IOTA/IOTA-ES occultation update for (2802) Weisell / TYC 6272-01687-1 event on 2012 Sep 05, 15:57 UT Visible from SE Asia, India, SW Asia Summary ------- On 2012 Sep 05 UT, the 18 km diameter asteroid (2802) Weisell will occult a 10.0 mag star in the constellation Sagittarius for observers along a path across SE Asia, India, SW Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.3 mag to 16.3 mag (the magnitude of the asteroid) for at most 2.1 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: 13 * date and approx. time of event: 2012 Sep 05, 15:51 - 2012 Sep 05, 16:06 UT * geocentric midpoint of event [JD]: 2456176.1654375 * magnitude of target star: 10.0 * magnitude drop [mag]: 6.3 * estimated maximum duration [s]: 2.1 * Moon: 76 % sunlit, 129° distance * Sun: 109° distance * rough path description: SE Asia, India, SW Asia The occultation path -------------------- * approximate projected width [km]: 27 * 1 sigma uncertainty interval [path widths]: +/- 5.06 * 1 sigma uncertainty interval [seconds]: +/- 12.2 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .056 +/- .044) * 1 sigma uncertainty ellipse (major, minor, PA): ( .056", .044", 97° ) * approx speed of asteroid's shadow [km/s]: 8.2445 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6272-01687-1 by 2802 Weisell on 2012 Sep 5 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 39 57 26 48 0 0 15 51 5 22 170 -1 39 44 17 40 10 36 37 32 16 42 25 0 41 1 38 47 0 0 15 51 14 23 171 -2 40 48 39 41 14 39 38 38 17 43 27 29 42 5 54 46 0 0 15 51 24 24 172 -2 41 53 4 42 18 46 39 44 10 44 30 13 43 10 19 45 0 0 15 51 35 25 173 -3 42 57 36 43 23 3 40 50 2 45 33 16 44 14 57 44 0 0 15 51 46 26 174 -4 44 2 21 44 27 35 41 55 58 46 36 44 45 19 55 43 0 0 15 51 58 27 176 -5 45 7 24 45 32 27 43 2 2 47 40 41 46 25 17 42 0 0 15 52 11 28 177 -7 46 12 51 46 37 44 44 8 21 48 45 13 47 31 9 41 0 0 15 52 24 29 178 -8 47 18 47 47 43 32 45 15 1 49 50 25 48 37 36 40 0 0 15 52 37 31 179 -9 48 25 18 48 49 57 46 22 5 50 56 23 49 44 45 39 0 0 15 52 51 32 181 -10 49 32 29 49 57 4 47 29 41 52 3 13 50 52 41 38 0 0 15 53 6 32 182 -11 50 40 26 51 4 59 48 37 55 53 11 2 52 1 32 37 0 0 15 53 21 33 183 -12 51 49 16 52 13 49 49 46 52 54 19 56 53 11 23 36 0 0 15 53 37 34 185 -14 52 59 6 53 23 41 50 56 39 55 30 2 54 22 22 35 0 0 15 53 53 35 186 -15 54 10 4 54 34 42 52 7 22 56 41 30 55 34 37 34 0 0 15 54 11 36 188 -16 55 22 16 55 47 0 53 19 11 57 54 28 56 48 18 33 0 0 15 54 28 37 189 -18 56 35 53 57 0 46 54 32 11 59 9 5 58 3 34 32 0 0 15 54 47 38 191 -19 57 51 3 58 16 7 55 46 33 60 25 34 59 20 35 31 0 0 15 55 6 38 193 -20 59 7 58 59 33 16 57 2 25 61 44 6 60 39 35 30 0 0 15 55 26 39 195 -22 60 26 49 60 52 24 58 19 59 63 4 56 62 0 47 29 0 0 15 55 46 40 197 -23 61 47 50 62 13 47 59 39 26 64 28 21 63 24 27 28 0 0 15 56 8 40 199 -25 63 11 17 63 37 40 61 1 0 65 54 41 64 50 54 27 0 0 15 56 30 41 201 -27 64 37 29 65 4 22 62 24 57 67 24 17 66 20 29 26 0 0 15 56 53 41 203 -28 66 6 47 66 34 15 63 51 33 68 57 39 67 53 39 25 0 0 15 57 17 42 205 -30 67 39 35 68 7 47 65 21 11 70 35 19 69 30 55 24 0 0 15 57 42 42 208 -32 69 16 26 69 45 29 66 54 15 72 17 59 71 12 56 23 0 0 15 58 8 42 210 -34 70 57 57 71 28 1 68 31 15 74 6 34 73 0 32 22 0 0 15 58 36 42 213 -36 72 44 56 73 16 15 70 12 48 76 2 13 74 54 46 21 0 0 15 59 4 42 215 -38 74 38 25 75 11 15 71 59 38 78 6 31 76 57 4 20 0 0 15 59 35 41 218 -40 76 39 46 77 14 32 73 52 47 80 21 44 Latitude Latitude Latitude Latitude 77 0 0 19 58 37 15 59 35 41 218 -40 19 50 25 20 6 50 18 28 43 21 31 32 78 0 0 19 30 50 15 59 50 41 219 -41 19 22 41 19 39 0 18 1 35 21 3 2 79 0 0 19 4 6 16 0 4 41 220 -43 18 56 1 19 12 12 17 35 29 20 35 37 80 0 0 18 38 25 16 0 19 40 222 -44 18 30 23 18 46 28 17 10 24 20 9 16 81 0 0 18 13 47 16 0 33 40 223 -45 18 5 48 18 21 46 16 46 20 19 44 1 82 0 0 17 50 11 16 0 47 39 224 -46 17 42 16 17 58 8 16 23 17 19 19 49 83 0 0 17 27 38 16 1 1 39 225 -47 17 19 46 17 35 32 16 1 15 18 56 42 84 0 0 17 6 7 16 1 14 39 226 -48 16 58 17 17 13 58 15 40 14 18 34 38 85 0 0 16 45 38 16 1 28 38 227 -49 16 37 51 16 53 26 15 20 14 18 13 38 86 0 0 16 26 11 16 1 41 37 228 -50 16 18 26 16 33 57 15 1 14 17 53 41 87 0 0 16 7 45 16 1 54 37 229 -51 16 0 3 16 15 28 14 43 13 17 34 48 88 0 0 15 50 20 16 2 6 36 230 -52 15 42 41 15 58 1 14 26 13 17 16 56 89 0 0 15 33 57 16 2 19 36 231 -53 15 26 19 15 41 35 14 10 12 17 0 8 90 0 0 15 18 34 16 2 31 35 232 -54 15 10 58 15 26 10 13 55 11 16 44 21 91 0 0 15 4 11 16 2 43 34 233 -55 14 56 37 15 11 46 13 41 8 16 29 36 92 0 0 14 50 48 16 2 55 34 234 -56 14 43 16 14 58 21 13 28 4 16 15 53 93 0 0 14 38 25 16 3 6 33 234 -57 14 30 54 14 45 56 13 15 59 16 3 10 94 0 0 14 27 1 16 3 18 32 235 -58 14 19 32 14 34 31 13 4 52 15 51 29 95 0 0 14 16 36 16 3 29 32 236 -59 14 9 9 14 24 5 12 54 42 15 40 48 96 0 0 14 7 11 16 3 39 31 236 -60 13 59 45 14 14 38 12 45 31 15 31 7 97 0 0 13 58 44 16 3 50 30 237 -60 13 51 19 14 6 10 12 37 16 15 22 26 98 0 0 13 51 15 16 4 0 29 238 -61 13 43 51 13 58 40 12 29 59 15 14 44 99 0 0 13 44 44 16 4 10 28 238 -62 13 37 21 13 52 8 12 23 39 15 8 2 100 0 0 13 39 11 16 4 20 28 239 -63 13 31 49 13 46 34 12 18 15 15 2 19 101 0 0 13 34 35 16 4 29 27 239 -63 13 27 14 13 41 58 12 13 47 14 57 35 102 0 0 13 30 57 16 4 38 26 240 -64 13 23 37 13 38 19 12 10 16 14 53 49 103 0 0 13 28 16 16 4 47 25 240 -65 13 20 56 13 35 37 12 7 40 14 51 2 104 0 0 13 26 31 16 4 56 24 241 -66 13 19 12 13 33 52 12 6 0 14 49 13 105 0 0 13 25 44 16 5 4 23 241 -66 13 18 24 13 33 4 12 5 16 14 48 21 106 0 0 13 25 52 16 5 12 23 242 -67 13 18 33 13 33 12 12 5 27 14 48 27 107 0 0 13 26 57 16 5 19 22 242 -67 13 19 38 13 34 17 12 6 33 14 49 30 108 0 0 13 28 57 16 5 27 21 243 -68 13 21 39 13 36 17 12 8 33 14 51 31 109 0 0 13 31 54 16 5 34 20 243 -68 13 24 35 13 39 14 12 11 29 14 54 28 110 0 0 13 35 46 16 5 41 19 243 -68 13 28 27 13 43 6 12 15 19 14 58 23 111 0 0 13 40 33 16 5 47 18 244 -69 13 33 14 13 47 54 12 20 3 15 3 13 112 0 0 13 46 16 16 5 53 17 244 -69 13 38 56 13 53 37 12 25 41 15 9 1 113 0 0 13 52 54 16 5 59 16 244 -69 13 45 34 14 0 15 12 32 14 15 15 44 114 0 0 14 0 27 16 6 4 15 245 -69 13 53 6 14 7 49 12 39 40 15 23 24 115 0 0 14 8 54 16 6 9 14 245 -69 14 1 33 14 16 17 12 48 0 15 32 0 116 0 0 14 18 17 16 6 14 13 245 -69 14 10 54 14 25 40 12 57 14 15 41 32 117 0 0 14 28 34 16 6 19 12 246 -69 14 21 10 14 35 58 13 7 21 15 51 59 118 0 0 14 39 45 16 6 23 11 246 -69 14 32 21 14 47 10 13 18 22 16 3 22 119 0 0 14 51 51 16 6 27 10 246 -69 14 44 25 14 59 17 13 30 16 16 15 40 120 0 0 15 4 50 16 6 30 9 247 -68 14 57 24 15 12 18 13 43 2 16 28 54 121 0 0 15 18 44 16 6 33 8 247 -68 15 11 16 15 26 13 13 56 42 16 43 3 122 0 0 15 33 32 16 6 36 7 247 -68 15 26 2 15 41 2 .. .. .. 16 58 7 123 0 0 15 49 13 16 6 38 6 248 -67 15 41 42 15 56 45 .. .. .. 17 14 7 124 0 0 16 5 49 16 6 40 5 248 -67 15 58 16 16 13 22 .. .. .. 17 31 1 125 0 0 16 23 17 16 6 42 4 248 -66 16 15 43 16 30 53 .. .. .. 17 48 49 126 0 0 16 41 40 16 6 43 3 248 -66 16 34 3 16 49 17 .. .. .. 18 7 33 127 0 0 17 0 55 16 6 44 2 249 -65 16 53 17 17 8 34 .. .. .. 18 27 11 128 0 0 17 21 4 16 6 45 1 249 -64 17 13 24 17 28 45 .. .. .. 18 47 43 129 0 0 17 42 5 16 6 45 0 249 -64 17 34 23 17 49 49 .. .. .. .. .. .. Uncertainty in time = +/- 13 secs Prediction of 2012 Jul 21.0 Data for the target star ------------------------ * name: TYC 6272-01687-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 09 48.1613 DE: -19 37 41.445 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .028, .029 ) * V mag [mag]: 10.0 * B mag [mag]: 10.1 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2802) Weisell approx. diameter [km]: 18 approx. diameter ["]: .009 distance from Earth [AU]: 2.65500 * orbital information: orbit source: Preston date of fit: 2012 Jul 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 950 number of rejected observations: 24 time covered by the observations: 1939 Jan 18 - 2011 Apr 27 1 sigma uncertainty ellipse (major, minor, PA): 0.049, 0.033, 99° remarks: * orbital elements for (2802) Weisell : Mean anomaly = 85.73789825 deg Arg. of pericenter = 60.54842547 deg Long. of node = 129.41730824 deg Inclination = 9.61848371 deg Eccentricity = 0.12326255 Semimajor axis = 3.11293699 AU Perihelion dist = 2.72922844 AU Mag: H = 10.82, G = 0.15 Epoch of elements : MJD 56175.66500000 TDT (2012 Sep 05.665) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 5 2802 Weisell 15h 58.2m UT 10.0 18 9 48.161-19 37 41.45TYC 6272-01687-1 10.1 16.3 18 2.1 2.655 0.952 -7.55 47.7322 -19.625 -59.93 6.49 15.9705 0.36987 0.64649 4.05603 -2.28099 0.00540 -0.00003 2000 84.7213022012 831.00000 60.548425129.417308 9.6184840.12326255 3.1129370 2.729228410.8 5.00.15 RATE 1.7945210 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.056 0.044 97 6.06 0.047 0 0 3 5 056129.0020120905_1687-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 21, 15:11 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org