IOTA/IOTA-ES occultation update for (35) Leukothea / TYC 5807-01091-1 event on 2012 Oct 31, 23:55 UT Visible from E Canada, E USA, Caribbean, Central America Summary ------- On 2012 Oct 31 UT, the 112 km diameter asteroid (35) Leukothea will occult a 10.6 mag star in the constellation Aquarius for observers along a path across E Canada, E USA, Caribbean, Central America. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.8 mag to 14.3 mag (the magnitude of the asteroid) for at most 39.1 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: 88 * date and approx. time of event: 2012 Oct 31, 23:48 - 2012 Nov 01, 00:28 UT * geocentric midpoint of event [JD]: 2456232.49639583 * magnitude of target star: 10.6 * magnitude drop [mag]: 3.8 * estimated maximum duration [s]: 39.1 * Moon: 96 % sunlit, 88° distance * Sun: 116° distance * rough path description: E Canada, E USA, Caribbean, Central America The occultation path -------------------- * approximate projected width [km]: 122 * 1 sigma uncertainty interval [path widths]: +/- 0.56 * 1 sigma uncertainty interval [seconds]: +/- 24.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .029 +/- .034) * 1 sigma uncertainty ellipse (major, minor, PA): ( .034", .029", 356° ) * approx speed of asteroid's shadow [km/s]: 2.8537 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5807-01091-1 by 35 Leukothea on 2012 Oct 31 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 -108 1 22 77 0 0 24 28 45 0 143 -13 -105 5 20 ... .. .. -101 56 2 ... .. .. -105 2 42 76 0 0 24 28 44 1 146 -13 -102 25 9 -107 45 59 - 99 34 28 -110 57 6 -102 34 44 75 0 0 24 28 42 3 149 -14 -100 11 42 -105 2 5 - 97 35 54 -107 53 7 -100 30 2 74 0 0 24 28 39 4 151 -14 - 98 18 44 -102 44 39 - 95 55 8 -105 20 2 - 98 43 27 73 0 0 24 28 36 5 152 -15 - 96 41 54 -100 47 39 - 94 28 32 -103 10 22 - 97 11 19 72 0 0 24 28 32 6 154 -15 - 95 18 1 - 99 6 48 - 93 13 23 -101 19 2 - 95 50 57 71 0 0 24 28 26 7 155 -15 - 94 4 43 - 97 38 59 - 92 7 38 - 99 42 23 - 94 40 17 70 0 0 24 28 20 8 156 -16 - 93 0 11 - 96 21 53 - 91 9 42 - 98 17 41 - 93 37 43 69 0 0 24 28 14 9 157 -16 - 92 3 1 - 95 13 42 - 90 18 21 - 97 2 55 - 92 42 0 68 0 0 24 28 6 10 158 -17 - 91 12 6 - 94 13 2 - 89 32 36 - 95 56 27 - 91 52 9 67 0 0 24 27 58 11 159 -17 - 90 26 30 - 93 18 46 - 88 51 39 - 94 57 3 - 91 7 19 66 0 0 24 27 49 12 159 -17 - 89 45 31 - 92 29 59 - 88 14 49 - 94 3 41 - 90 26 51 65 0 0 24 27 39 13 160 -18 - 89 8 31 - 91 45 57 - 87 41 36 - 93 15 33 - 89 50 11 64 0 0 24 27 29 14 160 -18 - 88 35 0 - 91 6 4 - 87 11 31 - 92 31 56 - 89 16 52 63 0 0 24 27 18 15 161 -18 - 88 4 32 - 90 29 48 - 86 44 12 - 91 52 18 - 88 46 29 62 0 0 24 27 6 16 161 -18 - 87 36 47 - 89 56 45 - 86 19 20 - 91 16 9 - 88 18 44 61 0 0 24 26 53 17 161 -19 - 87 11 26 - 89 26 31 - 85 56 38 - 90 43 6 - 87 53 17 60 0 0 24 26 40 18 162 -19 - 86 48 14 - 88 58 49 - 85 35 52 - 90 12 48 - 87 29 56 59 0 0 24 26 26 19 162 -19 - 86 26 56 - 88 33 22 - 85 16 50 - 89 44 58 - 87 8 27 58 0 0 24 26 11 20 162 -19 - 86 7 21 - 88 9 57 - 84 59 21 - 89 19 19 - 86 48 39 57 0 0 24 25 56 21 162 -20 - 85 49 20 - 87 48 21 - 84 43 17 - 88 55 40 - 86 30 23 56 0 0 24 25 40 22 162 -20 - 85 32 42 - 87 28 24 - 84 28 29 - 88 33 49 - 86 13 29 55 0 0 24 25 24 23 162 -20 - 85 17 21 - 87 9 56 - 84 14 49 - 88 13 35 - 85 57 51 54 0 0 24 25 6 24 162 -20 - 85 3 9 - 86 52 51 - 84 2 13 - 87 54 49 - 85 43 22 53 0 0 24 24 48 25 163 -20 - 84 50 1 - 86 37 0 - 83 50 34 - 87 37 25 - 85 29 56 52 0 0 24 24 30 26 163 -20 - 84 37 50 - 86 22 17 - 83 39 48 - 87 21 15 - 85 17 27 51 0 0 24 24 11 27 163 -21 - 84 26 33 - 86 8 36 - 83 29 50 - 87 6 13 - 85 5 52 50 0 0 24 23 51 28 162 -21 - 84 16 5 - 85 55 54 - 83 20 36 - 86 52 13 - 84 55 7 49 0 0 24 23 30 29 162 -21 - 84 6 23 - 85 44 4 - 83 12 3 - 86 39 12 - 84 45 6 48 0 0 24 23 9 30 162 -21 - 83 57 22 - 85 33 4 - 83 4 8 - 86 27 3 - 84 35 48 47 0 0 24 22 48 31 162 -21 - 83 49 0 - 85 22 49 - 82 56 48 - 86 15 44 - 84 27 9 46 0 0 24 22 25 32 162 -21 - 83 41 14 - 85 13 17 - 82 50 1 - 86 5 11 - 84 19 7 45 0 0 24 22 2 33 162 -21 - 83 34 1 - 85 4 24 - 82 43 44 - 85 55 21 - 84 11 39 44 0 0 24 21 39 34 162 -21 - 83 27 20 - 84 56 8 - 82 37 55 - 85 46 12 - 84 4 43 43 0 0 24 21 15 35 162 -21 - 83 21 9 - 84 48 27 - 82 32 34 - 85 37 39 - 83 58 17 42 0 0 24 20 50 36 161 -21 - 83 15 26 - 84 41 18 - 82 27 37 - 85 29 42 - 83 52 19 41 0 0 24 20 25 37 161 -21 - 83 10 8 - 84 34 40 - 82 23 5 - 85 22 19 - 83 46 49 40 0 0 24 19 59 38 161 -21 - 83 5 16 - 84 28 32 - 82 18 54 - 85 15 27 - 83 41 44 39 0 0 24 19 33 39 161 -21 - 83 0 47 - 84 22 50 - 82 15 5 - 85 9 4 - 83 37 3 38 0 0 24 19 6 40 160 -21 - 82 56 40 - 84 17 35 - 82 11 36 - 85 3 10 - 83 32 45 37 0 0 24 18 39 41 160 -21 - 82 52 54 - 84 12 45 - 82 8 27 - 84 57 43 - 83 28 49 36 0 0 24 18 11 42 160 -21 - 82 49 29 - 84 8 18 - 82 5 36 - 84 52 42 - 83 25 15 35 0 0 24 17 43 43 159 -20 - 82 46 24 - 84 4 14 - 82 3 3 - 84 48 5 - 83 22 1 34 0 0 24 17 14 43 159 -20 - 82 43 38 - 84 0 33 - 82 0 47 - 84 43 52 - 83 19 7 33 0 0 24 16 44 44 158 -20 - 82 41 9 - 83 57 12 - 81 58 48 - 84 40 2 - 83 16 32 32 0 0 24 16 14 45 158 -20 - 82 38 59 - 83 54 12 - 81 57 5 - 84 36 34 - 83 14 15 31 0 0 24 15 44 46 157 -20 - 82 37 6 - 83 51 32 - 81 55 38 - 84 33 27 - 83 12 17 30 0 0 24 15 13 47 157 -20 - 82 35 30 - 83 49 11 - 81 54 26 - 84 30 42 - 83 10 36 29 0 0 24 14 42 48 156 -20 - 82 34 10 - 83 47 10 - 81 53 30 - 84 28 16 - 83 9 13 28 0 0 24 14 10 49 156 -19 - 82 33 6 - 83 45 27 - 81 52 49 - 84 26 11 - 83 8 7 27 0 0 24 13 38 50 155 -19 - 82 32 19 - 83 44 2 - 81 52 22 - 84 24 25 - 83 7 18 26 0 0 24 13 5 51 154 -19 - 82 31 47 - 83 42 55 - 81 52 10 - 84 22 59 - 83 6 45 25 0 0 24 12 32 51 154 -19 - 82 31 32 - 83 42 7 - 81 52 13 - 84 21 51 - 83 6 30 24 0 0 24 11 59 52 153 -18 - 82 31 32 - 83 41 36 - 81 52 30 - 84 21 3 - 83 6 31 23 0 0 24 11 25 53 152 -18 - 82 31 48 - 83 41 22 - 81 53 2 - 84 20 33 - 83 6 49 22 0 0 24 10 50 54 151 -18 - 82 32 19 - 83 41 27 - 81 53 49 - 84 20 22 - 83 7 24 21 0 0 24 10 16 55 150 -18 - 82 33 6 - 83 41 49 - 81 54 50 - 84 20 30 - 83 8 15 20 0 0 24 9 41 55 149 -17 - 82 34 10 - 83 42 28 - 81 56 7 - 84 20 57 - 83 9 24 19 0 0 24 9 5 56 148 -17 - 82 35 29 - 83 43 26 - 81 57 38 - 84 21 42 - 83 10 50 18 0 0 24 8 30 57 147 -17 - 82 37 5 - 83 44 42 - 81 59 25 - 84 22 47 - 83 12 33 17 0 0 24 7 53 58 146 -16 - 82 38 57 - 83 46 16 - 82 1 28 - 84 24 10 - 83 14 34 16 0 0 24 7 17 58 145 -16 - 82 41 6 - 83 48 8 - 82 3 46 - 84 25 53 - 83 16 52 15 0 0 24 6 40 59 144 -15 - 82 43 33 - 83 50 19 - 82 6 21 - 84 27 56 - 83 19 29 14 0 0 24 6 3 60 142 -15 - 82 46 16 - 83 52 50 - 82 9 12 - 84 30 19 - 83 22 25 13 0 0 24 5 26 60 141 -15 - 82 49 18 - 83 55 40 - 82 12 21 - 84 33 2 - 83 25 40 12 0 0 24 4 48 61 139 -14 - 82 52 38 - 83 58 49 - 82 15 47 - 84 36 6 - 83 29 15 11 0 0 24 4 10 62 138 -14 - 82 56 17 - 84 2 19 - 82 19 31 - 84 39 32 - 83 33 9 10 0 0 24 3 32 62 136 -13 - 83 0 15 - 84 6 10 - 82 23 33 - 84 43 19 - 83 37 24 9 0 0 24 2 53 63 134 -13 - 83 4 33 - 84 10 23 - 82 27 55 - 84 47 28 - 83 42 1 8 0 0 24 2 15 63 133 -13 - 83 9 12 - 84 14 57 - 82 32 36 - 84 52 1 - 83 46 59 7 0 0 24 1 36 64 131 -12 - 83 14 12 - 84 19 55 - 82 37 37 - 84 56 56 - 83 52 20 6 0 0 24 0 56 64 129 -12 - 83 19 34 - 84 25 15 - 82 43 0 - 85 2 17 - 83 58 5 5 0 0 24 0 17 65 127 -11 - 83 25 18 - 84 31 0 - 82 48 44 - 85 8 2 - 84 4 13 4 0 0 23 59 37 65 125 -11 - 83 31 25 - 84 37 9 - 82 54 50 - 85 14 12 - 84 10 47 3 0 0 23 58 57 65 123 -10 - 83 37 57 - 84 43 45 - 83 1 20 - 85 20 50 - 84 17 46 2 0 0 23 58 17 66 121 -10 - 83 44 54 - 84 50 46 - 83 8 14 - 85 27 55 - 84 25 12 1 0 0 23 57 37 66 118 -9 - 83 52 16 - 84 58 16 - 83 15 33 - 85 35 28 - 84 33 5 0 0 0 23 56 57 66 116 -9 - 84 0 6 - 85 6 14 - 83 23 18 - 85 43 31 - 84 41 28 - 1 0 0 23 56 16 66 114 -8 - 84 8 23 - 85 14 41 - 83 31 31 - 85 52 5 - 84 50 20 - 2 0 0 23 55 36 66 111 -7 - 84 17 10 - 85 23 40 - 83 40 11 - 86 1 10 - 84 59 44 - 3 0 0 23 54 55 66 109 -7 - 84 26 27 - 85 33 10 - 83 49 21 - 86 10 48 - 85 9 40 - 4 0 0 23 54 14 66 107 -6 - 84 36 15 - 85 43 14 - 83 59 1 - 86 21 1 - 85 20 9 - 5 0 0 23 53 33 66 104 -6 - 84 46 37 - 85 53 52 - 84 9 13 - 86 31 49 - 85 31 14 - 6 0 0 23 52 52 66 102 -5 - 84 57 32 - 86 5 6 - 84 19 58 - 86 43 15 - 85 42 56 - 7 0 0 23 52 11 66 100 -4 - 85 9 3 - 86 16 59 - 84 31 18 - 86 55 19 - 85 55 15 - 8 0 0 23 51 29 66 97 -4 - 85 21 11 - 86 29 30 - 84 43 14 - 87 8 4 - 86 8 15 - 9 0 0 23 50 48 65 95 -3 - 85 33 59 - 86 42 42 - 84 55 48 - 87 21 31 - 86 21 56 -10 0 0 23 50 7 65 93 -3 - 85 47 27 - 86 56 37 - 85 9 1 - 87 35 42 - 86 36 21 -11 0 0 23 49 25 65 91 -2 - 86 1 37 - 87 11 17 - 85 22 56 - 87 50 39 - 86 51 32 -12 0 0 23 48 44 64 89 -1 - 86 16 32 - 87 26 44 - 85 37 34 - 88 6 24 - 87 7 31 -13 0 0 23 48 2 64 87 -1 - 86 32 14 - 87 43 0 - 85 52 57 - 88 23 1 Uncertainty in time = +/- 25 secs Prediction of 2012 Oct 26.0 Data for the target star ------------------------ * name: TYC 5807-01091-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 22 27 51.3356 DE: -10 20 12.590 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .032 ) * V mag [mag]: 10.6 * B mag [mag]: 10.9 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (35) Leukothea approx. diameter [km]: 112 approx. diameter ["]: .053 distance from Earth [AU]: 2.90400 * orbital information: orbit source: Preston date of fit: 2012 Oct 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1401 number of rejected observations: 101 time covered by the observations: 1907 Apr 04 - 2012 Oct 09 1 sigma uncertainty ellipse (major, minor, PA): 0.015, 0.012, 61° remarks: * orbital elements for (35) Leukothea : Mean anomaly = 124.02639110 deg Arg. of pericenter = 213.66540283 deg Long. of node = 353.78963827 deg Inclination = 7.93524232 deg Eccentricity = 0.22717484 Semimajor axis = 2.99033941 AU Perihelion dist = 2.31100953 AU Mag: H = 8.47, G = 0.15 Epoch of elements : MJD 56231.99700000 TDT (2012 Oct 31.997) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 31 35 Leukothea 23h 54.8m UT 10.6 22 27 51.336-10 20 12.59TYC 5807-01091-1 10.9 14.3 112 39.1 2.904 0.091 4.70 -62.4216 -10.338 177.20 -14.49 23.9135 -0.38651 0.11036 0.43900 1.54971 0.00495 0.00198 2000 123.64576220121030.00000213.665403353.789638 7.9352420.22717484 2.9903394 2.3110095 8.5 5.00.15 RATE 1.9060020 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.034 0.029 356 1.56 0.030 0 0-4 0 056226.0020121031_1091-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 25, 21:36 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org