IOTA/IOTA-ES occultation update for (139) Juewa / TYC 1218-00983-1 event on 2009 Jun 28, 10:55 UT Visible from W USA Summary ------- On 2009 Jun 28 UT, the 150 km diameter asteroid (139) Juewa will occult a 11.7 mag star in the constellation Aries for observers along a path across W USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.3 mag to 13.9 mag (the magnitude of the asteroid) for at most 4.7 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: 94 * date and approx. time of event: 2009 Jun 28, 10:53 - 2009 Jun 28, 10:54 UT * midpoint of event [JD]: 2455010.95525 * magnitude of target star: 11.7 * magnitude drop [mag]: 2.3 * estimated maximum duration [s]: 4.7 * Moon: 38 % sunlit, 133° distance * Sun: 57° distance * rough path description: W USA The occultation path -------------------- * approximate projected width [km]: 243 * 1 sigma uncertainty interval [path widths]: +/- 0.45 * 1 sigma uncertainty interval [seconds]: +/- 2.2 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .028 +/- .026) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .026", 84° ) * approx speed of asteroid's shadow [km/s]: 31.5704 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1218-00983-1 by 139 Juewa on 2009 Jun 28 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 -136 43 8 26 48 25 10 53 32 6 72 -34 ... .. .. .. .. .. -132 15 30 27 33 53 ... .. .. .. .. .. -129 23 44 27 51 27 -132 30 21 28 41 17 10 53 35 10 74 -31 -137 1 13 27 55 9 -129 18 39 29 0 36 ... .. .. .. .. .. -126 55 32 29 8 3 -129 37 41 30 6 58 10 53 38 12 76 -28 -132 54 15 29 46 29 -126 56 12 30 15 34 -136 58 20 29 5 17 -124 49 3 30 17 11 -127 17 44 31 21 29 10 53 41 15 77 -26 -130 4 1 31 11 47 -124 53 29 31 23 45 -133 4 43 30 52 32 -122 56 43 31 21 25 -125 16 50 32 29 27 10 53 44 17 79 -24 -127 45 42 32 26 11 -123 3 55 32 27 22 -130 19 25 32 16 34 -121 14 31 32 22 7 -123 28 42 33 33 0 10 53 48 18 80 -22 -125 46 5 33 34 9 -121 23 53 33 27 41 -128 4 7 33 30 22 -119 39 59 33 20 8 -121 49 53 34 33 19 10 53 51 20 81 -21 -123 59 4 34 37 47 -119 51 8 34 25 26 -126 6 41 34 38 2 -118 11 29 34 16 0 -120 18 12 35 31 8 10 53 54 21 82 -19 -122 21 13 35 38 14 -118 24 9 35 21 9 -124 21 23 35 41 31 -116 47 53 35 10 9 -118 52 11 36 26 59 10 53 57 23 83 -18 -120 50 26 36 36 14 -117 1 52 36 15 13 -122 45 1 36 41 56 -115 28 20 36 2 51 -117 30 47 37 21 13 10 54 1 24 85 -16 -119 25 16 37 32 17 -115 43 28 37 7 54 -121 15 30 37 39 58 -114 12 11 36 54 19 -116 13 13 38 14 6 10 54 4 25 86 -15 -118 4 39 38 26 45 -114 28 22 37 59 25 -119 51 29 38 36 7 -112 58 56 37 44 45 -114 58 54 39 5 50 10 54 7 26 87 -13 -116 47 52 39 19 54 -113 16 4 38 49 56 -118 31 57 39 30 43 -111 48 10 38 34 17 -113 47 21 39 56 36 10 54 10 27 88 -12 -115 34 17 40 11 55 -112 6 11 39 39 35 -117 16 9 40 24 1 -110 39 33 39 23 2 -112 38 11 40 46 31 10 54 13 28 89 -11 -114 23 28 41 2 59 -110 58 23 40 28 29 -116 3 31 41 16 15 -109 32 48 40 11 5 -111 31 4 41 35 42 10 54 17 29 90 -10 -113 15 0 41 53 14 -109 52 25 41 16 43 -114 53 36 42 7 34 -108 27 42 40 58 32 -110 25 46 42 24 16 10 54 20 29 92 -9 -112 8 37 42 42 46 -108 48 2 42 4 23 -113 46 1 42 58 5 -107 24 2 41 45 27 -109 22 3 43 12 15 10 54 23 30 93 -8 -111 4 1 43 31 41 -107 45 3 42 51 31 -112 40 28 43 47 54 -106 21 38 42 31 53 -108 19 42 43 59 46 10 54 26 31 94 -6 -110 0 59 44 20 4 -106 43 18 43 38 13 -111 36 42 44 37 9 -105 20 19 43 17 54 -107 18 35 44 46 51 10 54 29 32 95 -5 -108 59 20 45 7 59 -105 42 36 44 24 31 -110 34 30 45 25 52 -104 19 58 44 3 33 -106 18 31 45 33 33 10 54 33 32 96 -4 -107 58 54 45 55 29 -104 42 51 45 10 28 -109 33 40 46 14 8 -103 20 28 44 48 51 -105 19 22 46 19 55 10 54 36 33 98 -3 -106 59 32 46 42 38 -103 43 54 45 56 7 -108 34 3 47 2 2 -102 21 40 45 33 53 -104 21 2 47 6 0 10 54 39 33 99 -2 -106 1 5 47 29 28 -102 45 39 46 41 29 -107 35 29 47 49 35 -101 23 29 46 18 39 -103 23 23 47 51 50 10 54 42 34 100 -1 -105 3 27 48 16 2 -101 48 0 47 26 37 -106 37 51 48 36 51 -100 25 50 47 3 11 -102 26 20 48 37 27 10 54 45 34 102 0 -104 6 31 49 2 23 -100 50 50 48 11 33 -105 41 1 49 23 52 - 99 28 35 47 47 31 Uncertainty in time = +/- 2 secs Prediction of 2009 May 18.0 Data for the target star ------------------------ * name: TYC 1218-00983-1 * constellation : Aries * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 02 24 31.3469 DE: +18 10 42.910 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .025 ) * V mag [mag]: 11.7 * B mag [mag]: 12.9 * Apparent position with proper motion RA(deg): 36.2633000534 DE(deg): 18.2220080142 * Equation of equinoxes (radians) : 0.000066279275177 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (139) Juewa approx. diameter [km]: 150 approx. diameter ["]: .058 distance from Earth [AU]: 3.57300 * orbital information: orbit source: Preston date of fit: 2009 May 15 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 721 number of rejected observations: 103 time covered by the observations: 1912 Dec 31 - 2008 Dec 01 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.008, 61° remarks: * orbital elements for (139) Juewa : Mean anomaly = 229.42256071 deg Arg. of pericenter = 166.18520299 deg Long. of node = 1.87377273 deg Inclination = 10.90815970 deg Eccentricity = 0.17449893 Semimajor axis = 2.78097112 AU Perihelion dist = 2.29569464 AU Mag: H = 7.86, G = 0.15 Epoch of elements : MJD 55010.45500000 TDT (2009 Jun 28.455) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Jun 28 139 Juewa 10h 55.6m UT 11.7 2 24 31.347 18 10 42.91TYC 1218-00983-1 12.9 13.9 150 4.7 3.573 2.765 19.27 -44.4337 18.174 16.94 23.26 10.9260 -0.34958 0.70535 16.00705 7.82931 -0.00456 -0.00134 2000 229.3258622009 628.00000166.185203 1.873773 10.9081600.17449893 2.7809711 2.2956946 7.8 5.00.15 RATE 2.1252470 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.026 84 1.45 0.026 0 54969.0020090628_0983-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2009 May 18, 00:54 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org