IOTA/IOTA-ES occultation update for (1268) Libya / UCAC2 19978514 event on 2009 May 12, 10:04 UT Visible from Summary ------- On 2009 May 12 UT, the 94 km diameter asteroid (1268) Libya will occult a 11.9 mag star in the constellation Sagittarius for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 3.6 mag to 15.5 mag (the magnitude of the asteroid) for at most 9.0 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: 45 * date and approx. time of event: 2009 May 12, 09:57 - 2009 May 12, 10:11 UT * magnitude of target star: 11.9 * magnitude drop [mag]: 3.6 * estimated maximum duration [s]: 9.0 * Moon: 90 % sunlit, 4° distance * Sun: 145° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 137 * 1 sigma uncertainty interval [path widths]: +/- 1.44 * 1 sigma uncertainty interval [seconds]: +/- 12.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .060 +/- .055) * 1 sigma uncertainty ellipse (major, minor, PA): ( .060", .055", 90° ) * approx speed of asteroid's shadow [km/s]: 10.4705 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 19978514 by 1268 Libya on 2009 May 12 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 ' " Longitude Longitude Longitude Longitude - 73 43 11 34 0 0 9 57 48 17 216 0 - 75 2 37 - 72 25 5 - 78 59 57 - 68 46 47 - 75 26 57 33 0 0 9 57 57 18 215 -2 - 76 47 24 - 74 7 57 - 80 48 26 - 70 27 36 - 77 13 22 32 0 0 9 58 6 20 214 -4 - 78 35 3 - 75 53 16 - 82 40 33 - 72 10 23 - 79 2 47 31 0 0 9 58 16 22 212 -6 - 80 25 58 - 77 41 22 - 84 36 49 - 73 55 23 - 80 55 39 30 0 0 9 58 27 23 211 -8 - 82 20 36 - 79 32 39 - 86 37 54 - 75 42 56 - 82 52 28 29 0 0 9 58 39 25 210 -9 - 84 19 32 - 81 27 33 - 88 44 34 - 77 33 23 - 84 53 48 28 0 0 9 58 53 27 208 -11 - 86 23 25 - 83 26 36 - 90 57 50 - 79 27 8 Latitude Latitude Latitude Latitude - 86 0 0 27 28 17 9 59 0 28 207 -13 28 11 9 26 46 4 30 18 30 24 47 46 - 87 0 0 27 0 11 9 59 7 29 207 -14 27 42 47 26 18 13 29 49 19 24 20 34 - 88 0 0 26 32 41 9 59 15 29 206 -15 27 15 2 25 50 57 29 20 47 23 53 57 - 89 0 0 26 5 48 9 59 22 30 205 -16 26 47 55 25 24 19 28 52 53 23 27 56 - 90 0 0 25 39 33 9 59 30 31 204 -16 26 21 25 24 58 17 28 25 38 23 2 31 - 91 0 0 25 13 56 9 59 38 32 204 -17 25 55 33 24 32 53 27 59 3 22 37 42 - 92 0 0 24 48 56 9 59 46 32 203 -18 25 30 20 24 8 6 27 33 7 22 13 30 - 93 0 0 24 24 34 9 59 54 33 202 -19 25 5 46 23 43 57 27 7 51 21 49 55 - 94 0 0 24 0 51 10 0 2 34 201 -20 24 41 50 23 20 27 26 43 15 21 26 56 - 95 0 0 23 37 47 10 0 10 34 200 -21 24 18 33 22 57 34 26 19 20 21 4 36 - 96 0 0 23 15 22 10 0 19 35 199 -22 23 55 56 22 35 20 25 56 5 20 42 52 - 97 0 0 22 53 35 10 0 27 36 199 -23 23 33 58 22 13 45 25 33 30 20 21 47 - 98 0 0 22 32 28 10 0 36 36 198 -24 23 12 39 21 52 48 25 11 36 20 1 19 - 99 0 0 22 12 0 10 0 45 37 197 -25 22 52 0 21 32 31 24 50 23 19 41 29 -100 0 0 21 52 11 10 0 54 37 196 -26 22 32 1 21 12 52 24 29 52 19 22 18 -101 0 0 21 33 2 10 1 3 38 195 -27 22 12 42 20 53 53 24 10 1 19 3 44 -102 0 0 21 14 32 10 1 12 39 194 -28 21 54 3 20 35 32 23 50 51 18 45 49 -103 0 0 20 56 43 10 1 21 39 193 -29 21 36 3 20 17 51 23 32 23 18 28 32 -104 0 0 20 39 32 10 1 30 39 192 -30 21 18 44 20 0 50 23 14 36 18 11 54 -105 0 0 20 23 2 10 1 40 40 191 -30 21 2 5 19 44 28 22 57 30 17 55 54 -106 0 0 20 7 12 10 1 49 40 190 -31 20 46 7 19 28 45 22 41 6 17 40 32 -107 0 0 19 52 1 10 1 58 41 189 -32 20 30 48 19 13 42 22 25 23 17 25 49 -108 0 0 19 37 30 10 2 8 41 188 -33 20 16 10 18 59 19 22 10 22 17 11 45 -109 0 0 19 23 40 10 2 17 41 187 -34 20 2 12 18 45 35 21 56 2 16 58 20 -110 0 0 19 10 29 10 2 27 42 185 -35 19 48 55 18 32 31 21 42 24 16 45 33 -111 0 0 18 57 58 10 2 37 42 184 -36 19 36 18 18 20 6 21 29 27 16 33 25 -112 0 0 18 46 8 10 2 46 42 183 -36 19 24 21 18 8 21 21 17 12 16 21 56 -113 0 0 18 34 57 10 2 56 43 182 -37 19 13 5 17 57 16 21 5 38 16 11 5 -114 0 0 18 24 26 10 3 6 43 181 -38 19 2 29 17 46 51 20 54 46 16 0 53 -115 0 0 18 14 36 10 3 16 43 180 -39 18 52 34 17 37 5 20 44 35 15 51 21 -116 0 0 18 5 26 10 3 25 43 179 -40 18 43 19 17 27 59 20 35 6 15 42 26 -117 0 0 17 56 55 10 3 35 43 178 -40 18 34 44 17 19 33 20 26 18 15 34 11 -118 0 0 17 49 5 10 3 45 43 176 -41 18 26 50 17 11 46 20 18 12 15 26 35 -119 0 0 17 41 55 10 3 55 43 175 -42 18 19 36 17 4 39 20 10 47 15 19 37 -120 0 0 17 35 25 10 4 4 43 174 -42 18 13 3 16 58 12 20 4 4 15 13 19 -121 0 0 17 29 35 10 4 14 43 173 -43 18 7 10 16 52 25 19 58 2 15 7 39 -122 0 0 17 24 25 10 4 24 43 172 -44 18 1 58 16 47 18 19 52 42 15 2 38 -123 0 0 17 19 55 10 4 34 43 171 -44 17 57 26 16 42 50 19 48 4 14 58 16 -124 0 0 17 16 6 10 4 44 43 169 -45 17 53 35 16 39 2 19 44 7 14 54 33 -125 0 0 17 12 56 10 4 53 43 168 -46 17 50 24 16 35 54 19 40 52 14 51 28 -126 0 0 17 10 27 10 5 3 43 167 -46 17 47 53 16 33 26 19 38 18 14 49 3 -127 0 0 17 8 38 10 5 13 43 166 -47 17 46 4 16 31 38 19 36 25 14 47 17 -128 0 0 17 7 29 10 5 22 42 165 -47 17 44 54 16 30 29 19 35 15 14 46 9 -129 0 0 17 7 0 10 5 32 42 164 -48 17 44 25 16 30 0 19 34 46 14 45 41 -130 0 0 17 7 12 10 5 41 42 163 -48 17 44 37 16 30 12 19 34 58 14 45 51 -131 0 0 17 8 3 10 5 51 42 162 -49 17 45 30 16 31 3 19 35 53 14 46 41 -132 0 0 17 9 36 10 6 0 41 161 -49 17 47 3 16 32 34 19 37 29 14 48 10 -133 0 0 17 11 48 10 6 10 41 160 -50 17 49 16 16 34 45 19 39 47 14 50 17 -134 0 0 17 14 41 10 6 19 41 159 -50 17 52 11 16 37 36 19 42 46 14 53 4 -135 0 0 17 18 14 10 6 28 40 158 -51 17 55 46 16 41 8 19 46 27 14 56 30 -136 0 0 17 22 27 10 6 37 40 157 -51 18 0 2 16 45 19 19 50 51 15 0 35 -137 0 0 17 27 21 10 6 46 39 156 -51 18 4 59 16 50 10 19 55 56 15 5 20 -138 0 0 17 32 56 10 6 55 39 155 -52 18 10 36 16 55 42 20 1 43 15 10 43 -139 0 0 17 39 11 10 7 4 38 154 -52 18 16 55 17 1 54 20 8 12 15 16 46 -140 0 0 17 46 7 10 7 13 38 153 -52 18 23 54 17 8 46 20 15 23 15 23 29 -141 0 0 17 53 43 10 7 22 37 152 -52 18 31 34 17 16 18 20 23 16 15 30 50 -142 0 0 18 2 0 10 7 31 37 151 -52 18 39 56 17 24 30 20 31 51 15 38 51 -143 0 0 18 10 57 10 7 39 36 150 -52 18 48 58 17 33 23 20 41 8 15 47 31 -144 0 0 18 20 36 10 7 48 36 150 -53 18 58 41 17 42 57 20 51 8 15 56 51 -145 0 0 18 30 55 10 7 56 35 149 -53 19 9 6 17 53 10 21 1 50 16 6 50 -146 0 0 18 41 54 10 8 4 34 148 -53 19 20 12 18 4 4 21 13 14 16 17 29 -147 0 0 18 53 35 10 8 12 34 147 -53 19 31 59 18 15 39 21 25 21 16 28 47 -148 0 0 19 5 57 10 8 20 33 147 -52 19 44 27 18 27 54 21 38 10 16 40 45 -149 0 0 19 18 59 10 8 28 32 146 -52 19 57 37 18 40 50 21 51 41 16 53 23 -150 0 0 19 32 43 10 8 36 32 145 -52 20 11 28 18 54 26 22 5 55 17 6 40 -151 0 0 19 47 7 10 8 43 31 144 -52 20 26 0 19 8 43 22 20 52 17 20 37 -152 0 0 20 2 12 10 8 51 30 144 -52 20 41 13 19 23 41 22 36 30 17 35 13 -153 0 0 20 17 59 10 8 58 29 143 -52 20 57 8 19 39 19 22 52 52 17 50 29 -154 0 0 20 34 26 10 9 5 29 142 -51 21 13 44 19 55 37 23 9 56 18 6 25 -155 0 0 20 51 34 10 9 12 28 142 -51 21 31 2 20 12 37 23 27 43 18 23 0 -156 0 0 21 9 24 10 9 19 27 141 -51 21 49 1 20 30 17 23 46 12 18 40 15 -157 0 0 21 27 54 10 9 26 26 141 -50 22 7 41 20 48 37 24 5 24 18 58 9 -158 0 0 21 47 5 10 9 32 25 140 -50 22 27 3 21 7 38 24 25 19 19 16 43 -159 0 0 22 6 57 10 9 39 25 139 -49 22 47 6 21 27 19 24 45 56 19 35 56 -160 0 0 22 27 29 10 9 45 24 139 -49 23 7 50 21 47 41 25 7 15 19 55 49 -161 0 0 22 48 43 10 9 51 23 138 -48 23 29 15 22 8 43 25 29 17 20 16 21 -162 0 0 23 10 37 10 9 56 22 138 -48 23 51 21 22 30 26 25 52 1 20 37 32 -163 0 0 23 33 11 10 10 2 21 137 -47 24 14 8 22 52 48 26 15 27 20 59 23 -164 0 0 23 56 26 10 10 7 20 137 -47 24 37 36 23 15 51 26 39 35 21 21 52 -165 0 0 24 20 21 10 10 12 19 136 -46 25 1 44 23 39 33 27 4 26 21 45 0 -166 0 0 24 44 56 10 10 17 18 136 -45 25 26 33 24 3 55 27 29 58 22 8 47 -167 0 0 25 10 11 10 10 22 18 135 -45 25 52 2 24 28 56 27 56 11 22 33 12 -168 0 0 25 36 6 10 10 26 17 135 -44 26 18 11 24 54 37 28 23 6 22 58 16 -169 0 0 26 2 39 10 10 31 16 134 -43 26 45 0 25 20 56 28 50 42 23 23 57 -170 0 0 26 29 52 10 10 35 15 133 -43 27 12 28 25 47 54 29 18 58 23 50 16 -171 0 0 26 57 44 10 10 38 14 133 -42 27 40 35 26 15 31 29 47 55 24 17 13 -172 0 0 27 26 13 10 10 42 13 132 -41 28 9 21 26 43 45 30 17 32 24 44 46 -173 0 0 27 55 21 10 10 45 12 132 -40 28 38 45 27 12 37 30 47 49 25 12 57 -174 0 0 28 25 7 10 10 48 11 131 -39 29 8 47 27 42 6 31 18 44 25 41 43 -175 0 0 28 55 29 10 10 51 10 131 -39 29 39 27 28 12 12 31 50 19 26 11 5 -176 0 0 29 26 28 10 10 54 9 130 -38 30 10 43 28 42 54 32 22 31 26 41 3 -177 0 0 29 58 2 10 10 56 8 130 -37 30 42 36 29 14 12 32 55 21 27 11 35 -178 0 0 30 30 12 10 10 58 7 129 -36 31 15 4 29 46 4 33 28 48 .. .. .. -179 0 0 31 2 57 10 11 0 6 129 -35 31 48 8 30 18 31 34 2 51 .. .. .. -180 0 0 31 36 16 10 11 1 5 128 -34 32 21 45 30 51 32 34 37 29 .. .. .. 179 0 0 32 10 7 10 11 2 4 128 -33 32 55 56 31 25 5 35 12 42 .. .. .. 178 0 0 32 44 31 10 11 3 3 127 -32 33 30 40 31 59 10 35 48 28 .. .. .. 177 0 0 33 19 27 10 11 4 2 127 -31 34 5 55 32 33 47 .. .. .. .. .. .. 176 0 0 33 54 52 10 11 4 1 126 -31 34 41 41 33 8 54 .. .. .. .. .. .. Uncertainty in time = +/- 14 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: UCAC2 19978514 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 17 44 22.3619 DE: -28 56 25.788 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .050, .050 ) * V mag [mag]: 11.9 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1268) Libya approx. diameter [km]: 94 approx. diameter ["]: .038 distance from Earth [AU]: 3.39100 * orbital information: orbit source: Preston date of fit: 2008 Mar 20 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 887 number of rejected observations: 67 time covered by the observations: 1930 Apr 29 - 2008 Feb 10 1 sigma uncertainty ellipse (major, minor, PA): 0.034, 0.022, 91° remarks: * orbital elements for (1268) Libya : Mean anomaly = 131.96908631 deg Arg. of pericenter = 126.92114544 deg Long. of node = 351.76836121 deg Inclination = 4.42302932 deg Eccentricity = 0.10357901 Semimajor axis = 3.96032460 AU Perihelion dist = 3.55011808 AU Mag: H = 8.94, G = 0.15 Epoch of elements : MJD 54963.42000000 TDT (2009 May 12.420) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 May 12 1268 Libya 10h 4.1m UT 11.9 17 44 22.362-28 56 25.79UCAC2 19978514 0.0 15.5 94 9.0 3.391 -1.160 -1.80 -115.2471 -28.939 28.06 18.22 10.0685 -0.08524 0.72214 -5.86877 -0.69558 -0.00332 0.00055 2000 131.5413912009 5 9.00000126.921145351.768361 4.4230290.10357901 3.9603246 3.5501181 9.1 5.00.15 RATE 1.2505700 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.060 0.055 90 2.44 0.055 0 54545.5020090512_978514 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 08:12 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org