IOTA/IOTA-ES occultation update for (94) Aurora / TYC 7409-01081-1 event on 2012 Sep 24, 15:42 UT Visible from SW Asia, Arabia Summary ------- On 2012 Sep 24 UT, the 218 km diameter asteroid (94) Aurora will occult a 12.2 mag star in the constellation Sagittarius for observers along a path across SW Asia, Arabia. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.5 mag to 13.4 mag (the magnitude of the asteroid) for at most 21.0 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: 99 * date and approx. time of event: 2012 Sep 24, 15:44 - 2012 Sep 24, 15:50 UT * geocentric midpoint of event [JD]: 2456195.15467083 * magnitude of target star: 12.2 * magnitude drop [mag]: 1.5 * estimated maximum duration [s]: 21.0 * Moon: 69 % sunlit, 16° distance * Sun: 102° distance * rough path description: SW Asia, Arabia The occultation path -------------------- * approximate projected width [km]: 303 * 1 sigma uncertainty interval [path widths]: +/- 0.28 * 1 sigma uncertainty interval [seconds]: +/- 5.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .031 +/- .028) * 1 sigma uncertainty ellipse (major, minor, PA): ( .031", .028", 89° ) * approx speed of asteroid's shadow [km/s]: 10.3847 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 7409-01081-1 by 94 Aurora on 2012 Sep 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 71 25 5 56 0 0 15 50 2 1 203 -22 ... .. .. 68 47 30 ... .. .. 67 18 24 70 38 47 55 0 0 15 50 2 2 202 -22 73 11 15 68 4 42 74 36 5 66 37 34 69 52 46 54 0 0 15 50 1 3 202 -23 72 21 57 67 21 57 73 44 54 65 56 39 69 7 0 53 0 0 15 50 0 4 201 -23 71 33 6 66 39 14 72 54 20 65 15 38 68 21 24 52 0 0 15 49 59 5 201 -23 70 44 39 65 56 29 72 4 16 64 34 27 67 35 57 51 0 0 15 49 58 6 200 -23 69 56 32 65 13 40 71 14 38 63 53 7 66 50 35 50 0 0 15 49 56 7 199 -23 69 8 41 64 30 45 70 25 23 63 11 35 66 5 16 49 0 0 15 49 54 8 199 -23 68 21 3 63 47 43 69 36 26 62 29 48 65 19 56 48 0 0 15 49 51 9 198 -23 67 33 34 63 4 30 68 47 44 61 47 47 64 34 33 47 0 0 15 49 48 10 198 -23 66 46 12 62 21 6 67 59 14 61 5 28 63 49 5 46 0 0 15 49 45 12 197 -23 65 58 52 61 37 27 67 10 51 60 22 50 63 3 29 45 0 0 15 49 41 13 196 -23 65 11 33 60 53 33 66 22 33 59 39 51 62 17 43 44 0 0 15 49 38 14 196 -23 64 24 12 60 9 20 65 34 18 58 56 30 61 31 45 43 0 0 15 49 33 15 195 -23 63 36 46 59 24 48 64 46 1 58 12 45 60 45 31 42 0 0 15 49 29 16 195 -23 62 49 11 58 39 53 63 57 41 57 28 33 59 59 1 41 0 0 15 49 24 17 194 -22 62 1 27 57 54 33 63 9 14 56 43 53 59 12 10 40 0 0 15 49 19 18 193 -22 61 13 30 57 8 48 62 20 38 55 58 42 58 24 58 39 0 0 15 49 13 19 193 -22 60 25 17 56 22 33 61 31 50 55 12 59 57 37 21 38 0 0 15 49 7 21 192 -21 59 36 46 55 35 47 60 42 47 54 26 40 56 49 17 37 0 0 15 49 1 22 191 -21 58 47 54 54 48 28 59 53 27 53 39 44 56 0 43 36 0 0 15 48 54 23 191 -21 57 58 38 54 0 32 59 3 47 52 52 8 55 11 36 35 0 0 15 48 47 24 190 -20 57 8 56 53 11 57 58 13 43 52 3 49 54 21 54 34 0 0 15 48 39 25 189 -20 56 18 44 52 22 41 57 23 14 51 14 45 53 31 34 33 0 0 15 48 31 26 188 -19 55 28 0 51 32 39 56 32 15 50 24 51 52 40 31 32 0 0 15 48 23 27 188 -19 54 36 41 50 41 49 55 40 44 49 34 6 51 48 44 31 0 0 15 48 14 28 187 -18 53 44 43 49 50 7 54 48 38 48 42 24 50 56 8 30 0 0 15 48 5 29 186 -18 52 52 3 48 57 29 53 55 54 47 49 43 50 2 39 29 0 0 15 47 56 30 185 -17 51 58 37 48 3 52 53 2 26 46 55 57 49 8 14 28 0 0 15 47 46 31 184 -16 51 4 21 47 9 10 52 8 13 46 1 3 48 12 48 27 0 0 15 47 36 32 183 -16 50 9 11 46 13 19 51 13 9 45 4 55 47 16 15 26 0 0 15 47 25 34 182 -15 49 13 3 45 16 14 50 17 11 44 7 27 46 18 32 25 0 0 15 47 14 35 181 -14 48 15 51 44 17 49 49 20 14 43 8 33 45 19 31 24 0 0 15 47 2 36 180 -13 47 17 31 43 17 57 48 22 13 42 8 7 44 19 7 23 0 0 15 46 50 37 179 -12 46 17 57 42 16 31 47 23 2 41 6 0 43 17 12 22 0 0 15 46 37 38 178 -11 45 17 2 41 13 23 46 22 36 40 2 4 42 13 39 21 0 0 15 46 24 38 177 -10 44 14 40 40 8 24 45 20 47 38 56 9 41 8 19 20 0 0 15 46 10 39 175 -9 43 10 42 39 1 24 44 17 30 37 48 4 40 1 2 19 0 0 15 45 56 40 174 -8 42 5 1 37 52 11 43 12 35 36 37 35 38 51 37 18 0 0 15 45 41 41 172 -7 40 57 26 36 40 32 42 5 54 35 24 28 37 39 50 17 0 0 15 45 26 42 171 -6 39 47 47 35 26 10 40 57 17 34 8 26 36 25 27 16 0 0 15 45 10 43 169 -5 38 35 51 34 8 48 39 46 32 32 49 6 35 8 10 15 0 0 15 44 53 43 168 -3 37 21 24 32 48 4 38 33 26 31 26 5 33 47 38 14 0 0 15 44 36 44 166 -2 36 4 8 31 23 32 37 17 45 29 58 51 32 23 28 13 0 0 15 44 17 45 164 -1 34 43 45 29 54 38 35 59 10 28 26 47 Uncertainty in time = +/- 6 secs Prediction of 2012 Sep 8.0 Data for the target star ------------------------ * name: TYC 7409-01081-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 02 03.0372 DE: -30 35 05.816 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .029, .027 ) * V mag [mag]: 12.2 * B mag [mag]: 12.2 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (94) Aurora approx. diameter [km]: 218 approx. diameter ["]: .102 distance from Earth [AU]: 2.93900 * orbital information: orbit source: Preston date of fit: 2012 Sep 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1115 number of rejected observations: 97 time covered by the observations: 1901 Oct 14 - 2012 Sep 01 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.007, 82° remarks: * orbital elements for (94) Aurora : Mean anomaly = 246.77867923 deg Arg. of pericenter = 60.23485503 deg Long. of node = 2.66752699 deg Inclination = 7.96460065 deg Eccentricity = 0.08921104 Semimajor axis = 3.15902347 AU Perihelion dist = 2.87720369 AU Mag: H = 7.53, G = 0.15 Epoch of elements : MJD 56194.65500000 TDT (2012 Sep 24.655) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 24 94 Aurora 15h 42.7m UT 12.2 19 2 3.037-30 35 5.82TYC 7409-01081-1 12.2 13.4 218 21.0 2.939 1.164 9.06 45.9533 -30.587 -57.72 -0.80 15.7121 -0.35632 0.59565 5.01916 3.02725 0.00564 0.00076 2000 245.9615432012 920.00000 60.234855 2.667527 7.9646010.08921104 3.1590235 2.8772037 7.6 5.00.15 RATE 1.7553940 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.031 0.028 89 1.28 0.028 0 0 2 4 056178.0020120924_1081-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Sep 07, 23:08 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org