IOTA/IOTA-ES occultation update for (2022) West / TYC 1874-00409-1 event on 2012 Sep 06, 16:39 UT Visible from E Russia, China Summary ------- On 2012 Sep 06 UT, the 11 km diameter asteroid (2022) West will occult a 9.8 mag star in the constellation Taurus for observers along a path across E Russia, China. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.1 mag to 16.9 mag (the magnitude of the asteroid) for at most 0.5 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: 13 * date and approx. time of event: 2012 Sep 06, 16:35 - 2012 Sep 06, 16:38 UT * geocentric midpoint of event [JD]: 2456177.19389583 * magnitude of target star: 9.8 * magnitude drop [mag]: 7.1 * estimated maximum duration [s]: 0.5 * Moon: 67 % sunlit, 32° distance * Sun: 78° distance * rough path description: E Russia, China The occultation path -------------------- * approximate projected width [km]: 14 * 1 sigma uncertainty interval [path widths]: +/- 5.22 * 1 sigma uncertainty interval [seconds]: +/- 2.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .041 +/- .031) * 1 sigma uncertainty ellipse (major, minor, PA): ( .041", .031", 88° ) * approx speed of asteroid's shadow [km/s]: 24.1050 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1874-00409-1 by 2022 West on 2012 Sep 6 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 105 0 0 27 25 45 16 35 49 0 58 -56 .. .. .. 27 30 21 .. .. .. 28 18 49 106 0 0 27 59 45 16 35 49 1 58 -56 27 55 8 28 4 23 .. .. .. 28 53 5 107 0 0 28 34 8 16 35 50 2 59 -55 28 29 29 28 38 47 .. .. .. 29 27 42 108 0 0 29 8 50 16 35 50 3 59 -55 29 4 11 29 13 31 .. .. .. 30 2 40 109 0 0 29 43 53 16 35 50 4 60 -54 29 39 12 29 48 34 .. .. .. 30 37 57 110 0 0 30 19 14 16 35 51 5 60 -54 30 14 31 30 23 56 .. .. .. 31 13 33 111 0 0 30 54 51 16 35 52 6 61 -53 30 50 8 30 59 35 30 1 9 31 49 25 112 0 0 31 30 45 16 35 52 7 61 -52 31 26 0 31 35 30 30 36 49 32 25 33 113 0 0 32 6 53 16 35 53 8 62 -52 32 2 7 32 11 40 31 12 44 33 1 55 114 0 0 32 43 15 16 35 54 9 62 -51 32 38 27 32 48 2 31 48 52 33 38 31 115 0 0 33 19 48 16 35 55 10 63 -50 33 14 59 33 24 37 32 25 12 34 15 18 116 0 0 33 56 32 16 35 56 11 64 -50 33 51 42 34 1 22 33 1 43 34 52 15 117 0 0 34 33 24 16 35 58 12 64 -49 34 28 34 34 38 15 33 38 23 35 29 21 118 0 0 35 10 25 16 35 59 13 65 -48 35 5 33 35 15 17 34 15 12 36 6 34 119 0 0 35 47 31 16 36 1 14 65 -47 35 42 38 35 52 24 34 52 6 36 43 52 120 0 0 36 24 42 16 36 2 15 66 -47 36 19 48 36 29 36 35 29 6 37 21 15 121 0 0 37 1 56 16 36 4 16 67 -46 36 57 1 37 6 51 36 6 9 37 58 41 122 0 0 37 39 12 16 36 6 17 67 -45 37 34 16 37 44 8 36 43 15 38 36 7 123 0 0 38 16 28 16 36 8 18 68 -44 38 11 31 38 21 25 37 20 21 39 13 33 124 0 0 38 53 42 16 36 9 19 69 -43 38 48 45 38 58 40 37 57 26 39 50 57 125 0 0 39 30 53 16 36 12 20 70 -43 39 25 55 39 35 52 38 34 28 40 28 18 126 0 0 40 8 0 16 36 14 21 70 -42 40 3 1 40 12 59 39 11 27 41 5 33 127 0 0 40 45 1 16 36 16 22 71 -41 40 40 1 40 50 1 39 48 20 41 42 42 128 0 0 41 21 54 16 36 18 23 72 -40 41 16 54 41 26 55 40 25 6 42 19 42 129 0 0 41 58 38 16 36 20 24 73 -39 41 53 37 42 3 39 41 1 44 42 56 33 130 0 0 42 35 11 16 36 23 25 74 -38 42 30 10 42 40 13 41 38 12 43 33 12 131 0 0 43 11 33 16 36 25 26 74 -37 43 6 31 43 16 35 42 14 28 44 9 39 132 0 0 43 47 41 16 36 28 27 75 -37 43 42 39 43 52 44 42 50 32 44 45 52 133 0 0 44 23 35 16 36 30 28 76 -36 44 18 32 44 28 37 43 26 22 45 21 49 134 0 0 44 59 12 16 36 33 28 77 -35 44 54 9 45 4 15 44 1 57 45 57 29 135 0 0 45 34 32 16 36 36 29 78 -34 45 29 29 45 39 35 44 37 15 46 32 51 136 0 0 46 9 33 16 36 38 30 79 -33 46 4 30 46 14 36 45 12 14 47 7 54 137 0 0 46 44 14 16 36 41 31 80 -32 46 39 11 46 49 18 45 46 55 47 42 36 138 0 0 47 18 35 16 36 44 32 81 -31 47 13 32 47 23 38 46 21 16 48 16 56 139 0 0 47 52 33 16 36 47 32 82 -31 47 47 30 47 57 36 46 55 15 48 50 53 140 0 0 48 26 8 16 36 50 33 83 -30 48 21 5 48 31 11 47 28 52 49 24 26 141 0 0 48 59 19 16 36 53 34 84 -29 48 54 16 49 4 22 48 2 5 49 57 35 142 0 0 49 32 5 16 36 55 34 85 -28 49 27 3 49 37 8 48 34 54 50 30 17 143 0 0 50 4 25 16 36 58 35 86 -27 49 59 23 50 9 27 49 7 18 51 2 33 144 0 0 50 36 18 16 37 1 36 88 -26 50 31 17 50 41 20 49 39 16 51 34 21 145 0 0 51 7 44 16 37 4 36 89 -26 51 2 43 51 12 45 50 10 47 52 5 41 146 0 0 51 38 41 16 37 7 37 90 -25 51 33 41 51 43 42 50 41 51 52 36 33 147 0 0 52 9 10 16 37 10 38 91 -24 52 4 10 52 14 11 51 12 27 53 6 54 148 0 0 52 39 10 16 37 13 38 92 -23 52 34 11 52 44 10 51 42 33 53 36 46 149 0 0 53 8 40 16 37 16 39 94 -22 53 3 41 53 13 39 52 12 11 54 6 8 150 0 0 53 37 39 16 37 19 39 95 -22 53 32 42 53 42 37 52 41 19 54 34 58 151 0 0 54 6 8 16 37 22 40 96 -21 54 1 11 54 11 6 53 9 58 55 3 18 152 0 0 54 34 6 16 37 25 41 97 -20 54 29 10 54 39 3 53 38 5 55 31 5 153 0 0 55 1 33 16 37 28 41 99 -19 54 56 38 55 6 29 54 5 42 55 58 22 154 0 0 55 28 29 16 37 31 42 100 -19 55 23 35 55 33 24 54 32 49 56 25 6 155 0 0 55 54 53 16 37 34 42 101 -18 55 50 0 55 59 47 54 59 24 56 51 18 156 0 0 56 20 46 16 37 36 43 103 -17 56 15 54 56 25 38 55 25 28 57 16 59 157 0 0 56 46 7 16 37 39 43 104 -17 56 41 16 56 50 58 55 51 1 57 42 7 158 0 0 57 10 56 16 37 42 43 105 -16 57 6 6 57 15 46 56 16 3 58 6 43 159 0 0 57 35 14 16 37 45 44 107 -15 57 30 25 57 40 3 56 40 34 58 30 48 160 0 0 57 59 0 16 37 48 44 108 -15 57 54 12 58 3 48 57 4 33 58 54 20 161 0 0 58 22 15 16 37 51 45 109 -14 58 17 28 58 27 2 57 28 1 59 17 21 162 0 0 58 44 58 16 37 53 45 111 -13 58 40 13 58 49 44 57 50 58 59 39 50 163 0 0 59 7 11 16 37 56 45 112 -13 59 2 27 59 11 55 58 13 25 60 1 48 164 0 0 59 28 53 16 37 59 46 114 -12 59 24 10 59 33 36 58 35 20 60 23 16 165 0 0 59 50 4 16 38 1 46 115 -11 59 45 22 59 54 46 58 56 46 60 44 12 166 0 0 60 10 45 16 38 4 46 116 -11 60 6 5 60 15 25 59 17 41 61 4 38 167 0 0 60 30 56 16 38 7 47 118 -10 60 26 17 60 35 35 59 38 6 61 24 33 168 0 0 60 50 37 16 38 9 47 119 -9 60 45 59 60 55 15 59 58 2 61 43 59 169 0 0 61 9 48 16 38 12 47 121 -9 61 5 12 61 14 25 60 17 28 62 2 56 170 0 0 61 28 31 16 38 14 47 122 -8 61 23 56 61 33 6 60 36 26 62 21 23 171 0 0 61 46 45 16 38 17 48 124 -8 61 42 11 61 51 19 60 54 55 62 39 22 172 0 0 62 4 31 16 38 20 48 125 -7 61 59 58 62 9 4 61 12 55 62 56 52 173 0 0 62 21 49 16 38 22 48 127 -7 62 17 18 62 26 20 61 30 28 63 13 54 174 0 0 62 38 39 16 38 24 48 128 -6 62 34 9 62 43 9 61 47 32 63 30 29 175 0 0 62 55 2 16 38 27 48 129 -6 62 50 34 62 59 31 62 4 10 63 46 37 176 0 0 63 10 58 16 38 29 49 131 -5 63 6 31 63 15 26 62 20 21 64 2 18 177 0 0 63 26 28 16 38 32 49 132 -5 63 22 2 63 30 55 62 36 5 64 17 33 178 0 0 63 41 32 16 38 34 49 134 -4 63 37 8 63 45 57 62 51 24 64 32 23 179 0 0 63 56 11 16 38 36 49 135 -3 63 51 48 64 0 35 63 6 17 64 46 47 180 0 0 64 10 24 16 38 39 49 137 -3 64 6 2 64 14 47 63 20 44 65 0 45 -179 0 0 64 24 13 16 38 41 49 138 -3 64 19 52 64 28 34 63 34 47 65 14 20 -178 0 0 64 37 38 16 38 43 49 140 -2 64 33 18 64 41 58 63 48 25 65 27 30 -177 0 0 64 50 38 16 38 45 50 141 -2 64 46 20 64 54 57 64 1 39 65 40 16 -176 0 0 65 3 15 16 38 47 50 143 -1 64 58 58 65 7 33 64 14 29 65 52 40 -175 0 0 65 15 29 16 38 50 50 144 -1 65 11 13 65 19 46 64 26 56 66 4 40 -174 0 0 65 27 20 16 38 52 50 146 0 65 23 5 65 31 36 64 39 0 66 16 18 Uncertainty in time = +/- 3 secs Prediction of 2012 Jul 21.0 Data for the target star ------------------------ * name: TYC 1874-00409-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 05 43 58.4387 DE: +28 16 22.901 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .020, .025 ) * V mag [mag]: 9.8 * B mag [mag]: 11.1 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2022) West approx. diameter [km]: 11 approx. diameter ["]: .006 distance from Earth [AU]: 2.40200 * orbital information: orbit source: Preston date of fit: 2012 Jul 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1015 number of rejected observations: 15 time covered by the observations: 1938 Feb 07 - 2011 Dec 16 1 sigma uncertainty ellipse (major, minor, PA): 0.036, 0.019, 88° remarks: * orbital elements for (2022) West : Mean anomaly = 17.18440870 deg Arg. of pericenter = 37.78524556 deg Long. of node = 2.58815723 deg Inclination = 5.65972310 deg Eccentricity = 0.11969210 Semimajor axis = 2.70740139 AU Perihelion dist = 2.38334683 AU Mag: H = 11.58, G = 0.15 Epoch of elements : MJD 56176.69400000 TDT (2012 Sep 06.694) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 6 2022 West 16h 39.2m UT 9.8 5 43 58.439 28 16 22.90TYC 1874-00409-1 11.2 16.9 11 0.5 2.402 3.732 7.11 -149.9835 28.272 -70.27 6.11 16.6535 -0.09333 0.62938 13.46614 1.94255 -0.00536 -0.00005 2000 15.7033892012 831.00000 37.785246 2.588157 5.6597230.11969210 2.7074014 2.383346812.0 5.00.15 RATE 2.2124590 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.041 0.031 88 6.22 0.033 0 0-3 1 056129.0020120906_0409-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 21, 15:13 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org