IOTA/IOTA-ES occultation update for (287) Nephthys / 2UCAC 24006931 event on 2008 Oct 13, 04:25 UT Visible from S USA, N Mexico Summary ------- On 2008 Oct 13 UT, the 68 km diameter asteroid (287) Nephthys will occult a 13.3 mag star in the constellation Capricornus for observers along a path across S USA, N Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 0.4 mag to 12.4 mag (the magnitude of the asteroid) for at most 8.2 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: 30 * date and approx. time of event: 2008 Oct 13, 04:20 - 2008 Oct 13, 04:35 UT * magnitude of target star: 13.3 * magnitude drop [mag]: 0.4 * estimated maximum duration [s]: 8.2 * Moon: 97 % sunlit, 49° distance * Sun: 110° distance * rough path description: S USA, N Mexico The occultation path -------------------- * approximate projected width [km]: 97 * 1 sigma uncertainty interval [path widths]: +/- 2.26 * 1 sigma uncertainty interval [seconds]: +/- 17.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .118 +/- .118) * 1 sigma uncertainty ellipse (major, minor, PA): ( .118", .118", 90° ) * approx speed of asteroid's shadow [km/s]: 8.2752 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 24006931 by 287 Nephthys on 2008 Oct 13 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 -163 0 0 29 30 48 4 20 39 33 147 0 29 3 39 29 58 11 27 3 32 32 5 2 -162 0 0 29 16 11 4 20 49 34 148 -1 28 49 5 29 43 31 26 49 11 31 50 7 -161 0 0 29 2 0 4 20 59 34 149 -2 28 34 57 29 29 17 26 35 16 31 35 38 -160 0 0 28 48 15 4 21 10 35 149 -3 28 21 14 29 15 29 26 21 46 31 21 35 -159 0 0 28 34 55 4 21 20 36 150 -4 28 7 58 29 2 7 26 8 41 31 7 58 -158 0 0 28 22 3 4 21 31 36 151 -4 27 55 8 28 49 11 25 56 3 30 54 49 -157 0 0 28 9 37 4 21 42 37 152 -5 27 42 44 28 36 42 25 43 51 30 42 7 -156 0 0 27 57 38 4 21 53 37 154 -6 27 30 48 28 24 41 25 32 6 30 29 53 -155 0 0 27 46 7 4 22 4 38 155 -7 27 19 20 28 13 8 25 20 48 30 18 7 -154 0 0 27 35 4 4 22 15 39 156 -8 27 8 19 28 2 2 25 9 57 30 6 50 -153 0 0 27 24 29 4 22 26 39 157 -9 26 57 47 27 51 25 24 59 35 29 56 1 -152 0 0 27 14 23 4 22 38 40 158 -10 26 47 43 27 41 16 24 49 40 29 45 41 -151 0 0 27 4 45 4 22 50 40 159 -11 26 38 7 27 31 36 24 40 14 29 35 51 -150 0 0 26 55 37 4 23 1 41 160 -12 26 29 1 27 22 26 24 31 16 29 26 31 -149 0 0 26 46 58 4 23 13 41 161 -13 26 20 23 27 13 45 24 22 47 29 17 40 -148 0 0 26 38 48 4 23 25 41 163 -14 26 12 15 27 5 33 24 14 46 29 9 19 -147 0 0 26 31 8 4 23 38 42 164 -15 26 4 37 26 57 51 24 7 15 29 1 29 -146 0 0 26 23 58 4 23 50 42 165 -15 25 57 29 26 50 40 24 0 14 28 54 9 -145 0 0 26 17 18 4 24 2 43 166 -16 25 50 50 26 43 58 23 53 42 28 47 20 -144 0 0 26 11 8 4 24 15 43 168 -17 25 44 42 26 37 47 23 47 39 28 41 3 -143 0 0 26 5 29 4 24 27 43 169 -18 25 39 4 26 32 7 23 42 7 28 35 16 -142 0 0 26 0 20 4 24 40 43 170 -19 25 33 57 26 26 57 23 37 4 28 30 0 -141 0 0 25 55 42 4 24 52 44 172 -20 25 29 20 26 22 18 23 32 32 28 25 16 -140 0 0 25 51 35 4 25 5 44 173 -21 25 25 14 26 18 10 23 28 30 28 21 3 -139 0 0 25 47 59 4 25 18 44 174 -22 25 21 38 26 14 33 23 24 58 28 17 22 -138 0 0 25 44 54 4 25 30 44 176 -23 25 18 34 26 11 27 23 21 57 28 14 13 -137 0 0 25 42 20 4 25 43 44 177 -24 25 16 0 26 8 52 23 19 26 28 11 35 -136 0 0 25 40 17 4 25 56 44 179 -25 25 13 58 26 6 49 23 17 25 28 9 29 -135 0 0 25 38 45 4 26 9 44 180 -26 25 12 27 26 5 17 23 15 56 28 7 55 -134 0 0 25 37 45 4 26 21 44 181 -27 25 11 27 26 4 16 23 14 57 28 6 53 -133 0 0 25 37 16 4 26 34 44 183 -28 25 10 57 26 3 47 23 14 28 28 6 24 -132 0 0 25 37 18 4 26 47 44 184 -29 25 11 0 26 3 49 23 14 30 28 6 26 -131 0 0 25 37 51 4 27 0 44 185 -30 25 11 33 26 4 22 23 15 3 28 7 0 -130 0 0 25 38 56 4 27 12 44 187 -31 25 12 37 26 5 27 23 16 7 28 8 5 -129 0 0 25 40 32 4 27 25 44 188 -32 25 14 13 26 7 3 23 17 41 28 9 43 -128 0 0 25 42 39 4 27 38 44 190 -32 25 16 19 26 9 11 23 19 45 28 11 53 -127 0 0 25 45 17 4 27 50 43 191 -33 25 18 57 26 11 49 23 22 20 28 14 34 -126 0 0 25 48 26 4 28 3 43 192 -34 25 22 5 26 14 59 23 25 26 28 17 48 -125 0 0 25 52 6 4 28 15 43 194 -35 25 25 45 26 18 40 23 29 2 28 21 33 -124 0 0 25 56 17 4 28 28 43 195 -36 25 29 55 26 22 52 23 33 8 28 25 49 -123 0 0 26 0 59 4 28 40 42 196 -37 25 34 35 26 27 35 23 37 44 28 30 37 -122 0 0 26 6 11 4 28 52 42 197 -38 25 39 46 26 32 48 23 42 50 28 35 56 -121 0 0 26 11 54 4 29 5 42 199 -39 25 45 28 26 38 32 23 48 27 28 41 46 -120 0 0 26 18 7 4 29 17 41 200 -40 25 51 40 26 44 47 23 54 33 28 48 7 -119 0 0 26 24 50 4 29 29 41 201 -41 25 58 21 26 51 31 24 1 8 28 54 59 -118 0 0 26 32 3 4 29 40 40 202 -42 26 5 33 26 58 46 24 8 13 29 2 22 -117 0 0 26 39 46 4 29 52 40 203 -43 26 13 14 27 6 31 24 15 47 29 10 15 -116 0 0 26 47 59 4 30 4 39 204 -43 26 21 25 27 14 45 24 23 50 29 18 38 -115 0 0 26 56 40 4 30 15 39 206 -44 26 30 5 27 23 29 24 32 22 29 27 31 -114 0 0 27 5 51 4 30 27 38 207 -45 26 39 14 27 32 42 24 41 23 29 36 54 -113 0 0 27 15 31 4 30 38 38 208 -46 26 48 51 27 42 24 24 50 51 29 46 46 -112 0 0 27 25 39 4 30 49 37 209 -47 26 58 58 27 52 34 25 0 48 29 57 7 -111 0 0 27 36 16 4 31 0 36 210 -48 27 9 32 28 3 13 25 11 13 30 7 58 -110 0 0 27 47 21 4 31 11 36 211 -48 27 20 34 28 14 20 25 22 5 30 19 17 -109 0 0 27 58 53 4 31 21 35 212 -49 27 32 4 28 25 55 25 33 25 30 31 4 -108 0 0 28 10 53 4 31 31 35 213 -50 27 44 1 28 37 58 25 45 11 30 43 19 -107 0 0 28 23 20 4 31 42 34 214 -51 27 56 25 28 50 27 25 57 24 30 56 1 -106 0 0 28 36 13 4 31 52 33 215 -51 28 9 16 29 3 23 26 10 3 31 9 11 -105 0 0 28 49 33 4 32 1 32 216 -52 28 22 33 29 16 46 26 23 8 31 22 47 -104 0 0 29 3 18 4 32 11 32 216 -53 28 36 16 29 30 35 26 36 39 31 36 50 -103 0 0 29 17 30 4 32 20 31 217 -54 28 50 24 29 44 49 26 50 35 31 51 19 -102 0 0 29 32 6 4 32 30 30 218 -54 29 4 58 29 59 28 27 4 55 32 6 14 -101 0 0 29 47 7 4 32 39 30 219 -55 29 19 55 30 14 32 27 19 40 32 21 33 -100 0 0 30 2 32 4 32 47 29 220 -55 29 35 18 30 30 1 27 34 49 32 37 17 - 99 0 0 30 18 21 4 32 56 28 221 -56 29 51 3 30 45 53 27 50 21 32 53 26 - 98 0 0 30 34 34 4 33 4 27 221 -57 30 7 13 31 2 9 28 6 17 33 9 58 - 97 0 0 30 51 9 4 33 12 26 222 -57 30 23 45 31 18 48 28 22 35 33 26 53 - 96 0 0 31 8 7 4 33 20 26 223 -58 30 40 39 31 35 49 28 39 15 33 44 11 - 95 0 0 31 25 26 4 33 28 25 224 -58 30 57 55 31 53 12 28 56 16 34 1 51 - 94 0 0 31 43 7 4 33 35 24 224 -59 31 15 32 32 10 56 29 13 39 34 19 53 - 93 0 0 32 1 8 4 33 42 23 225 -59 31 33 30 32 29 1 29 31 22 34 38 15 - 92 0 0 32 19 30 4 33 49 22 226 -59 31 51 48 32 47 26 29 49 26 34 56 58 - 91 0 0 32 38 12 4 33 56 21 226 -60 32 10 26 33 6 11 30 7 49 35 16 1 - 90 0 0 32 57 12 4 34 2 21 227 -60 32 29 23 33 25 16 30 26 30 35 35 23 - 89 0 0 33 16 31 4 34 8 20 228 -60 32 48 39 33 44 38 30 45 31 35 55 4 - 88 0 0 33 36 8 4 34 14 19 229 -60 33 8 12 34 4 19 31 4 49 36 15 3 - 87 0 0 33 56 2 4 34 19 18 229 -61 33 28 2 34 24 17 31 24 24 36 35 19 - 86 0 0 34 16 13 4 34 25 17 230 -61 33 48 9 34 44 31 31 44 16 36 55 52 - 85 0 0 34 36 40 4 34 30 16 231 -61 34 8 33 35 5 2 32 4 24 37 16 41 - 84 0 0 34 57 22 4 34 35 15 231 -61 34 29 11 35 25 48 32 24 47 37 37 45 - 83 0 0 35 18 19 4 34 39 15 232 -61 34 50 5 35 46 49 32 45 25 37 59 5 - 82 0 0 35 39 30 4 34 43 14 232 -61 35 11 12 36 8 3 33 6 18 38 20 38 - 81 0 0 36 0 54 4 34 47 13 233 -61 35 32 33 36 29 32 33 27 23 38 42 24 - 80 0 0 36 22 32 4 34 51 12 234 -61 35 54 7 36 51 12 33 48 42 39 4 23 - 79 0 0 36 44 21 4 34 54 11 234 -61 36 15 52 37 13 5 34 10 13 39 26 34 - 78 0 0 37 6 22 4 34 57 10 235 -60 36 37 49 37 35 10 34 31 55 39 48 57 - 77 0 0 37 28 33 4 35 0 9 236 -60 36 59 57 37 57 25 34 53 48 40 11 29 - 76 0 0 37 50 54 4 35 3 8 236 -60 37 22 15 38 19 49 35 15 52 40 34 12 - 75 0 0 38 13 25 4 35 5 8 237 -60 37 44 42 38 42 23 .. .. .. 40 57 3 - 74 0 0 38 36 4 4 35 7 7 238 -59 38 7 18 39 5 6 .. .. .. 41 20 3 - 73 0 0 38 58 51 4 35 9 6 238 -59 38 30 1 39 27 56 .. .. .. 41 43 10 - 72 0 0 39 21 45 4 35 11 5 239 -59 38 52 52 39 50 54 .. .. .. 42 6 24 - 71 0 0 39 44 45 4 35 12 4 240 -58 39 15 50 40 13 57 .. .. .. 42 29 44 - 70 0 0 40 7 51 4 35 13 3 240 -58 39 38 53 40 37 7 .. .. .. 42 53 10 - 69 0 0 40 31 3 4 35 14 2 241 -57 40 2 1 41 0 21 .. .. .. 43 16 40 - 68 0 0 40 54 18 4 35 15 2 241 -57 40 25 13 41 23 40 .. .. .. 43 40 13 - 67 0 0 41 17 37 4 35 15 1 242 -56 40 48 30 41 47 2 .. .. .. .. .. .. Uncertainty in time = +/- 19 secs [Prediction of 2008 Oct 1.0] Data for the target star ------------------------ * name: 2UCAC 24006931 * constellation : Capricornus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 20 54 14.0183 DE: -20 11 11.003 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .117, .117 ) * V mag [mag]: 13.3 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (287) Nephthys approx. diameter [km]: 68 approx. diameter ["]: .052 distance from Earth [AU]: 1.79400 * orbital information: orbit source: Preston date of fit: 2008 Sep 30 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1487 number of rejected observations: 149 time covered by the observations: 1900 Sep 21 - 2008 Sep 24 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.008, 90° remarks: * orbital elements for (287) Nephthys : Mean anomaly = 70.25835463 deg Arg. of pericenter = 118.83134626 deg Long. of node = 142.44879873 deg Inclination = 10.02803065 deg Eccentricity = 0.02417687 Semimajor axis = 2.35296525 AU Perihelion dist = 2.29607793 AU Mag: H = 8.25, G = 0.22 Epoch of elements : MJD 54752.18500000 TDT (2008 Oct 13.185) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 13 287 Nephthys 4h 26.3m UT 13.3 20 54 14.018-20 11 11.002UCAC 24006931 0.0 12.4 68 8.2 1.794 1.627 -0.34 -135.1204 -20.185 109.99 -7.90 4.4379 0.00958 0.71447 4.67019 -0.07080 0.00499 0.00151 2000 69.66168820081011.00000118.831346142.448799 10.0280310.02417687 2.3529653 2.2960779 8.3 5.00.22 RATE 2.7307430 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.118 0.118 90 3.26 0.118 0 54740.5020081013_006931 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Oct 01, 04:43 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org