IOTA/IOTA-ES occultation update for (1426) Riviera / TYC 6871-00746-1 event on 2012 Sep 15, 17:11 UT Visible from SW Asia, Arabia, Africa Summary ------- On 2012 Sep 15 UT, the 17 km diameter asteroid (1426) Riviera will occult a 10.0 mag star in the constellation Sagittarius for observers along a path across SW Asia, Arabia, Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.0 mag to 15.0 mag (the magnitude of the asteroid) for at most 1.4 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: 28 * date and approx. time of event: 2012 Sep 15, 17:11 - 2012 Sep 15, 17:19 UT * geocentric midpoint of event [JD]: 2456186.21652083 * magnitude of target star: 10.0 * magnitude drop [mag]: 5.0 * estimated maximum duration [s]: 1.4 * Moon: 0 % sunlit, 112° distance * Sun: 107° distance * rough path description: SW Asia, Arabia, Africa The occultation path -------------------- * approximate projected width [km]: 20 * 1 sigma uncertainty interval [path widths]: +/- 2.36 * 1 sigma uncertainty interval [seconds]: +/- 3.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .035 +/- .030) * 1 sigma uncertainty ellipse (major, minor, PA): ( .035", .030", 85° ) * approx speed of asteroid's shadow [km/s]: 12.3297 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6871-00746-1 by 1426 Riviera on 2012 Sep 15 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 ' " Latitude Latitude Latitude Latitude 11 0 0 - 3 9 21 17 11 6 59 148 0 - 3 15 7 - 3 3 34 - 3 42 17 - 2 36 11 12 0 0 - 2 44 25 17 11 16 59 150 -1 - 2 50 13 - 2 38 37 - 3 17 32 - 2 11 6 13 0 0 - 2 18 34 17 11 26 59 152 -2 - 2 24 25 - 2 12 44 - 2 51 52 - 1 45 4 14 0 0 - 1 51 48 17 11 36 59 154 -3 - 1 57 40 - 1 45 56 - 2 25 17 - 1 18 7 15 0 0 - 1 24 6 17 11 46 60 156 -4 - 1 30 0 - 1 18 11 - 1 57 46 - 0 50 13 16 0 0 - 0 55 28 17 11 57 60 158 -5 - 1 1 24 - 0 49 31 - 1 29 19 - 0 21 23 17 0 0 - 0 25 53 17 12 7 59 160 -6 - 0 31 51 - 0 19 54 - 0 59 57 0 8 24 18 0 0 0 4 38 17 12 18 59 161 -7 - 0 1 23 0 10 38 - 0 29 39 0 39 7 19 0 0 0 36 5 17 12 28 59 163 -8 0 30 2 0 42 8 0 1 36 1 10 47 20 0 0 1 8 28 17 12 39 59 165 -9 1 2 23 1 14 33 0 33 46 1 43 24 21 0 0 1 41 48 17 12 49 59 167 -10 1 35 41 1 47 56 1 6 53 2 16 58 22 0 0 2 16 4 17 13 0 58 169 -11 2 9 54 2 22 14 1 40 55 2 51 28 23 0 0 2 51 17 17 13 10 58 171 -12 2 45 5 2 57 29 2 15 54 3 26 54 24 0 0 3 27 25 17 13 21 57 173 -13 3 21 11 3 33 40 2 51 48 4 3 18 25 0 0 4 4 30 17 13 32 57 175 -14 3 58 12 4 10 47 3 28 38 4 40 37 26 0 0 4 42 30 17 13 42 56 176 -15 4 36 10 4 48 50 4 6 23 5 18 52 27 0 0 5 21 25 17 13 53 56 178 -16 5 15 2 5 27 48 4 45 3 5 58 2 28 0 0 6 1 14 17 14 4 55 180 -17 5 54 49 6 7 40 5 24 38 6 38 8 29 0 0 6 41 58 17 14 14 54 181 -18 6 35 30 6 48 27 6 5 6 7 19 7 30 0 0 7 23 36 17 14 25 54 183 -19 7 17 5 7 30 7 6 46 28 8 1 1 31 0 0 8 6 6 17 14 35 53 184 -20 7 59 33 8 12 40 7 28 42 8 43 47 32 0 0 8 49 28 17 14 46 52 186 -21 8 42 52 8 56 5 8 11 49 9 27 26 33 0 0 9 33 42 17 14 56 51 187 -22 9 27 2 9 40 21 8 55 46 10 11 56 34 0 0 10 18 45 17 15 6 50 188 -23 10 12 3 10 25 28 9 40 33 10 57 16 35 0 0 11 4 37 17 15 17 50 190 -24 10 57 52 11 11 23 10 26 8 11 43 25 36 0 0 11 51 17 17 15 27 49 191 -25 11 44 29 11 58 5 11 12 32 12 30 21 37 0 0 12 38 43 17 15 37 48 192 -26 12 31 52 12 45 34 11 59 41 13 18 4 38 0 0 13 26 54 17 15 47 47 193 -27 13 20 0 13 33 48 12 47 35 14 6 32 39 0 0 14 15 47 17 15 56 46 194 -27 14 8 51 14 22 45 13 36 12 14 55 43 40 0 0 15 5 22 17 16 6 45 195 -28 14 58 23 15 12 23 14 25 31 15 45 35 41 0 0 15 55 37 17 16 16 43 196 -29 15 48 34 16 2 40 15 15 29 16 36 6 42 0 0 16 46 29 17 16 25 42 197 -30 16 39 23 16 53 35 16 6 5 17 27 14 43 0 0 17 37 56 17 16 34 41 198 -31 17 30 48 17 45 5 16 57 16 18 18 58 44 0 0 18 29 56 17 16 43 40 199 -31 18 22 45 18 37 8 17 49 0 19 11 14 45 0 0 19 22 27 17 16 52 39 200 -32 19 15 13 19 29 41 18 41 15 20 4 1 46 0 0 20 15 26 17 17 0 38 201 -33 20 8 9 20 22 43 19 33 59 20 57 16 47 0 0 21 8 50 17 17 9 37 201 -33 21 1 31 21 16 10 20 27 8 21 50 56 48 0 0 22 2 38 17 17 17 35 202 -34 21 55 16 22 10 0 21 20 41 22 44 58 49 0 0 22 56 45 17 17 24 34 203 -35 22 49 21 23 4 10 22 14 34 23 39 21 50 0 0 23 51 10 17 17 32 33 204 -35 23 43 43 23 58 37 23 8 45 24 34 0 51 0 0 24 45 49 17 17 39 32 204 -36 24 38 20 24 53 19 24 3 11 25 28 52 52 0 0 25 40 39 17 17 46 31 205 -36 25 33 8 25 48 11 24 57 48 26 23 56 53 0 0 26 35 37 17 17 53 29 206 -37 26 28 4 26 43 12 25 52 34 27 19 6 54 0 0 27 30 41 17 18 0 28 207 -37 27 23 5 27 38 17 26 47 26 28 14 22 55 0 0 28 25 46 17 18 6 27 207 -37 28 18 8 28 33 24 27 42 20 29 9 38 56 0 0 29 20 50 17 18 12 26 208 -38 29 13 10 29 28 30 28 37 14 30 4 53 57 0 0 30 15 49 17 18 18 25 209 -38 30 8 8 30 23 31 29 32 4 31 0 2 58 0 0 31 10 41 17 18 23 23 209 -38 31 2 58 31 18 24 30 26 47 31 55 3 59 0 0 32 5 22 17 18 28 22 210 -39 31 57 38 32 13 7 31 21 20 32 49 52 60 0 0 32 59 49 17 18 33 21 211 -39 32 52 4 33 7 35 32 15 39 33 44 27 61 0 0 33 53 59 17 18 37 20 211 -39 33 46 13 34 1 46 33 9 43 34 38 44 62 0 0 34 47 49 17 18 41 18 212 -39 34 40 2 34 55 38 34 3 28 35 32 40 63 0 0 35 41 17 17 18 45 17 213 -39 35 33 29 35 49 6 34 56 50 36 26 12 64 0 0 36 34 18 17 18 49 16 213 -39 36 26 30 36 42 8 35 49 48 37 19 18 65 0 0 37 26 52 17 18 52 15 214 -39 37 19 2 37 34 42 36 42 19 38 11 54 66 0 0 38 18 54 17 18 55 14 215 -39 38 11 4 38 26 45 37 34 19 39 3 59 67 0 0 39 10 23 17 18 58 13 215 -39 39 2 33 39 18 14 38 25 47 39 55 29 68 0 0 40 1 16 17 19 0 11 216 -39 39 53 26 40 9 7 39 16 40 40 46 22 69 0 0 40 51 31 17 19 3 10 217 -39 40 43 41 40 59 22 40 6 56 41 36 36 70 0 0 41 41 6 17 19 5 9 217 -39 41 33 17 41 48 57 40 56 32 42 26 10 71 0 0 42 29 59 17 19 6 8 218 -38 42 22 10 42 37 49 41 45 28 43 15 0 72 0 0 43 18 8 17 19 8 7 219 -38 43 10 20 43 25 58 42 33 40 44 3 6 73 0 0 44 5 32 17 19 9 6 219 -38 43 57 44 44 13 21 43 21 8 44 50 25 74 0 0 44 52 9 17 19 10 5 220 -38 44 44 22 44 59 56 44 7 50 45 36 56 75 0 0 45 37 57 17 19 11 4 221 -37 45 30 11 45 45 44 44 53 45 46 22 39 76 0 0 46 22 56 17 19 11 3 222 -37 46 15 12 46 30 42 45 38 51 47 7 31 77 0 0 47 7 5 17 19 12 2 222 -37 46 59 22 47 14 49 46 23 7 47 51 32 78 0 0 47 50 23 17 19 12 1 223 -36 47 42 41 47 58 5 .. .. .. 48 34 41 Uncertainty in time = +/- 4 secs Prediction of 2012 Sep 8.0 Data for the target star ------------------------ * name: TYC 6871-00746-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 46 28.7368 DE: -28 53 20.370 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .024, .027 ) * V mag [mag]: 10.0 * B mag [mag]: 10.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1426) Riviera approx. diameter [km]: 17 approx. diameter ["]: .013 distance from Earth [AU]: 1.79200 * orbital information: orbit source: Preston date of fit: 2012 Sep 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1348 number of rejected observations: 51 time covered by the observations: 1937 Apr 03 - 2012 Sep 01 1 sigma uncertainty ellipse (major, minor, PA): 0.026, 0.014, 80° remarks: * orbital elements for (1426) Riviera : Mean anomaly = 40.57327322 deg Arg. of pericenter = 274.96384135 deg Long. of node = 335.07905037 deg Inclination = 9.06164211 deg Eccentricity = 0.16188020 Semimajor axis = 2.58016966 AU Perihelion dist = 2.16249128 AU Mag: H = 10.85, G = 0.15 Epoch of elements : MJD 56185.71600000 TDT (2012 Sep 15.716) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 15 1426 Riviera 17h 11.8m UT 10.0 18 46 28.737-28 53 20.37TYC 6871-00746-1 10.3 15.0 17 1.4 1.792 2.300 15.96 28.6052 -28.893 -79.20 2.67 17.1965 -0.23692 0.44846 6.15240 3.25245 0.00522 0.00059 2000 39.2139462012 910.00000274.963841335.079050 9.0616420.16188020 2.5801697 2.162491310.8 5.00.15 RATE 2.3781090 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.035 0.030 85 3.36 0.031 0 0-2 0 056178.0020120915_0746-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Sep 07, 22:54 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org