IOTA/IOTA-ES occultation update for (424) Gratia / UCAC4 377-070442 event on 2023 Aug 23, 03:21 UT Visible from USA Summary ------- On 2023 Aug 23 UT, the 91.4 km diameter asteroid (424) Gratia will occult a 12.1 mag star in the constellation Libra 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 3.41 mag to 15.44 mag (the magnitude of the asteroid) for at most 4.740 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 Aug 23, 03:19 - 2023 Aug 23, 03:24 * geocentric midpoint of event [JD]: 2460179.64022534 * magnitude of target star: 12.08 * magnitude drop [mag]: 3.41 * estimated maximum duration [s]: 4.740 * Moon: 37 % sunlit, 10° distance * Sun: 83° distance * rough path description: USA The occultation path -------------------- * approximate projected width [km]: 208 * 1 sigma uncertainty interval [path widths]: +/- 0.27 * 1 sigma uncertainty interval [seconds]: +/- 1.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.015, +/- 0.012) * 1 sigma uncertainty ellipse (major, minor, PA): (0.015", 0.011", 112°) * approx speed of asteroid's shadow [km/s]: 19.2716 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 377-070442 by 424 Gratia on 2023 Aug 23 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 -156 0 0 .. .. .... .. .. .. .. .. .. .. .. .. .. .. .. 74 6 56 .. .. .. .... -155 0 0 .. .. .... .. .. .. .. .. .. .. .. .. .. .. .. 72 23 47 .. .. .. .... -154 0 0 .. .. .... .. .. .. .. .. .. 73 41 27 .. .. .. 70 52 52 .. .. .. .... -153 0 0 .. .. .... .. .. .. .. .. .. 71 46 16 .. .. .. 69 29 18 .. .. .. .... -152 0 0 .. .. .... .. .. .. .. .. .. 70 9 7 .. .. .. 68 10 49 .. .. .. .... -151 0 0 .. .. .... .. .. .. .. .. .. 68 41 39 .. .. .. 66 56 12 .. .. .. .... -150 0 2 71 44 54 3 19 34.2 4 179 14 67 20 34 .. .. .. 65 44 42 .. .. .. .... -149 0 1 69 44 28 3 19 36.3 6 180 14 66 4 10 .. .. .. 64 35 47 .. .. .. -1.65 -148 0 1 68 4 49 3 19 38.8 7 181 14 64 51 26 .. .. .. 63 29 7 .. .. .. -1.80 -147 0 1 66 36 9 3 19 41.6 9 182 14 63 41 42 72 1 6 62 24 27 .. .. .. -1.86 -146 0 1 65 14 36 3 19 44.6 10 183 13 62 34 33 69 18 12 61 21 36 .. .. .. -1.90 -145 0 1 63 58 17 3 19 47.9 11 184 13 61 29 39 67 24 37 60 20 26 70 51 18 -1.93 -144 0 1 62 46 1 3 19 51.4 12 185 12 60 26 48 65 48 36 59 20 50 68 15 9 -1.95 -143 0 1 61 37 8 3 19 55.1 14 187 12 59 25 49 64 22 39 58 22 41 66 23 24 -1.96 -142 0 1 60 31 7 3 19 59.0 15 188 11 58 26 33 63 3 32 57 25 57 64 48 37 -1.97 -141 0 1 59 27 36 3 20 3.1 16 189 11 57 28 53 61 49 33 56 30 35 63 23 47 -1.98 -140 0 1 58 26 20 3 20 7.3 16 190 10 56 32 45 60 39 40 55 36 31 62 5 47 -1.99 -139 0 1 57 27 7 3 20 11.6 17 191 9 55 38 5 59 33 12 54 43 44 60 52 56 -2.00 -138 0 1 56 29 47 3 20 16.1 18 192 9 54 44 50 58 29 38 53 52 11 59 44 13 -2.00 -137 0 1 55 34 13 3 20 20.7 19 193 8 53 52 56 57 28 40 53 1 52 58 38 58 -2.01 -136 0 1 54 40 19 3 20 25.4 20 194 7 53 2 22 56 30 1 52 12 44 57 36 40 -2.01 -135 0 1 53 48 0 3 20 30.2 20 195 7 52 13 6 55 33 30 51 24 47 56 37 1 -2.02 -134 0 1 52 57 13 3 20 35.1 21 196 6 51 25 5 54 38 56 50 38 1 55 39 43 -2.02 -133 0 1 52 7 54 3 20 40.1 22 197 5 50 38 19 53 46 13 49 52 23 54 44 35 -2.03 -132 0 1 51 20 1 3 20 45.1 22 199 4 49 52 46 52 55 15 49 7 54 53 51 28 -2.03 -131 0 1 50 33 30 3 20 50.2 23 200 4 49 8 25 52 5 56 48 24 33 53 0 14 -2.03 -130 0 1 49 48 19 3 20 55.4 23 201 3 48 25 15 51 18 12 47 42 19 52 10 46 -2.04 -129 0 1 49 4 28 3 21 0.6 24 202 2 47 43 16 50 32 0 47 1 12 51 22 59 -2.04 -128 0 1 48 21 54 3 21 5.9 24 203 1 47 2 26 49 47 16 46 21 11 50 36 49 -2.04 -127 0 1 47 40 37 3 21 11.2 24 204 0 46 22 46 49 3 58 45 42 16 49 52 12 -2.05 -126 0 1 47 0 33 3 21 16.5 25 206 -1 45 44 13 48 22 3 45 4 27 49 9 6 -2.05 -125 0 1 46 21 44 3 21 21.8 25 207 -2 45 6 49 47 41 31 44 27 43 48 27 27 -2.05 -124 0 1 45 44 7 3 21 27.1 25 208 -2 44 30 32 47 2 18 43 52 4 47 47 12 -2.05 -123 0 1 45 7 42 3 21 32.5 25 209 -3 43 55 21 46 24 23 43 17 30 47 8 21 -2.06 -122 0 1 44 32 27 3 21 37.8 26 210 -4 43 21 17 45 47 45 42 44 0 46 30 50 -2.06 -121 0 1 43 58 23 3 21 43.1 26 211 -5 42 48 19 45 12 23 42 11 34 45 54 39 -2.06 -120 0 1 43 25 28 3 21 48.4 26 213 -6 42 16 26 44 38 15 41 40 11 45 19 46 -2.06 -119 0 1 42 53 42 3 21 53.7 26 214 -7 41 45 39 44 5 21 41 9 52 44 46 9 -2.07 -118 0 0 42 23 4 3 21 58.9 26 215 -8 41 15 56 43 33 39 40 40 36 44 13 47 -2.07 -117 0 0 41 53 34 3 22 4.2 26 216 -9 40 47 18 43 3 8 40 12 24 43 42 39 -2.07 -116 0 0 41 25 11 3 22 9.3 26 217 -10 40 19 43 42 33 49 39 45 13 43 12 45 -2.07 -115 0 0 40 57 54 3 22 14.5 26 218 -10 39 53 13 42 5 39 39 19 5 42 44 3 -2.08 -114 0 0 40 31 43 3 22 19.5 25 219 -11 39 27 45 41 38 38 38 53 59 42 16 32 -2.08 -113 0 0 40 6 38 3 22 24.6 25 220 -12 39 3 21 41 12 47 38 29 55 41 50 12 -2.08 -112 0 0 39 42 38 3 22 29.5 25 221 -13 38 39 59 40 48 3 38 6 52 41 25 1 -2.08 -111 0 0 39 19 42 3 22 34.4 25 222 -14 38 17 40 40 24 26 37 44 51 41 0 59 -2.08 -110 0 0 38 57 51 3 22 39.3 25 223 -15 37 56 22 40 1 56 37 23 50 40 38 7 -2.09 -109 0 0 38 37 4 3 22 44.0 24 224 -16 37 36 6 39 40 33 37 3 50 40 16 21 -2.09 -108 0 0 38 17 19 3 22 48.7 24 225 -17 37 16 52 39 20 15 36 44 51 39 55 43 -2.09 -107 0 0 37 58 38 3 22 53.3 24 226 -17 36 58 39 39 1 2 36 26 52 39 36 12 -2.09 -106 0 0 37 41 0 3 22 57.8 23 227 -18 36 41 27 38 42 55 36 9 53 39 17 46 -2.09 -105 0 0 37 24 24 3 23 2.2 23 228 -19 36 25 15 38 25 52 35 53 53 39 0 27 -2.09 -104 0 0 37 8 51 3 23 6.5 22 229 -20 36 10 5 38 9 53 35 38 54 38 44 13 -2.09 -103 0 0 36 54 19 3 23 10.8 22 230 -21 35 55 54 37 54 58 35 24 54 38 29 4 -2.10 -102 0 0 36 40 49 3 23 14.9 21 231 -22 35 42 43 37 41 6 35 11 53 38 14 59 -2.10 -101 0 0 36 28 20 3 23 18.9 21 232 -22 35 30 32 37 28 17 34 59 50 38 1 58 -2.10 -100 0 0 36 16 52 3 23 22.9 20 233 -23 35 19 20 37 16 31 34 48 47 37 50 1 -2.10 - 99 0 0 36 6 24 3 23 26.7 20 233 -24 35 9 7 37 5 47 34 38 42 37 39 7 -2.10 - 98 0 0 35 56 57 3 23 30.4 19 234 -25 34 59 54 36 56 5 34 29 35 37 29 16 -2.10 - 97 0 0 35 48 30 3 23 34.0 19 235 -25 34 51 39 36 47 24 34 21 26 37 20 28 -2.10 - 96 0 0 35 41 4 3 23 37.4 18 236 -26 34 44 23 36 39 46 34 14 16 37 12 42 -2.10 - 95 0 0 35 34 37 3 23 40.8 17 237 -27 34 38 6 36 33 8 34 8 3 37 5 59 -2.11 - 94 0 0 35 29 10 3 23 44.0 17 237 -27 34 32 46 36 27 32 34 2 48 37 0 17 -2.11 - 93 0 0 35 24 42 3 23 47.1 16 238 -28 34 28 25 36 22 57 33 58 30 36 55 38 -2.11 - 92 0 0 35 21 13 3 23 50.1 15 239 -29 34 25 2 36 19 23 33 55 10 36 52 0 -2.11 - 91 0 0 35 18 44 3 23 52.9 15 240 -29 34 22 37 36 16 49 33 52 47 36 49 23 -2.11 - 90 0 0 35 17 14 3 23 55.7 14 240 -30 34 21 10 36 15 16 33 51 21 36 47 48 -2.11 - 89 0 0 35 16 43 3 23 58.2 13 241 -31 34 20 41 36 14 43 33 50 53 36 47 14 -2.12 - 88 0 0 35 17 11 3 24 0.7 13 242 -31 34 21 9 36 15 10 33 51 21 36 47 41 -2.12 - 87 0 0 35 18 37 3 24 3.0 12 242 -32 34 22 34 36 16 37 33 52 46 36 49 9 -2.12 - 86 0 0 35 21 2 3 24 5.2 11 243 -32 34 24 57 36 19 5 33 55 8 36 51 38 -2.13 - 85 0 0 35 24 26 3 24 7.2 10 244 -33 34 28 17 36 22 32 33 58 27 36 55 7 -2.13 - 84 0 0 35 28 48 3 24 9.1 10 244 -33 34 32 35 36 26 59 34 2 42 36 59 38 -2.13 - 83 0 0 35 34 9 3 24 10.8 9 245 -34 34 37 50 36 32 27 34 7 54 37 5 9 -2.14 - 82 0 0 35 40 28 3 24 12.4 8 245 -34 34 44 2 36 38 54 34 14 2 37 11 41 -2.15 - 81 0 0 35 47 46 3 24 13.8 7 246 -35 34 51 11 36 46 21 34 21 7 37 19 13 -2.15 - 80 0 0 35 56 1 3 24 15.1 6 247 -35 34 59 17 36 54 48 34 29 8 37 27 47 -2.17 - 79 0 0 36 5 16 3 24 16.2 6 247 -35 35 8 21 37 4 15 34 38 6 37 37 21 -2.18 - 78 0 0 36 15 29 3 24 17.2 5 248 -36 35 18 22 37 14 42 34 48 1 37 47 56 -2.20 - 77 0 0 36 26 41 3 24 18.1 4 248 -36 35 29 19 37 26 9 34 58 52 37 59 33 -2.23 - 76 0 0 36 38 51 3 24 18.7 3 249 -36 35 41 14 37 38 36 35 10 39 38 12 10 -2.27 - 75 0 0 36 52 0 3 24 19.2 2 250 -36 35 54 6 37 52 3 35 23 22 38 25 49 -2.35 - 74 0 0 37 6 7 3 24 19.6 1 250 -37 36 7 56 38 6 31 35 37 3 38 40 29 -2.51 - 73 0 0 37 21 14 3 24 19.8 1 251 -37 36 22 42 38 22 0 35 51 39 38 56 10 -3.11 - 72 0 0 .. .. .... .. .. .. .. .. .. 36 38 26 .. .. .. 36 7 13 .. .. .. .... Uncertainty in time = +/- 2 secs Prediction of 2023 Aug 6.7 Data for the target star ------------------------ * name: UCAC4 377-070442 * constellation : Libra * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 15 25 08.5843 DE: -14 42 16.180 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 15 25 08.5843 DE: -14 42 16.179 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.100,0.100) * V mag [mag]: 12.1 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (424) Gratia asteroid class: approx. diameter [km]: 91 approx. diameter ["]: 0.042 distance from Earth [AU]: 3.02750 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#82 date of fit: 2023 Jul 30 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", 0.011", 111.983° remarks: * orbital elements for (424)Gratia : Mean anomaly = 178.1750101814 deg Arg. of pericenter = 333.8754058276 deg Long. of node = 99.1290653470 deg Inclination = 8.2219637593 deg Eccentricity = 0.1093209402 Semimajor axis = 2.7738801593 AU Perihelion dist = 2.4706369724 AU Mag: H = 9.76, G = 0.15 Epoch of elements : MJD 60179.14020833 TDT (2023 Aug 23.1402) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#822023Jul30,4.74,2023,8,23,3.365408,0.383075,0.812913,9.838002,-4.640299,0.005482,-0.001351,0.000000,0.000000 -150.0376,-14.7873,130.23,11.55,False UCAC4 377-070442,15.41905121,-14.7044944,0.00,12.08,0.00,0.0,0,,15.44084873,-14.7872906,3.40,0.00,0,0,0 424,Gratia,15.44,91.400,3.0275,0,0,1.971,-13.48,,5.0,0 0,178.1451,2023,8,23,333.8754,99.1291,8.2220,0.10932,2.77388,2.47064,9.62,5.0,0.15 1.273,0.0150,0.0113,112,0.0188,Known errors,-1.00,0,-1,-1 20230823_070442,60162.67 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Aug 06, 16:05 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org