IOTA/IOTA-ES occultation update for (1508) Kemi / TYC 2860-00063-1 event on 2012 Oct 18, 11:51 UT Visible from Canada, USA, Mexico Summary ------- On 2012 Oct 18 UT, the 18 km diameter asteroid (1508) Kemi will occult a 11.0 mag star in the constellation Perseus for observers along a path across Canada, USA, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.6 mag to 14.6 mag (the magnitude of the asteroid) for at most 1.2 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: 21 * date and approx. time of event: 2012 Oct 18, 11:46 - 2012 Oct 18, 11:54 UT * geocentric midpoint of event [JD]: 2456218.99415417 * magnitude of target star: 11.0 * magnitude drop [mag]: 3.6 * estimated maximum duration [s]: 1.2 * Moon: 12 % sunlit, 151° distance * Sun: 139° distance * rough path description: Canada, USA, Mexico The occultation path -------------------- * approximate projected width [km]: 22 * 1 sigma uncertainty interval [path widths]: +/- 3.22 * 1 sigma uncertainty interval [seconds]: +/- 2.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .068 +/- .057) * 1 sigma uncertainty ellipse (major, minor, PA): ( .077", .045", 55° ) * approx speed of asteroid's shadow [km/s]: 15.5968 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 2860-00063-1 by 1508 Kemi on 2012 Oct 18 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude - 94 36 10 - 7 44 5 11 46 21 14 320 -3 - 94 46 59 - 7 37 10 - 94 25 12 - 7 51 8 - 95 53 55 - 6 55 45 - 93 11 3 - 8 40 32 - 96 16 14 - 4 39 18 11 46 29 17 320 -5 - 96 25 36 - 4 34 2 - 96 6 48 - 4 44 40 - 97 24 20 - 4 1 50 - 95 4 9 - 5 21 19 - 97 33 27 - 2 0 58 11 46 37 20 320 -7 - 97 42 0 - 1 56 36 - 97 24 50 - 2 5 22 - 98 36 1 - 1 29 49 - 96 28 12 - 2 35 12 - 98 36 36 0 20 53 11 46 46 23 320 -8 - 98 44 39 0 24 37 - 98 28 32 0 17 5 - 99 35 36 0 47 46 - 97 35 38 - 0 8 22 - 99 30 3 2 31 8 11 46 54 25 319 -9 - 99 37 44 2 34 27 - 99 22 20 2 27 48 -100 26 33 2 54 58 - 98 32 0 2 5 24 -100 16 15 4 32 42 11 47 2 27 319 -10 -100 23 40 4 35 41 -100 8 48 4 29 41 -101 10 56 4 54 12 - 99 20 17 4 9 36 -100 56 46 6 27 25 11 47 10 29 318 -11 -101 4 0 6 30 8 -100 49 31 6 24 40 -101 50 5 6 47 4 -100 2 21 6 6 22 -101 32 41 8 16 35 11 47 19 30 318 -12 -101 39 46 8 19 6 -101 25 35 8 14 3 -102 24 58 8 34 45 -100 39 27 7 57 11 -102 4 44 10 1 8 11 47 27 32 317 -13 -102 11 43 10 3 29 -101 57 45 9 58 47 -102 56 15 10 18 3 -101 12 24 9 43 5 -102 33 31 11 41 46 11 47 35 34 317 -14 -102 40 24 11 43 58 -102 26 37 11 39 33 -103 24 26 11 57 39 -101 41 50 11 24 50 -102 59 25 13 19 2 11 47 43 35 316 -14 -103 6 14 13 21 6 -102 52 34 13 16 56 -103 49 53 13 34 2 -102 8 15 13 3 3 -103 22 46 14 53 21 11 47 52 36 315 -15 -103 29 33 14 55 19 -103 15 58 14 51 22 -104 12 56 15 7 36 -102 31 58 14 38 11 -103 43 50 16 25 6 11 48 0 38 315 -15 -103 50 35 16 26 59 -103 37 4 16 23 12 -104 33 48 16 38 41 -102 53 17 16 10 38 -104 2 49 17 54 33 11 48 8 39 314 -16 -104 9 33 17 56 21 -103 56 5 17 52 44 -104 52 41 18 7 35 -103 12 25 17 40 42 -104 19 53 19 21 58 11 48 17 40 313 -16 -104 26 37 19 23 41 -104 13 9 19 20 13 -105 9 43 19 34 29 -103 29 33 19 8 38 -104 35 10 20 47 32 11 48 25 41 312 -16 -104 41 54 20 49 12 -104 28 26 20 45 51 -105 25 3 20 59 37 -103 44 49 20 34 40 -104 48 46 22 11 26 11 48 33 42 311 -17 -104 55 31 22 13 3 -104 42 1 22 9 49 -105 38 45 22 23 9 -103 58 20 21 58 59 -105 0 46 23 33 51 11 48 41 43 310 -17 -105 7 32 23 35 25 -104 53 59 23 32 16 -105 50 55 23 45 13 -104 10 11 23 21 44 -105 11 14 24 54 52 11 48 50 44 310 -17 -105 18 2 24 56 24 -105 4 26 24 53 20 -106 1 37 25 5 57 -104 20 26 24 43 5 -105 20 13 26 14 39 11 48 58 45 309 -17 -105 27 3 26 16 8 -105 13 23 26 13 8 -106 10 53 26 25 28 -104 29 10 26 3 7 -105 27 46 27 33 16 11 49 6 46 307 -17 -105 34 38 27 34 44 -105 20 53 27 31 47 -106 18 45 27 43 52 -104 36 23 27 21 58 -105 33 53 28 50 50 11 49 14 47 306 -17 -105 40 49 28 52 16 -105 26 57 28 49 23 -106 25 16 29 1 15 -104 42 9 28 39 44 -105 38 37 30 7 25 11 49 23 48 305 -17 -105 45 36 30 8 50 -105 31 37 30 6 0 -106 30 25 30 17 41 -104 46 27 29 56 30 -105 41 56 31 23 7 11 49 31 48 304 -18 -105 48 59 31 24 31 -105 34 53 31 21 42 -106 34 13 31 33 14 -104 49 19 31 12 19 -105 43 52 32 37 58 11 49 39 49 303 -18 -105 50 59 32 39 21 -105 36 45 32 36 34 -106 36 41 32 47 59 -104 50 44 32 27 17 -105 44 23 33 52 3 11 49 47 50 302 -18 -105 51 35 33 53 25 -105 37 11 33 50 40 -106 37 46 34 1 59 -104 50 41 33 41 28 -105 43 28 35 5 25 11 49 56 50 301 -17 -105 50 44 35 6 47 -105 36 11 35 4 2 -106 37 28 35 15 17 -104 49 9 34 54 53 -105 41 5 36 18 7 11 50 4 51 299 -17 -105 48 27 36 19 28 -105 33 42 36 16 44 -106 35 46 36 27 57 -104 46 6 36 7 37 -105 37 11 37 30 11 11 50 12 51 298 -17 -105 44 39 37 31 32 -105 29 43 37 28 49 -106 32 36 37 40 0 -104 41 30 37 19 42 -105 31 45 38 41 40 11 50 21 52 297 -17 -105 39 19 38 43 2 -105 24 11 38 40 18 -106 27 56 38 51 30 -104 35 18 38 31 11 -105 24 42 39 52 37 11 50 29 52 295 -17 -105 32 22 39 53 59 -105 17 1 39 51 14 -106 21 42 40 2 28 -104 27 26 39 42 6 -105 15 58 41 3 3 11 50 37 52 294 -17 -105 23 46 41 4 25 -105 8 10 41 1 40 -106 13 52 41 12 57 -104 17 49 40 52 28 -105 5 28 42 13 0 11 50 45 53 293 -17 -105 13 24 42 14 22 -104 57 33 42 11 36 -106 4 19 42 22 59 -104 6 24 42 2 20 -104 53 8 43 22 29 11 50 54 53 291 -16 -105 1 11 43 23 53 -104 45 4 43 21 5 -105 52 58 43 32 34 -103 53 4 43 11 43 -104 38 49 44 31 32 11 51 2 53 290 -16 -104 47 1 44 32 57 -104 30 37 44 30 7 -105 39 44 44 41 45 -103 37 43 44 20 39 -104 22 27 45 40 11 11 51 10 53 289 -16 -104 30 48 45 41 37 -104 14 6 45 38 44 -105 24 29 45 50 32 -103 20 13 45 29 8 -104 3 51 46 48 25 11 51 18 53 287 -16 -104 12 22 46 49 53 -103 55 21 46 46 57 -105 7 6 46 58 57 -103 0 26 46 37 11 -103 42 54 47 56 16 11 51 27 54 286 -15 -103 51 35 47 57 45 -103 34 13 47 54 47 -104 47 26 48 7 0 -102 38 14 47 44 49 -103 19 25 49 3 45 11 51 35 54 285 -15 -103 28 17 49 5 16 -103 10 33 49 2 13 -104 25 18 49 14 42 -102 13 24 48 52 3 -102 53 12 50 10 51 11 51 43 54 284 -15 -103 2 15 50 12 24 -102 44 8 50 9 17 -104 0 30 50 22 4 -101 45 46 49 58 52 -102 24 1 51 17 34 11 51 51 53 282 -14 -102 33 17 51 19 9 -102 14 46 51 15 57 -103 32 51 51 29 5 -101 15 7 51 5 17 -101 51 39 52 23 54 11 52 0 53 281 -14 -102 1 7 52 25 32 -101 42 10 52 22 15 -103 2 5 52 35 45 -100 41 10 52 11 16 -101 15 47 53 29 50 11 52 8 53 280 -14 -101 25 29 53 31 31 -101 6 6 53 28 8 -102 27 56 53 42 4 -100 3 39 53 16 48 -100 36 8 54 35 21 11 52 16 53 279 -13 -100 46 4 54 37 6 -100 26 12 54 33 36 -101 50 5 54 48 0 - 99 22 14 54 21 53 - 99 52 20 55 40 26 11 52 25 53 278 -13 -100 2 31 55 42 15 - 99 42 8 55 38 36 -101 8 10 55 53 33 - 98 36 35 55 26 29 - 99 3 57 56 45 2 11 52 33 52 278 -12 - 99 14 25 56 46 55 - 98 53 30 56 43 8 -100 21 48 56 58 40 - 97 46 16 56 30 32 - 98 10 34 57 49 6 11 52 41 52 277 -12 - 98 21 18 57 51 4 - 97 59 50 57 47 8 - 99 30 31 58 3 18 - 96 50 50 57 34 1 - 97 11 37 58 52 35 11 52 49 52 276 -11 - 97 22 39 58 54 38 - 97 0 36 58 50 31 - 98 33 47 59 7 25 - 95 49 46 58 36 50 - 96 6 33 59 55 24 11 52 58 51 276 -11 - 96 17 53 59 57 33 - 95 55 14 59 53 15 - 97 31 2 60 10 57 - 94 42 30 59 38 55 - 94 54 42 60 57 28 11 53 6 51 276 -10 - 95 6 20 60 59 43 - 94 43 3 60 55 12 - 96 21 34 61 13 48 - 93 28 21 60 40 10 - 93 35 17 61 58 40 11 53 14 50 275 -9 - 93 47 15 62 1 2 - 93 23 20 61 56 16 - 95 4 38 62 15 51 - 92 6 36 61 40 27 - 92 7 29 62 58 50 11 53 22 49 276 -9 - 92 19 47 63 1 20 - 91 55 12 62 56 19 - 93 39 22 63 17 0 - 90 36 26 62 39 38 - 90 30 21 63 57 50 11 53 31 49 276 -8 - 90 42 59 64 0 28 - 90 17 44 63 55 10 - 92 4 47 64 17 4 - 88 56 55 63 37 32 - 88 42 50 64 55 25 11 53 39 48 276 -7 - 88 55 47 64 58 14 - 88 29 53 64 52 36 - 90 19 48 65 15 50 - 87 7 5 64 33 55 - 86 43 46 65 51 22 11 53 47 47 277 -7 - 86 57 3 65 54 21 - 86 30 31 65 48 22 - 88 23 11 66 13 6 - 85 5 49 65 28 31 - 84 31 55 66 45 22 11 53 55 47 278 -6 - 84 45 29 66 48 33 - 84 18 23 66 42 10 - 86 13 37 67 8 32 - 82 51 59 66 21 3 - 82 5 58 67 37 2 11 54 4 46 279 -5 - 82 19 47 67 40 26 - 81 52 11 67 33 37 - 83 49 39 68 1 48 - 80 24 22 67 11 6 - 79 24 33 68 25 57 11 54 12 45 281 -4 - 79 38 33 68 29 35 - 79 10 35 68 22 18 - 81 9 47 68 52 28 - 77 41 45 67 58 15 - 76 26 22 69 11 36 11 54 20 44 282 -4 - 76 40 28 69 15 29 - 76 12 19 69 7 41 - 78 12 31 69 40 1 - 74 43 2 68 41 59 - 73 10 15 69 53 22 11 54 29 43 285 -3 - 73 24 20 69 57 32 - 72 56 14 69 49 11 - 74 56 27 70 23 51 - 71 27 15 69 21 41 - 69 35 21 70 30 34 11 54 37 42 287 -2 - 69 49 16 70 35 1 - 69 21 30 70 26 4 - 71 20 27 71 3 15 - 67 53 47 69 56 40 - 65 41 16 71 2 24 11 54 45 41 290 -1 - 65 54 49 71 7 10 - 65 27 46 70 57 36 - 67 23 52 71 37 26 - 64 2 29 70 26 10 - 61 28 19 71 28 0 11 54 53 40 293 0 - 61 41 19 71 33 6 - 61 15 24 71 22 52 - 63 6 44 72 5 29 - 59 53 53 70 49 22 Uncertainty in time = +/- 4 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: TYC 2860-00063-1 * constellation : Perseus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 11 04.5669 DE: +44 53 33.958 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .028, .027 ) * V mag [mag]: 11.0 * B mag [mag]: 12.7 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1508) Kemi approx. diameter [km]: 18 approx. diameter ["]: .024 distance from Earth [AU]: 1.05300 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 609 number of rejected observations: 32 time covered by the observations: 1935 Mar 28 - 2012 Oct 03 1 sigma uncertainty ellipse (major, minor, PA): 0.073, 0.037, 50° remarks: * orbital elements for (1508) Kemi : Mean anomaly = 333.52348049 deg Arg. of pericenter = 92.80016706 deg Long. of node = 14.34449637 deg Inclination = 28.73089736 deg Eccentricity = 0.41757903 Semimajor axis = 2.77077117 AU Perihelion dist = 1.61375522 AU Mag: H = 11.95, G = 0.15 Epoch of elements : MJD 56218.49400000 TDT (2012 Oct 18.494) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 18 1508 Kemi 11h 51.6m UT 11.0 3 11 4.567 44 53 33.96TYC 2860-00063-1 12.7 14.6 18 1.2 1.053 -3.055 65.97 -157.5003 44.875 -1.62 -9.86 11.8597 0.53076 0.25924 -3.88403 7.90014 -0.00211 -0.00270 2000 331.70831820121010.00000 92.800167 14.344496 28.7308970.41757903 2.7707712 1.613755212.0 5.00.15 RATE 2.1369930 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.077 0.045 55 4.22 0.076 0 0-1-2 056208.0020121018_0063-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 19:00 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org