IOTA/IOTA-ES occultation update for (264) Libussa / TYC 6954-00694-1 event on 2012 Oct 24, 12:38 UT Visible from China, SE Asia Summary ------- On 2012 Oct 24 UT, the 58 km diameter asteroid (264) Libussa will occult a 11.6 mag star in the constellation Aquarius for observers along a path across China, SE Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.6 mag to 12.9 mag (the magnitude of the asteroid) for at most 6.6 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: 77 * date and approx. time of event: 2012 Oct 24, 12:34 - 2012 Oct 24, 12:49 UT * geocentric midpoint of event [JD]: 2456225.02632083 * magnitude of target star: 11.6 * magnitude drop [mag]: 1.6 * estimated maximum duration [s]: 6.6 * Moon: 74 % sunlit, 18° distance * Sun: 112° distance * rough path description: China, SE Asia The occultation path -------------------- * approximate projected width [km]: 60 * 1 sigma uncertainty interval [path widths]: +/- 0.72 * 1 sigma uncertainty interval [seconds]: +/- 4.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .032 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .032", .025", 81° ) * approx speed of asteroid's shadow [km/s]: 8.7242 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6954-00694-1 by 264 Libussa on 2012 Oct 24 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 136 12 53 61 0 0 12 49 43 1 208 -37 136 50 10 135 35 45 137 44 6 134 42 30 135 9 10 60 0 0 12 49 43 2 207 -38 135 45 4 134 33 23 136 37 1 133 42 3 134 9 5 59 0 0 12 49 42 3 206 -38 134 43 44 133 34 32 135 33 50 132 44 58 133 12 14 58 0 0 12 49 41 4 205 -39 133 45 44 132 38 50 134 34 10 131 50 53 132 18 19 57 0 0 12 49 40 5 205 -39 132 50 46 131 45 58 133 37 38 130 59 31 131 27 2 56 0 0 12 49 39 6 204 -39 131 58 30 130 55 39 132 43 57 130 10 35 130 38 9 55 0 0 12 49 37 7 203 -40 131 8 42 130 7 39 131 52 49 129 23 52 129 51 25 54 0 0 12 49 35 9 202 -40 130 21 8 129 21 46 131 4 1 128 39 10 129 6 40 53 0 0 12 49 33 10 202 -41 129 35 35 128 37 47 130 17 20 127 56 18 128 23 42 52 0 0 12 49 30 11 201 -41 128 51 54 127 55 34 129 32 35 127 15 7 127 42 24 51 0 0 12 49 28 12 201 -41 128 9 55 127 14 56 128 49 36 126 35 28 127 2 37 50 0 0 12 49 25 13 200 -42 127 29 29 126 35 47 128 8 14 125 57 13 126 24 13 49 0 0 12 49 21 14 200 -42 126 50 29 125 57 59 127 28 22 125 20 16 125 47 6 48 0 0 12 49 18 15 199 -42 126 12 48 125 21 26 126 49 52 124 44 31 125 11 10 47 0 0 12 49 14 16 199 -42 125 36 20 124 46 1 126 12 38 124 9 52 124 36 19 46 0 0 12 49 10 17 198 -43 125 0 59 124 11 41 125 36 33 123 36 14 124 2 29 45 0 0 12 49 6 18 198 -43 124 26 41 123 38 19 125 1 34 123 3 32 123 29 35 44 0 0 12 49 1 19 197 -43 123 53 20 123 5 51 124 27 35 122 31 43 122 57 33 43 0 0 12 48 56 21 197 -43 123 20 53 122 34 15 123 54 31 122 0 42 122 26 20 42 0 0 12 48 51 22 197 -43 122 49 16 122 3 25 123 22 19 121 30 26 121 55 51 41 0 0 12 48 46 23 196 -43 122 18 24 121 33 18 122 50 55 121 0 51 121 26 3 40 0 0 12 48 41 24 196 -43 121 48 15 121 3 52 122 20 15 120 31 56 120 56 54 39 0 0 12 48 35 25 195 -43 121 18 46 120 35 3 121 50 17 120 3 35 120 28 21 38 0 0 12 48 29 26 195 -43 120 49 54 120 6 49 121 20 57 119 35 49 120 0 21 37 0 0 12 48 23 27 195 -43 120 21 36 119 39 7 120 52 13 119 8 32 119 32 52 36 0 0 12 48 16 28 194 -43 119 53 50 119 11 55 120 24 2 118 41 45 119 5 52 35 0 0 12 48 10 29 194 -43 119 26 34 118 45 11 119 56 22 118 15 24 118 39 18 34 0 0 12 48 3 30 194 -43 118 59 44 118 18 52 119 29 11 117 49 27 118 13 9 33 0 0 12 47 56 31 193 -43 118 33 21 117 52 57 119 2 26 117 23 53 117 47 22 32 0 0 12 47 48 32 193 -43 118 7 20 117 27 24 118 36 5 116 58 40 117 21 56 31 0 0 12 47 41 33 193 -43 117 41 41 117 2 12 118 10 8 116 33 46 116 56 50 30 0 0 12 47 33 34 192 -43 117 16 22 116 37 17 117 44 31 116 9 9 116 32 1 29 0 0 12 47 25 35 192 -43 116 51 22 116 12 40 117 19 14 115 44 48 116 7 28 28 0 0 12 47 17 36 192 -42 116 26 38 115 48 18 116 54 14 115 20 42 115 43 10 27 0 0 12 47 8 38 191 -42 116 2 10 115 24 11 116 29 30 114 56 49 115 19 5 26 0 0 12 47 0 39 191 -42 115 37 55 115 0 15 116 5 2 114 33 8 114 55 13 25 0 0 12 46 51 40 191 -42 115 13 53 114 36 32 115 40 46 114 9 37 114 31 30 24 0 0 12 46 42 41 190 -41 114 50 2 114 12 58 115 16 43 113 46 16 114 7 58 23 0 0 12 46 33 42 190 -41 114 26 21 113 49 33 114 52 50 113 23 3 113 44 33 22 0 0 12 46 23 43 189 -41 114 2 49 113 26 16 114 29 7 112 59 57 113 21 15 21 0 0 12 46 14 44 189 -40 113 39 24 113 3 6 114 5 32 112 36 56 112 58 4 20 0 0 12 46 4 45 189 -40 113 16 6 112 40 1 113 42 4 112 14 1 112 34 57 19 0 0 12 45 54 46 188 -40 112 52 53 112 17 0 113 18 42 111 51 9 112 11 53 18 0 0 12 45 44 47 188 -39 112 29 44 111 54 2 112 55 24 111 28 19 111 48 52 17 0 0 12 45 33 48 188 -39 112 6 38 111 31 6 112 32 11 111 5 31 111 25 53 16 0 0 12 45 23 49 187 -38 111 43 33 111 8 12 112 9 0 110 42 43 111 2 54 15 0 0 12 45 12 50 187 -38 111 20 30 110 45 17 111 45 50 110 19 54 110 39 54 14 0 0 12 45 1 51 186 -37 110 57 27 110 22 21 111 22 41 109 57 4 110 16 53 13 0 0 12 44 50 52 186 -37 110 34 22 109 59 24 110 59 31 109 34 11 109 53 49 12 0 0 12 44 39 53 185 -36 110 11 15 109 36 23 110 36 19 109 11 14 109 30 41 11 0 0 12 44 28 54 185 -36 109 48 4 109 13 17 110 13 5 108 48 13 109 7 28 10 0 0 12 44 16 55 184 -35 109 24 49 108 50 7 109 49 46 108 25 6 108 44 10 9 0 0 12 44 4 56 183 -35 109 1 29 108 26 50 109 26 23 108 1 51 108 20 44 8 0 0 12 43 52 57 183 -34 108 38 1 108 3 26 109 2 54 107 38 29 107 57 10 7 0 0 12 43 40 58 182 -33 108 14 27 107 39 53 108 39 17 107 14 58 107 33 28 6 0 0 12 43 28 59 181 -33 107 50 43 107 16 11 108 15 33 106 51 17 107 9 34 5 0 0 12 43 16 60 181 -32 107 26 50 106 52 18 107 51 39 106 27 24 106 45 30 4 0 0 12 43 3 61 180 -32 107 2 45 106 28 13 107 27 35 106 3 19 106 21 13 3 0 0 12 42 51 62 179 -31 106 38 29 106 3 55 107 3 19 105 39 0 105 56 42 2 0 0 12 42 38 63 178 -30 106 13 59 105 39 23 106 38 50 105 14 26 105 31 56 1 0 0 12 42 25 64 177 -30 105 49 14 105 14 36 106 14 7 104 49 37 105 6 53 0 0 0 12 42 12 65 176 -29 105 24 13 104 49 32 105 49 9 104 24 30 104 41 33 - 1 0 0 12 41 59 66 174 -28 104 58 56 104 24 10 105 23 54 103 59 4 104 15 54 - 2 0 0 12 41 46 67 173 -27 104 33 19 103 58 28 104 58 22 103 33 19 103 49 55 - 3 0 0 12 41 32 68 172 -27 104 7 23 103 32 25 104 32 30 103 7 12 103 23 34 - 4 0 0 12 41 19 69 170 -26 103 41 6 103 6 1 104 6 17 102 40 42 102 56 50 - 5 0 0 12 41 5 70 168 -25 103 14 25 102 39 12 103 39 43 102 13 47 102 29 40 - 6 0 0 12 40 52 71 166 -25 102 47 20 102 11 58 103 12 44 101 46 27 102 2 4 - 7 0 0 12 40 38 71 164 -24 102 19 49 101 44 18 102 45 20 101 18 38 101 34 0 - 8 0 0 12 40 24 72 162 -23 101 51 51 101 16 8 102 17 29 100 50 20 101 5 26 - 9 0 0 12 40 10 73 159 -22 101 23 23 100 47 28 101 49 10 100 21 31 100 36 20 -10 0 0 12 39 55 74 156 -21 100 54 23 100 18 15 101 20 19 99 52 9 100 6 40 -11 0 0 12 39 41 74 153 -21 100 24 50 99 48 27 100 50 56 99 22 11 99 36 23 -12 0 0 12 39 27 75 150 -20 99 54 41 99 18 3 100 20 59 98 51 35 Latitude Latitude Latitude Latitude 98 0 0 -15 2 55 12 38 42 76 138 -17 -15 37 15 -14 28 23 -16 26 23 -13 38 20 97 0 0 -16 50 35 12 38 16 77 129 -16 -17 24 2 -16 16 58 -18 11 55 -15 28 14 96 0 0 -18 33 39 12 37 50 77 121 -14 -19 6 14 -18 0 54 -19 52 53 -17 13 27 95 0 0 -20 12 13 12 37 26 77 113 -13 -20 43 58 -19 40 18 -21 29 27 -18 54 5 94 0 0 -21 46 26 12 37 2 76 106 -11 -22 17 24 -21 15 20 -23 1 44 -20 30 16 93 0 0 -23 16 27 12 36 39 76 100 -10 -23 46 39 -22 46 7 -24 29 55 -22 2 11 92 0 0 -24 42 26 12 36 17 75 94 -8 -25 11 55 -24 12 51 -25 54 8 -23 30 0 91 0 0 -26 4 34 12 35 56 74 90 -7 -26 33 20 -25 35 40 -27 14 35 -24 53 51 90 0 0 -27 22 59 12 35 35 73 86 -6 -27 51 6 -26 54 46 -28 31 24 -26 13 55 89 0 0 -28 37 53 12 35 16 72 83 -4 -29 5 22 -28 10 18 -29 44 45 -27 30 23 88 0 0 -29 49 24 12 34 57 71 80 -3 -30 16 17 -29 22 26 -30 54 49 -28 43 24 87 0 0 -30 57 43 12 34 39 69 78 -2 -31 24 1 -30 31 19 -32 1 44 -29 53 8 86 0 0 -32 2 57 12 34 22 68 77 -1 -32 28 43 -31 37 7 -33 5 39 -30 59 44 Uncertainty in time = +/- 5 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: TYC 6954-00694-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 22 03 18.4311 DE: -24 48 40.109 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .024, .022 ) * V mag [mag]: 11.6 * B mag [mag]: 12.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (264) Libussa approx. diameter [km]: 58 approx. diameter ["]: .041 distance from Earth [AU]: 1.95700 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 887 number of rejected observations: 70 time covered by the observations: 1914 Nov 09 - 2012 Sep 27 1 sigma uncertainty ellipse (major, minor, PA): 0.022, 0.011, 70° remarks: * orbital elements for (264) Libussa : Mean anomaly = 324.81461870 deg Arg. of pericenter = 341.22038753 deg Long. of node = 49.72738403 deg Inclination = 10.43106392 deg Eccentricity = 0.13486128 Semimajor axis = 2.79745701 AU Perihelion dist = 2.42018838 AU Mag: H = 8.31, G = 0.15 Epoch of elements : MJD 56224.52700000 TDT (2012 Oct 24.527) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 24 264 Libussa 12h 37.9m UT 11.6 22 3 18.431-24 48 40.11TYC 6954-00694-1 12.3 12.9 58 6.6 1.957 0.753 19.62 108.0310 -24.816 -13.43 -12.00 12.6317 -0.19855 0.10529 2.27642 4.36643 0.00476 0.00229 2000 323.86101220121020.00000341.220388 49.727384 10.4310640.13486128 2.7974570 2.4201884 8.4 5.00.15 RATE 2.1064880 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.032 0.025 81 1.72 0.030 0 0 1 1 056208.0020121024_0694-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 19:21 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org