IOTA/IOTA-ES occultation update for (218) Bianca / TYC 0733-01974-1 event on 2012 Sep 22, 11:36 UT Visible from Mexico Summary ------- On 2012 Sep 22 UT, the 61 km diameter asteroid (218) Bianca will occult a 10.9 mag star in the constellation Monoceros for observers along a path across Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.3 mag to 14.1 mag (the magnitude of the asteroid) for at most 2.9 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: 60 * date and approx. time of event: 2012 Sep 22, 11:31 - 2012 Sep 22, 11:35 UT * geocentric midpoint of event [JD]: 2456192.98377083 * magnitude of target star: 10.9 * magnitude drop [mag]: 3.3 * estimated maximum duration [s]: 2.9 * Moon: 46 % sunlit, 162° distance * Sun: 81° distance * rough path description: Mexico The occultation path -------------------- * approximate projected width [km]: 61 * 1 sigma uncertainty interval [path widths]: +/- 1.03 * 1 sigma uncertainty interval [seconds]: +/- 2.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .029 +/- .030) * 1 sigma uncertainty ellipse (major, minor, PA): ( .030", .029", 360° ) * approx speed of asteroid's shadow [km/s]: 21.2097 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0733-01974-1 by 218 Bianca on 2012 Sep 22 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 -168 0 0 24 38 21 11 31 39 1 82 -65 24 21 37 24 55 5 23 47 9 25 29 35 -167 0 0 24 46 13 11 31 39 2 82 -64 24 29 30 25 2 56 23 55 4 25 37 24 -166 0 0 24 53 44 11 31 39 3 83 -64 24 37 2 25 10 26 24 2 38 25 44 53 -165 0 0 25 0 53 11 31 39 4 83 -63 24 44 12 25 17 35 24 9 50 25 51 59 -164 0 0 25 7 41 11 31 39 5 83 -63 24 51 1 25 24 22 24 16 40 25 58 45 -163 0 0 25 14 8 11 31 40 5 84 -62 24 57 28 25 30 48 24 23 9 26 5 9 -162 0 0 25 20 13 11 31 40 6 84 -62 25 3 34 25 36 52 24 29 16 26 11 12 -161 0 0 25 25 56 11 31 41 7 85 -61 25 9 18 25 42 35 24 35 2 26 16 53 -160 0 0 25 31 18 11 31 42 8 85 -61 25 14 40 25 47 56 24 40 25 26 22 12 -159 0 0 25 36 18 11 31 42 9 86 -60 25 19 40 25 52 55 24 45 27 26 27 10 -158 0 0 25 40 56 11 31 43 10 86 -60 25 24 19 25 57 33 24 50 7 26 31 47 -157 0 0 25 45 12 11 31 44 11 86 -59 25 28 36 26 1 49 24 54 25 26 36 2 -156 0 0 25 49 7 11 31 45 12 87 -58 25 32 32 26 5 43 24 58 22 26 39 55 -155 0 0 25 52 40 11 31 46 13 87 -58 25 36 5 26 9 15 25 1 56 26 43 27 -154 0 0 25 55 51 11 31 47 14 88 -57 25 39 17 26 12 26 25 5 8 26 46 36 -153 0 0 25 58 40 11 31 48 15 88 -57 25 42 6 26 15 15 25 7 59 26 49 25 -152 0 0 26 1 8 11 31 49 15 89 -56 25 44 34 26 17 42 25 10 27 26 51 51 -151 0 0 26 3 14 11 31 51 16 89 -55 25 46 40 26 19 47 25 12 34 26 53 56 -150 0 0 26 4 57 11 31 52 17 89 -55 25 48 24 26 21 31 25 14 18 26 55 39 -149 0 0 26 6 19 11 31 53 18 90 -54 25 49 46 26 22 53 25 15 40 26 57 0 -148 0 0 26 7 19 11 31 55 19 90 -53 25 50 46 26 23 52 25 16 41 26 58 0 -147 0 0 26 7 57 11 31 57 20 91 -53 25 51 24 26 24 30 25 17 19 26 58 37 -146 0 0 26 8 13 11 31 58 21 91 -52 25 51 40 26 24 46 25 17 35 26 58 53 -145 0 0 26 8 6 11 32 0 22 92 -51 25 51 33 26 24 40 25 17 29 26 58 47 -144 0 0 26 7 38 11 32 2 23 92 -50 25 51 5 26 24 12 25 17 0 26 58 19 -143 0 0 26 6 48 11 32 4 24 93 -50 25 50 15 26 23 22 25 16 10 26 57 29 -142 0 0 26 5 36 11 32 6 24 93 -49 25 49 3 26 22 9 25 14 57 26 56 17 -141 0 0 26 4 2 11 32 8 25 94 -48 25 47 28 26 20 35 25 13 22 26 54 43 -140 0 0 26 2 5 11 32 10 26 94 -47 25 45 31 26 18 39 25 11 25 26 52 48 -139 0 0 25 59 47 11 32 12 27 94 -47 25 43 13 26 16 21 25 9 6 26 50 30 -138 0 0 25 57 6 11 32 14 28 95 -46 25 40 32 26 13 40 25 6 24 26 47 50 -137 0 0 25 54 3 11 32 16 29 95 -45 25 37 28 26 10 38 25 3 20 26 44 49 -136 0 0 25 50 38 11 32 19 30 96 -44 25 34 3 26 7 13 24 59 54 26 41 25 -135 0 0 25 46 51 11 32 21 31 96 -44 25 30 15 26 3 27 24 56 5 26 37 39 -134 0 0 25 42 42 11 32 24 32 97 -43 25 26 5 25 59 18 24 51 54 26 33 31 -133 0 0 25 38 10 11 32 26 33 97 -42 25 21 33 25 54 47 24 47 21 26 29 2 -132 0 0 25 33 16 11 32 29 34 98 -41 25 16 39 25 49 54 24 42 25 26 24 10 -131 0 0 25 28 0 11 32 31 34 98 -41 25 11 22 25 44 38 24 37 7 26 18 56 -130 0 0 25 22 22 11 32 34 35 99 -40 25 5 43 25 39 1 24 31 27 26 13 20 -129 0 0 25 16 22 11 32 37 36 99 -39 24 59 42 25 33 1 24 25 24 26 7 21 -128 0 0 25 9 59 11 32 40 37 99 -38 24 53 19 25 26 39 24 18 59 26 1 1 -127 0 0 25 3 14 11 32 43 38 100 -37 24 46 33 25 19 55 24 12 12 25 54 19 -126 0 0 24 56 7 11 32 46 39 100 -36 24 39 25 25 12 49 24 5 2 25 47 14 -125 0 0 24 48 37 11 32 49 40 101 -36 24 31 55 25 5 20 23 57 30 25 39 48 -124 0 0 24 40 46 11 32 52 41 101 -35 24 24 2 24 57 30 23 49 35 25 31 59 -123 0 0 24 32 32 11 32 55 42 102 -34 24 15 47 24 49 17 23 41 18 25 23 48 -122 0 0 24 23 56 11 32 59 43 102 -33 24 7 10 24 40 42 23 32 39 25 15 15 -121 0 0 24 14 57 11 33 2 44 103 -32 23 58 11 24 31 44 23 23 37 25 6 20 -120 0 0 24 5 37 11 33 6 45 103 -31 23 48 49 24 22 25 23 14 14 24 57 3 -119 0 0 23 55 54 11 33 9 46 104 -31 23 39 5 24 12 43 23 4 27 24 47 23 -118 0 0 23 45 49 11 33 13 47 104 -30 23 28 59 24 2 40 22 54 19 24 37 22 -117 0 0 23 35 22 11 33 16 47 105 -29 23 18 31 23 52 14 22 43 48 24 26 59 -116 0 0 23 24 33 11 33 20 48 105 -28 23 7 41 23 41 26 22 32 55 24 16 14 -115 0 0 23 13 22 11 33 24 49 106 -27 22 56 28 23 30 16 22 21 40 24 5 6 -114 0 0 23 1 49 11 33 28 50 106 -26 22 44 54 23 18 44 22 10 3 23 53 37 -113 0 0 22 49 54 11 33 32 51 107 -25 22 32 57 23 6 51 21 58 4 23 41 46 -112 0 0 22 37 37 11 33 36 52 107 -25 22 20 39 22 54 35 21 45 43 23 29 33 -111 0 0 22 24 58 11 33 40 53 107 -24 22 7 59 22 41 58 21 33 0 23 16 59 -110 0 0 22 11 58 11 33 44 54 108 -23 21 54 57 22 28 59 21 19 55 23 4 3 -109 0 0 21 58 36 11 33 48 55 108 -22 21 41 34 22 15 38 21 6 29 22 50 45 -108 0 0 21 44 52 11 33 52 56 109 -21 21 27 48 22 1 56 20 52 41 22 37 6 -107 0 0 21 30 47 11 33 56 57 109 -20 21 13 42 21 47 52 20 38 31 22 23 5 -106 0 0 21 16 20 11 34 1 58 110 -19 20 59 13 21 33 27 20 24 0 22 8 43 -105 0 0 21 1 32 11 34 5 59 111 -18 20 44 24 21 18 40 20 9 7 21 53 59 -104 0 0 20 46 23 11 34 10 60 111 -17 20 29 13 21 3 33 19 53 54 21 38 55 -103 0 0 20 30 53 11 34 14 61 112 -16 20 13 42 20 48 4 19 38 19 21 23 30 -102 0 0 20 15 2 11 34 19 62 112 -16 19 57 49 20 32 15 19 22 23 21 7 43 -101 0 0 19 58 50 11 34 23 63 113 -15 19 41 36 20 16 4 19 6 7 20 51 36 -100 0 0 19 42 18 11 34 28 64 113 -14 19 25 2 19 59 34 18 49 30 20 35 9 - 99 0 0 19 25 25 11 34 33 65 114 -13 19 8 8 19 42 43 18 32 32 20 18 21 - 98 0 0 19 8 12 11 34 37 66 115 -12 18 50 53 19 25 31 18 15 14 20 1 13 - 97 0 0 18 50 39 11 34 42 67 115 -11 18 33 19 19 8 0 17 57 37 19 43 45 - 96 0 0 18 32 47 11 34 47 68 116 -10 18 15 25 18 50 9 17 39 39 19 25 57 - 95 0 0 18 14 34 11 34 52 69 117 -9 17 57 11 18 31 58 17 21 22 19 7 49 - 94 0 0 17 56 3 11 34 57 70 117 -8 17 38 38 18 13 28 17 2 46 18 49 23 - 93 0 0 17 37 12 11 35 2 71 118 -7 17 19 45 17 54 39 16 43 50 18 30 37 - 92 0 0 17 18 2 11 35 7 72 119 -6 17 0 34 17 35 31 16 24 36 18 11 32 - 91 0 0 16 58 34 11 35 13 73 120 -5 16 41 5 17 16 4 16 5 3 17 52 8 - 90 0 0 16 38 48 11 35 18 74 121 -4 16 21 17 16 56 19 15 45 12 17 32 27 - 89 0 0 16 18 44 11 35 23 75 122 -3 16 1 11 16 36 17 15 25 3 17 12 27 - 88 0 0 15 58 22 11 35 28 76 123 -2 15 40 47 16 15 56 15 4 37 16 52 10 - 87 0 0 15 37 42 11 35 34 77 125 -1 15 20 7 15 55 18 14 43 53 16 31 35 - 86 0 0 15 16 46 11 35 39 78 126 0 14 59 9 15 34 24 14 22 52 16 10 43 Uncertainty in time = +/- 3 secs Prediction of 2012 Aug 7.0 Data for the target star ------------------------ * name: TYC 0733-01974-1 * constellation : Monoceros * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 36 36.3633 DE: +07 54 31.722 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .029 ) * V mag [mag]: 10.9 * B mag [mag]: 10.7 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (218) Bianca approx. diameter [km]: 61 approx. diameter ["]: .029 distance from Earth [AU]: 2.93200 * orbital information: orbit source: Preston date of fit: 2012 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 957 number of rejected observations: 103 time covered by the observations: 1901 Jun 08 - 2012 Jan 27 1 sigma uncertainty ellipse (major, minor, PA): 0.014, 0.008, 89° remarks: * orbital elements for (218) Bianca : Mean anomaly = 212.22271445 deg Arg. of pericenter = 62.41548761 deg Long. of node = 170.70595243 deg Inclination = 15.19347043 deg Eccentricity = 0.11583249 Semimajor axis = 2.66940248 AU Perihelion dist = 2.36019894 AU Mag: H = 8.60, G = 0.32 Epoch of elements : MJD 56192.48400000 TDT (2012 Sep 22.484) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 22 218 Bianca 11h 36.6m UT 10.9 6 36 36.363 7 54 31.72TYC 0733-01974-1 10.7 14.1 61 2.9 2.932 2.255 -12.92 -76.7431 7.912 3.99 0.05 11.6105 0.02024 0.05833 11.17036 -4.30535 -0.00567 0.00013 2000 211.6613632012 920.00000 62.415488170.705952 15.1934700.11583249 2.6694025 2.3601989 8.6 5.00.32 RATE 2.2598670 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.030 0.029 360 2.03 0.030 0 0 3 2 056146.0020120922_1974-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 20:43 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org