IOTA/IOTA-ES occultation update for (20) Massalia / UCAC4 339-091673 event on 2023 Sep 12, 18:28 UT Visible from Africa Summary ------- On 2023 Sep 12 UT, the 138.3 km diameter asteroid (20) Massalia will occult a 10.8 mag star in the constellation Ophiuchus for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.40 mag to 11.87 mag (the magnitude of the asteroid) for at most 9.160 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: 100 * date and approx. time of event: 2023 Sep 12, 18:24 - 2023 Sep 12, 18:33 * geocentric midpoint of event [JD]: 2460200.27016255 * magnitude of target star: 10.82 * magnitude drop [mag]: 1.40 * estimated maximum duration [s]: 9.160 * Moon: 5 % sunlit, 117° distance * Sun: 92° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 208 * 1 sigma uncertainty interval [path widths]: +/- 0.02 * 1 sigma uncertainty interval [seconds]: +/- 0.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.003, +/- 0.002) * 1 sigma uncertainty ellipse (major, minor, PA): (0.003", 0.001", 93°) * approx speed of asteroid's shadow [km/s]: 15.0959 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 339-091673 by 20 Massalia on 2023 Sep 12 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 - 70 0 0 47 50 31 18 24 22.1 0 124 41 46 43 31 .. .. .. 46 40 53 .. .. .. .... - 69 0 0 47 22 37 18 24 22.2 1 125 40 46 15 45 48 31 19 46 13 7 48 34 6 -0.27 - 68 0 0 46 54 40 18 24 22.4 2 126 40 45 47 56 48 3 12 45 45 19 48 5 58 -0.68 - 67 0 0 46 26 40 18 24 22.7 2 127 40 45 20 5 47 35 2 45 17 28 47 37 48 -0.82 - 66 0 0 45 58 38 18 24 23.1 3 127 40 44 52 12 47 6 50 44 49 36 47 9 36 -0.90 - 65 0 0 45 30 36 18 24 23.7 4 128 40 44 24 20 46 38 37 44 21 43 46 41 22 -0.94 - 64 0 0 45 2 33 18 24 24.5 5 129 40 43 56 28 46 10 24 43 53 52 46 13 9 -0.97 - 63 0 0 44 34 33 18 24 25.3 6 130 40 43 28 37 45 42 12 43 26 2 45 44 56 -0.99 - 62 0 0 44 6 34 18 24 26.4 7 130 40 43 0 49 45 14 2 42 58 14 45 16 45 -1.00 - 61 0 0 43 38 39 18 24 27.5 8 131 39 42 33 5 44 45 55 42 30 30 44 48 38 -1.02 - 60 0 0 43 10 47 18 24 28.9 8 132 39 42 5 25 44 17 51 42 2 51 44 20 34 -1.02 - 59 0 0 42 43 1 18 24 30.3 9 132 39 41 37 50 43 49 53 41 35 17 43 52 35 -1.03 - 58 0 0 42 15 22 18 24 32.0 10 133 38 41 10 22 43 22 0 41 7 49 43 24 42 -1.04 - 57 0 0 41 47 49 18 24 33.7 11 134 38 40 43 2 42 54 15 40 40 29 42 56 56 -1.05 - 56 0 0 41 20 24 18 24 35.7 12 134 38 40 15 49 42 26 37 40 13 17 42 29 17 -1.05 - 55 0 0 40 53 9 18 24 37.7 13 135 37 39 48 46 41 59 8 39 46 14 42 1 48 -1.05 - 54 0 0 40 26 4 18 24 40.0 14 136 37 39 21 53 41 31 49 39 19 22 41 34 29 -1.06 - 53 0 0 39 59 9 18 24 42.4 14 137 37 38 55 11 41 4 41 38 52 40 41 7 20 -1.06 - 52 0 0 39 32 27 18 24 44.9 15 137 36 38 28 41 40 37 45 38 26 11 40 40 23 -1.07 - 51 0 0 39 5 57 18 24 47.6 16 138 36 38 2 24 40 11 2 37 59 54 40 13 39 -1.07 - 50 0 0 38 39 41 18 24 50.4 17 139 35 37 36 21 39 44 32 37 33 52 39 47 9 -1.07 - 49 0 0 38 13 40 18 24 53.4 18 139 35 37 10 33 39 18 17 37 8 4 39 20 53 -1.07 - 48 0 0 37 47 54 18 24 56.6 19 140 34 36 45 0 38 52 17 36 42 32 38 54 53 -1.08 - 47 0 0 37 22 25 18 24 59.9 20 141 33 36 19 44 38 26 34 36 17 16 38 29 9 -1.08 - 46 0 0 36 57 13 18 25 3.3 20 142 33 35 54 45 38 1 8 35 52 17 38 3 43 -1.08 - 45 0 0 36 32 18 18 25 6.9 21 142 32 35 30 3 37 36 0 35 27 37 37 38 34 -1.08 - 44 0 0 36 7 43 18 25 10.6 22 143 32 35 5 41 37 11 11 35 3 15 37 13 44 -1.08 - 43 0 0 35 43 28 18 25 14.5 23 144 31 34 41 38 36 46 42 34 39 12 36 49 15 -1.09 - 42 0 0 35 19 32 18 25 18.5 24 145 30 34 17 56 36 22 33 34 15 30 36 25 5 -1.09 - 41 0 0 34 55 58 18 25 22.7 24 146 30 33 54 35 35 58 45 33 52 10 36 1 17 -1.09 - 40 0 0 34 32 46 18 25 26.9 25 146 29 33 31 35 35 35 20 33 29 10 35 37 51 -1.09 - 39 0 0 34 9 57 18 25 31.4 26 147 28 33 8 58 35 12 17 33 6 34 35 14 47 -1.09 - 38 0 0 33 47 30 18 25 35.9 27 148 28 32 46 44 34 49 37 32 44 20 34 52 7 -1.09 - 37 0 0 33 25 28 18 25 40.6 28 149 27 32 24 54 34 27 22 32 22 31 34 29 51 -1.10 - 36 0 0 33 3 50 18 25 45.4 28 150 26 32 3 28 34 5 31 32 1 5 34 8 0 -1.10 - 35 0 0 32 42 38 18 25 50.3 29 151 25 31 42 27 33 44 6 31 40 5 33 46 35 -1.10 - 34 0 0 32 21 51 18 25 55.4 30 151 25 31 21 52 33 23 7 31 19 31 33 25 35 -1.10 - 33 0 0 32 1 31 18 26 0.5 30 152 24 31 1 43 33 2 34 30 59 22 33 5 2 -1.10 - 32 0 0 31 41 37 18 26 5.8 31 153 23 30 42 1 32 42 29 30 39 40 32 44 56 -1.10 - 31 0 0 31 22 11 18 26 11.2 32 154 22 30 22 46 32 22 51 30 20 26 32 25 18 -1.10 - 30 0 0 31 3 13 18 26 16.7 32 155 21 30 3 59 32 3 41 30 1 39 32 6 8 -1.10 - 29 0 0 30 44 44 18 26 22.2 33 156 20 29 45 40 31 45 1 29 43 21 31 47 26 -1.11 - 28 0 0 30 26 43 18 26 27.9 34 157 20 29 27 50 31 26 49 29 25 31 31 29 14 -1.11 - 27 0 0 30 9 12 18 26 33.7 34 158 19 29 10 29 31 9 7 29 8 10 31 11 32 -1.11 - 26 0 0 29 52 10 18 26 39.6 35 159 18 28 53 37 30 51 55 28 51 19 30 54 19 -1.11 - 25 0 0 29 35 39 18 26 45.5 35 160 17 28 37 16 30 35 13 28 34 58 30 37 37 -1.11 - 24 0 0 29 19 38 18 26 51.6 36 161 16 28 21 24 30 19 3 28 19 7 30 21 26 -1.11 - 23 0 0 29 4 9 18 26 57.7 37 162 15 28 6 4 30 3 24 28 3 46 30 5 47 -1.11 - 22 0 0 28 49 10 18 27 3.9 37 163 14 27 51 14 29 48 16 27 48 57 29 50 38 -1.11 - 21 0 0 28 34 44 18 27 10.2 38 164 14 27 36 56 29 33 40 27 34 39 29 36 2 -1.11 - 20 0 0 28 20 49 18 27 16.5 38 165 13 27 23 10 29 19 37 27 20 53 29 21 59 -1.11 - 19 0 0 28 7 27 18 27 22.9 38 167 12 27 9 55 29 6 6 27 7 39 29 8 27 -1.12 - 18 0 0 27 54 37 18 27 29.4 39 168 11 26 57 13 28 53 8 26 54 57 28 55 29 -1.12 - 17 0 0 27 42 20 18 27 35.9 39 169 10 26 45 3 28 40 43 26 42 48 28 43 4 -1.12 - 16 0 0 27 30 36 18 27 42.4 40 170 9 26 33 27 28 28 52 26 31 11 28 31 12 -1.12 - 15 0 0 27 19 26 18 27 49.0 40 171 8 26 22 23 28 17 34 26 20 8 28 19 55 -1.12 - 14 0 0 27 8 49 18 27 55.7 40 173 7 26 11 52 28 6 51 26 9 37 28 9 11 -1.12 - 13 0 0 26 58 45 18 28 2.4 40 174 6 26 1 55 27 56 41 25 59 40 27 59 1 -1.12 - 12 0 0 26 49 16 18 28 9.1 41 175 5 25 52 31 27 47 6 25 50 17 27 49 25 -1.12 - 11 0 0 26 40 21 18 28 15.9 41 176 4 25 43 42 27 38 5 25 41 28 27 40 24 -1.12 - 10 0 0 26 32 0 18 28 22.6 41 177 4 25 35 26 27 29 39 25 33 12 27 31 58 -1.12 - 9 0 0 26 24 14 18 28 29.4 41 179 3 25 27 45 27 21 48 25 25 31 27 24 6 -1.12 - 8 0 0 26 17 2 18 28 36.3 41 180 2 25 20 37 27 14 31 25 18 24 27 16 50 -1.12 - 7 0 0 26 10 25 18 28 43.1 42 181 1 25 14 5 27 7 50 25 11 51 27 10 9 -1.12 - 6 0 0 26 4 23 18 28 49.9 42 183 0 25 8 6 27 1 44 25 5 53 27 4 2 -1.12 - 5 0 0 25 58 56 18 28 56.8 42 184 -1 25 2 42 26 56 13 25 0 29 26 58 31 -1.12 - 4 0 0 25 54 4 18 29 3.6 42 185 -2 24 57 53 26 51 18 24 55 40 26 53 36 -1.12 - 3 0 0 25 49 47 18 29 10.5 42 186 -3 24 53 39 26 46 58 24 51 26 26 49 16 -1.13 - 2 0 0 25 46 5 18 29 17.3 42 188 -4 24 49 59 26 43 13 24 47 46 26 45 31 -1.13 - 1 0 0 25 42 58 18 29 24.2 41 189 -5 24 46 54 26 40 5 24 44 41 26 42 22 -1.13 - 0 0 0 25 40 26 18 29 31.0 41 190 -6 24 44 24 26 37 31 24 42 12 26 39 49 -1.13 1 0 0 25 38 30 18 29 37.8 41 191 -7 24 42 29 26 35 34 24 40 17 26 37 51 -1.13 2 0 0 25 37 9 18 29 44.5 41 193 -8 24 41 9 26 34 12 24 38 57 26 36 29 -1.13 3 0 0 25 36 24 18 29 51.3 41 194 -8 24 40 24 26 33 25 24 38 12 26 35 43 -1.13 4 0 0 25 36 13 18 29 58.0 41 195 -9 24 40 14 26 33 15 24 38 1 26 35 32 -1.13 5 0 0 25 36 38 18 30 4.7 40 196 -10 24 40 39 26 33 40 24 38 26 26 35 57 -1.13 6 0 0 25 37 38 18 30 11.4 40 198 -11 24 41 38 26 34 40 24 39 26 26 36 58 -1.13 7 0 0 25 39 14 18 30 18.0 40 199 -12 24 43 13 26 36 17 24 41 1 26 38 34 -1.13 8 0 0 25 41 24 18 30 24.5 39 200 -13 24 45 23 26 38 29 24 43 10 26 40 46 -1.13 9 0 0 25 44 10 18 30 31.0 39 201 -14 24 48 7 26 41 16 24 45 54 26 43 34 -1.13 10 0 0 25 47 31 18 30 37.5 39 202 -15 24 51 26 26 44 39 24 49 13 26 46 57 -1.13 11 0 0 25 51 27 18 30 43.9 38 203 -16 24 55 20 26 48 37 24 53 7 26 50 55 -1.13 12 0 0 25 55 58 18 30 50.2 38 204 -17 24 59 48 26 53 11 24 57 35 26 55 29 -1.13 13 0 0 26 1 4 18 30 56.5 37 205 -17 25 4 51 26 58 19 25 2 38 27 0 38 -1.13 14 0 0 26 6 44 18 31 2.7 37 206 -18 25 10 28 27 4 3 25 8 15 27 6 22 -1.13 15 0 0 26 12 59 18 31 8.8 36 207 -19 25 16 40 27 10 22 25 14 27 27 12 40 -1.13 16 0 0 26 19 49 18 31 14.9 36 208 -20 25 23 25 27 17 16 25 21 12 27 19 34 -1.13 17 0 0 26 27 12 18 31 20.9 35 209 -21 25 30 45 27 24 44 25 28 31 27 27 3 -1.13 18 0 0 26 35 10 18 31 26.8 35 210 -22 25 38 38 27 32 47 25 36 25 27 35 6 -1.13 19 0 0 26 43 42 18 31 32.6 34 211 -23 25 47 5 27 41 24 25 44 52 27 43 43 -1.13 20 0 0 26 52 48 18 31 38.3 34 212 -23 25 56 6 27 50 35 25 53 52 27 52 55 -1.13 21 0 0 27 2 28 18 31 43.9 33 213 -24 26 5 40 28 0 21 26 3 26 28 2 40 -1.13 22 0 0 27 12 41 18 31 49.5 32 214 -25 26 15 47 28 10 40 26 13 33 28 13 0 -1.13 23 0 0 27 23 27 18 31 54.9 32 215 -26 26 26 27 28 21 33 26 24 12 28 23 53 -1.13 24 0 0 27 34 46 18 32 0.2 31 216 -27 26 37 40 28 32 59 26 35 25 28 35 19 -1.13 25 0 0 27 46 38 18 32 5.5 30 217 -27 26 49 25 28 44 58 26 47 10 28 47 18 -1.13 26 0 0 27 59 2 18 32 10.6 29 217 -28 27 1 42 28 57 30 26 59 27 28 59 51 -1.13 27 0 0 28 11 59 18 32 15.6 29 218 -29 27 14 31 29 10 34 27 12 15 29 12 55 -1.13 28 0 0 28 25 27 18 32 20.5 28 219 -30 27 27 52 29 24 11 27 25 36 29 26 32 -1.13 29 0 0 28 39 27 18 32 25.2 27 220 -30 27 41 44 29 38 19 27 39 27 29 40 41 -1.13 30 0 0 28 53 59 18 32 29.9 27 221 -31 27 56 7 29 52 59 27 53 50 29 55 22 -1.13 31 0 0 29 9 1 18 32 34.4 26 221 -32 28 11 1 30 8 11 28 8 44 30 10 34 -1.13 32 0 0 29 24 34 18 32 38.8 25 222 -32 28 26 25 30 23 53 28 24 7 30 26 16 -1.13 33 0 0 29 40 37 18 32 43.1 24 223 -33 28 42 19 30 40 6 28 40 1 30 42 30 -1.13 34 0 0 29 57 10 18 32 47.2 23 223 -34 28 58 42 30 56 49 28 56 24 30 59 13 -1.13 35 0 0 30 14 12 18 32 51.2 23 224 -34 29 15 35 31 14 2 29 13 17 31 16 26 -1.13 36 0 0 30 31 44 18 32 55.0 22 225 -35 29 32 57 31 31 44 29 30 38 31 34 8 -1.13 37 0 0 30 49 44 18 32 58.8 21 226 -36 29 50 47 31 49 54 29 48 27 31 52 20 -1.13 38 0 0 31 8 12 18 33 2.3 20 226 -36 30 9 5 32 8 34 30 6 45 32 11 0 -1.13 39 0 0 31 27 8 18 33 5.8 19 227 -37 30 27 50 32 27 41 30 25 30 32 30 7 -1.13 40 0 0 31 46 31 18 33 9.1 18 227 -37 30 47 2 32 47 16 30 44 42 32 49 42 -1.13 41 0 0 32 6 21 18 33 12.2 18 228 -38 31 6 41 33 7 17 31 4 20 33 9 45 -1.13 42 0 0 32 26 37 18 33 15.2 17 229 -38 31 26 46 33 27 45 31 24 24 33 30 13 -1.13 43 0 0 32 47 19 18 33 18.0 16 229 -39 31 47 16 33 48 39 31 44 54 33 51 7 -1.13 44 0 0 33 8 25 18 33 20.7 15 230 -39 32 8 11 34 9 58 32 5 49 34 12 27 -1.13 45 0 0 33 29 56 18 33 23.3 14 231 -40 32 29 30 34 31 42 32 27 7 34 34 11 -1.13 46 0 0 33 51 51 18 33 25.6 13 231 -40 32 51 13 34 53 49 32 48 50 34 56 18 -1.13 47 0 0 34 14 9 18 33 27.9 12 232 -40 33 13 19 35 16 19 33 10 55 35 18 50 -1.13 48 0 0 34 36 49 18 33 29.9 11 232 -41 33 35 47 35 39 13 33 33 23 35 41 44 -1.14 49 0 0 34 59 51 18 33 31.8 10 233 -41 33 58 37 36 2 28 33 56 12 36 5 0 -1.14 50 0 0 35 23 15 18 33 33.6 10 234 -41 34 21 48 36 26 5 34 19 23 36 28 37 -1.14 51 0 0 35 46 59 18 33 35.2 9 234 -42 34 45 19 36 50 3 34 42 54 36 52 35 -1.14 52 0 0 36 11 3 18 33 36.6 8 235 -42 35 9 11 37 14 21 35 6 45 37 16 54 -1.15 53 0 0 36 35 26 18 33 37.9 7 236 -42 35 33 21 37 38 57 35 30 54 37 41 31 -1.15 54 0 0 37 0 7 18 33 39.0 6 236 -42 35 57 49 38 3 52 35 55 22 38 6 26 -1.15 55 0 0 37 25 6 18 33 39.9 5 237 -42 36 22 35 38 29 4 36 20 8 38 31 39 -1.16 56 0 0 37 50 21 18 33 40.7 4 237 -42 36 47 38 38 54 33 36 45 10 38 57 9 -1.17 57 0 0 38 15 52 18 33 41.4 3 238 -42 37 12 56 39 20 18 37 10 28 39 22 54 -1.19 58 0 0 38 41 39 18 33 41.8 2 239 -42 37 38 30 39 46 18 37 36 1 39 48 55 -1.22 59 0 0 39 7 39 18 33 42.2 2 239 -43 38 4 18 40 12 33 38 1 49 40 15 10 -1.28 60 0 0 39 33 53 18 33 42.3 1 240 -43 38 30 19 40 39 0 38 27 49 40 41 38 -1.52 61 0 0 .. .. .... .. .. .. .. .. .. 38 56 33 .. .. .. 38 54 3 .. .. .. .... Uncertainty in time = +/- 0 secs Prediction of 2023 Aug 27.0 Data for the target star ------------------------ * name: UCAC4 339-091673 * constellation : Ophiuchus * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 17 21 11.9091 DE: -22 23 22.207 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 17 21 11.9090 DE: -22 23 22.207 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.200,0.100) * V mag [mag]: 10.8 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (20) Massalia asteroid class: ShapeModel approx. diameter [km]: 138 approx. diameter ["]: 0.075 distance from Earth [AU]: 2.53480 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#127 date of fit: 2023 Aug 22 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): 0.003", 0.001", 93.413° remarks: * orbital elements for (20)Massalia : Mean anomaly = 178.7088483974 deg Arg. of pericenter = 257.4705146052 deg Long. of node = 205.9792153416 deg Inclination = 0.7092776217 deg Eccentricity = 0.1434674973 Semimajor axis = 2.4081809844 AU Perihelion dist = 2.0626852855 AU Mag: H = 6.54, G = 0.25 Epoch of elements : MJD 60199.77006945 TDT (2023 Sep 12.7701) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#1272023Aug22,9.16,2023,9,12,18.483901,0.060817,0.744006,8.492089,-0.695804,0.005669,-0.000372,0.000000,0.000000 -8.1069,-22.4135,-98.19,4.06,False UCAC4 339-091673,17.35330810,-22.3895021,0.00,10.82,0.00,0.0,0,,17.37697888,-22.4135194,1.40,0.00,0,0,0 20,Massalia,11.87,138.300,2.5348,0,0,2.125,-2.42,,7.2,0 0,178.5058,2023,9,12,257.4705,205.9792,0.7093,0.14347,2.40818,2.06269,6.61,5.0,0.15 1.020,0.0026,0.0015,93,0.0030,Known errors,-1.00,0,-1,-1 20230912_091673,60182.99 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Aug 26, 23:44 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org