IOTA/IOTA-ES occultation update for (183) Istria / 2UCAC 23292383 event on 2012 Oct 24, 05:15 UT Visible from Africa, Europe Summary ------- On 2012 Oct 24 UT, the 35 km diameter asteroid (183) Istria will occult a 12.6 mag star in the constellation Lepus for observers along a path across Africa, Europe. In the case of an occultation, the combined light of the asteroid and the star will drop by 0.8 mag to 12.6 mag (the magnitude of the asteroid) for at most 4.4 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: 45 * date and approx. time of event: 2012 Oct 24, 05:05 - 2012 Oct 24, 05:15 UT * geocentric midpoint of event [JD]: 2456224.7194625 * magnitude of target star: 12.6 * magnitude drop [mag]: 0.8 * estimated maximum duration [s]: 4.4 * Moon: 72 % sunlit, 112° distance * Sun: 116° distance * rough path description: Africa, Europe The occultation path -------------------- * approximate projected width [km]: 45 * 1 sigma uncertainty interval [path widths]: +/- 1.43 * 1 sigma uncertainty interval [seconds]: +/- 4.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .058 +/- .042) * 1 sigma uncertainty ellipse (major, minor, PA): ( .060", .038", 68° ) * approx speed of asteroid's shadow [km/s]: 7.8172 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 23292383 by 183 Istria on 2012 Oct 24 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 4 54 57 66 0 0 5 5 37 0 207 -13 4 21 52 5 28 18 ... .. .. ... .. .. 3 45 14 65 0 0 5 5 37 1 206 -13 3 13 56 4 16 46 ... .. .. 5 48 20 2 43 36 64 0 0 5 5 38 2 205 -14 2 13 51 3 13 34 0 49 49 4 40 25 1 48 57 63 0 0 5 5 39 3 204 -14 1 20 34 2 17 30 0 0 21 3 40 13 1 0 21 62 0 0 5 5 40 5 203 -14 0 33 12 1 27 40 - 0 43 38 2 46 42 0 17 4 61 0 0 5 5 42 6 203 -15 - 0 8 59 0 43 16 - 1 22 45 1 59 1 - 0 21 32 60 0 0 5 5 44 7 202 -15 - 0 46 35 0 3 40 - 1 57 35 1 16 27 - 0 55 57 59 0 0 5 5 46 8 202 -16 - 1 20 7 - 0 31 40 - 2 28 35 0 38 26 - 1 26 39 58 0 0 5 5 49 9 201 -16 - 1 49 59 - 1 3 12 - 2 56 9 0 4 28 - 1 54 0 57 0 0 5 5 52 10 201 -16 - 2 16 35 - 1 31 19 - 3 20 39 - 0 25 53 - 2 18 19 56 0 0 5 5 55 11 201 -16 - 2 40 13 - 1 56 20 - 3 42 20 - 0 52 57 - 2 39 54 55 0 0 5 5 59 12 200 -17 - 3 1 9 - 2 18 34 - 4 1 29 - 1 17 3 - 2 58 59 54 0 0 5 6 3 13 200 -17 - 3 19 39 - 2 38 14 - 4 18 19 - 1 38 27 - 3 15 46 53 0 0 5 6 7 14 200 -17 - 3 35 53 - 2 55 35 - 4 33 2 - 1 57 24 - 3 30 28 52 0 0 5 6 12 15 200 -17 - 3 50 4 - 3 10 47 - 4 45 47 - 2 14 5 - 3 43 13 51 0 0 5 6 16 16 200 -17 - 4 2 21 - 3 24 0 - 4 56 45 - 2 28 41 - 3 54 10 50 0 0 5 6 22 17 200 -18 - 4 12 52 - 3 35 24 - 5 6 2 - 2 41 23 - 4 3 28 49 0 0 5 6 27 18 200 -18 - 4 21 46 - 3 45 7 - 5 13 45 - 2 52 17 - 4 11 13 48 0 0 5 6 33 19 200 -18 - 4 29 7 - 3 53 15 - 5 20 2 - 3 1 32 - 4 17 30 47 0 0 5 6 39 20 200 -18 - 4 35 4 - 3 59 54 - 5 24 58 - 3 9 14 - 4 22 27 46 0 0 5 6 45 21 200 -18 - 4 39 40 - 4 5 11 - 5 28 37 - 3 15 29 - 4 26 6 45 0 0 5 6 52 21 200 -18 - 4 43 0 - 4 9 9 - 5 31 5 - 3 20 23 - 4 28 34 44 0 0 5 6 59 22 200 -18 - 4 45 10 - 4 11 54 - 5 32 24 - 3 24 0 - 4 29 52 43 0 0 5 7 6 23 200 -18 - 4 46 12 - 4 13 30 - 5 32 39 - 3 26 23 - 4 30 6 42 0 0 5 7 13 24 200 -18 - 4 46 11 - 4 13 59 - 5 31 54 - 3 27 38 - 4 29 18 41 0 0 5 7 21 25 201 -18 - 4 45 8 - 4 13 26 - 5 30 10 - 3 27 47 - 4 27 31 40 0 0 5 7 29 26 201 -18 - 4 43 7 - 4 11 53 - 5 27 30 - 3 26 54 - 4 24 47 39 0 0 5 7 37 27 201 -18 - 4 40 10 - 4 9 22 - 5 23 57 - 3 25 0 - 4 21 9 38 0 0 5 7 46 28 201 -18 - 4 36 20 - 4 5 56 - 5 19 32 - 3 22 9 - 4 16 39 37 0 0 5 7 54 29 202 -18 - 4 31 38 - 4 1 36 - 5 14 18 - 3 18 23 - 4 11 17 36 0 0 5 8 3 30 202 -18 - 4 26 6 - 3 56 26 - 5 8 16 - 3 13 43 - 4 5 7 35 0 0 5 8 13 31 202 -17 - 4 19 46 - 3 50 25 - 5 1 28 - 3 8 11 - 3 58 9 34 0 0 5 8 22 31 203 -17 - 4 12 38 - 3 43 36 - 4 53 54 - 3 1 49 - 3 50 24 33 0 0 5 8 32 32 203 -17 - 4 4 45 - 3 36 0 - 4 45 36 - 2 54 37 - 3 41 53 32 0 0 5 8 42 33 204 -17 - 3 56 6 - 3 27 38 - 4 36 35 - 2 46 38 - 3 32 38 31 0 0 5 8 52 34 204 -17 - 3 46 44 - 3 18 30 - 4 26 51 - 2 37 52 - 3 22 39 30 0 0 5 9 3 35 205 -16 - 3 36 38 - 3 8 38 - 4 16 25 - 2 28 20 - 3 11 56 29 0 0 5 9 14 36 205 -16 - 3 25 49 - 2 58 1 - 4 5 18 - 2 18 2 - 3 0 30 28 0 0 5 9 25 37 206 -16 - 3 14 17 - 2 46 42 - 3 53 29 - 2 6 59 - 2 48 22 27 0 0 5 9 36 37 206 -15 - 3 2 3 - 2 34 39 - 3 41 0 - 1 55 11 - 2 35 31 26 0 0 5 9 48 38 207 -15 - 2 49 8 - 2 21 53 - 3 27 51 - 1 42 39 - 2 21 58 25 0 0 5 10 0 39 208 -15 - 2 35 30 - 2 8 24 - 3 14 1 - 1 29 23 - 2 7 42 24 0 0 5 10 12 40 208 -14 - 2 21 11 - 1 54 12 - 2 59 30 - 1 15 22 - 1 52 44 23 0 0 5 10 24 40 209 -14 - 2 6 9 - 1 39 17 - 2 44 19 - 1 0 37 - 1 37 4 22 0 0 5 10 36 41 210 -14 - 1 50 25 - 1 23 40 - 2 28 26 - 0 45 8 - 1 20 40 21 0 0 5 10 49 42 211 -13 - 1 33 59 - 1 7 18 - 2 11 53 - 0 28 53 - 1 3 32 20 0 0 5 11 2 43 211 -13 - 1 16 49 - 0 50 12 - 1 54 37 - 0 11 53 - 0 45 40 19 0 0 5 11 15 43 212 -12 - 0 58 56 - 0 32 22 - 1 36 39 0 5 52 - 0 27 4 18 0 0 5 11 29 44 213 -12 - 0 40 18 - 0 13 47 - 1 17 58 0 24 25 - 0 7 41 17 0 0 5 11 42 44 214 -11 - 0 20 55 0 5 35 - 0 58 33 0 43 45 0 12 28 16 0 0 5 11 56 45 215 -11 - 0 0 46 0 25 44 - 0 38 23 1 3 53 0 33 24 15 0 0 5 12 10 46 216 -10 0 20 10 0 46 41 - 0 17 27 1 24 52 0 55 10 14 0 0 5 12 24 46 217 -10 0 41 55 1 8 27 0 4 16 1 46 40 1 17 45 13 0 0 5 12 39 47 218 -9 1 4 30 1 31 4 0 26 47 2 9 21 1 41 13 12 0 0 5 12 54 47 219 -8 1 27 55 1 54 33 0 50 8 2 32 56 2 5 33 11 0 0 5 13 9 48 221 -8 1 52 13 2 18 56 1 14 20 2 57 26 2 30 49 10 0 0 5 13 24 48 222 -7 2 17 26 2 44 14 1 39 25 3 22 53 2 57 2 9 0 0 5 13 39 49 223 -6 2 43 36 3 10 31 2 5 25 3 49 19 3 24 14 8 0 0 5 13 55 49 224 -6 3 10 44 3 37 47 2 32 22 4 16 47 3 52 27 7 0 0 5 14 10 49 226 -5 3 38 53 4 6 5 3 0 18 4 45 19 4 21 45 6 0 0 5 14 26 50 227 -4 4 8 5 4 35 28 3 29 16 5 14 58 4 52 10 5 0 0 5 14 42 50 228 -3 4 38 24 5 5 59 3 59 19 5 45 47 5 23 45 4 0 0 5 14 59 50 230 -3 5 9 52 5 37 40 4 30 29 6 17 49 5 56 33 3 0 0 5 15 15 50 231 -2 5 42 33 6 10 36 5 2 49 6 51 7 6 30 39 2 0 0 5 15 32 50 233 -1 6 16 31 6 44 51 5 36 24 7 25 46 7 6 7 1 0 0 5 15 49 50 234 0 6 51 49 7 20 28 6 11 17 8 1 51 Uncertainty in time = +/- 6 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: 2UCAC 23292383 * constellation : Lepus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 05 41 06.0968 DE: -21 13 21.848 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .026, .035 ) * V mag [mag]: 12.6 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (183) Istria approx. diameter [km]: 35 approx. diameter ["]: .042 distance from Earth [AU]: 1.14800 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 988 number of rejected observations: 42 time covered by the observations: 1906 Feb 22 - 2012 Oct 03 1 sigma uncertainty ellipse (major, minor, PA): 0.055, 0.017, 63° remarks: * orbital elements for (183) Istria : Mean anomaly = 3.65534051 deg Arg. of pericenter = 264.27870295 deg Long. of node = 141.97105647 deg Inclination = 26.38675189 deg Eccentricity = 0.35173049 Semimajor axis = 2.79116404 AU Perihelion dist = 1.80942653 AU Mag: H = 9.49, G = 0.15 Epoch of elements : MJD 56224.21900000 TDT (2012 Oct 24.219) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 24 183 Istria 5h 16.0m UT 12.6 5 41 6.097-21 13 21.852UCAC 23292383 0.0 12.6 35 4.4 1.148 1.147 -29.72 -26.7485 -21.214 97.04 -11.89 5.2671 0.56134 0.30396 2.09799 -3.88153 -0.00412 0.00198 2000 2.76360720121020.00000264.278703141.971056 26.3867520.35173049 2.7911640 1.8094265 9.7 5.00.15 RATE 2.1136150 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.060 0.038 68 2.43 0.060 0 0-2 2 056208.0020121024_292383 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 19:19 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org