IOTA/IOTA-ES occultation update for (856) Backlunda / UCAC4 402-110929 event on 2023 May 25, 17:50 UT Visible from China, SE Asia, India Summary ------- On 2023 May 25 UT, the 45.2 km diameter asteroid (856) Backlunda will occult a 11.4 mag star in the constellation Aquila for observers along a path across China, SE Asia, India. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.04 mag to 14.38 mag (the magnitude of the asteroid) for at most 19.120 seconds. This update is based on, astrometry for the asteroid kindly provided by the IAU Minor Planet Center. This work has made use of data from the European Space Agency (ESA) mission Gaia (http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, http://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The event at a glimpse ---------------------- * Rank: 99 * date and approx. time of event: 2023 May 25, 17:19 - 2023 May 25, 18:21 * geocentric midpoint of event [JD]: 2460090.24346192 * magnitude of target star: 11.41 * magnitude drop [mag]: 3.04 * estimated maximum duration [s]: 19.120 * Moon: 32 % sunlit, 152° distance * Sun: 131° distance * rough path description: China, SE Asia, India The occultation path -------------------- * approximate projected width [km]: 69 * 1 sigma uncertainty interval [path widths]: +/- 0.24 * 1 sigma uncertainty interval [seconds]: +/- 5.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.015, +/- 0.003) * 1 sigma uncertainty ellipse (major, minor, PA): (0.015", 0.002", 97°) * approx speed of asteroid's shadow [km/s]: 2.3641 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 402-110929 by 856 Backlunda on 2023 May 25 Centre Star Star Sun Path Limits Error Limits Alt E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 Crn o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " Latitude Latitude Latitude Latitude 47 0 0 15 56 33 18 19 58.8 1 100 -38 16 16 4 15 37 11 16 25 19 15 28 5 .... 48 0 0 15 47 19 18 19 57.4 2 101 -39 16 6 44 15 28 2 16 15 57 15 18 58 -0.80 49 0 0 15 38 59 18 19 54.9 3 101 -40 15 58 19 15 19 46 16 7 29 15 10 46 -0.95 50 0 0 15 31 32 18 19 51.2 4 101 -40 15 50 48 15 12 25 15 59 55 15 3 26 -1.01 51 0 0 15 24 58 18 19 46.4 5 101 -41 15 44 9 15 5 55 15 53 15 14 56 58 -1.05 52 0 0 15 19 17 18 19 40.5 5 102 -42 15 38 23 15 0 17 15 47 27 14 51 23 -1.07 53 0 0 15 14 26 18 19 33.6 6 102 -43 15 33 29 14 55 30 15 42 31 14 46 37 -1.08 54 0 0 15 10 26 18 19 25.6 7 102 -43 15 29 25 14 51 33 15 38 25 14 42 42 -1.09 55 0 0 15 7 15 18 19 16.6 8 102 -44 15 26 12 14 48 26 15 35 10 14 39 36 -1.10 56 0 0 15 4 54 18 19 6.5 9 103 -44 15 23 47 14 46 7 15 32 44 14 37 19 -1.10 57 0 0 15 3 21 18 18 55.5 10 103 -45 15 22 11 14 44 37 15 31 7 14 35 49 -1.11 58 0 0 15 2 35 18 18 43.5 11 103 -46 15 21 24 14 43 54 15 30 19 14 35 7 -1.11 59 0 0 15 2 37 18 18 30.6 12 104 -46 15 21 24 14 43 58 15 30 17 14 35 12 -1.11 60 0 0 15 3 25 18 18 16.7 13 104 -47 15 22 10 14 44 48 15 31 3 14 36 3 -1.11 61 0 0 15 5 0 18 18 1.9 14 104 -47 15 23 43 14 46 23 15 32 35 14 37 39 -1.11 62 0 0 15 7 19 18 17 46.3 14 104 -48 15 26 1 14 48 44 15 34 53 14 40 1 -1.11 63 0 0 15 10 24 18 17 29.7 15 105 -48 15 29 5 14 51 50 15 37 56 14 43 7 -1.11 64 0 0 15 14 13 18 17 12.2 16 105 -48 15 32 53 14 55 40 15 41 44 14 46 57 -1.11 65 0 0 15 18 46 18 16 53.9 17 105 -49 15 37 25 15 0 13 15 46 16 14 51 31 -1.11 66 0 0 15 24 3 18 16 34.8 18 106 -49 15 42 42 15 5 30 15 51 32 14 56 48 -1.11 67 0 0 15 30 2 18 16 14.8 19 106 -49 15 48 41 15 11 30 15 57 31 15 2 48 -1.10 68 0 0 15 36 44 18 15 54.0 19 106 -50 15 55 23 15 18 12 16 4 14 15 9 30 -1.10 69 0 0 15 44 9 18 15 32.5 20 107 -50 16 2 48 15 25 36 16 11 39 15 16 54 -1.10 70 0 0 15 52 15 18 15 10.1 21 107 -50 16 10 55 15 33 42 16 19 46 15 24 59 -1.10 71 0 0 16 1 3 18 14 47.0 22 108 -50 16 19 44 15 42 29 16 28 35 15 33 46 -1.10 72 0 0 16 10 32 18 14 23.1 23 108 -51 16 29 13 15 51 57 16 38 5 15 43 13 -1.10 73 0 0 16 20 41 18 13 58.5 23 108 -51 16 39 24 16 2 5 16 48 16 15 53 21 -1.10 74 0 0 16 31 31 18 13 33.2 24 109 -51 16 50 16 16 12 54 16 59 8 16 4 9 -1.10 75 0 0 16 43 1 18 13 7.1 25 109 -51 17 1 47 16 24 22 17 10 41 16 15 37 -1.10 76 0 0 16 55 11 18 12 40.3 26 110 -51 17 13 59 16 36 31 17 22 54 16 27 44 -1.10 77 0 0 17 8 1 18 12 12.9 26 110 -51 17 26 51 16 49 18 17 35 46 16 40 31 -1.10 78 0 0 17 21 30 18 11 44.7 27 111 -51 17 40 22 17 2 45 17 49 18 16 53 56 -1.09 79 0 0 17 35 37 18 11 15.9 28 111 -51 17 54 32 17 16 50 18 3 30 17 8 1 -1.09 80 0 0 17 50 24 18 10 46.5 28 112 -51 18 9 21 17 31 34 18 18 20 17 22 43 -1.09 81 0 0 18 5 48 18 10 16.4 29 113 -51 18 24 49 17 46 56 18 33 49 17 38 4 -1.09 82 0 0 18 21 51 18 9 45.7 30 113 -50 18 40 55 18 2 56 18 49 57 17 54 2 -1.09 83 0 0 18 38 32 18 9 14.4 30 114 -50 18 57 39 18 19 33 19 6 42 18 10 39 -1.09 84 0 0 18 55 51 18 8 42.5 31 114 -50 19 15 1 18 36 49 19 24 7 18 27 52 -1.09 85 0 0 19 13 48 18 8 10.0 32 115 -50 19 33 1 18 54 41 19 42 8 18 45 43 -1.09 86 0 0 19 32 21 18 7 36.9 32 116 -50 19 51 39 19 13 11 20 0 48 19 4 11 -1.09 87 0 0 19 51 32 18 7 3.3 33 116 -49 20 10 54 19 32 18 20 20 5 19 23 16 -1.09 88 0 0 20 11 20 18 6 29.1 33 117 -49 20 30 46 19 52 1 20 39 59 19 42 58 -1.10 89 0 0 20 31 44 18 5 54.4 34 118 -49 20 51 15 20 12 21 21 0 30 20 3 15 -1.10 90 0 0 20 52 45 18 5 19.2 35 119 -48 21 12 21 20 33 17 21 21 38 20 24 9 -1.10 91 0 0 21 14 22 18 4 43.5 35 119 -48 21 34 3 20 54 50 21 43 23 20 45 39 -1.10 92 0 0 21 36 36 18 4 7.3 36 120 -47 21 56 22 21 16 58 22 5 44 21 7 45 -1.10 93 0 0 21 59 25 18 3 30.6 36 121 -47 22 19 17 21 39 42 22 28 42 21 30 27 -1.10 94 0 0 22 22 50 18 2 53.5 36 122 -46 22 42 48 22 3 1 22 52 16 21 53 44 -1.10 95 0 0 22 46 51 18 2 15.9 37 123 -46 23 6 55 22 26 56 23 16 26 22 17 36 -1.10 96 0 0 23 11 27 18 1 37.9 37 124 -45 23 31 37 22 51 27 23 41 11 22 42 3 -1.11 97 0 0 23 36 39 18 0 59.4 38 125 -45 23 56 55 23 16 32 24 6 32 23 7 6 -1.11 98 0 0 24 2 26 18 0 20.6 38 126 -44 24 22 49 23 42 12 24 32 29 23 32 43 -1.11 99 0 0 24 28 48 17 59 41.4 38 127 -44 24 49 18 24 8 27 24 59 1 23 58 54 -1.11 100 0 0 24 55 44 17 59 1.9 39 128 -43 25 16 21 24 35 16 25 26 8 24 25 41 -1.11 101 0 0 25 23 15 17 58 22.0 39 129 -42 25 44 0 25 2 40 25 53 51 24 53 1 -1.12 102 0 0 25 51 21 17 57 41.7 39 130 -42 26 12 14 25 30 38 26 22 8 25 20 56 -1.12 103 0 0 26 20 1 17 57 1.2 40 131 -41 26 41 2 25 59 10 26 51 0 25 49 24 -1.12 104 0 0 26 49 15 17 56 20.3 40 132 -40 27 10 24 26 28 16 27 20 27 26 18 26 -1.12 105 0 0 27 19 3 17 55 39.2 40 133 -40 27 40 21 26 57 56 27 50 28 26 48 2 -1.13 106 0 0 27 49 25 17 54 57.9 40 134 -39 28 10 52 27 28 9 28 21 3 27 18 11 -1.13 107 0 0 28 20 21 17 54 16.3 40 135 -38 28 41 57 27 58 56 28 52 12 27 48 53 -1.13 108 0 0 28 51 50 17 53 34.5 41 136 -38 29 13 36 28 30 15 29 23 56 28 20 8 -1.14 109 0 0 29 23 52 17 52 52.5 41 137 -37 29 45 47 29 2 8 29 56 12 28 51 56 -1.14 110 0 0 29 56 27 17 52 10.3 41 139 -36 30 18 33 29 34 32 30 29 2 29 24 17 -1.14 111 0 0 30 29 34 17 51 28.0 41 140 -35 30 51 51 30 7 30 31 2 26 29 57 9 -1.15 112 0 0 31 3 15 17 50 45.5 41 141 -34 31 25 42 30 41 0 31 36 23 30 30 34 -1.15 113 0 0 31 37 27 17 50 3.0 41 142 -34 32 0 6 31 15 1 32 10 52 31 4 31 -1.15 114 0 0 32 12 12 17 49 20.3 41 143 -33 32 35 3 31 49 34 32 45 54 31 38 59 -1.16 115 0 0 32 47 28 17 48 37.7 41 145 -32 33 10 31 32 24 39 33 21 28 32 13 58 -1.16 116 0 0 33 23 16 17 47 54.9 41 146 -31 33 46 31 33 0 15 33 57 35 32 49 28 -1.17 117 0 0 33 59 35 17 47 12.2 41 147 -30 34 23 3 33 36 21 34 34 13 33 25 29 -1.17 118 0 0 34 36 25 17 46 29.5 40 148 -30 35 0 6 34 12 58 35 11 22 34 2 0 -1.17 119 0 0 35 13 45 17 45 46.9 40 150 -29 35 37 40 34 50 5 35 49 3 34 39 1 -1.18 120 0 0 35 51 36 17 45 4.3 40 151 -28 36 15 45 35 27 42 36 27 14 35 16 32 -1.18 121 0 0 36 29 56 17 44 21.8 40 152 -27 36 54 20 36 5 48 37 5 56 35 54 31 -1.19 122 0 0 37 8 45 17 43 39.5 39 153 -26 37 33 24 36 44 23 37 45 8 36 33 0 -1.19 123 0 0 37 48 4 17 42 57.3 39 154 -25 38 12 58 37 23 27 38 24 49 37 11 56 -1.19 124 0 0 38 27 50 17 42 15.3 39 156 -24 38 53 1 38 2 58 39 5 0 37 51 21 -1.20 125 0 0 39 8 5 17 41 33.6 38 157 -23 39 33 32 38 42 57 39 45 38 38 31 12 -1.20 126 0 0 39 48 47 17 40 52.1 38 158 -22 40 14 30 39 23 23 40 26 45 39 11 30 -1.21 127 0 0 40 29 55 17 40 10.8 38 159 -21 40 55 56 40 4 14 41 8 19 39 52 14 -1.21 128 0 0 41 11 29 17 39 29.9 37 160 -21 41 37 48 40 45 31 41 50 20 40 33 23 -1.22 129 0 0 41 53 28 17 38 49.4 37 162 -20 42 20 5 41 27 13 42 32 46 41 14 57 -1.22 130 0 0 42 35 52 17 38 9.2 36 163 -19 43 2 48 42 9 19 43 15 38 41 56 55 -1.22 131 0 0 43 18 40 17 37 29.4 36 164 -18 43 45 54 42 51 48 43 58 54 42 39 15 -1.23 132 0 0 44 1 49 17 36 50.1 35 165 -17 44 29 24 43 34 39 44 42 33 43 21 58 -1.23 133 0 0 44 45 21 17 36 11.3 35 166 -16 45 13 16 44 17 51 45 26 35 44 5 1 -1.24 134 0 0 45 29 13 17 35 33.0 34 167 -15 45 57 28 45 1 23 46 10 57 44 48 24 -1.24 135 0 0 46 13 24 17 34 55.3 34 168 -14 46 42 1 45 45 14 46 55 40 45 32 6 -1.24 136 0 0 46 57 54 17 34 18.1 33 169 -13 47 26 52 46 29 23 47 40 42 46 16 6 -1.25 137 0 0 47 42 40 17 33 41.6 32 171 -12 48 12 0 47 13 49 48 26 0 47 0 22 -1.25 138 0 0 48 27 41 17 33 5.7 32 172 -11 48 57 24 47 58 29 49 11 35 47 44 52 -1.25 139 0 0 49 12 57 17 32 30.6 31 173 -10 49 43 2 48 43 23 49 57 24 48 29 36 -1.26 140 0 0 49 58 24 17 31 56.1 30 174 -9 50 28 52 49 28 28 50 43 26 49 14 32 -1.26 141 0 0 50 44 2 17 31 22.4 30 175 -8 51 14 53 50 13 44 51 29 39 49 59 38 -1.26 142 0 0 51 29 48 17 30 49.6 29 176 -7 52 1 3 50 59 8 52 16 0 50 44 52 -1.27 143 0 0 52 15 41 17 30 17.5 28 177 -7 52 47 19 51 44 38 53 2 28 51 30 12 -1.27 144 0 0 53 1 38 17 29 46.3 27 178 -6 53 33 40 52 30 13 53 49 0 52 15 36 -1.27 145 0 0 53 47 37 17 29 16.0 27 179 -5 54 20 3 53 15 49 54 35 35 53 1 3 -1.27 146 0 0 54 33 36 17 28 46.6 26 180 -4 55 6 25 54 1 26 55 22 9 53 46 29 -1.27 147 0 0 55 19 31 17 28 18.2 25 181 -3 55 52 45 54 46 59 56 8 40 54 31 52 -1.28 148 0 0 56 5 22 17 27 50.7 24 182 -2 56 38 58 55 32 28 56 55 5 55 17 11 -1.28 149 0 0 56 51 4 17 27 24.2 24 183 -1 57 25 4 56 17 48 57 41 22 56 2 21 -1.28 150 0 0 57 36 35 17 26 58.7 23 183 0 58 10 57 57 2 58 58 27 27 56 47 22 -1.28 151 0 0 58 21 52 17 26 34.2 22 184 1 58 56 36 57 47 55 59 13 17 57 32 9 -1.28 152 0 0 59 6 53 17 26 10.8 21 185 1 59 41 58 58 32 35 59 58 49 58 16 41 -1.28 153 0 0 59 51 33 17 25 48.4 20 186 2 60 26 59 59 16 56 60 43 59 59 0 53 -1.28 154 0 0 60 35 50 17 25 27.1 20 187 3 61 11 35 60 0 55 61 28 45 59 44 44 -1.28 155 0 0 61 19 41 17 25 6.8 19 188 4 61 55 44 60 44 29 62 13 3 60 28 10 -1.28 156 0 0 62 3 2 17 24 47.6 18 189 5 62 39 22 61 27 35 62 56 50 61 11 8 -1.28 157 0 0 62 45 51 17 24 29.4 17 190 5 63 22 26 62 10 9 63 40 2 61 53 36 -1.28 158 0 0 63 28 4 17 24 12.2 16 191 6 64 4 53 62 52 9 64 22 35 62 35 30 -1.28 159 0 0 64 9 38 17 23 56.1 16 192 7 64 46 40 63 33 31 65 4 28 63 16 47 -1.28 160 0 0 64 50 31 17 23 41.0 15 193 8 65 27 43 64 14 14 65 45 36 63 57 25 -1.28 161 0 0 65 30 39 17 23 26.9 14 194 8 66 7 59 64 54 14 66 25 57 64 37 22 -1.28 162 0 0 66 10 0 17 23 13.8 14 195 9 66 47 27 65 33 29 67 5 27 65 16 34 -1.28 163 0 0 66 48 32 17 23 1.6 13 195 10 67 26 3 66 11 56 67 44 5 65 54 59 -1.28 164 0 0 67 26 12 17 22 50.3 12 196 10 68 3 45 66 49 34 68 21 49 66 32 36 -1.28 165 0 0 68 2 58 17 22 39.8 11 197 11 68 40 32 67 26 20 68 58 35 67 9 21 -1.28 166 0 0 68 38 49 17 22 30.3 11 198 12 69 16 21 68 2 13 69 34 23 67 45 15 -1.28 167 0 0 69 13 43 17 22 21.5 10 199 12 69 51 11 68 37 10 70 9 11 68 20 14 -1.27 168 0 0 69 47 40 17 22 13.5 9 200 13 70 25 1 69 11 12 70 42 58 68 54 18 -1.27 169 0 0 70 20 37 17 22 6.2 9 201 13 70 57 50 69 44 17 71 15 42 69 27 26 -1.27 170 0 0 70 52 35 17 21 59.7 8 202 14 71 29 37 70 16 24 71 47 25 69 59 37 -1.27 171 0 0 71 23 32 17 21 53.7 8 203 14 72 0 23 70 47 33 72 18 4 70 30 51 -1.27 172 0 0 71 53 30 17 21 48.4 7 204 15 72 30 7 71 17 43 72 47 41 71 1 7 -1.27 173 0 0 72 22 28 17 21 43.7 6 205 15 72 58 49 71 46 55 73 16 15 71 30 25 -1.27 174 0 0 72 50 26 17 21 39.5 6 206 16 73 26 30 72 15 9 73 43 48 71 58 46 -1.26 175 0 0 73 17 25 17 21 35.7 5 207 16 73 53 11 72 42 25 74 10 20 72 26 10 -1.26 176 0 0 73 43 26 17 21 32.5 5 208 17 74 18 52 73 8 45 74 35 51 72 52 37 -1.26 177 0 0 74 8 30 17 21 29.6 4 209 17 74 43 36 73 34 8 75 0 24 73 18 9 -1.26 178 0 0 74 32 38 17 21 27.2 4 210 17 75 7 22 73 58 36 75 24 0 73 42 46 -1.26 179 0 0 74 55 51 17 21 25.1 3 210 18 75 30 12 74 22 10 75 46 39 74 6 30 -1.26 180 0 0 75 18 11 17 21 23.4 3 211 18 75 52 9 74 44 51 76 8 24 74 29 21 -1.26 -179 0 0 75 39 38 17 21 21.9 2 212 18 76 13 13 75 6 41 76 29 16 74 51 21 -1.26 -178 0 0 76 0 15 17 21 20.8 2 213 19 76 33 25 75 27 41 76 49 17 75 12 30 -1.26 -177 0 0 76 20 3 17 21 19.8 2 214 19 76 52 49 75 47 52 77 8 28 75 32 52 -1.26 -176 0 0 76 39 4 17 21 19.2 1 215 19 77 11 25 76 7 15 77 26 52 75 52 26 -1.27 -175 0 0 76 57 18 17 21 18.7 1 216 19 77 29 15 76 25 54 77 44 30 76 11 15 -1.28 -174 0 0 77 14 49 17 21 18.4 0 217 20 77 46 20 76 43 48 .. .. .. 76 29 20 -1.31 -173 0 0 77 31 37 17 21 18.3 0 218 20 .. .. .. 77 0 59 .. .. .. 76 46 42 -1.50 -172 0 0 .. .. .... .. .. .. .. .. .. .. .. .. 77 17 30 .. .. .. 77 3 23 .... -171 0 0 .. .. .... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 77 19 24 .... Uncertainty in time = +/- 7 secs Prediction of 2023 Apr 29.2 Data for the target star ------------------------ * name: UCAC4 402-110929 * constellation : Aquila * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 19 24 58.9946 DE: -09 44 54.868 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 19 24 58.9946 DE: -09 44 54.868 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.200,0.100) * V mag [mag]: 11.4 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (856) Backlunda asteroid class: approx. diameter [km]: 45 approx. diameter ["]: 0.041 distance from Earth [AU]: 1.52450 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#94 date of fit: 2023 Apr 24 source of used astrometry: MPC, JPL number of used observations: 0 number of rejected observations: 0 time covered by the observations: 1800 Jan 01 - 1800 Jan 01 1 sigma uncertainty ellipse (major, minor, PA): 0.015", 0.002", 97.332° remarks: * orbital elements for (856)Backlunda : Mean anomaly = 60.7476573898 deg Arg. of pericenter = 72.6340140578 deg Long. of node = 125.5328088930 deg Inclination = 14.3266767761 deg Eccentricity = 0.1191828056 Semimajor axis = 2.4350848822 AU Perihelion dist = 2.1448646341 AU Mag: H = 10.66, G = 0.15 Epoch of elements : MJD 60089.74312500 TDT (2023 May 25.7431) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#942023Apr24,19.12,2023,5,25,17.843086,-0.410138,0.634226,-1.120456,-0.724605,-0.003797,-0.001356,0.000001,0.000000 140.8666,-9.7036,-88.40,21.00,False UCAC4 402-110929,19.41638737,-9.7485745,0.00,11.41,0.00,0.0,0,,19.43784790,-9.7036404,3.03,0.00,0,0,0 856,Backlunda,14.38,45.2,1.5245,0,0,-0.438,-4.18,,2.6,0 0,60.5549,2023,5,25,72.6340,125.5328,14.3267,0.11918,2.43508,2.14486,10.66,5.0,0.15 1.236,0.0147,0.0024,97,0.0096,Known errors,-1.00,-1,-1,-1 20230525_110929,60063.19 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Apr 29, 04:29 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org