IOTA/IOTA-ES occultation update for (196) Philomela / TYC 6854-02307-1 event on 2012 Sep 04, 17:01 UT Visible from India, Arabia, Africa Summary ------- On 2012 Sep 04 UT, the 142 km diameter asteroid (196) Philomela will occult a 10.2 mag star in the constellation Sagittarius for observers along a path across India, Arabia, Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.0 mag to 12.0 mag (the magnitude of the asteroid) for at most 19.8 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: 98 * date and approx. time of event: 2012 Sep 04, 16:58 - 2012 Sep 04, 17:11 UT * geocentric midpoint of event [JD]: 2456175.20925833 * magnitude of target star: 10.2 * magnitude drop [mag]: 2.0 * estimated maximum duration [s]: 19.8 * Moon: 84 % sunlit, 119° distance * Sun: 109° distance * rough path description: India, Arabia, Africa The occultation path -------------------- * approximate projected width [km]: 208 * 1 sigma uncertainty interval [path widths]: +/- 0.37 * 1 sigma uncertainty interval [seconds]: +/- 6.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .029 +/- .028) * 1 sigma uncertainty ellipse (major, minor, PA): ( .029", .028", 91° ) * approx speed of asteroid's shadow [km/s]: 7.1542 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6854-02307-1 by 196 Philomela on 2012 Sep 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 ' " Latitude Latitude Latitude Latitude 18 0 0 18 42 16 16 58 20 41 163 -1 17 46 1 19 39 32 17 4 59 20 22 35 19 0 0 18 36 23 16 58 35 41 164 -2 17 40 11 19 33 35 16 59 13 20 16 36 20 0 0 18 31 18 16 58 50 41 165 -3 17 35 9 19 28 26 16 54 13 20 11 25 21 0 0 18 27 1 16 59 5 42 166 -4 17 30 55 19 24 6 16 50 0 20 7 2 22 0 0 18 23 31 16 59 21 42 168 -5 17 27 28 19 20 35 16 46 35 20 3 29 23 0 0 18 20 50 16 59 36 42 169 -6 17 24 48 19 17 51 16 43 56 20 0 44 24 0 0 18 18 56 16 59 52 42 170 -7 17 22 55 19 15 57 16 42 4 19 58 49 25 0 0 18 17 51 17 0 8 43 171 -8 17 21 50 19 14 51 16 41 0 19 57 42 26 0 0 18 17 34 17 0 23 43 173 -9 17 21 33 19 14 34 16 40 42 19 57 25 27 0 0 18 18 4 17 0 39 43 174 -10 17 22 3 19 15 5 16 41 12 19 57 57 28 0 0 18 19 23 17 0 55 43 175 -11 17 23 21 19 16 25 16 42 29 19 59 18 29 0 0 18 21 30 17 1 10 43 176 -12 17 25 27 19 18 34 16 44 34 20 1 28 30 0 0 18 24 26 17 1 26 43 178 -13 17 28 20 19 21 31 16 47 25 20 4 27 31 0 0 18 28 9 17 1 42 43 179 -14 17 32 0 19 25 18 16 51 4 20 8 16 32 0 0 18 32 41 17 1 58 43 180 -14 17 36 29 19 29 52 16 55 30 20 12 53 33 0 0 18 38 0 17 2 13 43 182 -15 17 41 44 19 35 16 17 0 43 20 18 20 34 0 0 18 44 8 17 2 29 43 183 -16 17 47 48 19 41 28 17 6 43 20 24 36 35 0 0 18 51 3 17 2 45 43 184 -17 17 54 38 19 48 29 17 13 31 20 31 40 36 0 0 18 58 47 17 3 0 42 185 -18 18 2 16 19 56 18 17 21 5 20 39 34 37 0 0 19 7 18 17 3 16 42 187 -19 18 10 42 20 4 55 17 29 26 20 48 16 38 0 0 19 16 37 17 3 31 42 188 -20 18 19 54 20 14 21 17 38 34 20 57 47 39 0 0 19 26 43 17 3 47 41 189 -21 18 29 54 20 24 35 17 48 28 21 8 7 40 0 0 19 37 38 17 4 2 41 190 -22 18 40 40 20 35 37 17 59 10 21 19 15 41 0 0 19 49 19 17 4 17 41 191 -23 18 52 14 20 47 27 18 10 37 21 31 11 42 0 0 20 1 47 17 4 33 40 193 -24 19 4 34 21 0 5 18 22 51 21 43 56 43 0 0 20 15 3 17 4 48 40 194 -25 19 17 40 21 13 30 18 35 51 21 57 29 44 0 0 20 29 5 17 5 2 39 195 -26 19 31 33 21 27 42 18 49 37 22 11 49 45 0 0 20 43 54 17 5 17 39 196 -26 19 46 12 21 42 42 19 4 9 22 26 57 46 0 0 20 59 30 17 5 32 38 197 -27 20 1 37 21 58 28 19 19 26 22 42 52 47 0 0 21 15 51 17 5 46 38 198 -28 20 17 47 22 15 2 19 35 28 22 59 35 48 0 0 21 32 58 17 6 0 37 199 -29 20 34 42 22 32 21 19 52 16 23 17 4 49 0 0 21 50 51 17 6 15 37 200 -30 20 52 23 22 50 27 20 9 48 23 35 19 50 0 0 22 9 29 17 6 28 36 201 -31 21 10 48 23 9 18 20 28 4 23 54 21 51 0 0 22 28 52 17 6 42 35 202 -31 21 29 58 23 28 55 20 47 5 24 14 9 52 0 0 22 48 59 17 6 56 35 203 -32 21 49 52 23 49 17 21 6 49 24 34 42 53 0 0 23 9 51 17 7 9 34 204 -33 22 10 29 24 10 23 21 27 16 24 56 0 54 0 0 23 31 26 17 7 22 33 205 -34 22 31 49 24 32 13 21 48 26 25 18 2 55 0 0 23 53 44 17 7 35 32 206 -34 22 53 53 24 54 47 22 10 19 25 40 49 56 0 0 24 16 45 17 7 47 32 207 -35 23 16 38 25 18 5 22 32 53 26 4 19 57 0 0 24 40 28 17 7 59 31 207 -36 23 40 5 25 42 5 22 56 9 26 28 32 58 0 0 25 4 52 17 8 11 30 208 -36 24 4 13 26 6 46 23 20 6 26 53 27 59 0 0 25 29 58 17 8 23 29 209 -37 24 29 2 26 32 10 23 44 43 27 19 5 60 0 0 25 55 44 17 8 35 28 210 -37 24 54 31 26 58 14 24 9 59 27 45 23 61 0 0 26 22 9 17 8 46 28 211 -38 25 20 39 27 24 58 24 35 55 28 12 22 62 0 0 26 49 14 17 8 56 27 211 -38 25 47 25 27 52 22 25 2 29 28 40 1 63 0 0 27 16 56 17 9 7 26 212 -39 26 14 50 28 20 24 25 29 40 29 8 19 64 0 0 27 45 17 17 9 17 25 213 -39 26 42 51 28 49 5 25 57 29 29 37 15 65 0 0 28 14 14 17 9 27 24 214 -40 27 11 29 29 18 22 26 25 53 30 6 48 66 0 0 28 43 46 17 9 36 23 214 -40 27 40 42 29 48 15 26 54 53 30 36 58 67 0 0 29 13 54 17 9 45 22 215 -41 28 10 30 30 18 44 27 24 27 31 7 43 68 0 0 29 44 35 17 9 54 21 216 -41 28 40 51 30 49 47 27 54 34 31 39 3 69 0 0 30 15 50 17 10 3 20 216 -41 29 11 45 31 21 23 28 25 14 32 10 56 70 0 0 30 47 36 17 10 11 19 217 -41 29 43 11 31 53 32 28 56 25 32 43 22 71 0 0 31 19 53 17 10 18 18 218 -42 30 15 8 32 26 11 29 28 7 33 16 20 72 0 0 31 52 40 17 10 25 17 218 -42 30 47 33 32 59 21 30 0 18 33 49 47 73 0 0 32 25 56 17 10 32 16 219 -42 31 20 28 33 33 0 30 32 58 34 23 44 74 0 0 32 59 39 17 10 39 16 220 -42 31 53 49 34 7 6 31 6 5 34 58 8 75 0 0 33 33 48 17 10 45 15 220 -42 32 27 37 34 41 38 31 39 37 35 33 0 76 0 0 34 8 22 17 10 50 14 221 -42 33 1 50 35 16 36 32 13 35 36 8 16 77 0 0 34 43 20 17 10 56 13 222 -42 33 36 26 35 51 57 32 47 55 36 43 56 78 0 0 35 18 40 17 11 0 12 222 -42 34 11 24 36 27 41 33 22 39 37 19 59 79 0 0 35 54 22 17 11 5 11 223 -42 34 46 43 37 3 46 33 57 42 37 56 23 80 0 0 36 30 22 17 11 9 10 223 -42 35 22 22 37 40 11 34 33 6 38 33 7 81 0 0 37 6 41 17 11 12 9 224 -42 35 58 19 38 16 54 35 8 48 39 10 9 82 0 0 37 43 17 17 11 16 8 225 -42 36 34 32 38 53 53 35 44 46 39 47 27 83 0 0 38 20 7 17 11 18 7 225 -42 37 11 1 39 31 8 36 21 0 40 25 1 84 0 0 38 57 12 17 11 21 6 226 -41 37 47 44 40 8 36 36 57 28 41 2 48 85 0 0 39 34 28 17 11 23 5 227 -41 38 24 38 40 46 16 37 34 8 41 40 47 86 0 0 40 11 55 17 11 24 4 227 -41 39 1 44 41 24 6 38 10 59 42 18 56 87 0 0 40 49 31 17 11 26 3 228 -41 39 38 59 42 2 6 38 47 59 42 57 14 88 0 0 41 27 15 17 11 26 2 229 -40 40 16 22 42 40 12 39 25 7 43 35 39 89 0 0 42 5 4 17 11 27 1 229 -40 40 53 50 .. .. .. .. .. .. .. .. .. Uncertainty in time = +/- 8 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 6854-02307-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 05 10.1157 DE: -28 36 59.445 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .028, .027 ) * V mag [mag]: 10.2 * B mag [mag]: 11.1 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (196) Philomela approx. diameter [km]: 142 approx. diameter ["]: .076 distance from Earth [AU]: 2.57700 * orbital information: orbit source: Preston date of fit: 2012 Aug 25 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 1675 number of rejected observations: 193 time covered by the observations: 1904 Nov 16 - 2012 Aug 12 1 sigma uncertainty ellipse (major, minor, PA): 0.009, 0.007, 99° remarks: * orbital elements for (196) Philomela : Mean anomaly = 16.72589427 deg Arg. of pericenter = 199.69903101 deg Long. of node = 72.53071814 deg Inclination = 7.26007623 deg Eccentricity = 0.02009599 Semimajor axis = 3.11384963 AU Perihelion dist = 3.05127373 AU Mag: H = 6.44, G = 0.15 Epoch of elements : MJD 56174.70900000 TDT (2012 Sep 04.709) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 4 196 Philomela 17h 1.3m UT 10.2 18 5 10.116-28 36 59.45TYC 6854-02307-1 11.1 12.0 142 19.8 2.577 1.046 0.73 31.7407 -28.616 -75.63 6.85 17.0222 -0.03877 0.72937 4.03232 0.21439 0.00538 0.00021 2000 15.8812252012 831.00000199.699031 72.530718 7.2600760.02009599 3.1138496 3.0512737 6.5 5.00.15 RATE 1.7937330 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.029 0.028 91 1.37 0.028 0 0-3 5 056165.0020120904_2307-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 25, 22:26 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org