IOTA/IOTA-ES occultation update for (345) Tercidina / 2UCAC 26730531 event on 2008 Oct 18, 03:19 UT Visible from W USA Summary ------- On 2008 Oct 18 UT, the 108 km diameter asteroid (345) Tercidina will occult a 12.8 mag star in the constellation Serpens for observers along a path across W USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.4 mag to 13.9 mag (the magnitude of the asteroid) for at most 3.9 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: 97 * date and approx. time of event: 2008 Oct 18, 03:19 - 2008 Oct 18, 03:21 UT * midpoint of event [JD]: 2454757.63843333 * magnitude of target star: 12.8 * magnitude drop [mag]: 1.4 * estimated maximum duration [s]: 3.9 * Moon: 85 % sunlit, 153° distance * Sun: 70° distance * rough path description: W USA The occultation path -------------------- * approximate projected width [km]: 178 * 1 sigma uncertainty interval [path widths]: +/- 0.39 * 1 sigma uncertainty interval [seconds]: +/- 1.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .023 +/- .022) * 1 sigma uncertainty ellipse (major, minor, PA): ( .023", .022", 89° ) * approx speed of asteroid's shadow [km/s]: 27.9446 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 26730531 by 345 Tercidina on 2008 Oct 18 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 -151 0 0 38 5 46 3 19 43 37 194 0 37 17 47 38 54 38 36 40 57 39 33 26 -150 0 0 38 3 55 3 19 46 37 195 -1 37 15 57 38 52 47 36 39 8 39 31 33 -149 0 0 38 2 27 3 19 49 36 196 -2 37 14 29 38 51 17 36 37 40 39 30 3 -148 0 0 38 1 19 3 19 52 36 197 -3 37 13 23 38 50 10 36 36 34 39 28 55 -147 0 0 38 0 34 3 19 55 36 198 -3 37 12 38 38 49 24 36 35 49 39 28 9 -146 0 0 38 0 10 3 19 58 36 200 -4 37 12 14 38 49 0 36 35 26 39 27 44 -145 0 0 38 0 8 3 20 1 35 201 -5 37 12 12 38 48 58 36 35 24 39 27 42 -144 0 0 38 0 27 3 20 4 35 202 -6 37 12 31 38 49 17 36 35 43 39 28 2 -143 0 0 38 1 9 3 20 7 35 203 -7 37 13 12 38 49 59 36 36 24 39 28 44 -142 0 0 38 2 12 3 20 10 34 204 -7 37 14 15 38 51 2 36 37 26 39 29 47 -141 0 0 38 3 36 3 20 13 34 205 -8 37 15 39 38 52 27 36 38 50 39 31 13 -140 0 0 38 5 22 3 20 16 34 206 -9 37 17 24 38 54 14 36 40 35 39 33 0 -139 0 0 38 7 30 3 20 19 33 207 -10 37 19 31 38 56 22 36 42 41 39 35 10 -138 0 0 38 9 59 3 20 22 33 209 -11 37 21 59 38 58 53 36 45 8 39 37 41 -137 0 0 38 12 50 3 20 25 32 210 -11 37 24 49 39 1 44 36 47 57 39 40 33 -136 0 0 38 16 2 3 20 27 32 211 -12 37 27 59 39 4 58 36 51 7 39 43 48 -135 0 0 38 19 35 3 20 30 32 212 -13 37 31 31 39 8 32 36 54 37 39 47 24 -134 0 0 38 23 29 3 20 33 31 213 -14 37 35 24 39 12 28 36 58 29 39 51 21 -133 0 0 38 27 44 3 20 36 31 214 -14 37 39 37 39 16 45 37 2 41 39 55 40 -132 0 0 38 32 21 3 20 38 30 215 -15 37 44 12 39 21 24 37 7 14 40 0 19 -131 0 0 38 37 18 3 20 41 30 216 -16 37 49 7 39 26 23 37 12 8 40 5 20 -130 0 0 38 42 35 3 20 43 29 217 -17 37 54 23 39 31 43 37 17 22 40 10 42 -129 0 0 38 48 14 3 20 46 28 218 -18 37 59 59 39 37 24 37 22 56 40 16 25 -128 0 0 38 54 12 3 20 48 28 218 -18 38 5 55 39 43 25 37 28 51 40 22 28 -127 0 0 39 0 31 3 20 51 27 219 -19 38 12 11 39 49 46 37 35 5 40 28 52 -126 0 0 39 7 10 3 20 53 27 220 -20 38 18 48 39 56 28 37 41 39 40 35 36 -125 0 0 39 14 9 3 20 56 26 221 -21 38 25 44 40 3 30 37 48 33 40 42 41 -124 0 0 39 21 28 3 20 58 26 222 -22 38 32 59 40 10 52 37 55 47 40 50 5 -123 0 0 39 29 6 3 21 0 25 223 -22 38 40 34 40 18 33 38 3 20 40 57 49 -122 0 0 39 37 3 3 21 2 24 224 -23 38 48 28 40 26 34 38 11 11 41 5 52 -121 0 0 39 45 20 3 21 4 24 225 -24 38 56 42 40 34 54 38 19 22 41 14 15 -120 0 0 39 53 55 3 21 6 23 226 -25 39 5 14 40 43 33 38 27 52 41 22 57 -119 0 0 40 2 49 3 21 8 22 226 -25 39 14 4 40 52 31 38 36 39 41 31 58 -118 0 0 40 12 2 3 21 10 22 227 -26 39 23 13 41 1 47 38 45 45 41 41 18 -117 0 0 40 21 32 3 21 12 21 228 -27 39 32 40 41 11 22 38 55 10 41 50 55 -116 0 0 40 31 21 3 21 14 20 229 -27 39 42 24 41 21 14 39 4 51 42 0 51 -115 0 0 40 41 27 3 21 16 20 230 -28 39 52 26 41 31 24 39 14 51 42 11 5 -114 0 0 40 51 50 3 21 17 19 230 -29 40 2 46 41 41 52 39 25 7 42 21 36 -113 0 0 41 2 31 3 21 19 18 231 -30 40 13 22 41 52 37 39 35 40 42 32 25 -112 0 0 41 13 28 3 21 21 18 232 -30 40 24 15 42 3 39 39 46 30 42 43 30 -111 0 0 41 24 42 3 21 22 17 233 -31 40 35 25 42 14 57 39 57 37 42 54 52 -110 0 0 41 36 12 3 21 24 16 233 -32 40 46 50 42 26 32 40 8 59 43 6 31 -109 0 0 41 47 57 3 21 25 15 234 -32 40 58 32 42 38 22 40 20 37 43 18 25 -108 0 0 41 59 59 3 21 26 15 235 -33 41 10 29 42 50 28 40 32 30 43 30 35 -107 0 0 42 12 15 3 21 28 14 236 -34 41 22 41 43 2 50 40 44 39 43 43 1 -106 0 0 42 24 47 3 21 29 13 236 -34 41 35 7 43 15 26 40 57 2 43 55 41 -105 0 0 42 37 33 3 21 30 12 237 -35 41 47 48 43 28 17 41 9 40 44 8 36 -104 0 0 42 50 33 3 21 31 12 238 -35 42 0 44 43 41 22 41 22 32 44 21 45 -103 0 0 43 3 46 3 21 32 11 239 -36 42 13 53 43 54 41 41 35 37 44 35 9 -102 0 0 43 17 14 3 21 33 10 239 -37 42 27 15 44 8 13 41 48 56 44 48 45 -101 0 0 43 30 54 3 21 34 9 240 -37 42 40 51 44 21 59 42 2 28 45 2 35 -100 0 0 43 44 47 3 21 35 9 241 -38 42 54 39 44 35 57 42 16 12 45 16 37 - 99 0 0 43 58 52 3 21 35 8 241 -38 43 8 39 44 50 7 42 30 9 45 30 52 - 98 0 0 44 13 9 3 21 36 7 242 -39 43 22 51 45 4 29 42 44 17 45 45 18 - 97 0 0 44 27 37 3 21 36 6 243 -39 43 37 14 45 19 3 42 58 37 45 59 56 - 96 0 0 44 42 17 3 21 37 6 244 -40 43 51 49 45 33 48 43 13 8 46 14 45 - 95 0 0 44 57 7 3 21 37 5 244 -40 44 6 34 45 48 43 43 27 50 46 29 45 - 94 0 0 45 12 7 3 21 38 4 245 -41 44 21 29 46 3 49 43 42 41 46 44 55 - 93 0 0 45 27 17 3 21 38 4 246 -41 44 36 35 46 19 4 43 57 43 47 0 14 - 92 0 0 45 42 37 3 21 38 3 246 -42 44 51 49 46 34 28 .. .. .. 47 15 43 - 91 0 0 45 58 5 3 21 39 2 247 -42 45 7 12 46 50 2 .. .. .. 47 31 21 - 90 0 0 46 13 41 3 21 39 1 248 -42 45 22 44 47 5 43 .. .. .. 47 47 7 - 89 0 0 46 29 26 3 21 39 1 249 -43 45 38 24 47 21 33 .. .. .. .. .. .. Uncertainty in time = +/- 2 secs [Prediction of 2008 Sep 12.0] Data for the target star ------------------------ * name: 2UCAC 26730531 * constellation : Serpens * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 18 11.1486 DE: -14 15 55.633 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .021 ) * V mag [mag]: 12.8 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 274.6724289043 DE(deg): -14.2625230314 * Equation of equinoxes (radians) : 0.000047416422810 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (345) Tercidina approx. diameter [km]: 108 approx. diameter ["]: .057 distance from Earth [AU]: 2.59800 * orbital information: orbit source: Preston date of fit: 2008 Sep 05 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 792 number of rejected observations: 139 time covered by the observations: 1901 Mar 27 - 2008 Aug 21 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.007, 83° remarks: * orbital elements for (345) Tercidina : Mean anomaly = 218.72441957 deg Arg. of pericenter = 229.99624095 deg Long. of node = 212.74365808 deg Inclination = 9.74594574 deg Eccentricity = 0.06047537 Semimajor axis = 2.32642320 AU Perihelion dist = 2.18573189 AU Mag: H = 8.68, G = 0.10 Epoch of elements : MJD 54757.13800000 TDT (2008 Oct 18.138) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 18 345 Tercidina 3h 19.3m UT 12.8 18 18 11.149-14 15 55.632UCAC 26730531 0.0 13.9 108 3.9 2.598 3.662 -3.99 -162.2819 -14.264 126.45 -9.72 3.3224 0.05818 0.79228 15.72864 -1.17863 0.00527 0.00047 2000 216.74176320081011.00000229.996241212.743658 9.7459460.06047537 2.3264232 2.1857319 8.7 5.00.10 RATE 2.7776080 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.023 0.022 89 1.39 0.022 0 54721.5020081018_730531 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Sep 12, 18:17 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org