IOTA/IOTA-ES occultation update for (1255) Schilowa / TYC 1351-00520-1 event on 2012 Oct 07, 06:50 UT Visible from Brazil, Peru Summary ------- On 2012 Oct 07 UT, the 37 km diameter asteroid (1255) Schilowa will occult a 8.7 mag star in the constellation Gemini for observers along a path across Brazil, Peru. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.1 mag to 15.8 mag (the magnitude of the asteroid) for at most 2.0 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 44 * date and approx. time of event: 2012 Oct 07, 06:45 - 2012 Oct 07, 06:50 UT * geocentric midpoint of event [JD]: 2456207.78488333 * magnitude of target star: 8.7 * magnitude drop [mag]: 7.1 * estimated maximum duration [s]: 2.0 * Moon: 59 % sunlit, 16° distance * Sun: 85° distance * rough path description: Brazil, Peru The occultation path -------------------- * approximate projected width [km]: 44 * 1 sigma uncertainty interval [path widths]: +/- 1.50 * 1 sigma uncertainty interval [seconds]: +/- 3.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .032 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .032", .027", 98° ) * approx speed of asteroid's shadow [km/s]: 18.1926 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1351-00520-1 by 1255 Schilowa on 2012 Oct 7 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 - 93 0 0 -11 1 56 6 45 21 1 72 -70 -11 14 26 -10 49 28 -11 52 7 .. .. .. - 92 0 0 -10 43 35 6 45 21 2 72 -70 -10 56 4 -10 31 9 -11 33 39 .. .. .. - 91 0 0 -10 25 45 6 45 22 3 72 -69 -10 38 12 -10 13 21 -11 15 42 .. .. .. - 90 0 0 -10 8 27 6 45 22 4 72 -69 -10 20 52 - 9 56 4 -10 58 17 .. .. .. - 89 0 0 - 9 51 40 6 45 23 5 71 -68 -10 4 3 - 9 39 19 -10 41 23 - 9 2 25 - 88 0 0 - 9 35 25 6 45 23 6 71 -68 - 9 47 46 - 9 23 5 -10 25 1 - 8 46 17 - 87 0 0 - 9 19 41 6 45 24 7 71 -67 - 9 32 1 - 9 7 23 -10 9 11 - 8 30 40 - 86 0 0 - 9 4 31 6 45 25 8 71 -66 - 9 16 49 - 8 52 14 - 9 53 54 - 8 15 35 - 85 0 0 - 8 49 52 6 45 26 9 71 -66 - 9 2 9 - 8 37 37 - 9 39 10 - 8 1 2 - 84 0 0 - 8 35 46 6 45 27 10 71 -65 - 8 48 2 - 8 23 33 - 9 24 58 - 7 47 2 - 83 0 0 - 8 22 14 6 45 29 11 70 -64 - 8 34 28 - 8 10 2 - 9 11 20 - 7 33 35 - 82 0 0 - 8 9 14 6 45 30 12 70 -64 - 8 21 26 - 7 57 3 - 8 58 15 - 7 20 41 - 81 0 0 - 7 56 47 6 45 32 13 70 -63 - 8 8 59 - 7 44 38 - 8 45 43 - 7 8 19 - 80 0 0 - 7 44 54 6 45 34 14 70 -62 - 7 57 4 - 7 32 46 - 8 33 45 - 6 56 31 - 79 0 0 - 7 33 35 6 45 35 15 70 -61 - 7 45 44 - 7 21 28 - 8 22 21 - 6 45 16 - 78 0 0 - 7 22 49 6 45 37 16 69 -61 - 7 34 57 - 7 10 43 - 8 11 30 - 6 34 35 - 77 0 0 - 7 12 37 6 45 40 17 69 -60 - 7 24 44 - 7 0 32 - 8 1 14 - 6 24 27 - 76 0 0 - 7 3 0 6 45 42 18 69 -59 - 7 15 5 - 6 50 55 - 7 51 33 - 6 14 53 - 75 0 0 - 6 53 56 6 45 44 19 69 -58 - 7 6 1 - 6 41 53 - 7 42 25 - 6 5 53 - 74 0 0 - 6 45 26 6 45 47 20 69 -57 - 6 57 30 - 6 33 24 - 7 33 52 - 5 57 27 - 73 0 0 - 6 37 31 6 45 49 21 68 -56 - 6 49 34 - 6 25 30 - 7 25 54 - 5 49 35 - 72 0 0 - 6 30 11 6 45 52 22 68 -55 - 6 42 13 - 6 18 10 - 7 18 30 - 5 42 17 - 71 0 0 - 6 23 24 6 45 55 23 68 -54 - 6 35 26 - 6 11 24 - 7 11 41 - 5 35 34 - 70 0 0 - 6 17 13 6 45 58 24 68 -54 - 6 29 14 - 6 5 14 - 7 5 27 - 5 29 25 - 69 0 0 - 6 11 36 6 46 1 25 68 -53 - 6 23 37 - 5 59 37 - 6 59 48 - 5 23 50 - 68 0 0 - 6 6 34 6 46 4 26 67 -52 - 6 18 34 - 5 54 36 - 6 54 44 - 5 18 50 - 67 0 0 - 6 2 7 6 46 7 27 67 -51 - 6 14 7 - 5 50 9 - 6 50 16 - 5 14 25 - 66 0 0 - 5 58 15 6 46 10 28 67 -50 - 6 10 15 - 5 46 18 - 6 46 22 - 5 10 35 - 65 0 0 - 5 54 58 6 46 14 29 66 -49 - 6 6 57 - 5 43 1 - 6 43 4 - 5 7 19 - 64 0 0 - 5 52 17 6 46 17 30 66 -48 - 6 4 15 - 5 40 20 - 6 40 21 - 5 4 38 - 63 0 0 - 5 50 10 6 46 21 31 66 -47 - 6 2 8 - 5 38 13 - 6 38 14 - 5 2 32 - 62 0 0 - 5 48 39 6 46 25 31 66 -46 - 6 0 37 - 5 36 42 - 6 36 42 - 5 1 1 - 61 0 0 - 5 47 42 6 46 29 32 65 -45 - 5 59 41 - 5 35 46 - 6 35 46 - 5 0 5 - 60 0 0 - 5 47 22 6 46 33 33 65 -44 - 5 59 20 - 5 35 25 - 6 35 25 - 4 59 44 - 59 0 0 - 5 47 36 6 46 37 34 64 -43 - 5 59 35 - 5 35 39 - 6 35 40 - 4 59 58 - 58 0 0 - 5 48 26 6 46 41 35 64 -42 - 6 0 25 - 5 36 29 - 6 36 31 - 5 0 47 - 57 0 0 - 5 49 52 6 46 45 36 64 -41 - 6 1 51 - 5 37 54 - 6 37 57 - 5 2 12 - 56 0 0 - 5 51 53 6 46 50 37 63 -40 - 6 3 52 - 5 39 55 - 6 40 0 - 5 4 12 - 55 0 0 - 5 54 29 6 46 54 38 63 -39 - 6 6 29 - 5 42 31 - 6 42 38 - 5 6 47 - 54 0 0 - 5 57 41 6 46 59 39 62 -38 - 6 9 41 - 5 45 43 - 6 45 51 - 5 9 57 - 53 0 0 - 6 1 29 6 47 4 40 62 -37 - 6 13 29 - 5 49 30 - 6 49 41 - 5 13 43 - 52 0 0 - 6 5 52 6 47 8 40 61 -36 - 6 17 53 - 5 53 53 - 6 54 7 - 5 18 4 - 51 0 0 - 6 10 51 6 47 13 41 60 -35 - 6 22 53 - 5 58 51 - 6 59 8 - 5 23 0 - 50 0 0 - 6 16 25 6 47 18 42 60 -34 - 6 28 28 - 6 4 25 - 7 4 45 - 5 28 32 - 49 0 0 - 6 22 35 6 47 23 43 59 -33 - 6 34 39 - 6 10 34 - 7 10 58 - 5 34 39 - 48 0 0 - 6 29 21 6 47 28 44 58 -32 - 6 41 25 - 6 17 19 - 7 17 48 - 5 41 21 - 47 0 0 - 6 36 42 6 47 33 45 58 -31 - 6 48 47 - 6 24 39 - 7 25 12 - 5 48 39 - 46 0 0 - 6 44 39 6 47 39 45 57 -30 - 6 56 45 - 6 32 35 - 7 33 13 - 5 56 32 - 45 0 0 - 6 53 12 6 47 44 46 56 -29 - 7 5 19 - 6 41 6 - 7 41 50 - 6 5 0 - 44 0 0 - 7 2 20 6 47 49 47 55 -28 - 7 14 28 - 6 50 13 - 7 51 2 - 6 14 4 - 43 0 0 - 7 12 3 6 47 55 48 54 -27 - 7 24 12 - 6 59 56 - 8 0 50 - 6 23 43 - 42 0 0 - 7 22 22 6 48 1 48 53 -26 - 7 34 33 - 7 10 13 - 8 11 14 - 6 33 57 - 41 0 0 - 7 33 16 6 48 6 49 52 -25 - 7 45 28 - 7 21 6 - 8 22 14 - 6 44 46 - 40 0 0 - 7 44 46 6 48 12 50 51 -24 - 7 56 59 - 7 32 35 - 8 33 49 - 6 56 10 - 39 0 0 - 7 56 51 6 48 18 50 50 -23 - 8 9 5 - 7 44 38 - 8 46 0 - 7 8 10 - 38 0 0 - 8 9 31 6 48 23 51 49 -22 - 8 21 47 - 7 57 17 - 8 58 46 - 7 20 44 - 37 0 0 - 8 22 46 6 48 29 52 48 -21 - 8 35 4 - 8 10 30 - 9 12 7 - 7 33 53 - 36 0 0 - 8 36 36 6 48 35 52 47 -20 - 8 48 55 - 8 24 19 - 9 26 3 - 7 47 37 - 35 0 0 - 8 51 1 6 48 41 53 45 -19 - 9 3 22 - 8 38 42 - 9 40 35 - 8 1 55 - 34 0 0 - 9 6 1 6 48 47 53 44 -17 - 9 18 23 - 8 53 40 - 9 55 42 - 8 16 48 - 33 0 0 - 9 21 35 6 48 54 54 43 -16 - 9 33 59 - 9 9 12 -10 11 23 - 8 32 15 - 32 0 0 - 9 37 44 6 49 0 54 41 -15 - 9 50 10 - 9 25 19 -10 27 39 - 8 48 17 - 31 0 0 - 9 54 26 6 49 6 55 40 -14 -10 6 54 - 9 42 0 -10 44 29 - 9 4 52 - 30 0 0 -10 11 43 6 49 12 55 38 -13 -10 24 13 - 9 59 15 -11 1 54 - 9 22 2 - 29 0 0 -10 29 34 6 49 18 55 36 -12 -10 42 6 -10 17 4 -11 19 53 - 9 39 45 - 28 0 0 -10 47 58 6 49 25 56 35 -11 -11 0 32 -10 35 26 -11 38 25 - 9 58 1 - 27 0 0 -11 6 56 6 49 31 56 33 -10 -11 19 32 -10 54 22 -11 57 31 -10 16 50 - 26 0 0 -11 26 26 6 49 38 56 31 -9 -11 39 5 -11 13 50 -12 17 10 -10 36 13 - 25 0 0 -11 46 30 6 49 44 57 30 -8 -11 59 10 -11 33 52 -12 37 23 -10 56 8 - 24 0 0 -12 7 6 6 49 51 57 28 -7 -12 19 48 -11 54 25 -12 58 7 -11 16 35 - 23 0 0 -12 28 14 6 49 57 57 26 -6 -12 40 58 -12 15 31 -13 19 24 -11 37 34 - 22 0 0 -12 49 54 6 50 4 57 24 -5 -13 2 40 -12 37 9 -13 41 13 -11 59 5 - 21 0 0 -13 12 5 6 50 10 57 22 -4 -13 24 54 -12 59 17 -14 3 34 -12 21 7 - 20 0 0 -13 34 47 6 50 17 57 20 -3 -13 47 38 -13 21 57 -14 26 25 -12 43 40 - 19 0 0 -13 58 0 6 50 23 57 19 -2 -14 10 54 -13 45 8 -14 49 48 -13 6 43 - 18 0 0 -14 21 42 6 50 30 57 17 -1 -14 34 39 -14 8 48 -15 13 40 -13 30 17 Uncertainty in time = +/- 4 secs Prediction of 2012 Jul 10.0 Data for the target star ------------------------ * name: TYC 1351-00520-1 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 20 36.3785 DE: +17 26 28.932 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .023 ) * V mag [mag]: 8.7 * B mag [mag]: 8.7 * Apparent position with proper motion RA(deg): 110.3396202306 DE(deg): 17.4156102052 * Equation of equinoxes (radians) : 0.000062343403187 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1255) Schilowa approx. diameter [km]: 37 approx. diameter ["]: .018 distance from Earth [AU]: 2.85800 * orbital information: orbit source: Preston date of fit: 2012 Jul 09 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1266 number of rejected observations: 38 time covered by the observations: 1905 Oct 24 - 2012 Feb 02 1 sigma uncertainty ellipse (major, minor, PA): 0.024, 0.014, 104° remarks: * orbital elements for (1255) Schilowa : Mean anomaly = 58.83342961 deg Arg. of pericenter = 134.47518477 deg Long. of node = 237.65963782 deg Inclination = 8.54890463 deg Eccentricity = 0.17302959 Semimajor axis = 3.14779631 AU Perihelion dist = 2.60313440 AU Mag: H = 10.30, G = 0.15 Epoch of elements : MJD 56207.28500000 TDT (2012 Oct 07.285) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 7 1255 Schilowa 6h 50.2m UT 8.7 7 20 36.378 17 26 28.93TYC 1351-00520-1 8.7 15.8 37 2.0 2.858 2.058 -11.41 -8.7322 17.444 74.39 -5.68 6.8372 -0.19998 -0.50504 9.57588 -3.70712 -0.00572 0.00075 2000 57.5477772012 930.00000134.475185237.659638 8.5489050.17302959 3.1477963 2.603134410.2 5.00.15 RATE 1.7647950 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.032 0.027 98 2.50 0.027 0 0 5 2 056118.0020121007_0520-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 26, 01:55 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org