IOTA/IOTA-ES occultation update for (196) Philomela / UCAC2 20253012 event on 2012 Oct 16, 07:00 UT Visible from S Pacific Summary ------- On 2012 Oct 16 UT, the 142 km diameter asteroid (196) Philomela will occult a 11.2 mag star in the constellation Sagittarius for observers along a path across S Pacific. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.5 mag to 12.4 mag (the magnitude of the asteroid) for at most 5.9 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, 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: 55 * date and approx. time of event: 2012 Oct 16, 07:01 - 2012 Oct 16, 07:05 UT * geocentric midpoint of event [JD]: 2456216.79225417 * magnitude of target star: 11.2 * magnitude drop [mag]: 1.5 * estimated maximum duration [s]: 5.9 * Moon: 1 % sunlit, 64° distance * Sun: 76° distance * rough path description: S Pacific The occultation path -------------------- * approximate projected width [km]: 148 * 1 sigma uncertainty interval [path widths]: +/- 1.14 * 1 sigma uncertainty interval [seconds]: +/- 5.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .071 +/- .070) * 1 sigma uncertainty ellipse (major, minor, PA): ( .071", .070", 90° ) * approx speed of asteroid's shadow [km/s]: 24.1931 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 20253012 by 196 Philomela on 2012 Oct 16 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 170 0 0 -42 14 13 7 1 53 68 303 -1 -42 55 49 -41 32 47 -44 31 16 -39 58 48 171 0 0 -42 1 54 7 1 57 67 301 -1 -42 43 35 -41 20 22 -44 19 15 -39 46 11 172 0 0 -41 49 10 7 2 0 67 299 -2 -42 30 57 -41 7 32 -44 6 50 -39 33 8 173 0 0 -41 36 0 7 2 4 66 297 -3 -42 17 53 -40 54 16 -43 53 59 -39 19 40 174 0 0 -41 22 24 7 2 7 66 295 -4 -42 4 23 -40 40 35 -43 40 44 -39 5 45 175 0 0 -41 8 24 7 2 11 65 293 -5 -41 50 29 -40 26 28 -43 27 3 -38 51 25 176 0 0 -40 53 57 7 2 14 65 292 -5 -41 36 8 -40 11 55 -43 12 58 -38 36 38 177 0 0 -40 39 5 7 2 18 64 290 -6 -41 21 23 -39 56 57 -42 58 26 -38 21 26 178 0 0 -40 23 47 7 2 21 63 288 -7 -41 6 11 -39 41 33 -42 43 30 -38 5 47 179 0 0 -40 8 3 7 2 25 63 287 -8 -40 50 34 -39 25 42 -42 28 8 -37 49 43 180 0 0 -39 51 53 7 2 28 62 285 -9 -40 34 30 -39 9 26 -42 12 20 -37 33 11 -179 0 0 -39 35 17 7 2 32 61 283 -9 -40 18 1 -38 52 43 -41 56 6 -37 16 14 -178 0 0 -39 18 15 7 2 35 61 282 -10 -40 1 5 -38 35 34 -41 39 26 -36 58 50 -177 0 0 -39 0 47 7 2 39 60 281 -11 -39 43 44 -38 17 59 -41 22 20 -36 41 0 -176 0 0 -38 42 52 7 2 42 59 279 -12 -39 25 56 -37 59 58 -41 4 49 -36 22 43 -175 0 0 -38 24 31 7 2 46 58 278 -13 -39 7 42 -37 41 30 -40 46 51 -36 4 0 -174 0 0 -38 5 44 7 2 49 58 277 -14 -38 49 2 -37 22 36 -40 28 27 -35 44 51 -173 0 0 -37 46 30 7 2 53 57 275 -15 -38 29 55 -37 3 15 -40 9 36 -35 25 15 -172 0 0 -37 26 50 7 2 56 56 274 -15 -38 10 22 -36 43 28 -39 50 20 -35 5 12 -171 0 0 -37 6 44 7 3 0 55 273 -16 -37 50 23 -36 23 15 -39 30 37 -34 44 43 -170 0 0 -36 46 11 7 3 3 55 272 -17 -37 29 57 -36 2 35 -39 10 28 -34 23 48 -169 0 0 -36 25 12 7 3 7 54 271 -18 -37 9 6 -35 41 30 -38 49 52 -34 2 27 -168 0 0 -36 3 47 7 3 10 53 270 -19 -36 47 47 -35 19 57 -38 28 51 -33 40 39 -167 0 0 -35 41 56 7 3 14 52 269 -20 -36 26 3 -34 57 59 -38 7 23 -33 18 26 -166 0 0 -35 19 39 7 3 17 51 268 -21 -36 3 53 -34 35 35 -37 45 29 -32 55 46 -165 0 0 -34 56 56 7 3 20 50 267 -22 -35 41 17 -34 12 45 -37 23 9 -32 32 41 -164 0 0 -34 33 47 7 3 24 50 266 -23 -35 18 15 -33 49 30 -37 0 23 -32 9 10 -163 0 0 -34 10 12 7 3 27 49 265 -23 -34 54 47 -33 25 48 -36 37 11 -31 45 14 -162 0 0 -33 46 12 7 3 31 48 264 -24 -34 30 54 -33 1 42 -36 13 34 -31 20 52 -161 0 0 -33 21 47 7 3 34 47 263 -25 -34 6 35 -32 37 10 -35 49 31 -30 56 6 -160 0 0 -32 56 57 7 3 37 46 262 -26 -33 41 52 -32 12 14 -35 25 3 -30 30 55 -159 0 0 -32 31 42 7 3 40 45 261 -27 -33 16 44 -31 46 52 -35 0 9 -30 5 20 -158 0 0 -32 6 3 7 3 44 44 260 -28 -32 51 11 -31 21 7 -34 34 51 -29 39 20 -157 0 0 -31 40 0 7 3 47 43 260 -29 -32 25 14 -30 54 58 -34 9 9 -29 12 57 -156 0 0 -31 13 33 7 3 50 42 259 -30 -31 58 53 -30 28 24 -33 43 2 -28 46 11 -155 0 0 -30 46 42 7 3 53 41 258 -31 -31 32 8 -30 1 28 -33 16 31 -28 19 2 -154 0 0 -30 19 29 7 3 56 40 257 -32 -31 5 0 -29 34 9 -32 49 37 -27 51 30 -153 0 0 -29 51 53 7 3 59 40 257 -33 -30 37 30 -29 6 28 -32 22 19 -27 23 36 -152 0 0 -29 23 55 7 4 2 39 256 -34 -30 9 37 -28 38 24 -31 54 39 -26 55 21 -151 0 0 -28 55 35 7 4 5 38 255 -35 -29 41 23 -28 10 0 -31 26 37 -26 26 45 -150 0 0 -28 26 55 7 4 8 37 255 -36 -29 12 47 -27 41 14 -30 58 13 -25 57 49 -149 0 0 -27 57 53 7 4 11 36 254 -37 -28 43 51 -27 12 8 -30 29 28 -25 28 32 -148 0 0 -27 28 32 7 4 14 35 253 -38 -28 14 34 -26 42 43 -30 0 22 -24 58 57 -147 0 0 -26 58 52 7 4 17 34 253 -39 -27 44 58 -26 12 58 -29 30 56 -24 29 3 -146 0 0 -26 28 53 7 4 19 33 252 -40 -27 15 3 -25 42 55 -29 1 11 -23 58 51 -145 0 0 -25 58 36 7 4 22 32 252 -41 -26 44 50 -25 12 34 -28 31 6 -23 28 22 -144 0 0 -25 28 1 7 4 25 31 251 -42 -26 14 19 -24 41 56 -28 0 44 -22 57 36 -143 0 0 -24 57 11 7 4 27 30 250 -43 -25 43 32 -24 11 2 -27 30 4 -22 26 35 -142 0 0 -24 26 4 7 4 30 29 250 -44 -25 12 28 -23 39 53 -26 59 7 -21 55 18 -141 0 0 -23 54 42 7 4 32 27 249 -45 -24 41 9 -23 8 28 -26 27 55 -21 23 48 -140 0 0 -23 23 6 7 4 34 26 249 -46 -24 9 36 -22 36 50 -25 56 27 -20 52 5 -139 0 0 -22 51 17 7 4 37 25 249 -47 -23 37 49 -22 4 59 -25 24 46 -20 20 9 -138 0 0 -22 19 16 7 4 39 24 248 -48 -23 5 49 -21 32 55 -24 52 50 -19 48 1 -137 0 0 -21 47 3 7 4 41 23 248 -49 -22 33 38 -21 0 41 -24 20 43 -19 15 43 -136 0 0 -21 14 39 7 4 43 22 247 -50 -22 1 15 -20 28 15 -23 48 23 -18 43 15 -135 0 0 -20 42 5 7 4 45 21 247 -51 -21 28 42 -19 55 41 -23 15 53 -18 10 38 -134 0 0 -20 9 23 7 4 47 20 246 -52 -20 56 1 -19 22 58 -22 43 13 -17 37 54 -133 0 0 -19 36 32 7 4 48 19 246 -53 -20 23 11 -18 50 7 -22 10 24 -17 5 2 -132 0 0 -19 3 35 7 4 50 18 246 -54 -19 50 14 -18 17 10 -21 37 27 -16 32 5 -131 0 0 -18 30 32 7 4 52 17 245 -55 -19 17 11 -17 44 7 -21 4 23 -15 59 3 -130 0 0 -17 57 25 7 4 53 16 245 -57 -18 44 2 -17 11 0 -20 31 14 -15 25 57 -129 0 0 -17 24 13 7 4 55 15 245 -58 -18 10 50 -16 37 49 -19 57 59 -14 52 48 -128 0 0 -16 50 59 7 4 56 13 244 -59 -17 37 34 -16 4 36 -19 24 41 -14 19 38 -127 0 0 -16 17 42 7 4 57 12 244 -60 -17 4 17 -15 31 21 -18 51 20 -13 46 26 -126 0 0 -15 44 25 7 4 58 11 244 -61 -16 30 58 -14 58 6 -18 17 57 -13 13 14 -125 0 0 -15 11 9 7 4 59 10 243 -62 -15 57 39 -14 24 51 -17 44 34 -12 40 4 -124 0 0 -14 37 53 7 5 0 9 243 -63 -15 24 21 -13 51 38 -17 11 11 -12 6 56 -123 0 0 -14 4 40 7 5 1 8 243 -64 -14 51 6 -13 18 27 -16 37 49 -11 33 51 -122 0 0 -13 31 30 7 5 1 7 243 -64 -14 17 53 -12 45 20 -16 4 30 -11 0 50 -121 0 0 -12 58 25 7 5 2 6 242 -65 -13 44 44 -12 12 18 -15 31 14 -10 27 55 -120 0 0 -12 25 25 7 5 3 5 242 -66 -13 11 41 -11 39 21 -14 58 3 - 9 55 6 -119 0 0 -11 52 31 7 5 3 3 242 -67 -12 38 44 -11 6 31 -14 24 57 - 9 22 23 -118 0 0 -11 19 44 7 5 3 2 242 -68 -12 5 53 -10 33 48 -13 51 58 - 8 49 49 -117 0 0 -10 47 6 7 5 3 1 242 -69 -11 33 11 -10 1 14 -13 19 6 .. .. .. -116 0 0 -10 14 38 7 5 3 0 241 -70 -11 0 38 .. .. .. -12 46 23 .. .. .. Uncertainty in time = +/- 7 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: UCAC2 20253012 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 39 11.5813 DE: -28 06 28.510 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .070, .070 ) * V mag [mag]: 11.2 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (196) Philomela approx. diameter [km]: 142 approx. diameter ["]: .062 distance from Earth [AU]: 3.14800 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 1683 number of rejected observations: 193 time covered by the observations: 1904 Nov 16 - 2012 Sep 30 1 sigma uncertainty ellipse (major, minor, PA): 0.007, 0.006, 94° remarks: * orbital elements for (196) Philomela : Mean anomaly = 24.28157645 deg Arg. of pericenter = 199.60092082 deg Long. of node = 72.53084746 deg Inclination = 7.26009611 deg Eccentricity = 0.02004416 Semimajor axis = 3.11365723 AU Perihelion dist = 3.05124659 AU Mag: H = 6.44, G = 0.15 Epoch of elements : MJD 56216.29200000 TDT (2012 Oct 16.292) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 16 196 Philomela 7h 0.8m UT 11.2 18 39 11.581-28 6 28.51UCAC2 20253012 0.0 12.4 142 5.9 3.148 2.872 3.35 149.3825 -28.109 71.17 -9.06 7.0141 0.02500 -0.28406 13.60265 1.19740 0.00570 0.00026 2000 23.15285520121010.00000199.600921 72.530847 7.2600960.02004416 3.1136572 3.0512466 6.5 5.00.15 RATE 1.7938990 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.071 0.070 90 2.14 0.071 0 0 3 0 056208.0020121016_253012 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 18:52 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org