IOTA/IOTA-ES occultation update for (147) Protogeneia / 2UCAC 23211501 event on 2008 Oct 16, 12:23 UT Visible from Japan, China, SE Asia Summary ------- On 2008 Oct 16 UT, the 133 km diameter asteroid (147) Protogeneia will occult a 12.1 mag star in the constellation Sagittarius for observers along a path across Japan, China, SE Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 14.2 mag (the magnitude of the asteroid) for at most 5.2 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 90 * date and approx. time of event: 2008 Oct 16, 12:24 - 2008 Oct 16, 12:26 UT * midpoint of event [JD]: 2454756.0160625 * magnitude of target star: 12.1 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 5.2 * Moon: 96 % sunlit, 129° distance * Sun: 73° distance * rough path description: Japan, China, SE Asia The occultation path -------------------- * approximate projected width [km]: 167 * 1 sigma uncertainty interval [path widths]: +/- 0.52 * 1 sigma uncertainty interval [seconds]: +/- 4.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .049 +/- .030) * 1 sigma uncertainty ellipse (major, minor, PA): ( .049", .030", 90° ) * approx speed of asteroid's shadow [km/s]: 25.4330 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 23211501 by 147 Protogeneia on 2008 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 78 0 0 16 27 27 12 24 7 50 198 0 15 41 55 17 13 28 14 55 2 18 1 49 79 0 0 16 36 49 12 24 11 49 200 -1 15 51 13 17 22 52 15 4 16 18 11 17 80 0 0 16 46 38 12 24 15 49 201 -2 16 0 59 17 32 45 15 13 59 18 21 15 81 0 0 16 56 56 12 24 19 48 202 -3 16 11 13 17 43 7 15 24 9 18 31 40 82 0 0 17 7 42 12 24 23 48 203 -4 16 21 55 17 53 57 15 34 47 18 42 34 83 0 0 17 18 56 12 24 27 47 205 -5 16 33 5 18 5 15 15 45 53 18 53 56 84 0 0 17 30 37 12 24 31 47 206 -6 16 44 42 18 17 0 15 57 26 19 5 47 85 0 0 17 42 46 12 24 35 46 207 -7 16 56 46 18 29 13 16 9 26 19 18 4 86 0 0 17 55 22 12 24 39 45 208 -8 17 9 18 18 41 54 16 21 53 19 30 50 87 0 0 18 8 24 12 24 43 45 209 -9 17 22 16 18 55 1 16 34 47 19 44 2 88 0 0 18 21 54 12 24 47 44 210 -10 17 35 41 19 8 36 16 48 7 19 57 42 89 0 0 18 35 50 12 24 50 43 211 -11 17 49 32 19 22 37 17 1 53 20 11 48 90 0 0 18 50 12 12 24 54 43 212 -12 18 3 50 19 37 4 17 16 6 20 26 21 91 0 0 19 5 0 12 24 58 42 213 -13 18 18 33 19 51 57 17 30 44 20 41 20 92 0 0 19 20 14 12 25 1 41 214 -14 18 33 41 20 7 16 17 45 47 20 56 45 93 0 0 19 35 53 12 25 5 40 215 -15 18 49 15 20 23 1 18 1 15 21 12 35 94 0 0 19 51 57 12 25 8 40 216 -16 19 5 14 20 39 10 18 17 8 21 28 50 95 0 0 20 8 25 12 25 12 39 216 -17 19 21 37 20 55 44 18 33 26 21 45 30 96 0 0 20 25 18 12 25 15 38 217 -18 19 38 24 21 12 43 18 50 8 22 2 35 97 0 0 20 42 35 12 25 19 37 218 -19 19 55 35 21 30 5 19 7 13 22 20 3 98 0 0 21 0 15 12 25 22 36 219 -20 20 13 9 21 47 51 19 24 42 22 37 56 99 0 0 21 18 18 12 25 25 36 220 -21 20 31 6 22 6 0 19 42 33 22 56 11 100 0 0 21 36 44 12 25 28 35 220 -22 20 49 26 22 24 32 20 0 47 23 14 49 101 0 0 21 55 32 12 25 31 34 221 -23 21 8 9 22 43 26 20 19 23 23 33 50 102 0 0 22 14 41 12 25 34 33 222 -24 21 27 12 23 2 42 20 38 21 23 53 12 103 0 0 22 34 12 12 25 37 32 222 -25 21 46 38 23 22 19 20 57 40 24 12 56 104 0 0 22 54 4 12 25 40 31 223 -26 22 6 23 23 42 17 21 17 20 24 33 1 105 0 0 23 14 17 12 25 43 30 224 -27 22 26 30 24 2 36 21 37 20 24 53 26 106 0 0 23 34 49 12 25 46 30 224 -27 22 46 56 24 23 14 21 57 40 25 14 12 107 0 0 23 55 40 12 25 48 29 225 -28 23 7 41 24 44 12 22 18 20 25 35 16 108 0 0 24 16 50 12 25 51 28 226 -29 23 28 45 25 5 28 22 39 18 25 56 39 109 0 0 24 38 19 12 25 53 27 226 -30 23 50 8 25 27 3 23 0 34 26 18 21 110 0 0 25 0 5 12 25 56 26 227 -31 24 11 48 25 48 55 23 22 8 26 40 20 111 0 0 25 22 8 12 25 58 25 228 -32 24 33 45 26 11 5 23 43 59 27 2 36 112 0 0 25 44 28 12 26 0 24 228 -33 24 55 59 26 33 31 24 6 7 27 25 9 113 0 0 26 7 4 12 26 2 23 229 -34 25 18 28 26 56 13 24 28 30 27 47 57 114 0 0 26 29 54 12 26 4 22 229 -35 25 41 13 27 19 10 24 51 9 28 11 1 115 0 0 26 53 0 12 26 6 21 230 -35 26 4 13 27 42 21 25 14 3 28 34 19 116 0 0 27 16 19 12 26 8 20 230 -36 26 27 27 28 5 47 25 37 11 28 57 51 117 0 0 27 39 52 12 26 10 19 231 -37 26 50 54 28 29 25 26 0 32 29 21 36 118 0 0 28 3 38 12 26 12 18 231 -38 27 14 33 28 53 17 26 24 6 29 45 34 119 0 0 28 27 35 12 26 13 17 232 -39 27 38 25 29 17 20 26 47 52 30 9 44 120 0 0 28 51 44 12 26 15 17 233 -39 28 2 28 29 41 34 27 11 50 30 34 4 121 0 0 29 16 3 12 26 16 16 233 -40 28 26 42 30 5 59 27 35 59 30 58 35 122 0 0 29 40 32 12 26 18 15 234 -41 28 51 6 30 30 34 28 0 17 31 23 16 123 0 0 30 5 11 12 26 19 14 234 -42 29 15 40 30 55 18 28 24 45 31 48 5 124 0 0 30 29 58 12 26 20 13 235 -42 29 40 21 31 20 10 28 49 22 32 13 3 125 0 0 30 54 52 12 26 21 12 235 -43 30 5 11 31 45 9 29 14 7 32 38 8 126 0 0 31 19 54 12 26 22 11 236 -44 30 30 8 32 10 16 29 38 59 33 3 20 127 0 0 31 45 2 12 26 23 10 236 -44 30 55 11 32 35 29 30 3 58 33 28 38 128 0 0 32 10 15 12 26 24 9 237 -45 31 20 20 33 0 46 30 29 2 33 54 1 129 0 0 32 35 33 12 26 25 8 238 -46 31 45 34 33 26 9 30 54 12 34 19 28 130 0 0 33 0 55 12 26 26 7 238 -46 32 10 52 33 51 35 31 19 25 34 44 59 131 0 0 33 26 20 12 26 26 6 239 -47 32 36 13 34 17 5 31 44 43 35 10 33 132 0 0 33 51 48 12 26 27 5 239 -47 33 1 37 34 42 37 32 10 3 35 36 9 133 0 0 34 17 18 12 26 27 4 240 -48 33 27 4 35 8 10 32 35 26 36 1 46 134 0 0 34 42 49 12 26 27 3 240 -49 33 52 31 35 33 44 33 0 50 36 27 24 135 0 0 35 8 20 12 26 28 2 241 -49 34 17 59 35 59 19 33 26 15 36 53 2 136 0 0 35 33 51 12 26 28 2 241 -49 34 43 27 36 24 52 .. .. .. 37 18 39 137 0 0 35 59 20 12 26 28 1 242 -50 35 8 54 36 50 25 .. .. .. .. .. .. Uncertainty in time = +/- 5 secs [Prediction of 2008 Sep 11.0] Data for the target star ------------------------ * name: 2UCAC 23211501 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 26 34.5355 DE: -21 58 54.722 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .047, .028 ) * V mag [mag]: 12.1 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 276.7774783545 DE(deg): -21.9778676075 * Equation of equinoxes (radians) : 0.000046892830192 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (147) Protogeneia approx. diameter [km]: 133 approx. diameter ["]: .057 distance from Earth [AU]: 3.22800 * orbital information: orbit source: Preston date of fit: 2008 Sep 05 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 905 number of rejected observations: 119 time covered by the observations: 1903 Aug 05 - 2008 Aug 28 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.010, 85° remarks: * orbital elements for (147) Protogeneia : Mean anomaly = 305.81688010 deg Arg. of pericenter = 102.78601617 deg Long. of node = 248.67178865 deg Inclination = 1.93154717 deg Eccentricity = 0.03266165 Semimajor axis = 3.14144791 AU Perihelion dist = 3.03884303 AU Mag: H = 8.56, G = 0.15 Epoch of elements : MJD 54755.51600000 TDT (2008 Oct 16.516) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 16 147 Protogeneia 12h 23.1m UT 12.1 18 26 34.536-21 58 54.722UCAC 23211501 0.0 14.2 133 5.2 3.228 2.810 1.61 65.4683 -21.982 -9.41 -9.13 12.3855 -0.02607 0.60163 14.34299 0.58948 0.00556 0.00029 2000 304.84046720081011.00000102.786016248.671789 1.9315470.03266165 3.1414479 3.0388430 8.3 5.00.15 RATE 1.7701470 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.049 0.030 90 1.52 0.030 0 54720.5020081016_211501 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Sep 11, 20:22 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org