IOTA/IOTA-ES occultation update for (63) Ausonia / 2UCAC 19242050 event on 2010 Mar 25, 10:26 UT Visible from USA Summary ------- On 2010 Mar 25 UT, the 103 km diameter asteroid (63) Ausonia will occult a 13.2 mag star in the constellation Sagittarius 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 0.2 mag to 11.6 mag (the magnitude of the asteroid) for at most 5.4 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 74 * date and approx. time of event: 2010 Mar 25, 10:23 - 2010 Mar 25, 10:26 UT * magnitude of target star: 13.2 * magnitude drop [mag]: 0.2 * estimated maximum duration [s]: 5.4 * Moon: 72 % sunlit, 150° distance * Sun: 92° distance * rough path description: USA The occultation path -------------------- * approximate projected width [km]: 182 * 1 sigma uncertainty interval [path widths]: +/- 0.77 * 1 sigma uncertainty interval [seconds]: +/- 3.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .060 +/- .059) * 1 sigma uncertainty ellipse (major, minor, PA): ( .060", .059", 90° ) * approx speed of asteroid's shadow [km/s]: 18.9690 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 19242050 by 63 Ausonia on 2010 Mar 25 Centre Star Star Sun Path Limits Error Limits E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " Longitude Longitude Longitude Longitude -112 22 10 50 0 0 10 23 30 0 141 -27 ... .. .. -110 43 52 ... .. .. -108 8 51 -111 7 3 49 0 0 10 23 30 1 142 -27 -112 42 58 -109 29 26 ... .. .. -106 55 21 -109 50 58 48 0 0 10 23 31 3 143 -27 -111 26 17 -108 13 53 ... .. .. -105 40 27 -108 33 46 47 0 0 10 23 31 4 144 -27 -110 8 39 -106 57 2 ... .. .. -104 24 0 -107 15 19 46 0 0 10 23 32 5 145 -27 -108 49 55 -105 38 48 ... .. .. -103 5 52 -105 55 29 45 0 0 10 23 34 7 146 -27 -107 29 58 -104 18 59 ... .. .. -101 45 52 -104 34 6 44 0 0 10 23 36 8 147 -26 -106 8 38 -102 57 26 ... .. .. -100 23 49 -103 10 59 43 0 0 10 23 38 9 148 -26 -104 45 45 -101 33 57 -107 7 46 - 98 59 29 -101 45 56 42 0 0 10 23 41 11 149 -25 -103 21 8 -100 8 20 -105 43 35 - 97 32 39 -100 18 44 41 0 0 10 23 44 12 150 -25 -101 54 35 - 98 40 20 -104 17 44 - 96 2 59 - 98 49 8 40 0 0 10 23 47 14 151 -24 -100 25 50 - 97 9 38 -102 50 1 - 94 30 10 - 97 16 49 39 0 0 10 23 51 15 152 -24 - 98 54 40 - 95 35 57 -101 20 13 - 92 53 47 - 95 41 26 38 0 0 10 23 56 17 153 -23 - 97 20 44 - 93 58 51 - 99 48 4 - 91 13 19 - 94 2 36 37 0 0 10 24 1 18 155 -22 - 95 43 41 - 92 17 52 - 98 13 16 - 89 28 12 - 92 19 48 36 0 0 10 24 7 20 156 -21 - 94 3 6 - 90 32 26 - 96 35 27 - 87 37 37 - 90 32 26 35 0 0 10 24 13 21 157 -20 - 92 18 28 - 88 41 49 - 94 54 12 - 85 40 35 - 88 39 44 34 0 0 10 24 20 23 159 -19 - 90 29 7 - 86 45 4 - 93 9 1 - 83 35 46 - 86 40 44 33 0 0 10 24 28 24 161 -17 - 88 34 17 - 84 41 0 - 91 19 17 - 81 21 22 - 84 34 8 32 0 0 10 24 37 26 162 -16 - 86 32 54 - 82 27 56 - 89 24 14 - 78 54 40 Latitude Latitude Latitude Latitude - 84 0 0 31 44 30 10 24 40 26 163 -15 30 49 28 32 41 2 29 27 21 34 11 19 - 83 0 0 31 17 58 10 24 44 27 164 -15 30 23 21 32 14 3 29 1 49 33 43 34 - 82 0 0 30 52 20 10 24 49 27 165 -14 29 58 7 31 47 59 28 37 8 33 16 45 - 81 0 0 30 27 36 10 24 54 28 166 -13 29 33 46 31 22 50 28 13 20 32 50 54 - 80 0 0 30 3 47 10 24 59 29 167 -12 29 10 19 30 58 37 27 50 23 32 26 1 - 79 0 0 29 40 52 10 25 3 29 167 -11 28 47 44 30 35 19 27 28 18 32 2 5 - 78 0 0 29 18 51 10 25 8 30 168 -11 28 26 4 30 12 57 27 7 5 31 39 6 - 77 0 0 28 57 45 10 25 13 30 169 -10 28 5 17 29 51 31 26 46 45 31 17 5 - 76 0 0 28 37 34 10 25 18 31 170 -9 27 45 23 29 31 0 26 27 17 30 56 1 - 75 0 0 28 18 17 10 25 23 31 171 -8 27 26 24 29 11 25 26 8 42 30 35 55 - 74 0 0 27 59 55 10 25 29 32 172 -7 27 8 18 28 52 46 25 50 59 30 16 46 - 73 0 0 27 42 28 10 25 34 32 173 -6 26 51 6 28 35 2 25 34 9 29 58 35 - 72 0 0 27 25 56 10 25 39 32 174 -5 26 34 48 28 18 14 25 18 11 29 41 21 - 71 0 0 27 10 18 10 25 44 33 175 -5 26 19 24 28 2 22 25 3 7 29 25 4 - 70 0 0 26 55 35 10 25 50 33 176 -4 26 4 54 27 47 26 24 48 54 29 9 45 - 69 0 0 26 41 47 10 25 55 33 177 -3 25 51 18 27 33 25 24 35 35 28 55 22 - 68 0 0 26 28 53 10 26 0 34 179 -2 25 38 35 27 20 19 24 23 8 28 41 57 - 67 0 0 26 16 55 10 26 6 34 180 -1 25 26 47 27 8 10 24 11 35 28 29 29 - 66 0 0 26 5 51 10 26 11 34 181 0 25 15 52 26 56 56 24 0 54 28 17 58 Uncertainty in time = +/- 4 secs Prediction of 2010 Feb 4.0 Data for the target star ------------------------ * name: 2UCAC 19242050 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 10 01.8815 DE: -30 06 17.426 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .059, .059 ) * V mag [mag]: 13.2 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (63) Ausonia approx. diameter [km]: 103 approx. diameter ["]: .077 distance from Earth [AU]: 1.83800 * orbital information: orbit source: Preston date of fit: 2010 Feb 03 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1431 number of rejected observations: 183 time covered by the observations: 1909 Jan 27 - 2009 May 26 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.008, 86° remarks: * orbital elements for (63) Ausonia : Mean anomaly = 336.83172266 deg Arg. of pericenter = 295.96519563 deg Long. of node = 337.89444944 deg Inclination = 5.78583299 deg Eccentricity = 0.12552052 Semimajor axis = 2.39521338 AU Perihelion dist = 2.09456496 AU Mag: H = 7.44, G = 0.25 Epoch of elements : MJD 55280.43500000 TDT (2010 Mar 25.435) ------ occelmnt file for Occult BEGIN ----------------------------------- 2010 Mar 25 63 Ausonia 10h 26.6m UT 13.2 18 10 1.882-30 6 17.432UCAC 19242050 0.0 11.6 103 5.4 1.838 3.923 -5.71 -66.9319 -30.102 24.85 1.86 10.4440 0.09074 0.81991 10.63994 -1.19302 -0.00541 -0.00006 2000 336.7160652010 325.00000295.965196337.894449 5.7858330.12552052 2.3952134 2.0945650 7.6 5.00.25 RATE 2.6588120 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.060 0.059 90 1.77 0.060 0 055231.0020100325_242050 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2010 Feb 03, 19:21 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org