -27 56 15 -26 49 48 -28 34 16 -26 13 20 150 0 0 -27 31 4 16 41 42 21 50 -37 -28 4 34 -26 58 0 -28 42 39 -26 21 28 149 0 0 -27 40 3 16 41 38 20 50 -38 -28 13 38 -27 6 55 -28 51 48 -26 30 19 148 0 0 -27 49 47 16 41 35 19 51 -39 -28 23 26 -27 16 34 -29 1 41 -26 39 53 147 0 0 -28 0 14 16 41 32 19 52 -39 -28 33 58 -27 26 57 -29 12 19 -26 50 11 146 0 0 -28 11 25 16 41 28 18 52 -40 -28 45 14 -27 38 3 -29 23 41 -27 1 12 145 0 0 -28 23 20 16 41 25 17 53 -41 -28 57 14 -27 49 52 -29 35 48 -27 12 55 144 0 0 -28 35 57 16 41 22 16 53 -41 -29 9 58 -28 2 24 -29 48 38 -27 25 21 143 0 0 -28 49 18 16 41 20 15 54 -42 -29 23 26 -28 15 39 -30 2 13 -27 38 29 142 0 0 -29 3 22 16 41 17 14 55 -42 -29 37 36 -28 29 37 -30 16 32 -27 52 20 141 0 0 -29 18 9 16 41 15 14 55 -43 -29 52 30 -28 44 17 -30 31 34 -28 6 53 140 0 0 -29 33 38 16 41 12 13 56 -43 -30 8 7 -28 59 39 -30 47 20 -28 22 7 139 0 0 -29 49 50 16 41 10 12 56 -44 -30 24 26 -29 15 43 -31 3 48 -28 38 3 138 0 0 -30 6 44 16 41 8 11 57 -44 -30 41 28 -29 32 29 -31 21 0 -28 54 40 137 0 0 -30 24 19 16 41 6 10 57 -45 -30 59 12 -29 49 56 -31 38 54 -29 11 58 136 0 0 -30 42 36 16 41 5 9 58 -45 -31 17 38 -30 8 4 -31 57 31 -29 29 57 135 0 0 -31 1 34 16 41 3 8 58 -45 -31 36 46 -30 26 53 -32 16 49 -29 48 37 134 0 0 -31 21 13 16 41 2 7 59 -46 -31 56 35 -30 46 23 -32 36 50 -30 7 56 133 0 0 -31 41 33 16 41 0 6 60 -46 -32 17 4 -31 6 32 -32 57 31 -30 27 56 132 0 0 -32 2 32 16 40 59 5 60 -46 -32 38 15 -31 27 22 -33 18 54 -30 48 35 131 0 0 -32 24 12 16 40 58 5 61 -46 -33 0 5 -31 48 51 -33 40 58 -31 9 52 130 0 0 -32 46 31 16 40 58 4 61 -47 -33 22 35 -32 10 59 -34 3 41 .. .. .. 129 0 0 -33 9 28 16 40 57 3 62 -47 -33 45 45 -32 33 46 -34 27 5 .. .. .. 128 0 0 -33 33 5 16 40 57 2 62 -47 -34 9 33 -32 57 10 -34 51 8 .. .. .. 127 0 0 -33 57 19 16 40 56 1 63 -47 -34 34 0 -33 21 13 -35 15 49 .. .. .. Uncertainty in time = +/- 3 secs Prediction of 2012 Aug 6.0 Data for the target star ------------------------ * name: UCAC2 39470326 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 56 24.3179 DE: +21 50 17.636 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .019, .023 ) * V mag [mag]: 11.7 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 104.2963923359 DE(deg): 21.8193640696 * Equation of equinoxes (radians) : 0.000062178466132 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (322) Phaeo approx. diameter [km]: 72 approx. diameter ["]: .045 distance from Earth [AU]: 2.22900 * orbital information: orbit source: Preston date of fit: 2012 Jul 09 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 961 number of rejected observations: 74 time covered by the observations: 1900 Sep 25 - 2011 Oct 28 1 sigma uncertainty ellipse (major, minor, PA): 0.018, 0.010, 104° remarks: * orbital elements for (322) Phaeo : Mean anomaly = 45.97587323 deg Arg. of pericenter = 115.49923263 deg Long. of node = 252.37951612 deg Inclination = 8.05437199 deg Eccentricity = 0.24600647 Semimajor axis = 2.78374860 AU Perihelion dist = 2.09892844 AU Mag: H = 8.99, G = 0.15 Epoch of elements : MJD 56204.69800000 TDT (2012 Oct 04.698) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 4 322 Phaeo 16h 44.7m UT 11.7 6 56 24.318 21 50 17.64UCAC2 39470326 0.0 13.8 72 4.3 2.229 2.567 -10.50 -160.8470 21.840 -74.04 -4.69 16.7448 -0.22955 -0.77052 9.05962 -2.66116 -0.00555 0.00054 2000 44.9789262012 930.00000115.499233252.379516 8.0543720.24600647 2.7837486 2.0989284 9.0 5.00.15 RATE 2.1220670 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.026 0.025 97 1.56 0.025 0 0-1-4 056145.0020121004_470326 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 19:19 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org