IOTA/IOTA-ES occultation update for (1609) Brenda / UCAC2 25579262 event on 2009 Jul 09, 04:08 UT Visible from Canada, USA, Mexico Summary ------- On 2009 Jul 09 UT, the 30 km diameter asteroid (1609) Brenda will occult a 11.3 mag star in the constellation Ophiuchus 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 2.2 mag to 13.3 mag (the magnitude of the asteroid) for at most 2.8 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 27 * date and approx. time of event: 2009 Jul 09, 04:00 - 2009 Jul 09, 04:13 UT * magnitude of target star: 11.3 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 2.8 * Moon: 97 % sunlit, 43° distance * Sun: 156° distance * rough path description: Canada, USA, Mexico The occultation path -------------------- * approximate projected width [km]: 41 * 1 sigma uncertainty interval [path widths]: +/- 2.46 * 1 sigma uncertainty interval [seconds]: +/- 6.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .088 +/- .085) * 1 sigma uncertainty ellipse (major, minor, PA): ( .088", .085", 93° ) * approx speed of asteroid's shadow [km/s]: 10.5794 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 25579262 by 1609 Brenda on 2009 Jul 9 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 - 72 35 51 67 0 0 4 0 7 6 191 0 - 73 5 44 - 72 6 1 - 75 33 15 - 69 39 33 - 73 20 18 66 0 0 4 0 9 7 190 -1 - 73 49 4 - 72 51 34 - 76 11 7 - 70 30 37 - 74 4 0 65 0 0 4 0 11 8 189 -2 - 74 31 45 - 73 36 17 - 76 48 48 - 71 20 20 - 74 47 4 64 0 0 4 0 13 9 189 -3 - 75 13 52 - 74 20 17 - 77 26 21 - 72 8 56 - 75 29 36 63 0 0 4 0 15 10 188 -4 - 75 55 34 - 75 3 40 - 78 3 49 - 72 56 33 - 76 11 43 62 0 0 4 0 18 11 187 -5 - 76 36 53 - 75 46 34 - 78 41 16 - 73 43 20 - 76 53 28 61 0 0 4 0 21 12 187 -6 - 77 17 55 - 76 29 4 - 79 18 44 - 74 29 24 - 77 34 58 60 0 0 4 0 25 13 186 -6 - 77 58 44 - 77 11 14 - 79 56 14 - 75 14 53 - 78 16 15 59 0 0 4 0 28 14 185 -7 - 78 39 24 - 77 53 8 - 80 33 50 - 75 59 52 - 78 57 23 58 0 0 4 0 32 15 185 -8 - 79 19 58 - 78 34 51 - 81 11 33 - 76 44 25 - 79 38 26 57 0 0 4 0 36 16 184 -9 - 80 0 28 - 79 16 26 - 81 49 25 - 77 28 39 - 80 19 25 56 0 0 4 0 41 17 183 -10 - 80 40 58 - 79 57 55 - 82 27 27 - 78 12 36 - 81 0 25 55 0 0 4 0 46 18 183 -11 - 81 21 29 - 80 39 23 - 83 5 42 - 78 56 20 - 81 41 27 54 0 0 4 0 51 19 182 -11 - 82 2 5 - 81 20 51 - 83 44 10 - 79 39 56 - 82 22 34 53 0 0 4 0 56 20 181 -12 - 82 42 48 - 82 2 22 - 84 22 54 - 80 23 26 - 83 3 47 52 0 0 4 1 1 21 181 -13 - 83 23 39 - 82 43 58 - 85 1 54 - 81 6 54 - 83 45 10 51 0 0 4 1 7 22 180 -14 - 84 4 41 - 83 25 42 - 85 41 13 - 81 50 21 - 84 26 44 50 0 0 4 1 13 23 179 -14 - 84 45 55 - 84 7 35 - 86 20 51 - 82 33 51 - 85 8 31 49 0 0 4 1 20 24 179 -15 - 85 27 24 - 84 49 40 - 87 0 50 - 83 17 26 - 85 50 33 48 0 0 4 1 26 25 178 -16 - 86 9 9 - 85 31 59 - 87 41 11 - 84 1 8 - 86 32 51 47 0 0 4 1 33 26 177 -17 - 86 51 11 - 86 14 33 - 88 21 57 - 84 45 0 - 87 15 28 46 0 0 4 1 40 27 176 -17 - 87 33 33 - 86 57 24 - 89 3 7 - 85 29 4 - 87 58 25 45 0 0 4 1 48 28 176 -18 - 88 16 17 - 87 40 35 - 89 44 44 - 86 13 22 - 88 41 44 44 0 0 4 1 56 29 175 -18 - 88 59 23 - 88 24 7 - 90 26 49 - 86 57 56 - 89 25 27 43 0 0 4 2 4 30 174 -19 - 89 42 55 - 89 8 1 - 91 9 24 - 87 42 47 - 90 9 35 42 0 0 4 2 12 31 173 -20 - 90 26 52 - 89 52 20 - 91 52 29 - 88 27 59 - 90 54 11 41 0 0 4 2 20 32 172 -20 - 91 11 18 - 90 37 6 - 92 36 8 - 89 13 34 - 91 39 16 40 0 0 4 2 29 33 171 -21 - 91 56 15 - 91 22 20 - 93 20 21 - 89 59 32 - 92 24 52 39 0 0 4 2 38 34 170 -21 - 92 41 43 - 92 8 4 - 94 5 10 - 90 45 56 - 93 11 2 38 0 0 4 2 48 35 169 -22 - 93 27 45 - 92 54 21 - 94 50 38 - 91 32 49 - 93 57 46 37 0 0 4 2 57 36 168 -22 - 94 14 23 - 93 41 11 - 95 36 45 - 92 20 12 - 94 45 8 36 0 0 4 3 7 37 167 -23 - 95 1 39 - 94 28 39 - 96 23 34 - 93 8 8 - 95 33 8 35 0 0 4 3 17 37 166 -23 - 95 49 35 - 95 16 44 - 97 11 7 - 93 56 38 - 96 21 51 34 0 0 4 3 28 38 165 -24 - 96 38 13 - 96 5 31 - 97 59 27 - 94 45 45 - 97 11 17 33 0 0 4 3 38 39 164 -24 - 97 27 37 - 96 55 1 - 98 48 35 - 95 35 32 - 98 1 30 32 0 0 4 3 49 40 163 -25 - 98 17 47 - 97 45 16 - 99 38 35 - 96 26 1 - 98 52 33 31 0 0 4 4 1 41 162 -25 - 99 8 48 - 98 36 20 -100 29 28 - 97 17 15 - 99 44 27 30 0 0 4 4 12 41 160 -25 -100 0 41 - 99 28 15 -101 21 18 - 98 9 16 -100 37 16 29 0 0 4 4 24 42 159 -25 -100 53 30 -100 21 5 -102 14 9 - 99 2 7 -101 31 4 28 0 0 4 4 36 43 158 -26 -101 47 19 -101 14 52 -103 8 3 - 99 55 52 -102 25 53 27 0 0 4 4 48 43 156 -26 -102 42 10 -102 9 39 -104 3 4 -100 50 33 -103 21 48 26 0 0 4 5 1 44 155 -26 -103 38 7 -103 5 32 -104 59 16 -101 46 15 -104 18 52 25 0 0 4 5 14 44 153 -26 -104 35 15 -104 2 33 -105 56 43 -102 43 1 -105 17 10 24 0 0 4 5 27 45 152 -26 -105 33 38 -105 0 46 -106 55 31 -103 40 55 -106 16 47 23 0 0 4 5 40 45 150 -26 -106 33 21 -106 0 18 -107 55 43 -104 40 2 -107 17 48 22 0 0 4 5 54 46 149 -26 -107 34 28 -107 1 12 -108 57 27 -105 40 26 -108 20 19 21 0 0 4 6 8 46 147 -26 -108 37 7 -108 3 35 -110 0 48 -106 42 13 -109 24 26 20 0 0 4 6 22 46 145 -26 -109 41 23 -109 7 33 -111 5 53 -107 45 29 -110 30 16 19 0 0 4 6 37 47 143 -26 -110 47 24 -110 13 12 -112 12 51 -108 50 20 -111 37 57 18 0 0 4 6 52 47 142 -26 -111 55 17 -111 20 41 -113 21 50 -109 56 54 -112 47 38 17 0 0 4 7 7 47 140 -25 -113 5 12 -112 30 8 -114 33 0 -111 5 17 -113 59 29 16 0 0 4 7 22 47 138 -25 -114 17 19 -113 41 43 -115 46 32 -112 15 40 -115 13 41 15 0 0 4 7 38 47 136 -25 -115 31 50 -114 55 38 -117 2 41 -113 28 11 -116 30 28 14 0 0 4 7 54 47 134 -24 -116 48 58 -116 12 4 -118 21 40 -114 43 3 -117 50 5 13 0 0 4 8 11 46 132 -24 -118 8 59 -117 31 17 -119 43 48 -116 0 29 -119 12 48 12 0 0 4 8 28 46 130 -23 -119 32 10 -118 53 35 -121 9 25 -117 20 44 -120 39 1 11 0 0 4 8 45 46 128 -23 -120 58 54 -120 19 16 -122 38 58 -118 44 5 -122 9 6 10 0 0 4 9 3 45 126 -22 -122 29 36 -121 48 46 -124 12 57 -120 10 53 -123 43 36 9 0 0 4 9 21 45 124 -21 -124 4 48 -123 22 34 -125 52 0 -121 41 34 -125 23 6 8 0 0 4 9 39 44 122 -20 -125 45 10 -125 1 16 -127 36 55 -123 16 36 -127 8 26 7 0 0 4 9 59 43 121 -19 -127 31 29 -126 45 37 -129 28 45 -124 56 38 -129 0 35 6 0 0 4 10 18 42 119 -18 -129 24 51 -128 36 36 -131 28 53 -126 42 27 -131 0 56 5 0 0 4 10 39 41 117 -17 -131 26 43 -130 35 30 -133 39 16 -128 35 2 Latitude Latitude Latitude Latitude -133 0 0 4 5 1 4 10 58 39 115 -15 4 17 9 3 52 56 5 17 31 2 54 2 -134 0 0 3 38 56 4 11 8 39 115 -15 3 51 0 3 26 56 4 50 56 2 28 25 -135 0 0 3 13 56 4 11 17 38 114 -14 3 25 55 3 2 0 4 25 28 2 3 52 -136 0 0 2 50 0 4 11 26 37 113 -13 3 1 54 2 38 8 4 1 5 1 40 21 -137 0 0 2 27 8 4 11 35 37 113 -13 2 38 58 2 15 20 3 37 47 1 17 52 -138 0 0 2 5 18 4 11 44 36 112 -12 2 17 4 1 53 34 3 15 34 0 56 25 -139 0 0 1 44 31 4 11 53 35 112 -11 1 56 14 1 32 51 2 54 24 0 36 0 -140 0 0 1 24 46 4 12 1 34 111 -10 1 36 25 1 13 10 2 34 18 0 16 35 -141 0 0 1 6 3 4 12 9 33 111 -9 1 17 39 0 54 30 2 15 15 - 0 1 50 -142 0 0 0 48 21 4 12 17 33 110 -9 0 59 54 0 36 51 1 57 14 - 0 19 14 -143 0 0 0 31 40 4 12 25 32 110 -8 0 43 10 0 20 12 1 40 16 - 0 35 39 -144 0 0 0 15 59 4 12 32 31 110 -7 0 27 26 0 4 34 1 24 19 - 0 51 4 -145 0 0 0 1 19 4 12 40 30 109 -6 0 12 43 - 0 10 4 1 9 23 - 1 5 30 -146 0 0 - 0 12 22 4 12 47 29 109 -6 - 0 1 0 - 0 23 42 0 55 28 - 1 18 58 -147 0 0 - 0 25 3 4 12 54 29 109 -5 - 0 13 43 - 0 36 21 0 42 35 - 1 31 27 -148 0 0 - 0 36 45 4 13 0 28 109 -4 - 0 25 27 - 0 48 1 0 30 41 - 1 42 58 -149 0 0 - 0 47 28 4 13 7 27 108 -3 - 0 36 11 - 0 58 42 0 19 48 - 1 53 31 -150 0 0 - 0 57 12 4 13 13 26 108 -2 - 0 45 57 - 1 8 25 0 9 55 - 2 3 6 -151 0 0 - 1 5 57 4 13 19 25 108 -1 - 0 54 43 - 1 17 8 0 1 2 - 2 11 43 -152 0 0 - 1 13 43 4 13 25 24 108 -1 - 1 2 31 - 1 24 54 - 0 6 52 - 2 19 23 Uncertainty in time = +/- 7 secs Prediction of 2009 Jun 30.0 Data for the target star ------------------------ * name: UCAC2 25579262 * constellation : Ophiuchus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 17 34 21.2719 DE: -16 38 00.930 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .081, .081 ) * V mag [mag]: 11.3 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1609) Brenda approx. diameter [km]: 30 approx. diameter ["]: .035 distance from Earth [AU]: 1.18300 * orbital information: orbit source: Preston date of fit: 2009 Jun 30 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 846 number of rejected observations: 41 time covered by the observations: 1934 Jun 05 - 2009 Jun 25 1 sigma uncertainty ellipse (major, minor, PA): 0.034, 0.024, 109° remarks: * orbital elements for (1609) Brenda : Mean anomaly = 322.44752058 deg Arg. of pericenter = 228.62774720 deg Long. of node = 105.46326660 deg Inclination = 18.66644353 deg Eccentricity = 0.25070525 Semimajor axis = 2.58226260 AU Perihelion dist = 1.93487580 AU Mag: H = 10.54, G = 0.15 Epoch of elements : MJD 55021.17200000 TDT (2009 Jul 09.172) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Jul 9 1609 Brenda 4h 7.3m UT 11.3 17 34 21.272-16 38 0.93UCAC2 25579262 0.0 13.3 30 2.8 1.183 -2.289 -29.81 -85.4825 -16.624 119.47 22.34 4.1223 -0.45843 0.50633 -4.42608 -4.00831 0.00200 -0.00064 2000 322.1691452009 7 8.00000228.627747105.463267 18.6664440.25070525 2.5822626 1.934875810.6 5.00.15 RATE 2.3752180 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.088 0.085 93 3.46 0.086 0 55012.0020090709_579262 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2009 Jun 30, 16:01 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org