IOTA/IOTA-ES occultation update for (666) Desdemona / UCAC4 391-061904 event on 2024 Jul 02, 19:23 UT Visible from Summary ------- On 2024 Jul 02 UT, the 28.343 km diameter asteroid (666) Desdemona will occult a 11.7 mag star in the constellation Libra for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 4.23 mag to 15.93 mag (the magnitude of the asteroid) for at most 16.790 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 02, 18:53 - 2024 Jul 02, 19:53 * geocentric midpoint of event [JD]: 2460494.30798571 * magnitude of target star: 11.72 * magnitude drop [mag]: 4.23 * estimated maximum duration [s]: 16.790 * Moon: 12 % sunlit, 160° distance * Sun: 122° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 64 * 1 sigma uncertainty interval [path widths]: +/- 0.17 * 1 sigma uncertainty interval [seconds]: +/- 6.2 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.006, +/- 0.002) * 1 sigma uncertainty ellipse (major, minor, PA): (0.006", 0.002", 102°) * approx speed of asteroid's shadow [km/s]: 1.6885 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 391-061904 by 666 Desdemona on 2024 Jul 2 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 ' " Longitude Longitude Longitude Longitude 32 16 30 76 0 0 19 50 54.7 0 209 11 33 43 55 30 51 18 34 14 12 30 22 47 .... 30 18 22 75 0 0 19 50 52.4 1 207 10 31 37 19 29 1 6 32 4 36 28 35 10 1.25 28 47 13 74 0 0 19 50 47.1 2 206 9 29 59 35 27 36 10 30 24 32 27 12 17 1.69 27 37 3 73 0 0 19 50 38.9 4 204 9 28 44 8 26 31 4 29 7 14 26 8 51 1.86 26 43 44 72 0 0 19 50 28.0 5 204 8 27 46 27 25 41 55 28 8 1 25 21 5 1.96 26 4 12 71 0 0 19 50 14.5 6 203 7 27 3 17 25 5 55 27 23 34 24 46 16 2.02 25 36 13 70 0 0 19 49 58.5 7 202 7 26 32 11 24 40 58 26 51 24 24 22 19 2.06 25 18 4 69 0 0 19 49 39.9 8 202 6 26 11 21 24 25 25 26 29 38 24 7 38 2.10 25 8 24 68 0 0 19 49 18.8 9 202 5 25 59 22 24 18 0 26 16 50 24 0 59 2.13 25 6 9 67 0 0 19 48 55.4 9 202 4 25 55 4 24 17 44 26 11 50 24 1 23 2.15 25 10 27 66 0 0 19 48 29.5 10 202 4 25 57 34 24 23 48 26 13 43 24 8 2 -2.17 25 20 37 65 0 0 19 48 1.1 11 202 3 26 6 9 24 35 32 26 21 44 24 20 17 -2.18 25 36 5 64 0 0 19 47 30.4 12 202 2 26 20 12 24 52 23 26 35 19 24 37 36 -2.19 25 56 24 63 0 0 19 46 57.3 13 202 1 26 39 16 25 13 56 26 53 57 24 59 35 -2.20 26 21 12 62 0 0 19 46 21.7 14 203 0 27 2 56 25 39 50 27 17 13 25 25 50 -2.21 26 50 9 61 0 0 19 45 43.8 15 203 -1 27 30 53 26 9 46 27 44 50 25 56 6 -2.21 27 22 59 60 0 0 19 45 3.4 16 204 -2 28 2 50 26 43 29 28 16 29 26 30 7 -2.22 27 59 31 59 0 0 19 44 20.6 17 204 -3 28 38 35 27 20 48 28 51 57 27 7 42 -2.22 28 39 34 58 0 0 19 43 35.4 17 205 -4 29 17 55 28 1 32 29 31 3 27 48 40 -2.22 29 22 59 57 0 0 19 42 47.7 18 205 -5 30 0 43 28 45 34 30 13 38 28 32 54 -2.21 30 9 40 56 0 0 19 41 57.6 19 206 -6 30 46 52 29 32 47 30 59 36 29 20 19 -2.21 30 59 33 55 0 0 19 41 5.1 20 207 -7 31 36 17 30 23 8 31 48 51 30 10 49 -2.20 31 52 33 54 0 0 19 40 10.0 20 208 -8 32 28 53 31 16 32 32 41 19 31 4 21 -2.20 32 48 40 53 0 0 19 39 12.4 21 209 -9 33 24 40 32 12 58 33 36 59 32 0 54 -2.19 33 47 51 52 0 0 19 38 12.4 22 210 -10 34 23 35 33 12 26 34 35 50 33 0 27 -2.18 34 50 8 51 0 0 19 37 9.7 22 211 -11 35 25 41 34 14 55 35 37 51 34 3 0 -2.17 35 55 33 50 0 0 19 36 4.5 23 212 -12 36 30 58 35 20 28 36 43 6 35 8 36 -2.16 37 4 8 49 0 0 19 34 56.6 23 213 -13 37 39 29 36 29 8 37 51 36 36 17 17 -2.15 38 15 59 48 0 0 19 33 46.1 24 214 -14 38 51 20 37 40 59 39 3 27 37 29 9 -2.14 39 31 12 47 0 0 19 32 32.9 24 215 -16 40 6 38 38 56 8 40 18 47 38 44 16 -2.12 40 49 54 46 0 0 19 31 16.9 25 216 -17 41 25 30 40 14 41 41 37 42 40 2 47 -2.11 42 12 16 45 0 0 19 29 58.1 25 218 -18 42 48 6 41 36 49 43 0 23 41 24 51 -2.10 43 38 29 44 0 0 19 28 36.3 26 219 -19 44 14 40 43 2 44 44 27 4 42 50 39 -2.09 45 8 49 43 0 0 19 27 11.6 26 220 -21 45 45 26 44 32 39 45 58 0 44 20 26 -2.07 46 43 35 42 0 0 19 25 43.7 26 222 -22 47 20 47 46 6 53 47 33 33 45 54 30 -2.06 48 23 12 41 0 0 19 24 12.6 26 223 -23 49 1 6 47 45 49 49 14 7 47 33 13 -2.05 50 8 7 40 0 0 19 22 38.0 26 225 -24 50 46 53 49 29 54 51 0 13 49 17 1 -2.03 51 58 52 39 0 0 19 20 59.9 26 227 -26 52 38 45 51 19 39 52 52 28 51 6 26 -2.02 53 56 18 38 0 0 19 19 17.8 26 228 -27 54 37 33 53 15 48 54 51 45 53 2 10 -2.01 56 1 24 37 0 0 19 17 31.5 25 230 -28 56 44 22 55 19 18 56 59 11 55 5 9 -2.00 Latitude Latitude Latitude Latitude 57 0 0 36 33 15 19 16 42.6 25 231 -29 36 52 53 36 13 53 36 59 38 36 7 21 -1.99 58 0 0 36 6 45 19 15 53.2 25 232 -30 36 26 10 35 47 35 36 32 50 35 41 7 -1.98 59 0 0 35 41 6 19 15 4.4 25 232 -30 36 0 19 35 22 8 36 6 55 35 15 45 -1.98 60 0 0 35 16 20 19 14 16.3 24 233 -31 35 35 22 34 57 33 35 41 53 34 51 13 -1.98 61 0 0 34 52 25 19 13 28.9 24 234 -31 35 11 16 34 33 48 35 17 44 34 27 32 -1.97 62 0 0 34 29 21 19 12 42.2 24 235 -32 34 48 2 34 10 54 34 54 27 34 4 40 -1.97 63 0 0 34 7 8 19 11 56.2 24 235 -32 34 25 40 33 48 49 34 32 1 33 42 38 -1.97 64 0 0 33 45 44 19 11 11.0 23 236 -33 34 4 8 33 27 34 34 10 26 33 21 26 -1.97 65 0 0 33 25 11 19 10 26.6 23 237 -33 33 43 27 33 7 8 33 49 42 33 1 3 -1.97 66 0 0 33 5 28 19 9 42.9 22 238 -34 33 23 36 32 47 32 33 29 49 32 41 29 -1.97 67 0 0 32 46 34 19 9 0.1 22 238 -34 33 4 36 32 28 45 33 10 47 32 22 44 -1.97 68 0 0 32 28 30 19 8 18.1 22 239 -34 32 46 26 32 10 47 32 52 34 32 4 48 -1.97 69 0 0 32 11 16 19 7 36.9 21 240 -35 32 29 6 31 53 38 32 35 13 31 47 41 -1.97 70 0 0 31 54 52 19 6 56.7 21 240 -35 32 12 36 31 37 18 32 18 41 31 31 23 -1.97 71 0 0 31 39 17 19 6 17.3 20 241 -35 31 56 57 31 21 48 32 3 1 31 15 54 -1.97 72 0 0 31 24 32 19 5 38.9 20 242 -36 31 42 8 31 7 7 31 48 10 31 1 14 -1.98 73 0 0 31 10 36 19 5 1.3 19 242 -36 31 28 9 30 53 15 31 34 10 30 47 23 -1.98 74 0 0 30 57 31 19 4 24.8 19 243 -36 31 15 1 30 40 13 31 21 0 30 34 22 -1.98 75 0 0 30 45 17 19 3 49.3 18 244 -36 31 2 43 30 28 1 31 8 42 30 22 11 -1.99 76 0 0 30 33 53 19 3 14.7 17 244 -37 30 51 18 30 16 39 30 57 16 30 10 50 -1.99 77 0 0 30 23 20 19 2 41.3 17 245 -37 30 40 43 30 6 8 30 46 40 30 0 19 -2.00 78 0 0 30 13 39 19 2 8.9 16 245 -37 30 31 1 29 56 28 30 36 58 29 50 40 -2.01 79 0 0 30 4 50 19 1 37.6 16 246 -37 30 22 11 29 47 40 30 28 7 29 41 52 -2.01 80 0 0 29 56 54 19 1 7.4 15 246 -37 30 14 14 29 39 44 30 20 11 29 33 56 -2.02 81 0 0 29 49 50 19 0 38.4 14 247 -37 30 7 11 29 32 41 30 13 8 29 26 53 -2.03 82 0 0 29 43 41 19 0 10.5 14 247 -37 30 1 3 29 26 31 30 7 0 29 20 42 -2.04 83 0 0 29 38 27 18 59 43.9 13 248 -37 29 55 50 29 21 15 30 1 47 29 15 26 -2.05 84 0 0 29 34 8 18 59 18.6 12 248 -37 29 51 32 29 16 54 29 57 30 29 11 5 -2.06 85 0 0 29 30 45 18 58 54.5 11 249 -37 29 48 12 29 13 29 29 54 11 29 7 39 -2.07 86 0 0 29 28 20 18 58 31.7 11 250 -37 29 45 49 29 11 1 29 51 49 29 5 10 -2.09 87 0 0 29 26 52 18 58 10.3 10 250 -37 29 44 25 29 9 31 29 50 25 29 3 39 -2.10 88 0 0 29 26 24 18 57 50.3 9 251 -37 29 44 0 29 8 59 29 50 2 29 3 6 -2.12 89 0 0 29 26 56 18 57 31.8 9 251 -36 29 44 36 29 9 26 29 50 40 29 3 32 -2.13 90 0 0 29 28 29 18 57 14.7 8 251 -36 29 46 15 29 10 55 29 52 20 29 4 59 -2.15 91 0 0 29 31 5 18 56 59.2 7 252 -36 29 48 57 29 13 26 29 55 4 29 7 28 -2.18 92 0 0 29 34 46 18 56 45.2 6 252 -36 29 52 43 29 17 0 29 58 53 29 11 0 -2.20 93 0 0 29 39 32 18 56 32.8 5 253 -35 29 57 36 29 21 39 30 3 48 29 15 37 -2.23 94 0 0 29 45 25 18 56 22.1 5 253 -35 30 3 38 29 27 26 30 9 52 29 21 21 -2.27 95 0 0 29 52 28 18 56 13.1 4 254 -35 30 10 49 29 34 20 30 17 6 29 28 13 -2.32 96 0 0 30 0 42 18 56 5.9 3 254 -34 30 19 11 29 42 25 30 25 32 29 36 14 -2.40 97 0 0 30 10 8 18 56 0.6 2 255 -34 30 28 48 29 51 41 30 35 12 29 45 28 -2.53 98 0 0 30 20 50 18 55 57.1 1 255 -33 30 39 41 30 2 13 30 46 9 29 55 55 -2.85 99 0 0 30 32 49 18 55 55.7 0 256 -33 30 51 52 30 14 0 30 58 25 30 7 39 -5.45 Uncertainty in time = +/- 7 secs Prediction of 2023 Jul 15.2 Data for the target star ------------------------ * name: UCAC4 391-061904 * constellation : Libra * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 14 45 40.2241 DE: -11 55 40.303 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 14 45 40.2240 DE: -11 55 40.303 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.200,0.100) * V mag [mag]: 11.7 * B mag [mag]: 12.1 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (666) Desdemona asteroid class: approx. diameter [km]: 28 approx. diameter ["]: 0.016 distance from Earth [AU]: 2.42630 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#56 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): 0.006", 0.002", 101.937° remarks: * orbital elements for (666)Desdemona : Mean anomaly = 225.6851901011 deg Arg. of pericenter = 174.0610520301 deg Long. of node = 215.2968869367 deg Inclination = 7.5823399830 deg Eccentricity = 0.2364835154 Semimajor axis = 2.5950195262 AU Perihelion dist = 1.9813401860 AU Mag: H = 10.68, G = 0.15 Epoch of elements : MJD 60493.80798513 TDT (2024 Jul 02.8080) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#562023Apr24,16.79,2024,7,2,19.391657,0.485222,0.754597,-0.801832,0.515143,0.004519,-0.001622,0.000001,0.000000 9.5560,-12.0318,-109.81,22.95,False UCAC4 391-061904,14.76117338,-11.9278621,12.06,11.72,11.54,0.0,0,,14.78350327,-12.0317577,4.23,3.97,0,0,0 666,Desdemona,15.93,28.343,2.4263,0,0,-0.197,1.86,,1.8,0 0,225.4947,2024,7,2,174.0611,215.2969,7.5823,0.23648,2.59502,1.98134,10.68,5.0,0.15 1.170,0.0063,0.0017,102,0.0027,Known errors,0.94,0,-1,-1 20240702_061904,60140.18 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Jul 15, 04:20 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org