IOTA/IOTA-ES occultation update for (1447) Utra / TYC 6870-00570-1 event on 2012 Sep 10, 00:37 UT Visible from SE Canada, E USA Summary ------- On 2012 Sep 10 UT, the 12 km diameter asteroid (1447) Utra will occult a 9.9 mag star in the constellation Sagittarius for observers along a path across SE Canada, E USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.1 mag to 16.0 mag (the magnitude of the asteroid) for at most 1.7 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: 13 * date and approx. time of event: 2012 Sep 10, 00:37 - 2012 Sep 10, 00:46 UT * geocentric midpoint of event [JD]: 2456180.5263 * magnitude of target star: 9.9 * magnitude drop [mag]: 6.1 * estimated maximum duration [s]: 1.7 * Moon: 36 % sunlit, 171° distance * Sun: 111° distance * rough path description: SE Canada, E USA The occultation path -------------------- * approximate projected width [km]: 21 * 1 sigma uncertainty interval [path widths]: +/- 4.99 * 1 sigma uncertainty interval [seconds]: +/- 8.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .044 +/- .039) * 1 sigma uncertainty ellipse (major, minor, PA): ( .044", .039", 89° ) * approx speed of asteroid's shadow [km/s]: 6.9587 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6870-00570-1 by 1447 Utra on 2012 Sep 10 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 - 55 31 58 58 0 0 0 46 26 0 202 -18 - 55 20 34 - 55 43 23 ... .. .. - 57 38 23 - 56 19 42 57 0 0 0 46 26 1 202 -19 - 56 8 32 - 56 30 52 ... .. .. - 58 23 27 - 57 8 6 56 0 0 0 46 25 3 201 -19 - 56 57 10 - 57 19 3 ... .. .. - 59 9 24 - 57 57 11 55 0 0 0 46 23 4 200 -19 - 57 46 27 - 58 7 56 ... .. .. - 59 56 16 - 58 47 0 54 0 0 0 46 21 5 200 -20 - 58 36 27 - 58 57 33 ... .. .. - 60 44 2 - 59 37 32 53 0 0 0 46 18 6 199 -20 - 59 27 9 - 59 47 55 ... .. .. - 61 32 43 - 60 28 50 52 0 0 0 46 15 7 198 -20 - 60 18 36 - 60 39 4 - 58 37 31 - 62 22 21 - 61 20 55 51 0 0 0 46 11 8 198 -20 - 61 10 50 - 61 31 2 - 59 31 7 - 63 12 56 - 62 13 51 50 0 0 0 46 6 9 197 -20 - 62 3 53 - 62 23 50 - 60 25 25 - 64 4 32 - 63 7 39 49 0 0 0 46 0 10 196 -20 - 62 57 47 - 63 17 31 - 61 20 25 - 64 57 9 - 64 2 22 48 0 0 0 45 54 12 195 -21 - 63 52 36 - 64 12 9 - 62 16 12 - 65 50 51 - 64 58 3 47 0 0 0 45 47 13 195 -21 - 64 48 23 - 65 7 45 - 63 12 49 - 66 45 41 - 65 54 47 46 0 0 0 45 39 14 194 -20 - 65 45 10 - 66 4 25 - 64 10 18 - 67 41 42 - 66 52 36 45 0 0 0 45 31 15 193 -20 - 66 43 3 - 67 2 11 - 65 8 45 - 68 38 58 - 67 51 36 44 0 0 0 45 22 16 192 -20 - 67 42 5 - 68 1 8 - 66 8 13 - 69 37 34 - 68 51 51 43 0 0 0 45 11 17 191 -20 - 68 42 21 - 69 1 21 - 67 8 48 - 70 37 34 - 69 53 26 42 0 0 0 45 1 18 190 -20 - 69 43 57 - 70 2 56 - 68 10 34 - 71 39 5 - 70 56 27 41 0 0 0 44 49 19 189 -19 - 70 46 58 - 71 5 58 - 69 13 36 - 72 42 13 - 72 1 3 40 0 0 0 44 36 21 188 -19 - 71 51 33 - 72 10 34 - 70 18 2 - 73 47 5 - 73 7 19 39 0 0 0 44 22 22 187 -19 - 72 57 47 - 73 16 53 - 71 23 59 - 74 53 51 - 74 15 26 38 0 0 0 44 8 23 186 -18 - 74 5 51 - 74 25 3 - 72 31 35 - 76 2 41 - 75 25 33 37 0 0 0 43 52 24 185 -18 - 75 15 53 - 75 35 15 - 73 40 58 - 77 13 45 - 76 37 53 36 0 0 0 43 36 25 184 -17 - 76 28 7 - 76 47 41 - 74 52 19 - 78 27 18 - 77 52 38 35 0 0 0 43 18 26 183 -16 - 77 42 45 - 78 2 33 - 76 5 50 - 79 43 34 - 79 10 5 34 0 0 0 42 59 27 181 -15 - 79 0 2 - 79 20 9 - 77 21 46 - 81 2 54 - 80 30 32 33 0 0 0 42 39 28 180 -15 - 80 20 19 - 80 40 48 - 78 40 21 - 82 25 39 - 81 54 23 32 0 0 0 42 17 29 179 -14 - 81 43 56 - 82 4 53 - 80 1 56 - 83 52 18 - 83 22 6 31 0 0 0 41 54 30 177 -13 - 83 11 22 - 83 32 53 - 81 26 52 - 85 23 25 - 84 54 14 30 0 0 0 41 29 31 175 -11 - 84 43 10 - 85 5 21 - 82 55 39 - 86 59 44 - 86 31 30 29 0 0 0 41 3 32 173 -10 - 86 20 2 - 86 43 3 - 84 28 50 - 88 42 10 - 88 14 52 28 0 0 0 40 34 32 171 -9 - 88 2 53 - 88 26 56 - 86 7 9 - 90 32 1 - 90 5 35 27 0 0 0 40 3 33 169 -7 - 89 52 57 - 90 18 19 - 87 51 33 - 92 31 2 - 92 5 23 26 0 0 0 39 30 34 167 -6 - 91 51 54 - 92 18 58 - 89 43 15 - 94 41 50 - 94 16 49 25 0 0 0 38 53 34 164 -4 - 94 2 13 - 94 31 34 - 91 44 1 - 97 8 31 Latitude Latitude Latitude Latitude - 96 0 0 24 17 8 0 38 24 34 162 -2 24 10 52 24 23 24 23 9 21 25 27 4 - 97 0 0 23 53 53 0 38 7 34 161 -1 23 47 41 24 0 7 22 46 38 25 3 17 - 98 0 0 23 31 54 0 37 50 34 160 0 23 25 44 23 38 4 22 25 7 24 40 45 Uncertainty in time = +/- 10 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 6870-00570-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 37 39.0812 DE: -29 07 40.453 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .024, .033 ) * V mag [mag]: 9.9 * B mag [mag]: 11.2 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1447) Utra approx. diameter [km]: 12 approx. diameter ["]: .008 distance from Earth [AU]: 2.10400 * orbital information: orbit source: Preston date of fit: 2012 Aug 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1176 number of rejected observations: 37 time covered by the observations: 1938 Jan 26 - 2012 Aug 07 1 sigma uncertainty ellipse (major, minor, PA): 0.037, 0.022, 89° remarks: * orbital elements for (1447) Utra : Mean anomaly = 199.44795802 deg Arg. of pericenter = 65.75357218 deg Long. of node = 35.60663014 deg Inclination = 4.78664281 deg Eccentricity = 0.04102216 Semimajor axis = 2.53478985 AU Perihelion dist = 2.43080729 AU Mag: H = 11.70, G = 0.15 Epoch of elements : MJD 56180.02600000 TDT (2012 Sep 10.026) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 10 1447 Utra 0h 37.9m UT 9.9 18 37 39.081-29 7 40.45TYC 6870-00570-1 11.2 16.0 12 1.7 2.104 1.172 5.85 -79.5136 -29.129 169.78 4.85 0.6312 -0.29198 0.77026 3.66977 1.39979 0.00522 0.00055 2000 196.9993522012 831.00000 65.753572 35.606630 4.7866430.04102216 2.5347899 2.430807311.3 5.00.15 RATE 2.4422560 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.044 0.039 89 5.99 0.039 0 0 2-3 056165.0020120910_0570-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 25, 22:37 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org