IOTA/IOTA-ES occultation update for (476) Hedwig / UCAC4 308-080940 event on 2021 Jan 28, 10:11 UT Visible from E USA Summary ------- On 2021 Jan 28 UT, the 121.7 km diameter asteroid (476) Hedwig will occult a 12.1 mag star in the constellation Libra for observers along a path across E USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.96 mag to 13.84 mag (the magnitude of the asteroid) for at most 4.7 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, astrometry for the asteroid kindly provided by Bill Owen, 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: 2021 Jan 28, 10:08 - 2021 Jan 28, 10:14 * geocentric midpoint of event [JD]: 2459242.92453750 * magnitude of target star: 12.08 * magnitude drop [mag]: 1.96 * estimated maximum duration [s]: 4.7 * Moon: 100 % sunlit, 110° distance * Sun: 75° distance * rough path description: E USA Additional comments ------------------- RUWE high, The occultation path -------------------- * approximate projected width [km]: 169 * 1 sigma uncertainty interval [path widths]: +/- 0.13 * 1 sigma uncertainty interval [seconds]: +/- 1.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.014, +/- 0.008) * 1 sigma uncertainty ellipse (major, minor, PA): (0.014", 0.008", 98°) * approx speed of asteroid's shadow [km/s]: 25.8402 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC4 308-080940 by 476 Hedwig on 2021 Jan 28 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 .. .. .. 54 0 0 .. .. .... .. .. .. ... .. .. - 92 36 33 ... .. .. - 92 10 42 .... - 92 58 52 53 0 0 10 8 23.2 1 145 -35 - 94 32 14 - 91 25 9 - 94 57 20 - 90 59 50 .... - 91 46 36 52 0 0 10 8 23.4 2 146 -34 - 93 18 6 - 90 14 42 - 93 42 43 - 89 49 51 -0.57 - 90 35 17 51 0 0 10 8 23.7 3 146 -34 - 92 5 5 - 89 5 3 - 92 29 14 - 88 40 40 -0.71 - 89 24 47 50 0 0 10 8 24.3 5 147 -33 - 90 53 1 - 87 56 6 - 91 16 44 - 87 32 7 -0.78 - 88 14 59 49 0 0 10 8 24.9 6 148 -33 - 89 41 46 - 86 47 42 - 90 5 5 - 86 24 6 -0.81 - 87 5 45 48 0 0 10 8 25.8 7 149 -32 - 88 31 13 - 85 39 46 - 88 54 10 - 85 16 30 -0.84 - 85 56 59 47 0 0 10 8 26.8 8 150 -31 - 87 21 13 - 84 32 11 - 87 43 51 - 84 9 13 -0.86 - 84 48 34 46 0 0 10 8 28.0 10 151 -31 - 86 11 42 - 83 24 50 - 86 34 1 - 83 2 10 -0.87 - 83 40 24 45 0 0 10 8 29.4 11 152 -30 - 85 2 32 - 82 17 40 - 85 24 34 - 81 55 15 -0.88 - 82 32 24 44 0 0 10 8 30.9 12 153 -29 - 83 53 37 - 81 10 33 - 84 15 24 - 80 48 22 -0.89 - 81 24 28 43 0 0 10 8 32.6 14 153 -29 - 82 44 52 - 80 3 24 - 83 6 25 - 79 41 26 -0.89 - 80 16 31 42 0 0 10 8 34.5 15 154 -28 - 81 36 10 - 78 56 9 - 81 57 32 - 78 34 21 -0.90 - 79 8 26 41 0 0 10 8 36.6 16 155 -27 - 80 27 28 - 77 48 41 - 80 48 39 - 77 27 3 -0.90 - 78 0 10 40 0 0 10 8 38.9 17 156 -26 - 79 18 38 - 76 40 56 - 79 39 40 - 76 19 27 -0.91 - 76 51 37 39 0 0 10 8 41.4 19 157 -25 - 78 9 36 - 75 32 49 - 78 30 30 - 75 11 26 -0.91 - 75 42 41 38 0 0 10 8 44.0 20 158 -24 - 77 0 17 - 74 24 14 - 77 21 3 - 74 2 57 -0.92 - 74 33 16 37 0 0 10 8 46.9 21 159 -23 - 75 50 34 - 73 15 6 - 76 11 15 - 72 53 52 -0.92 - 73 23 18 36 0 0 10 8 49.9 22 160 -22 - 74 40 23 - 72 5 19 - 75 1 0 - 71 44 7 -0.92 - 72 12 41 35 0 0 10 8 53.2 24 160 -21 - 73 29 37 - 70 54 47 - 73 50 12 - 70 33 36 -0.92 - 71 1 18 34 0 0 10 8 56.6 25 161 -20 - 72 18 11 - 69 43 23 - 72 38 45 - 69 22 13 -0.93 - 69 49 3 33 0 0 10 9 0.3 26 162 -19 - 71 5 59 - 68 31 3 - 71 26 33 - 68 9 50 -0.93 - 68 35 50 32 0 0 10 9 4.2 27 163 -17 - 69 52 54 - 67 17 38 - 70 13 29 - 66 56 21 -0.93 - 67 21 31 31 0 0 10 9 8.3 29 164 -16 - 68 38 49 - 66 3 1 - 68 59 28 - 65 41 38 -0.93 - 66 5 58 30 0 0 10 9 12.7 30 166 -15 - 67 23 37 - 64 47 3 - 67 44 21 - 64 25 34 -0.93 - 64 49 4 29 0 0 10 9 17.3 31 167 -13 - 66 7 11 - 63 29 37 - 66 28 1 - 63 7 58 -0.94 - 63 30 39 28 0 0 10 9 22.1 32 168 -12 - 64 49 20 - 62 10 32 - 65 10 19 - 61 48 41 -0.94 - 62 10 33 27 0 0 10 9 27.2 34 169 -11 - 63 29 57 - 60 49 37 - 63 51 6 - 60 27 32 -0.94 - 60 48 34 26 0 0 10 9 32.6 35 171 -9 - 62 8 49 - 59 26 40 - 62 30 11 - 59 4 18 -0.94 - 59 24 31 25 0 0 10 9 38.2 36 172 -8 - 60 45 47 - 58 1 27 - 61 7 24 - 57 38 45 -0.94 - 57 58 8 24 0 0 10 9 44.2 37 173 -6 - 59 20 36 - 56 33 43 - 59 42 31 - 56 10 36 -0.94 - 56 29 8 23 0 0 10 9 50.4 38 175 -5 - 57 53 2 - 55 3 8 - 58 15 18 - 54 39 33 -0.95 - 54 57 14 22 0 0 10 9 57.0 39 177 -3 - 56 22 47 - 53 29 21 - 56 45 28 - 53 5 14 -0.95 - 53 22 2 21 0 0 10 10 4.0 40 179 -1 - 54 49 31 - 51 51 57 - 55 12 42 - 51 27 11 -0.95 - 51 43 5 20 0 0 10 10 11.3 41 181 1 - 53 12 51 - 50 10 24 - 53 36 36 - 49 44 53 -0.95 - 49 59 51 19 0 0 10 10 19.0 42 183 3 - 51 32 19 - 48 24 5 - 51 56 43 - 47 57 40 -0.95 - 48 11 39 18 0 0 10 10 27.2 43 185 5 - 49 47 19 - 46 32 12 - 50 12 31 - 46 4 41 -0.96 - 46 17 39 17 0 0 10 10 35.9 44 187 7 - 47 57 9 - 44 33 44 - 48 23 18 - 44 4 52 -0.96 - 44 16 46 16 0 0 10 10 45.2 45 190 9 - 46 0 56 - 42 27 19 - 46 28 13 - 41 56 47 -0.96 Latitude Latitude Latitude Latitude - 44 0 0 15 51 59 10 10 46.5 45 190 9 15 1 11 16 43 35 14 47 38 16 57 38 -0.96 - 43 0 0 15 23 51 10 10 51.1 45 192 10 14 33 23 16 15 7 14 19 55 16 29 5 -0.96 - 42 0 0 14 56 39 10 10 55.7 45 193 11 14 6 30 15 47 35 13 53 6 16 1 27 -0.96 - 41 0 0 14 30 22 10 11 0.3 46 194 12 13 40 31 15 20 59 13 27 12 15 34 46 -0.96 - 40 0 0 14 5 0 10 11 4.9 46 196 13 13 15 27 14 55 20 13 2 13 15 9 1 -0.97 - 39 0 0 13 40 34 10 11 9.5 46 197 15 12 51 18 14 30 36 12 38 8 14 44 13 -0.97 - 38 0 0 13 17 4 10 11 14.1 46 198 16 12 28 3 14 6 49 12 14 58 14 20 21 -0.97 - 37 0 0 12 54 28 10 11 18.6 46 200 17 12 5 43 13 43 57 11 52 42 13 57 25 -0.97 - 36 0 0 12 32 48 10 11 23.2 46 201 18 11 44 18 13 22 2 11 31 20 13 35 25 -0.97 - 35 0 0 12 12 3 10 11 27.7 46 202 19 11 23 47 13 1 2 11 10 53 13 14 21 -0.97 - 34 0 0 11 52 13 10 11 32.2 46 204 20 11 4 10 12 40 58 10 51 20 12 54 13 -0.97 - 33 0 0 11 33 18 10 11 36.7 46 205 21 10 45 28 12 21 49 10 32 41 12 35 1 -0.97 - 32 0 0 11 15 17 10 11 41.2 46 206 22 10 27 39 12 3 36 10 14 56 12 16 44 -0.97 - 31 0 0 10 58 11 10 11 45.6 45 207 23 10 10 45 11 46 18 9 58 4 11 59 23 -0.97 - 30 0 0 10 42 0 10 11 50.0 45 209 24 9 54 44 11 29 55 9 42 6 11 42 57 -0.97 - 29 0 0 10 26 42 10 11 54.4 45 210 25 9 39 37 11 14 27 9 27 2 11 27 26 -0.97 - 28 0 0 10 12 19 10 11 58.7 45 211 26 9 25 24 10 59 53 9 12 51 11 12 49 -0.97 - 27 0 0 9 58 50 10 12 3.0 44 212 27 9 12 3 10 46 15 8 59 33 10 59 8 -0.97 - 26 0 0 9 46 14 10 12 7.3 44 213 28 8 59 37 10 33 30 8 47 9 10 46 21 -0.97 - 25 0 0 9 34 33 10 12 11.5 43 214 29 8 48 3 10 21 41 8 35 37 10 34 29 -0.97 - 24 0 0 9 23 45 10 12 15.7 43 215 30 8 37 22 10 10 45 8 24 58 10 23 31 -0.97 - 23 0 0 9 13 50 10 12 19.9 43 216 31 8 27 34 10 0 43 8 15 12 10 13 28 -0.97 - 22 0 0 9 4 49 10 12 24.0 42 217 32 8 18 39 9 51 35 8 6 18 10 4 18 -0.97 - 21 0 0 8 56 40 10 12 28.0 42 218 33 8 10 36 9 43 21 7 58 17 9 56 3 -0.97 - 20 0 0 8 49 25 10 12 32.0 41 219 34 8 3 26 9 36 1 7 51 8 9 48 41 -0.97 - 19 0 0 8 43 3 10 12 36.0 40 220 35 7 57 8 9 29 34 7 44 51 9 42 13 -0.97 - 18 0 0 8 37 33 10 12 39.9 40 221 36 7 51 42 9 24 1 7 39 27 9 36 38 -0.97 - 17 0 0 8 32 57 10 12 43.7 39 222 36 7 47 9 9 19 21 7 34 54 9 31 57 -0.97 - 16 0 0 8 29 13 10 12 47.5 39 222 37 7 43 28 9 15 34 7 31 14 9 28 10 -0.97 - 15 0 0 8 26 21 10 12 51.3 38 223 38 7 40 38 9 12 40 7 28 25 9 25 16 -0.97 - 14 0 0 8 24 22 10 12 54.9 37 224 39 7 38 41 9 10 40 7 26 28 9 23 15 -0.98 - 13 0 0 8 23 16 10 12 58.6 37 225 40 7 37 35 9 9 32 7 25 23 9 22 7 -0.98 - 12 0 0 8 23 2 10 13 2.1 36 225 41 7 37 22 9 9 18 7 25 9 9 21 52 -0.98 - 11 0 0 8 23 40 10 13 5.6 35 226 42 7 38 0 9 9 56 7 25 47 9 22 31 -0.98 - 10 0 0 8 25 11 10 13 9.1 35 226 43 7 39 30 9 11 28 7 27 17 9 24 2 -0.98 - 9 0 0 8 27 34 10 13 12.5 34 227 43 7 41 52 9 13 52 7 29 38 9 26 27 -0.98 - 8 0 0 8 30 49 10 13 15.8 33 228 44 7 45 5 9 17 9 7 32 51 9 29 44 -0.98 - 7 0 0 8 34 56 10 13 19.0 32 228 45 7 49 10 9 21 19 7 36 56 9 33 55 -0.98 - 6 0 0 8 39 56 10 13 22.2 31 229 46 7 54 7 9 26 22 7 41 52 9 38 59 -0.98 - 5 0 0 8 45 48 10 13 25.3 31 229 46 7 59 55 9 32 17 7 47 39 9 44 55 -0.98 - 4 0 0 8 52 33 10 13 28.3 30 230 47 8 6 36 9 39 6 7 54 19 9 51 45 -0.98 - 3 0 0 9 0 9 10 13 31.3 29 230 48 8 14 8 9 46 47 8 1 50 9 59 28 -0.98 - 2 0 0 9 8 38 10 13 34.2 28 231 48 8 22 32 9 55 22 8 10 12 10 8 4 -0.98 - 1 0 0 9 18 0 10 13 37.0 27 231 49 8 31 47 10 4 49 8 19 26 10 17 33 -0.98 0 0 0 9 28 14 10 13 39.7 26 231 50 8 41 55 10 15 10 8 29 32 10 27 55 -0.98 1 0 0 9 39 20 10 13 42.3 25 232 50 8 52 55 10 26 23 8 40 30 10 39 11 -0.98 2 0 0 9 51 19 10 13 44.9 24 232 51 9 4 46 10 38 30 8 52 20 10 51 20 -0.98 3 0 0 10 4 11 10 13 47.4 24 233 51 9 17 30 10 51 30 9 5 1 11 4 22 -0.98 4 0 0 10 17 55 10 13 49.8 23 233 52 9 31 5 11 5 23 9 18 35 11 18 18 -0.98 5 0 0 10 32 32 10 13 52.1 22 233 52 9 45 33 11 20 10 9 33 0 11 33 7 -0.98 6 0 0 10 48 2 10 13 54.3 21 234 53 10 0 53 11 35 50 9 48 17 11 48 50 -0.98 7 0 0 11 4 25 10 13 56.4 20 234 53 10 17 6 11 52 23 10 4 27 12 5 26 -0.98 8 0 0 11 21 40 10 13 58.5 19 234 54 10 34 10 12 9 50 10 21 29 12 22 57 -0.98 9 0 0 11 39 49 10 14 0.4 18 235 54 10 52 7 12 28 11 10 39 23 12 41 21 -0.98 10 0 0 11 58 51 10 14 2.3 17 235 54 11 10 57 12 47 25 10 58 9 13 0 38 -0.98 11 0 0 12 18 45 10 14 4.0 16 235 54 11 30 39 13 7 33 11 17 48 13 20 50 -0.98 12 0 0 12 39 33 10 14 5.7 15 235 55 11 51 13 13 28 35 11 38 18 13 41 56 -0.98 13 0 0 13 1 14 10 14 7.2 14 236 55 12 12 40 13 50 31 11 59 42 14 3 55 -0.98 14 0 0 13 23 48 10 14 8.6 13 236 55 12 35 0 14 13 20 12 21 57 14 26 49 -0.98 15 0 0 13 47 16 10 14 10.0 12 236 55 12 58 12 14 37 4 12 45 6 14 50 37 -0.99 16 0 0 14 11 36 10 14 11.2 11 237 55 13 22 16 15 1 41 13 9 6 15 15 19 -0.99 17 0 0 14 36 50 10 14 12.3 10 237 55 13 47 14 15 27 12 13 33 59 15 40 54 -0.99 18 0 0 15 2 57 10 14 13.3 9 237 55 14 13 3 15 53 37 13 59 44 16 7 24 -1.00 19 0 0 15 29 57 10 14 14.2 8 237 55 14 39 45 16 20 55 14 26 22 16 34 48 -1.00 20 0 0 15 57 49 10 14 15.0 7 238 55 15 7 20 16 49 7 14 53 51 17 3 5 -1.01 21 0 0 16 26 35 10 14 15.7 5 238 55 15 35 46 17 18 13 15 22 13 17 32 17 -1.02 22 0 0 16 56 14 10 14 16.2 4 238 54 16 5 5 17 48 12 15 51 26 18 2 22 -1.03 23 0 0 17 26 45 10 14 16.7 3 239 54 16 35 16 18 19 5 16 21 32 18 33 20 -1.05 24 0 0 17 58 8 10 14 17.0 2 239 54 17 6 18 18 50 50 16 52 28 19 5 12 -1.10 25 0 0 18 30 24 10 14 17.2 1 239 53 17 38 12 19 23 29 17 24 16 19 37 57 -1.23 26 0 0 19 3 31 10 14 17.2 0 240 53 18 10 57 .. .. .. 17 56 56 .. .. .. -14.75 Uncertainty in time = +/- 1 secs Prediction of 2020 Dec 31.0 Data for the target star ------------------------ * name: UCAC4 308-080940 * constellation : Libra * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 15 11 53.7186 DE: -28 32 04.864 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 15 11 53.7186 DE: -28 32 04.864 * position source: Gaia EDR3 * 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: (476) Hedwig asteroid class: ShapeModel approx. diameter [km]: 122 approx. diameter ["]: 0.063 distance from Earth [AU]: 2.65900 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: Preston date of fit: 2020 Nov 29 source of used astrometry: MPC, FASTT, TMO number of used observations: 2649 number of rejected observations: 20 time covered by the observations: 1960 Feb 28 - 2020 Jul 12 1 sigma uncertainty ellipse (major, minor, PA): 0.014", 0.008", 97.8° remarks: * orbital elements for (476)Hedwig : Mean anomaly = 291.46700469 deg Arg. of pericenter = 1.28412300 deg Long. of node = 286.33937880 deg Inclination = 10.92686768 deg Eccentricity = 0.07271625 Semimajor axis = 2.64961364 AU Perihelion dist = 2.45694368 AU Mag: H = 8.60, G = 0.15 Epoch of elements : MJD 59242.42500000 TDT (2021 Jan 28.4250) ------ occelmnt file for Occult BEGIN ----------------------------------- Preston2020Nov29,4.7,2021,1,28,10.1889,0.26443,0.64280,13.49026,-5.54374,-0.00551,0.00126,0.00000,0.00000 -52.4435,-28.6109,30.41,-18.08,False UCAC4 308-080940,15.19825513,-28.5346844,0.00,12.08,0.00,0.0,0,,15.21902245,-28.6108995 476,Hedwig,13.84,121.7,2.6590,0,0,3.389,-18.34,,6.8 0,291.3699,2021,1,28,1.2841,286.3394,10.9269,0.07272,2.64961,2.45694,8.60,5.0,0.15 1.135,0.0140,0.0080,98,0.0085,Known errors 20210128_080940,59214.00 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2020 Dec 31, 00:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org