IOTA/IOTA-ES occultation update for (494) Virtus / TYC 1947-01369-1 event on 2023 Feb 20, 11:30 UT Visible from New Zealand, Australia Summary ------- On 2023 Feb 20 UT, the 91.1 km diameter asteroid (494) Virtus will occult a 10.3 mag star in the constellation Cancer for observers along a path across New Zealand, Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.67 mag to 13.93 mag (the magnitude of the asteroid) for at most 8.830 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 Feb 20, 11:25 - 2023 Feb 20, 11:35 * geocentric midpoint of event [JD]: 2459995.97942016 * magnitude of target star: 10.30 * magnitude drop [mag]: 3.67 * estimated maximum duration [s]: 8.830 * Moon: 0 % sunlit, 148° distance * Sun: 149° distance * rough path description: New Zealand, Australia The occultation path -------------------- * approximate projected width [km]: 223 * 1 sigma uncertainty interval [path widths]: +/- 0.12 * 1 sigma uncertainty interval [seconds]: +/- 3.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 0.023, +/- 0.008) * 1 sigma uncertainty ellipse (major, minor, PA): (0.024", 0.005", 104°) * approx speed of asteroid's shadow [km/s]: 10.3228 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1947-01369-1 by 494 Virtus on 2023 Feb 20 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 117 0 0 .. .. .... .. .. .. .. .. .. -50 58 23 .. .. .. -50 35 25 .. .. .. .... 118 0 0 .. .. .... .. .. .. .. .. .. -50 12 5 .. .. .. -49 49 47 .. .. .. .... 119 0 0 -51 1 44 11 34 31.2 1 37 -3 -49 27 21 .. .. .. -49 5 41 .. .. .. .... 120 0 0 -50 15 47 11 34 30.7 2 37 -4 -48 44 10 -51 56 59 -48 23 3 -52 23 26 1.42 121 0 0 -49 31 33 11 34 29.7 3 36 -5 -48 2 26 -51 9 24 -47 41 51 -51 34 50 1.75 122 0 0 -48 48 57 11 34 28.3 4 35 -6 -47 22 8 -50 23 47 -47 2 2 -50 48 21 1.90 123 0 0 -48 7 55 11 34 26.5 5 34 -7 -46 43 13 -49 40 2 -46 23 33 -50 3 48 1.99 124 0 0 -47 28 24 11 34 24.3 6 34 -8 -46 5 38 -48 58 3 -45 46 23 -49 21 6 2.05 125 0 0 -46 50 21 11 34 21.8 6 33 -9 -45 29 21 -48 17 44 -45 10 29 -48 40 8 2.09 126 0 0 -46 13 42 11 34 18.9 7 32 -9 -44 54 22 -47 39 1 -44 35 51 -48 0 50 2.12 127 0 0 -45 38 25 11 34 15.7 8 31 -10 -44 20 37 -47 1 51 -44 2 25 -47 23 8 2.14 128 0 0 -45 4 28 11 34 12.1 9 31 -11 -43 48 5 -46 26 9 -43 30 12 -46 46 57 2.16 129 0 0 -44 31 49 11 34 8.3 10 30 -12 -43 16 45 -45 51 53 -42 59 10 -46 12 14 2.17 130 0 0 -44 0 26 11 34 4.1 11 29 -13 -42 46 36 -45 19 1 -42 29 17 -45 38 57 2.18 131 0 0 -43 30 17 11 33 59.7 11 28 -14 -42 17 36 -44 47 29 -42 0 32 -45 7 3 2.19 132 0 0 -43 1 21 11 33 55.0 12 28 -15 -41 49 45 -44 17 17 -41 32 54 -44 36 29 2.20 133 0 0 -42 33 37 11 33 50.1 13 27 -16 -41 23 0 -43 48 21 -41 6 23 -44 7 14 2.21 134 0 0 -42 7 3 11 33 44.9 14 26 -16 -40 57 22 -43 20 41 -40 40 57 -43 39 16 2.21 135 0 0 -41 41 38 11 33 39.5 14 25 -17 -40 32 49 -42 54 14 -40 16 36 -43 12 32 2.22 136 0 0 -41 17 21 11 33 33.9 15 25 -18 -40 9 21 -42 29 0 -39 53 19 -42 47 3 2.22 137 0 0 -40 54 11 11 33 28.0 16 24 -19 -39 46 57 -42 4 57 -39 31 5 -42 22 45 2.22 138 0 0 -40 32 7 11 33 22.0 16 23 -20 -39 25 36 -41 42 3 -39 9 53 -41 59 38 2.23 139 0 0 -40 11 8 11 33 15.7 17 22 -20 -39 5 17 -41 20 18 -38 49 43 -41 37 41 2.23 140 0 0 -39 51 14 11 33 9.3 18 21 -21 -38 46 0 -40 59 41 -38 30 34 -41 16 52 2.23 141 0 0 -39 32 24 11 33 2.7 18 21 -22 -38 27 43 -40 40 11 -38 12 26 -40 57 11 2.23 142 0 0 -39 14 36 11 32 55.9 19 20 -23 -38 10 28 -40 21 47 -37 55 17 -40 38 37 2.23 143 0 0 -38 57 51 11 32 49.0 19 19 -24 -37 54 13 -40 4 27 -37 39 9 -40 21 9 2.24 144 0 0 -38 42 7 11 32 42.0 20 18 -24 -37 38 57 -39 48 12 -37 24 0 -40 4 45 2.24 145 0 0 -38 27 26 11 32 34.8 20 17 -25 -37 24 41 -39 33 1 -37 9 49 -39 49 26 2.24 146 0 0 -38 13 45 11 32 27.4 21 16 -26 -37 11 23 -39 18 53 -36 56 37 -39 35 11 2.24 147 0 0 -38 1 4 11 32 20.0 21 16 -27 -36 59 4 -39 5 48 -36 44 22 -39 22 0 2.24 148 0 0 -37 49 23 11 32 12.4 21 15 -27 -36 47 43 -38 53 45 -36 33 6 -39 9 51 2.24 149 0 0 -37 38 42 11 32 4.7 22 14 -28 -36 37 20 -38 42 44 -36 22 46 -38 58 44 2.24 150 0 0 -37 29 1 11 31 57.0 22 13 -29 -36 27 54 -38 32 44 -36 13 25 -38 48 40 2.24 151 0 0 -37 20 18 11 31 49.1 22 12 -29 -36 19 26 -38 23 45 -36 5 0 -38 39 36 2.24 152 0 0 -37 12 34 11 31 41.2 23 11 -30 -36 11 55 -38 15 46 -35 57 31 -38 31 34 2.24 153 0 0 -37 5 48 11 31 33.2 23 10 -31 -36 5 20 -38 8 48 -35 50 59 -38 24 32 2.24 154 0 0 -37 0 0 11 31 25.1 23 9 -31 -35 59 41 -38 2 49 -35 45 22 -38 18 31 2.24 155 0 0 -36 55 10 11 31 16.9 23 9 -32 -35 55 0 -37 57 51 -35 40 42 -38 13 30 2.25 156 0 0 -36 51 18 11 31 8.7 23 8 -32 -35 51 14 -37 53 52 -35 36 58 -38 9 29 2.25 157 0 0 -36 48 24 11 31 0.5 24 7 -33 -35 48 25 -37 50 52 -35 34 10 -38 6 28 2.25 158 0 0 -36 46 28 11 30 52.2 24 6 -33 -35 46 31 -37 48 52 -35 32 17 -38 4 27 2.25 159 0 0 -36 45 29 11 30 43.9 24 5 -34 -35 45 34 -37 47 51 -35 31 20 -38 3 26 2.25 160 0 0 -36 45 27 11 30 35.6 24 4 -34 -35 45 33 -37 47 50 -35 31 19 -38 3 24 2.25 161 0 0 -36 46 23 11 30 27.2 24 3 -35 -35 46 27 -37 48 47 -35 32 13 -38 4 22 2.25 162 0 0 -36 48 17 11 30 18.9 24 2 -35 -35 48 18 -37 50 44 -35 34 3 -38 6 19 2.25 163 0 0 -36 51 8 11 30 10.5 24 1 -36 -35 51 4 -37 53 39 -35 36 49 -38 9 16 2.25 164 0 0 -36 54 56 11 30 2.2 24 0 -36 -35 54 47 -37 57 34 -35 40 30 -38 13 13 2.26 165 0 0 -36 59 42 11 29 53.9 24 359 -36 -35 59 26 -38 2 29 -35 45 7 -38 18 10 2.26 166 0 0 -37 5 26 11 29 45.6 24 358 -37 -36 5 1 -38 8 23 -35 50 40 -38 24 7 2.26 167 0 0 -37 12 8 11 29 37.3 24 358 -37 -36 11 32 -38 15 17 -35 57 9 -38 31 4 2.26 168 0 0 -37 19 48 11 29 29.0 23 357 -37 -36 19 0 -38 23 11 -36 4 35 -38 39 1 2.26 169 0 0 -37 28 27 11 29 20.8 23 356 -37 -36 27 25 -38 32 6 -36 12 56 -38 48 0 2.27 170 0 0 -37 38 4 11 29 12.7 23 355 -38 -36 36 47 -38 42 1 -36 22 14 -38 58 0 2.27 171 0 0 -37 48 41 11 29 4.6 23 354 -38 -36 47 5 -38 52 56 -36 32 29 -39 9 1 2.27 172 0 0 -38 0 16 11 28 56.6 22 353 -38 -36 58 22 -39 4 54 -36 43 41 -39 21 4 2.27 173 0 0 -38 12 51 11 28 48.6 22 352 -38 -37 10 36 -39 17 53 -36 55 50 -39 34 9 2.27 174 0 0 -38 26 26 11 28 40.7 22 351 -38 -37 23 47 -39 31 54 -37 8 57 -39 48 17 2.28 175 0 0 -38 41 1 11 28 33.0 21 350 -38 -37 37 58 -39 46 58 -37 23 2 -40 3 29 2.28 176 0 0 -38 56 37 11 28 25.3 21 349 -38 -37 53 7 -40 3 5 -37 38 5 -40 19 44 2.28 177 0 0 -39 13 15 11 28 17.7 21 349 -38 -38 9 16 -40 20 16 -37 54 7 -40 37 4 2.29 178 0 0 -39 30 54 11 28 10.3 20 348 -38 -38 26 24 -40 38 31 -38 11 8 -40 55 29 2.29 179 0 0 -39 49 36 11 28 2.9 20 347 -38 -38 44 32 -40 57 52 -38 29 9 -41 15 0 2.29 180 0 0 -40 9 21 11 27 55.8 19 346 -38 -39 3 40 -41 18 19 -38 48 9 -41 35 38 2.30 -179 0 0 -40 30 10 11 27 48.7 19 345 -38 -39 23 50 -41 39 53 -39 8 10 -41 57 24 2.30 -178 0 0 -40 52 3 11 27 41.8 18 344 -38 -39 45 2 -42 2 35 -39 29 12 -42 20 19 2.30 -177 0 0 -41 15 2 11 27 35.1 18 343 -37 -40 7 16 -42 26 26 -39 51 16 -42 44 24 2.31 -176 0 0 -41 39 7 11 27 28.5 17 343 -37 -40 30 33 -42 51 27 -40 14 23 -43 9 41 2.31 -175 0 0 -42 4 19 11 27 22.2 16 342 -37 -40 54 53 -43 17 39 -40 38 32 -43 36 9 2.31 -174 0 0 -42 30 39 11 27 16.0 16 341 -36 -41 20 19 -43 45 4 -41 3 45 -44 3 52 2.32 -173 0 0 -42 58 9 11 27 10.0 15 340 -36 -41 46 50 -44 13 44 -41 30 3 -44 32 51 2.32 -172 0 0 -43 26 49 11 27 4.3 14 339 -36 -42 14 27 -44 43 39 -41 57 27 -45 3 6 2.33 -171 0 0 -43 56 40 11 26 58.7 14 339 -35 -42 43 11 -45 14 51 -42 25 56 -45 34 41 2.33 -170 0 0 -44 27 46 11 26 53.4 13 338 -35 -43 13 4 -45 47 24 -42 55 33 -46 7 38 2.34 -169 0 0 -45 0 6 11 26 48.4 12 337 -34 -43 44 6 -46 21 18 -43 26 19 -46 41 58 2.34 -168 0 0 -45 33 42 11 26 43.6 11 336 -34 -44 16 20 -46 56 37 -43 58 14 -47 17 45 2.35 -167 0 0 -46 8 37 11 26 39.1 11 335 -33 -44 49 45 -47 33 22 -44 31 20 -47 55 2 2.36 -166 0 0 -46 44 53 11 26 34.9 10 335 -32 -45 24 24 -48 11 39 -45 5 38 -48 33 53 2.37 -165 0 0 -47 22 31 11 26 31.0 9 334 -32 -46 0 18 -48 51 29 -45 41 9 -49 14 20 2.38 -164 0 0 -48 1 35 11 26 27.5 8 333 -31 -46 37 29 -49 32 57 -46 17 57 -49 56 30 2.39 -163 0 0 -48 42 8 11 26 24.3 7 332 -30 -47 15 59 -50 16 9 -46 56 1 -50 40 28 2.40 -162 0 0 -49 24 14 11 26 21.4 6 332 -30 -47 55 50 -51 1 9 -47 35 24 -51 26 20 2.42 -161 0 0 -50 7 55 11 26 18.9 5 331 -29 -48 37 5 -51 48 5 -48 16 8 -52 14 14 2.44 -160 0 0 -50 53 17 11 26 16.8 4 330 -28 -49 19 46 -52 37 4 -48 58 17 -53 4 18 2.48 -159 0 0 -51 40 25 11 26 15.1 3 329 -27 -50 3 57 -53 28 17 -49 41 52 -53 56 46 2.54 -158 0 0 -52 29 25 11 26 13.9 2 328 -26 -50 49 42 -54 21 55 -50 26 56 -54 51 51 2.65 -157 0 0 -53 20 24 11 26 13.2 1 328 -25 -51 37 3 .. .. .. -51 13 34 .. .. .. 2.96 -156 0 0 -54 13 33 11 26 12.9 0 327 -24 -52 26 7 .. .. .. -52 1 50 .. .. .. 9.91 -155 0 0 .. .. .... .. .. .. .. .. .. -53 16 59 .. .. .. -52 51 48 .. .. .. .... Uncertainty in time = +/- 4 secs Prediction of 2023 Feb 15.9 Data for the target star ------------------------ * name: TYC 1947-01369-1 * constellation : Cancer * BCRS position with proper motion to date of event [h,m,s ; °,',"] RA: 08 26 19.4536 DE: +29 27 46.975 * GCRS Astrometric position with proper motion and parallax to date of event [h,m,s ; °,',"] RA: 08 26 19.4535 DE: +29 27 46.975 * position source: Gaia DR3 * standard error: RA,DE [mas]: (0.100,0.100) * V mag [mag]: 10.3 * Diameter [mas]: 0.00 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (494) Virtus asteroid class: approx. diameter [km]: 91 approx. diameter ["]: 0.057 distance from Earth [AU]: 2.18890 asteroid position offset in RA [mas]: 0 asteroid position offset in DE [mas]: 0 * orbital information: orbit source: JPL#58 date of fit: 2023 Feb 07 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): 0.024", 0.005", 104.208° remarks: * orbital elements for (494)Virtus : Mean anomaly = 243.8385113960 deg Arg. of pericenter = 215.3928798457 deg Long. of node = 38.0731733490 deg Inclination = 7.0786998501 deg Eccentricity = 0.0643603040 Semimajor axis = 2.9849671534 AU Perihelion dist = 2.7928537600 AU Mag: H = 9.14, G = 0.15 Epoch of elements : MJD 59995.47937500 TDT (2023 Feb 20.4794) ------ occelmnt file for Occult BEGIN ----------------------------------- JPL#582023Feb07,8.83,2023,2,20,11.506084,-0.035870,-0.912022,-5.821927,0.230115,0.002642,-0.001590,0.000001,0.000000 164.2042,29.3875,10.84,-10.92,False TYC 1947-01369-1,8.43873711,29.4630485,0.00,10.30,0.00,0.0,0,,8.46263410,29.3874897,3.67,0.00,0,0,0 494,Virtus,13.93,91.1,2.1889,0,0,-1.789,0.92,,5.0,0 0,243.7469,2023,2,20,215.3929,38.0732,7.0787,0.06436,2.98497,2.79285,9.16,5.0,0.15 1.122,0.0240,0.0050,104,0.0070,Known errors,-1.00,-1,-1,-1 20230220_1369-1,59990.86 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2023 Feb 15, 20:38 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 stevepr@acm.org