IOTA/IOTA-ES occultation update for (431) Nephele / UCAC4 334-144639 event on 2023 Sep 27, 02:03 UT Visible from USA Summary ------- On 2023 Sep 27 UT, the 91.5 km diameter asteroid (431) Nephele will occult a 11.2 mag star in the constellation Sagittarius for observers along a path across USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.03 mag to 14.20 mag (the magnitude of the asteroid) for at most 5.240 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 27, 01:59 - 2023 Sep 27, 02:06 * geocentric midpoint of event [JD]: 2460214.58557537 * magnitude of target star: 11.24 * magnitude drop [mag]: 3.03 * estimated maximum duration [s]: 5.240 * Moon: 92 % sunlit, 56° distance * Sun: 91° distance * rough path description: USA The occultation path -------------------- * approximate projected width [km]: 173 * 1 sigma uncertainty interval [path widths]: +/- 0.01 * 1 sigma uncertainty interval [seconds]: +/- 0.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.008, +/- 0.000) * 1 sigma uncertainty ellipse (major, minor, PA): (0.008", 0.000", 90°) * approx speed of asteroid's shadow [km/s]: 17.4750 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 334-144639 by 431 Nephele on 2023 Sep 27 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 -178 0 1 51 32 48 2 0 1.8 0 130 30 50 33 29 .. .. .. 50 32 25 .. .. .. .... -177 0 1 51 2 1 2 0 1.8 1 130 30 50 3 6 52 3 5 50 2 3 52 4 13 -0.60 -176 0 1 50 31 27 2 0 2.1 2 131 30 49 32 57 51 32 4 49 31 55 51 33 12 -1.05 -175 0 1 50 1 9 2 0 2.4 3 132 30 49 3 3 51 1 19 49 2 1 51 2 26 -1.22 -174 0 1 49 31 6 2 0 2.9 3 133 29 48 33 25 50 30 49 48 32 23 50 31 56 -1.31 -173 0 1 49 1 21 2 0 3.6 4 133 29 48 4 4 50 0 37 48 3 3 50 1 43 -1.37 -172 0 1 48 31 54 2 0 4.3 5 134 29 47 35 1 49 30 44 47 34 0 49 31 49 -1.40 -171 0 1 48 2 47 2 0 5.3 6 135 29 47 6 17 49 1 10 47 5 17 49 2 15 -1.43 -170 0 1 47 34 0 2 0 6.4 7 136 29 46 37 54 48 31 58 46 36 54 48 33 2 -1.45 -169 0 1 47 5 35 2 0 7.6 7 136 29 46 9 51 48 3 8 46 8 52 48 4 11 -1.47 -168 0 1 46 37 32 2 0 8.9 8 137 28 45 42 11 47 34 40 45 41 12 47 35 44 -1.48 -167 0 1 46 9 53 2 0 10.4 9 138 28 45 14 54 47 6 37 45 13 55 47 7 40 -1.49 -166 0 1 45 42 39 2 0 12.1 10 139 28 44 48 1 46 38 59 44 47 3 46 40 1 -1.50 -165 0 1 45 15 50 2 0 13.9 11 139 27 44 21 33 46 11 46 44 20 35 46 12 48 -1.51 -164 0 1 44 49 26 2 0 15.8 12 140 27 43 55 31 45 45 0 43 54 33 45 46 2 -1.52 -163 0 1 44 23 30 2 0 17.9 12 141 27 43 29 56 45 18 42 43 28 58 45 19 43 -1.52 -162 0 1 43 58 2 2 0 20.1 13 142 26 43 4 47 44 52 52 43 3 50 44 53 52 -1.53 -161 0 1 43 33 2 2 0 22.5 14 143 26 42 40 7 44 27 31 42 39 10 44 28 31 -1.53 -160 0 1 43 8 32 2 0 25.0 15 143 25 42 15 56 44 2 39 42 14 59 44 3 39 -1.54 -159 0 1 42 44 32 2 0 27.6 15 144 25 41 52 14 43 38 19 41 51 18 43 39 18 -1.54 -158 0 1 42 21 2 2 0 30.3 16 145 24 41 29 2 43 14 29 41 28 6 43 15 29 -1.55 -157 0 1 41 58 4 2 0 33.2 17 146 24 41 6 21 42 51 12 41 5 26 42 52 11 -1.55 -156 0 1 41 35 37 2 0 36.2 18 147 23 40 44 12 42 28 27 40 43 17 42 29 25 -1.55 -155 0 1 41 13 43 2 0 39.4 18 147 23 40 22 35 42 6 15 40 21 40 42 7 13 -1.56 -154 0 1 40 52 22 2 0 42.6 19 148 22 40 1 30 41 44 36 40 0 35 41 45 34 -1.56 -153 0 1 40 31 35 2 0 46.0 20 149 22 39 40 59 41 23 32 39 40 4 41 24 30 -1.56 -152 0 1 40 11 22 2 0 49.5 20 150 21 39 21 1 41 3 3 39 20 7 41 4 0 -1.56 -151 0 1 39 51 44 2 0 53.1 21 151 21 39 1 37 40 43 8 39 0 43 40 44 5 -1.57 -150 0 1 39 32 40 2 0 56.8 22 152 20 38 42 48 40 23 49 38 41 54 40 24 46 -1.57 -149 0 1 39 14 12 2 1 0.6 22 152 19 38 24 34 40 5 7 38 23 40 40 6 3 -1.57 -148 0 1 38 56 20 2 1 4.5 23 153 19 38 6 55 39 47 0 38 6 1 39 47 56 -1.57 -147 0 1 38 39 4 2 1 8.6 24 154 18 37 49 52 39 29 31 37 48 59 39 30 27 -1.58 -146 0 1 38 22 25 2 1 12.7 24 155 17 37 33 25 39 12 39 37 32 32 39 13 34 -1.58 -145 0 1 38 6 23 2 1 16.9 25 156 17 37 17 35 38 56 24 37 16 42 38 57 19 -1.58 -144 0 1 37 50 59 2 1 21.2 25 157 16 37 2 21 38 40 47 37 1 29 38 41 42 -1.58 -143 0 1 37 36 12 2 1 25.6 26 158 15 36 47 45 38 25 49 36 46 53 38 26 44 -1.58 -142 0 1 37 22 3 2 1 30.1 26 159 14 36 33 46 38 11 29 36 32 54 38 12 23 -1.59 -141 0 1 37 8 32 2 1 34.7 27 160 14 36 20 25 37 57 48 36 19 33 37 58 42 -1.59 -140 0 1 36 55 40 2 1 39.3 27 161 13 36 7 42 37 44 45 36 6 51 37 45 40 -1.59 -139 0 1 36 43 26 2 1 44.0 28 162 12 35 55 37 37 32 22 35 54 46 37 33 16 -1.59 -138 0 1 36 31 51 2 1 48.8 28 163 11 35 44 11 37 20 39 35 43 20 37 21 33 -1.59 -137 0 1 36 20 56 2 1 53.6 29 164 11 35 33 23 37 9 35 35 32 32 37 10 28 -1.59 -136 0 1 36 10 40 2 1 58.5 29 165 10 35 23 14 36 59 11 35 22 23 37 0 4 -1.59 -135 0 1 36 1 3 2 2 3.5 29 166 9 35 13 45 36 49 27 35 12 54 36 50 20 -1.60 -134 0 1 35 52 6 2 2 8.5 30 167 8 35 4 54 36 40 23 35 4 3 36 41 16 -1.60 -133 0 1 35 43 49 2 2 13.5 30 168 7 34 56 43 36 32 0 34 55 52 36 32 53 -1.60 -132 0 1 35 36 12 2 2 18.6 30 169 7 34 49 11 36 24 17 34 48 20 36 25 10 -1.60 -131 0 1 35 29 15 2 2 23.8 31 170 6 34 42 19 36 17 14 34 41 28 36 18 7 -1.60 -130 0 1 35 22 58 2 2 29.0 31 171 5 34 36 7 36 10 53 34 35 16 36 11 45 -1.60 -129 0 1 35 17 21 2 2 34.2 31 172 4 34 30 34 36 5 12 34 29 43 36 6 5 -1.60 -128 0 1 35 12 25 2 2 39.4 31 173 3 34 25 41 36 0 12 34 24 51 36 1 5 -1.60 -127 0 1 35 8 9 2 2 44.7 31 174 3 34 21 29 35 55 53 34 20 38 35 56 46 -1.60 -126 0 1 35 4 34 2 2 50.0 32 175 2 34 17 56 35 52 15 34 17 6 35 53 8 -1.61 -125 0 1 35 1 40 2 2 55.3 32 176 1 34 15 3 35 49 19 34 14 13 35 50 11 -1.61 -124 0 1 34 59 26 2 3 0.6 32 178 0 34 12 51 35 47 3 34 12 1 35 47 55 -1.61 -123 0 1 34 57 53 2 3 6.0 32 179 -1 34 11 19 35 45 28 34 10 29 35 46 21 -1.61 -122 0 1 34 57 0 2 3 11.3 32 180 -2 34 10 27 35 44 35 34 9 37 35 45 28 -1.61 -121 0 1 34 56 48 2 3 16.7 32 181 -2 34 10 15 35 44 23 34 9 25 35 45 16 -1.61 -120 0 1 34 57 17 2 3 22.0 32 182 -3 34 10 44 35 44 52 34 9 54 35 45 45 -1.61 -119 0 1 34 58 26 2 3 27.3 32 183 -4 34 11 53 35 46 3 34 11 2 35 46 55 -1.61 -118 0 1 35 0 17 2 3 32.7 32 184 -5 34 13 42 35 47 54 34 12 51 35 48 47 -1.61 -117 0 1 35 2 48 2 3 38.0 32 185 -6 34 16 11 35 50 27 34 15 20 35 51 20 -1.61 -116 0 1 35 5 59 2 3 43.3 31 186 -7 34 19 20 35 53 41 34 18 30 35 54 34 -1.61 -115 0 1 35 9 51 2 3 48.5 31 187 -8 34 23 9 35 57 36 34 22 19 35 58 29 -1.61 -114 0 1 35 14 24 2 3 53.8 31 189 -8 34 27 39 36 2 12 34 26 49 36 3 5 -1.61 -113 0 1 35 19 37 2 3 59.0 31 190 -9 34 32 48 36 7 29 34 31 58 36 8 22 -1.61 -112 0 1 35 25 30 2 4 4.2 31 191 -10 34 38 38 36 13 27 34 37 47 36 14 20 -1.61 -111 0 1 35 32 4 2 4 9.3 30 192 -11 34 45 7 36 20 6 34 44 16 36 20 59 -1.61 -110 0 1 35 39 18 2 4 14.4 30 193 -12 34 52 15 36 27 25 34 51 25 36 28 18 -1.61 -109 0 1 35 47 12 2 4 19.5 30 194 -12 35 0 4 36 35 25 34 59 13 36 36 18 -1.61 -108 0 1 35 55 46 2 4 24.5 29 195 -13 35 8 31 36 44 5 35 7 40 36 44 58 -1.61 -107 0 1 36 4 59 2 4 29.4 29 196 -14 35 17 38 36 53 26 35 16 47 36 54 19 -1.61 -106 0 1 36 14 52 2 4 34.3 29 197 -15 35 27 24 37 3 26 35 26 33 37 4 20 -1.61 -105 0 1 36 25 25 2 4 39.2 28 198 -16 35 37 49 37 14 7 35 36 58 37 15 1 -1.61 -104 0 1 36 36 37 2 4 43.9 28 199 -16 35 48 53 37 25 28 35 48 2 37 26 22 -1.61 -103 0 1 36 48 28 2 4 48.6 27 200 -17 36 0 36 37 37 28 35 59 44 37 38 22 -1.61 -102 0 1 37 0 58 2 4 53.3 27 201 -18 36 12 57 37 50 7 36 12 5 37 51 2 -1.61 -101 0 1 37 14 6 2 4 57.8 26 202 -19 36 25 56 38 3 26 36 25 4 38 4 20 -1.61 -100 0 1 37 27 53 2 5 2.3 26 203 -19 36 39 33 38 17 23 36 38 41 38 18 18 -1.61 - 99 0 1 37 42 18 2 5 6.7 25 204 -20 36 53 47 38 31 59 36 52 55 38 32 54 -1.61 - 98 0 1 37 57 21 2 5 11.0 25 205 -21 37 8 39 38 47 14 37 7 46 38 48 9 -1.61 - 97 0 1 38 13 1 2 5 15.2 24 205 -22 37 24 7 39 3 6 37 23 15 39 4 2 -1.61 - 96 0 1 38 29 18 2 5 19.3 24 206 -22 37 40 13 39 19 37 37 39 20 39 20 32 -1.61 - 95 0 1 38 46 12 2 5 23.3 23 207 -23 37 56 55 39 36 44 37 56 2 39 37 40 -1.61 - 94 0 1 39 3 43 2 5 27.2 22 208 -24 38 14 12 39 54 29 38 13 19 39 55 25 -1.62 - 93 0 1 39 21 50 2 5 31.1 22 209 -24 38 32 6 40 12 50 38 31 12 40 13 46 -1.62 - 92 0 1 39 40 32 2 5 34.8 21 210 -25 38 50 34 40 31 48 38 49 41 40 32 44 -1.62 - 91 0 1 39 59 50 2 5 38.4 20 211 -25 39 9 38 40 51 21 39 8 44 40 52 18 -1.62 - 90 0 1 40 19 43 2 5 41.8 20 212 -26 39 29 15 41 11 30 39 28 21 41 12 27 -1.62 - 89 0 1 40 40 10 2 5 45.2 19 212 -27 39 49 27 41 32 13 39 48 33 41 33 11 -1.62 - 88 0 1 41 1 11 2 5 48.5 18 213 -27 40 10 12 41 53 32 40 9 17 41 54 29 -1.62 - 87 0 1 41 22 45 2 5 51.6 18 214 -28 40 31 30 42 15 24 40 30 35 42 16 22 -1.62 - 86 0 1 41 44 52 2 5 54.6 17 215 -28 40 53 20 42 37 49 40 52 25 42 38 48 -1.62 - 85 0 1 42 7 31 2 5 57.5 16 216 -29 41 15 42 43 0 47 41 14 47 43 1 46 -1.62 - 84 0 1 42 30 42 2 6 0.2 15 216 -29 41 38 36 43 24 18 41 37 40 43 25 17 -1.62 - 83 0 1 42 54 25 2 6 2.8 15 217 -30 42 1 59 43 48 20 42 1 3 43 49 19 -1.62 - 82 0 1 43 18 37 2 6 5.3 14 218 -30 42 25 53 44 12 53 42 24 56 44 13 53 -1.62 - 81 0 1 43 43 19 2 6 7.6 13 219 -31 42 50 16 44 37 56 42 49 19 44 38 56 -1.62 - 80 0 1 44 8 30 2 6 9.8 12 219 -31 43 15 8 45 3 28 43 14 10 45 4 29 -1.62 - 79 0 1 44 34 10 2 6 11.9 11 220 -31 43 40 27 45 29 30 43 39 29 45 30 31 -1.63 - 78 0 1 45 0 16 2 6 13.8 11 221 -32 44 6 13 45 55 59 44 5 15 45 57 1 -1.63 - 77 0 1 45 26 50 2 6 15.6 10 222 -32 44 32 25 46 22 55 44 31 27 46 23 58 -1.63 - 76 0 1 45 53 49 2 6 17.3 9 222 -32 44 59 3 46 50 18 44 58 4 46 51 21 -1.63 - 75 0 1 46 21 13 2 6 18.8 8 223 -33 45 26 5 47 18 6 45 25 6 47 19 9 -1.64 - 74 0 1 46 49 1 2 6 20.1 7 224 -33 45 53 31 47 46 19 45 52 32 47 47 22 -1.64 - 73 0 1 47 17 12 2 6 21.3 7 225 -33 46 21 20 48 14 55 46 20 20 48 15 59 -1.65 - 72 0 1 47 45 46 2 6 22.4 6 226 -33 46 49 30 48 43 54 46 48 30 48 44 58 -1.65 - 71 0 1 48 14 40 2 6 23.3 5 226 -33 47 18 2 49 13 14 47 17 1 49 14 19 -1.66 - 70 0 0 48 43 55 2 6 24.1 4 227 -34 47 46 53 49 42 55 47 45 51 49 44 0 -1.68 - 69 0 0 49 13 29 2 6 24.7 3 228 -34 48 16 2 50 12 55 48 15 1 50 14 1 -1.70 - 68 0 0 49 43 20 2 6 25.2 3 229 -34 48 45 30 50 43 13 48 44 28 50 44 20 -1.73 - 67 0 0 50 13 28 2 6 25.6 2 229 -34 49 15 14 51 13 49 49 14 11 51 14 56 -1.79 - 66 0 0 50 43 52 2 6 25.8 1 230 -34 49 45 13 51 44 40 49 44 10 51 45 48 -1.96 - 65 0 0 51 14 31 2 6 25.9 0 231 -34 50 15 27 .. .. .. 50 14 23 .. .. .. -5.19 Uncertainty in time = +/- 1 secs Prediction of 2023 Aug 27.0 Data for the target star ------------------------ * name: UCAC4 334-144639 * constellation : Sagittarius * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 18 17 11.3806 DE: -23 20 04.401 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 18 17 11.3806 DE: -23 20 04.401 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.200,0.100) * V mag [mag]: 11.2 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (431) Nephele asteroid class: approx. diameter [km]: 92 approx. diameter ["]: 0.051 distance from Earth [AU]: 2.48560 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#78 date of fit: 2023 Aug 23 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): 0.008", 0.000", 90.292° remarks: * orbital elements for (431)Nephele : Mean anomaly = 332.3104921356 deg Arg. of pericenter = 217.4398696029 deg Long. of node = 117.1822293107 deg Inclination = 1.8279492962 deg Eccentricity = 0.1705173600 Semimajor axis = 3.1376477257 AU Perihelion dist = 2.6026243189 AU Mag: H = 9.13, G = 0.15 Epoch of elements : MJD 60214.08562500 TDT (2023 Sep 27.0856) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#782023Aug23,5.24,2023,9,27,2.053809,0.003018,0.847975,9.863300,-0.038273,0.005649,0.000185,0.000000,0.000000 -121.7639,-23.3267,147.00,-1.48,False UCAC4 334-144639,18.28649464,-23.3345558,0.00,11.24,0.00,0.0,0,,18.31040918,-23.3267485,3.03,0.00,0,0,0 431,Nephele,14.20,91.500,2.4856,0,0,2.534,-0.14,,4.6,0 0,332.2953,2023,9,27,217.4399,117.1822,1.8279,0.17052,3.13765,2.60262,9.02,5.0,0.15 1.009,0.0083,0.0005,90,0.0083,Known errors,-1.00,0,-1,-1 20230927_144639,60182.99 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Aug 26, 23:50 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org