IOTA/IOTA-ES occultation update for (959) Arne / TYC 6375-00171-1 event on 2012 Aug 21, 06:02 UT Visible from SW Canada, NW USA Summary ------- On 2012 Aug 21 UT, the 53 km diameter asteroid (959) Arne will occult a 11.8 mag star in the constellation Capricornus for observers along a path across SW Canada, NW USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.4 mag to 14.1 mag (the magnitude of the asteroid) for at most 4.9 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: 58 * date and approx. time of event: 2012 Aug 21, 05:59 - 2012 Aug 21, 06:05 UT * geocentric midpoint of event [JD]: 2456160.75172083 * magnitude of target star: 11.8 * magnitude drop [mag]: 2.4 * estimated maximum duration [s]: 4.9 * Moon: 15 % sunlit, 127° distance * Sun: 170° distance * rough path description: SW Canada, NW USA The occultation path -------------------- * approximate projected width [km]: 197 * 1 sigma uncertainty interval [path widths]: +/- 1.08 * 1 sigma uncertainty interval [seconds]: +/- 6.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .056 +/- .044) * 1 sigma uncertainty ellipse (major, minor, PA): ( .056", .043", 79° ) * approx speed of asteroid's shadow [km/s]: 10.9142 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6375-00171-1 by 959 Arne on 2012 Aug 21 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 -103 54 23 68 0 0 5 59 58 1 170 -9 -106 29 27 -101 29 7 -112 52 29 ... .. .. -103 41 34 67 0 0 5 59 59 2 170 -10 -106 9 11 -101 22 46 -112 10 26 ... .. .. -103 39 34 66 0 0 6 0 0 3 170 -11 -106 1 8 -101 26 8 -111 45 13 ... .. .. -103 47 9 65 0 0 6 0 3 4 170 -12 -106 3 46 -101 38 8 -111 34 19 ... .. .. -104 3 22 64 0 0 6 0 6 5 170 -13 -106 15 59 -101 58 0 -111 35 54 ... .. .. -104 27 32 63 0 0 6 0 9 6 170 -14 -106 36 57 -102 25 6 -111 48 43 - 98 19 25 -104 59 6 62 0 0 6 0 14 7 169 -15 -107 6 5 -102 58 59 -112 11 54 - 98 57 58 -105 37 45 61 0 0 6 0 19 8 169 -16 -107 42 58 -103 39 21 -112 44 53 - 99 41 56 -106 23 15 60 0 0 6 0 24 9 168 -17 -108 27 23 -104 26 0 -113 27 25 -100 31 13 -107 15 33 59 0 0 6 0 31 9 167 -18 -109 19 17 -105 18 53 -114 19 31 -101 25 43 -108 14 43 58 0 0 6 0 39 10 166 -18 -110 18 46 -106 18 2 -115 21 29 -102 25 27 -109 20 59 57 0 0 6 0 47 11 165 -19 -111 26 9 -107 23 37 -116 34 0 -103 30 33 -110 34 43 56 0 0 6 0 56 12 164 -20 -112 41 56 -108 35 56 -117 58 17 -104 41 12 -111 56 35 55 0 0 6 1 7 13 163 -21 -114 7 0 -109 55 30 -119 36 17 -105 57 43 -113 27 30 54 0 0 6 1 18 13 161 -21 -115 42 36 -111 23 2 -121 31 18 -107 20 33 -115 8 50 53 0 0 6 1 31 14 160 -22 -117 30 42 -112 59 32 -123 49 22 -108 50 19 -117 2 42 52 0 0 6 1 45 15 158 -22 -119 34 26 -114 46 31 -126 43 12 -110 27 54 -119 12 25 51 0 0 6 2 2 15 156 -22 -121 59 12 -116 46 16 -130 51 21 -112 14 30 Latitude Latitude Latitude Latitude -121 0 0 50 16 17 6 2 15 15 154 -22 51 23 18 49 14 32 54 15 21 47 14 20 -122 0 0 49 54 8 6 2 23 15 153 -22 50 59 42 48 53 30 53 46 32 46 55 5 -123 0 0 49 33 29 6 2 30 15 152 -22 50 37 47 48 33 51 53 20 6 46 37 4 -124 0 0 49 14 17 6 2 37 15 151 -22 50 17 28 48 15 34 52 55 52 46 20 15 -125 0 0 48 56 32 6 2 44 15 150 -22 49 58 42 47 58 37 52 33 41 46 4 37 -126 0 0 48 40 10 6 2 51 15 149 -22 49 41 26 47 42 58 52 13 26 45 50 9 -127 0 0 48 25 9 6 2 58 15 148 -21 49 25 38 47 28 36 51 55 2 45 36 51 -128 0 0 48 11 28 6 3 5 15 148 -21 49 11 15 47 15 30 51 38 23 45 24 41 -129 0 0 47 59 6 6 3 12 15 147 -21 48 58 16 47 3 38 51 23 26 45 13 40 -130 0 0 47 48 2 6 3 18 14 146 -21 48 46 40 46 53 0 51 10 7 45 3 46 -131 0 0 47 38 14 6 3 25 14 145 -20 48 36 24 46 43 35 50 58 25 44 54 58 -132 0 0 47 29 42 6 3 31 14 144 -20 48 27 29 46 35 22 50 48 16 44 47 18 -133 0 0 47 22 25 6 3 37 14 143 -20 48 19 53 46 28 21 50 39 39 44 40 44 -134 0 0 47 16 22 6 3 43 13 142 -19 48 13 35 46 22 31 50 32 32 44 35 16 -135 0 0 47 11 34 6 3 49 13 141 -19 48 8 34 46 17 53 50 26 55 44 30 54 -136 0 0 47 8 0 6 3 55 13 141 -18 48 4 52 46 14 25 50 22 47 44 27 38 -137 0 0 47 5 39 6 4 1 12 140 -18 48 2 27 46 12 9 50 20 7 44 25 28 -138 0 0 47 4 32 6 4 6 12 139 -17 48 1 19 46 11 3 50 18 55 44 24 24 -139 0 0 47 4 39 6 4 11 11 138 -17 48 1 28 46 11 8 50 19 11 44 24 26 -140 0 0 47 6 1 6 4 16 11 137 -16 48 2 55 46 12 24 50 20 56 44 25 33 -141 0 0 47 8 36 6 4 21 10 136 -16 48 5 40 46 14 52 50 24 9 44 27 48 -142 0 0 47 12 26 6 4 25 10 136 -15 48 9 43 46 18 31 50 28 52 44 31 8 -143 0 0 47 17 32 6 4 30 9 135 -15 48 15 5 46 23 23 50 35 6 44 35 36 -144 0 0 47 23 53 6 4 34 9 134 -14 48 21 48 46 29 27 50 42 52 44 41 11 -145 0 0 47 31 32 6 4 38 8 133 -13 48 29 51 46 36 45 50 52 12 44 47 54 -146 0 0 47 40 28 6 4 41 8 133 -13 48 39 16 46 45 17 51 3 8 44 55 46 -147 0 0 47 50 43 6 4 45 7 132 -12 48 50 4 46 55 4 51 15 43 45 4 46 -148 0 0 48 2 18 6 4 48 6 131 -11 49 2 18 47 6 7 51 30 0 45 14 56 -149 0 0 48 15 14 6 4 51 6 130 -11 49 15 58 47 18 28 51 46 2 45 26 17 -150 0 0 48 29 34 6 4 53 5 130 -10 49 31 7 47 32 7 52 3 54 45 38 49 -151 0 0 48 45 19 6 4 55 4 129 -9 49 47 48 47 47 7 52 23 41 .. .. .. -152 0 0 49 2 31 6 4 57 4 128 -9 50 6 4 48 3 28 52 45 30 .. .. .. -153 0 0 49 21 14 6 4 59 3 127 -8 50 25 57 48 21 14 53 9 28 .. .. .. -154 0 0 49 41 29 6 5 0 2 126 -7 50 47 32 48 40 26 .. .. .. .. .. .. -155 0 0 50 3 20 6 5 1 2 126 -6 51 10 53 49 1 6 .. .. .. .. .. .. -156 0 0 50 26 51 6 5 1 1 125 -6 51 36 6 49 23 18 .. .. .. .. .. .. -157 0 0 50 52 7 6 5 2 0 124 -5 .. .. .. 49 47 5 .. .. .. .. .. .. Uncertainty in time = +/- 7 secs Prediction of 2012 Jul 21.0 Data for the target star ------------------------ * name: TYC 6375-00171-1 * constellation : Capricornus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 45 02.7720 DE: -20 55 57.705 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .035, .035 ) * V mag [mag]: 11.8 * B mag [mag]: 12.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (959) Arne approx. diameter [km]: 53 approx. diameter ["]: .040 distance from Earth [AU]: 1.81100 * orbital information: orbit source: Preston date of fit: 2012 Jul 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1382 number of rejected observations: 31 time covered by the observations: 1916 Dec 27 - 2012 Jul 17 1 sigma uncertainty ellipse (major, minor, PA): 0.044, 0.025, 72° remarks: * orbital elements for (959) Arne : Mean anomaly = 312.95602782 deg Arg. of pericenter = 333.86960872 deg Long. of node = 58.78125183 deg Inclination = 4.49849316 deg Eccentricity = 0.21590049 Semimajor axis = 3.18225035 AU Perihelion dist = 2.49520094 AU Mag: H = 10.66, G = 0.15 Epoch of elements : MJD 56160.25200000 TDT (2012 Aug 21.252) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Aug 21 959 Arne 6h 2.5m UT 11.8 21 45 2.772-20 55 57.71TYC 6375-00171-1 12.3 14.1 53 4.9 1.811 -2.020 -9.68 -94.3261 -20.929 90.16 11.96 6.0413 -0.31184 0.91116 -5.82838 -1.99467 0.00044 0.00088 2000 312.9122752012 821.00000333.869609 58.781252 4.4984930.21590049 3.1822504 2.495200910.2 5.00.15 RATE 1.7362120 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.056 0.043 79 2.08 0.044 0 0 0 5 056129.0020120821_0171-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 21, 14:38 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org