IOTA/IOTA-ES occultation update for (42) Isis / UCAC4 306-210784 event on 2024 Jul 15, 13:58 UT Visible from Summary ------- On 2024 Jul 15 UT, the 113.011 km diameter asteroid (42) Isis will occult a 11.7 mag star in the constellation Sagittarius for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 0.17 mag to 9.74 mag (the magnitude of the asteroid) for at most 18.180 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: 2024 Jul 15, 13:49 - 2024 Jul 15, 14:07 * geocentric midpoint of event [JD]: 2460507.08250495 * magnitude of target star: 11.69 * magnitude drop [mag]: 0.17 * estimated maximum duration [s]: 18.180 * Moon: 66 % sunlit, 51° distance * Sun: 159° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 231 * 1 sigma uncertainty interval [path widths]: +/- 0.16 * 1 sigma uncertainty interval [seconds]: +/- 4.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.042, +/- 0.007) * 1 sigma uncertainty ellipse (major, minor, PA): (0.042", 0.003", 99°) * approx speed of asteroid's shadow [km/s]: 6.2168 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 306-210784 by 42 Isis on 2024 Jul 15 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 55 0 0 .. .. .... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 27 32 57 .... 56 0 0 28 38 40 14 7 8.1 0 124 13 .. .. .. 27 22 42 .. .. .. 26 59 2 .... 57 0 0 28 4 45 14 7 7.7 1 124 12 29 23 9 26 50 3 29 49 14 26 26 44 -0.87 58 0 0 27 32 33 14 7 6.5 2 125 11 28 49 36 26 19 1 29 15 12 25 56 3 -1.32 59 0 0 27 2 1 14 7 4.7 3 125 10 28 17 50 25 49 34 28 42 59 25 26 56 -1.49 60 0 0 26 33 6 14 7 2.3 4 125 9 27 47 46 25 21 40 28 12 31 24 59 19 -1.58 61 0 0 26 5 46 14 6 59.3 5 126 8 27 19 22 24 55 16 27 43 45 24 33 12 -1.63 62 0 0 25 39 58 14 6 55.7 6 126 7 26 52 35 24 30 19 27 16 38 24 8 31 -1.67 63 0 0 25 15 40 14 6 51.5 7 127 6 26 27 23 24 6 49 26 51 6 23 45 15 -1.69 64 0 0 24 52 49 14 6 46.8 8 127 5 26 3 41 23 44 43 26 27 7 23 23 22 -1.71 65 0 0 24 31 24 14 6 41.5 9 128 4 25 41 30 23 23 59 26 4 39 23 2 50 -1.72 66 0 0 24 11 22 14 6 35.7 10 128 3 25 20 46 23 4 35 25 43 41 22 43 38 -1.73 67 0 0 23 52 43 14 6 29.5 11 129 2 25 1 28 22 46 31 25 24 9 22 25 44 -1.74 68 0 0 23 35 24 14 6 22.8 12 129 1 24 43 33 22 29 45 25 6 1 22 9 8 -1.75 69 0 0 23 19 25 14 6 15.6 13 130 1 24 27 0 22 14 15 24 49 17 21 53 47 -1.75 70 0 0 23 4 44 14 6 7.9 13 130 0 24 11 49 22 0 1 24 33 55 21 39 41 -1.76 71 0 0 22 51 19 14 5 59.9 14 130 -1 23 57 57 21 47 1 24 19 53 21 26 49 -1.76 72 0 0 22 39 11 14 5 51.4 15 131 -2 23 45 23 21 35 15 24 7 11 21 15 9 -1.76 73 0 0 22 28 16 14 5 42.5 16 131 -3 23 34 6 21 24 41 23 55 46 21 4 42 -1.76 74 0 0 22 18 36 14 5 33.2 17 132 -4 23 24 5 21 15 19 23 45 39 20 55 25 -1.76 75 0 0 22 10 8 14 5 23.5 17 132 -5 23 15 20 21 7 8 23 36 47 20 47 18 -1.76 76 0 0 22 2 53 14 5 13.5 18 133 -6 23 7 49 21 0 6 23 29 10 20 40 21 -1.77 77 0 0 21 56 49 14 5 3.1 19 133 -7 23 1 31 20 54 15 23 22 48 20 34 33 -1.77 78 0 0 21 51 56 14 4 52.4 20 134 -7 22 56 27 20 49 32 23 17 40 20 29 54 -1.77 79 0 0 21 48 13 14 4 41.3 20 135 -8 22 52 34 20 45 58 23 13 44 20 26 22 -1.77 80 0 0 21 45 40 14 4 29.8 21 135 -9 22 49 54 20 43 31 23 11 1 20 23 58 -1.77 81 0 0 21 44 16 14 4 18.1 22 136 -10 22 48 24 20 42 13 23 9 30 20 22 41 -1.77 82 0 0 21 44 1 14 4 6.1 22 136 -11 22 48 6 20 42 1 23 9 10 20 22 30 -1.77 83 0 0 21 44 56 14 3 53.7 23 137 -11 22 48 59 20 42 57 23 10 2 20 23 26 -1.77 84 0 0 21 46 58 14 3 41.1 23 138 -12 22 51 1 20 44 59 23 12 5 20 25 28 -1.77 85 0 0 21 50 9 14 3 28.1 24 138 -13 22 54 14 20 48 8 23 15 19 20 28 37 -1.77 86 0 0 21 54 28 14 3 14.9 24 139 -14 22 58 38 20 52 23 23 19 43 20 32 51 -1.77 87 0 0 21 59 55 14 3 1.4 25 140 -14 23 4 11 20 57 46 23 25 19 20 38 12 -1.77 88 0 0 22 6 31 14 2 47.7 25 140 -15 23 10 54 21 4 14 23 32 5 20 44 38 -1.77 89 0 0 22 14 15 14 2 33.7 26 141 -16 23 18 48 21 11 49 23 40 2 20 52 10 -1.77 90 0 0 22 23 7 14 2 19.5 26 142 -16 23 27 52 21 20 30 23 49 10 21 0 48 -1.77 91 0 0 22 33 8 14 2 5.0 27 143 -17 23 38 7 21 30 18 23 59 29 21 10 33 -1.77 92 0 0 22 44 17 14 1 50.3 27 143 -18 23 49 32 21 41 14 24 11 0 21 21 24 -1.77 93 0 0 22 56 36 14 1 35.4 27 144 -18 24 2 9 21 53 16 24 23 43 21 33 21 -1.77 94 0 0 23 10 4 14 1 20.3 28 145 -19 24 15 57 22 6 26 24 37 39 21 46 26 -1.77 95 0 0 23 24 42 14 1 4.9 28 146 -19 24 30 58 22 20 44 24 52 48 22 0 38 -1.77 96 0 0 23 40 31 14 0 49.4 28 147 -20 24 47 11 22 36 10 25 9 9 22 15 57 -1.77 97 0 0 23 57 30 14 0 33.7 28 147 -20 25 4 38 22 52 45 25 26 46 22 32 25 -1.78 98 0 0 24 15 42 14 0 17.8 29 148 -21 25 23 19 23 10 30 25 45 37 22 50 1 -1.78 99 0 0 24 35 5 14 0 1.8 29 149 -21 25 43 16 23 29 25 26 5 45 23 8 48 -1.78 100 0 0 24 55 42 13 59 45.5 29 150 -22 26 4 28 23 49 30 26 27 9 23 28 44 -1.78 101 0 0 25 17 34 13 59 29.2 29 151 -22 26 26 57 24 10 47 26 49 52 23 49 50 -1.78 102 0 0 25 40 40 13 59 12.6 29 152 -23 26 50 45 24 33 17 27 13 55 24 12 9 -1.79 103 0 0 26 5 3 13 58 56.0 29 153 -23 27 15 53 24 57 0 27 39 18 24 35 40 -1.79 104 0 0 26 30 43 13 58 39.2 29 154 -23 27 42 21 25 21 57 28 6 4 25 0 25 -1.79 105 0 0 26 57 42 13 58 22.3 29 155 -24 28 10 13 25 48 10 28 34 13 25 26 24 -1.80 106 0 0 27 26 1 13 58 5.4 29 156 -24 28 39 28 26 15 40 29 3 49 25 53 39 -1.80 107 0 0 27 55 42 13 57 48.3 29 156 -24 29 10 10 26 44 27 29 34 52 26 22 11 -1.80 108 0 0 28 26 46 13 57 31.1 29 157 -25 29 42 20 27 14 35 30 7 25 26 52 1 -1.81 109 0 0 28 59 16 13 57 13.9 29 158 -25 30 16 1 27 46 3 30 41 31 27 23 12 -1.81 110 0 0 29 33 14 13 56 56.6 28 159 -25 30 51 15 28 18 54 31 17 12 27 55 43 -1.81 111 0 0 30 8 41 13 56 39.3 28 160 -25 31 28 5 28 53 10 31 54 32 28 29 39 -1.82 112 0 0 30 45 41 13 56 22.0 28 161 -25 32 6 35 29 28 54 32 33 35 29 4 59 -1.82 113 0 0 31 24 17 13 56 4.6 27 162 -25 32 46 49 30 6 6 33 14 23 29 41 47 -1.83 114 0 0 32 4 30 13 55 47.3 27 163 -25 33 28 49 30 44 50 33 57 2 30 20 5 -1.83 115 0 0 32 46 26 13 55 29.9 27 164 -25 34 12 41 31 25 8 34 41 37 30 59 55 -1.84 116 0 0 33 30 8 13 55 12.6 26 165 -25 34 58 30 32 7 4 35 28 12 31 41 20 -1.84 117 0 0 34 15 40 13 54 55.4 25 166 -25 35 46 22 32 50 41 36 16 56 32 24 24 -1.85 118 0 0 35 3 8 13 54 38.3 25 167 -25 36 36 25 33 36 3 37 7 56 33 9 10 -1.85 119 0 0 35 52 38 13 54 21.2 24 168 -24 37 28 45 34 23 14 38 1 21 33 55 43 -1.86 120 0 0 36 44 15 13 54 4.3 24 169 -24 38 23 34 35 12 19 38 57 22 34 44 5 -1.86 121 0 0 37 38 9 13 53 47.5 23 170 -24 39 21 2 36 3 24 39 56 13 35 34 23 -1.87 122 0 0 38 34 27 13 53 30.8 22 171 -23 40 21 23 36 56 35 40 58 9 36 26 42 -1.88 123 0 0 39 33 22 13 53 14.4 21 172 -23 41 24 54 37 52 0 42 3 30 37 21 10 -1.88 124 0 0 40 35 5 13 52 58.2 20 173 -22 42 31 58 38 49 47 43 12 43 38 17 53 -1.89 125 0 0 41 39 54 13 52 42.3 19 174 -22 43 43 1 39 50 7 44 26 22 39 17 1 -1.90 126 0 0 42 48 8 13 52 26.7 18 175 -21 44 58 40 40 53 11 45 45 12 40 18 44 -1.91 127 0 0 44 0 12 13 52 11.4 17 176 -20 46 19 46 41 59 15 47 10 21 41 23 15 -1.92 128 0 0 45 16 40 13 51 56.5 16 176 -20 47 47 32 43 8 38 48 43 28 42 30 51 -1.93 129 0 0 46 38 19 13 51 42.1 14 177 -19 49 23 52 44 21 42 50 27 20 43 41 51 -1.95 130 0 0 48 6 11 13 51 28.3 13 178 -17 51 11 58 45 38 59 52 27 14 44 56 39 -1.96 131 0 0 49 41 57 13 51 15.0 11 179 -16 53 18 18 47 1 10 54 56 11 46 15 49 -1.99 132 0 0 51 28 17 13 51 2.5 10 180 -15 56 0 31 48 29 12 59 8 17 47 40 6 -2.03 133 0 0 53 30 15 13 50 50.9 8 181 -13 .. .. .. 50 4 31 .. .. .. 49 10 31 -2.10 134 0 0 56 0 5 13 50 40.6 5 182 -11 .. .. .. 51 49 22 .. .. .. 50 48 41 -2.29 135 0 0 59 58 39 13 50 32.9 1 182 -7 .. .. .. 53 47 51 .. .. .. 52 37 12 -4.85 136 0 0 .. .. .... .. .. .. .. .. .. .. .. .. 56 8 49 .. .. .. 54 40 53 .... 137 0 0 .. .. .... .. .. .. .. .. .. .. .. .. 59 22 49 .. .. .. 57 11 7 .... 138 0 0 .. .. .... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 60 58 46 .... Uncertainty in time = +/- 5 secs Prediction of 2023 Jul 15.2 Data for the target star ------------------------ * name: UCAC4 306-210784 * constellation : Sagittarius * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 18 13 53.2931 DE: -28 59 50.672 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 18 13 53.2930 DE: -28 59 50.672 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.200,0.100) * V mag [mag]: 11.7 * B mag [mag]: 11.8 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (42) Isis asteroid class: Barbarian approx. diameter [km]: 113 approx. diameter ["]: 0.157 distance from Earth [AU]: 0.99320 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#120 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): 0.042", 0.003", 98.75° remarks: * orbital elements for (42)Isis : Mean anomaly = 335.8196484063 deg Arg. of pericenter = 237.2514099446 deg Long. of node = 84.1659144646 deg Inclination = 8.5112106648 deg Eccentricity = 0.2220356251 Semimajor axis = 2.4427254690 AU Perihelion dist = 1.9003533926 AU Mag: H = 7.61, G = 0.15 Epoch of elements : MJD 60506.58250588 TDT (2024 Jul 15.5825) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#1202023Apr24,18.18,2024,7,15,13.980119,-0.404561,0.773034,-3.108932,-1.627024,0.001750,0.000508,0.000001,0.000000 130.2525,-28.9911,-28.18,21.38,False UCAC4 306-210784,18.23147030,-28.9974089,11.76,11.69,11.65,0.0,0,,18.25781958,-28.9911192,0.17,0.12,0,0,0 42,Isis,9.74,113.011,0.9932,0,0,-2.097,-14.40,,6.0,0 0,335.6693,2024,7,15,237.2514,84.1659,8.5112,0.22204,2.44273,1.90035,7.61,5.0,0.15 1.161,0.0423,0.0028,99,0.0252,Known errors,0.51,0,-1,-1 20240715_210784,60140.20 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Jul 15, 04:51 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org