IOTA/IOTA-ES occultation update for (1076) Viola / TYC 1291-01004-1 event on 2012 Sep 28, 21:04 UT Visible from Philippines, SE Asia Summary ------- On 2012 Sep 28 UT, the 26 km diameter asteroid (1076) Viola will occult a 9.4 mag star in the constellation Taurus for observers along a path across Philippines, SE Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.9 mag to 16.3 mag (the magnitude of the asteroid) for at most 2.3 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: 20 * date and approx. time of event: 2012 Sep 28, 20:55 - 2012 Sep 28, 21:06 UT * geocentric midpoint of event [JD]: 2456199.377925 * magnitude of target star: 9.4 * magnitude drop [mag]: 6.9 * estimated maximum duration [s]: 2.3 * Moon: 98 % sunlit, 90° distance * Sun: 106° distance * rough path description: Philippines, SE Asia Additional comments ------------------- 5" double star The occultation path -------------------- * approximate projected width [km]: 26 * 1 sigma uncertainty interval [path widths]: +/- 3.40 * 1 sigma uncertainty interval [seconds]: +/- 5.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .051 +/- .075) * 1 sigma uncertainty ellipse (major, minor, PA): ( .075", .051", 359° ) * approx speed of asteroid's shadow [km/s]: 11.4578 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1291-01004-1 by 1076 Viola on 2012 Sep 28 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 31 0 0 - 7 16 38 20 55 6 0 71 -74 - 7 24 12 - 7 9 3 - 8 15 49 .. .. .. 32 0 0 - 6 56 6 20 55 6 1 71 -75 - 7 3 41 - 6 48 32 - 7 55 16 .. .. .. 33 0 0 - 6 35 39 20 55 7 2 71 -76 - 6 43 13 - 6 28 4 - 7 34 47 - 5 36 41 34 0 0 - 6 15 15 20 55 7 4 71 -77 - 6 22 49 - 6 7 41 - 7 14 22 - 5 16 20 35 0 0 - 5 54 57 20 55 8 5 71 -78 - 6 2 31 - 5 47 23 - 6 54 2 - 4 56 3 36 0 0 - 5 34 44 20 55 9 6 70 -79 - 5 42 17 - 5 27 10 - 6 33 47 - 4 35 51 37 0 0 - 5 14 36 20 55 10 7 70 -80 - 5 22 10 - 5 7 3 - 6 13 38 - 4 15 46 38 0 0 - 4 54 35 20 55 11 8 70 -81 - 5 2 8 - 4 47 2 - 5 53 35 - 3 55 47 39 0 0 - 4 34 41 20 55 13 9 70 -82 - 4 42 14 - 4 27 8 - 5 33 38 - 3 35 54 40 0 0 - 4 14 53 20 55 15 10 70 -82 - 4 22 26 - 4 7 21 - 5 13 49 - 3 16 9 41 0 0 - 3 55 14 20 55 16 11 70 -83 - 4 2 46 - 3 47 42 - 4 54 7 - 2 56 32 42 0 0 - 3 35 42 20 55 18 12 70 -84 - 3 43 14 - 3 28 11 - 4 34 33 - 2 37 3 43 0 0 - 3 16 19 20 55 21 13 70 -84 - 3 23 51 - 3 8 48 - 4 15 7 - 2 17 42 44 0 0 - 2 57 5 20 55 23 14 70 -85 - 3 4 37 - 2 49 34 - 3 55 51 - 1 58 31 45 0 0 - 2 38 1 20 55 26 15 70 -85 - 2 45 32 - 2 30 30 - 3 36 43 - 1 39 29 46 0 0 - 2 19 6 20 55 29 16 70 -85 - 2 26 37 - 2 11 35 - 3 17 46 - 1 20 37 47 0 0 - 2 0 21 20 55 32 17 70 -84 - 2 7 52 - 1 52 51 - 2 58 59 - 1 1 56 48 0 0 - 1 41 48 20 55 35 18 70 -84 - 1 49 18 - 1 34 18 - 2 40 22 - 0 43 25 49 0 0 - 1 23 25 20 55 38 19 70 -83 - 1 30 55 - 1 15 56 - 2 21 56 - 0 25 5 50 0 0 - 1 5 14 20 55 42 20 69 -83 - 1 12 43 - 0 57 45 - 2 3 42 - 0 6 57 51 0 0 - 0 47 15 20 55 46 21 69 -82 - 0 54 44 - 0 39 47 - 1 45 40 0 10 59 52 0 0 - 0 29 28 20 55 49 23 69 -81 - 0 36 57 - 0 22 0 - 1 27 50 0 28 42 53 0 0 - 0 11 54 20 55 54 24 69 -80 - 0 19 22 - 0 4 27 - 1 10 13 0 46 13 54 0 0 0 5 26 20 55 58 25 69 -79 - 0 2 1 0 12 54 - 0 52 49 1 3 30 55 0 0 0 22 34 20 56 2 26 69 -78 0 15 7 0 30 1 - 0 35 38 1 20 34 56 0 0 0 39 27 20 56 7 27 69 -77 0 32 1 0 46 54 - 0 18 41 1 37 24 57 0 0 0 56 6 20 56 12 28 69 -76 0 48 40 1 3 32 - 0 1 59 1 54 0 58 0 0 1 12 31 20 56 17 29 69 -75 1 5 5 1 19 56 0 14 29 2 10 21 59 0 0 1 28 40 20 56 22 30 69 -74 1 21 15 1 36 6 0 30 42 2 26 27 60 0 0 1 44 35 20 56 27 31 69 -73 1 37 10 1 51 59 0 46 40 2 42 18 61 0 0 2 0 14 20 56 33 32 69 -72 1 52 49 2 7 38 1 2 22 2 57 54 62 0 0 2 15 36 20 56 38 33 69 -71 2 8 12 2 23 0 1 17 49 3 13 13 63 0 0 2 30 43 20 56 44 34 69 -70 2 23 19 2 38 6 1 32 59 3 28 16 64 0 0 2 45 33 20 56 50 35 69 -69 2 38 10 2 52 56 1 47 52 3 43 2 65 0 0 3 0 6 20 56 56 36 69 -68 2 52 43 3 7 28 2 2 29 3 57 32 66 0 0 3 14 22 20 57 2 37 69 -67 3 7 0 3 21 44 2 16 49 4 11 44 67 0 0 3 28 21 20 57 8 38 69 -66 3 20 59 3 35 42 2 30 51 4 25 40 68 0 0 3 42 2 20 57 15 39 69 -65 3 34 40 3 49 23 2 44 35 4 39 17 69 0 0 3 55 25 20 57 22 40 69 -64 3 48 4 4 2 45 2 58 2 4 52 37 70 0 0 4 8 29 20 57 28 41 68 -63 4 1 9 4 15 50 3 11 10 5 5 38 71 0 0 4 21 16 20 57 35 42 68 -62 4 13 56 4 28 36 3 24 0 5 18 21 72 0 0 4 33 43 20 57 42 43 68 -61 4 26 24 4 41 3 3 36 31 5 30 45 73 0 0 4 45 52 20 57 49 44 68 -60 4 38 33 4 53 11 3 48 43 5 42 51 74 0 0 4 57 42 20 57 57 45 68 -59 4 50 23 5 5 0 4 0 36 5 54 37 75 0 0 5 9 12 20 58 4 46 68 -58 5 1 54 5 16 30 4 12 10 6 6 4 76 0 0 5 20 23 20 58 12 48 68 -57 5 13 5 5 27 41 4 23 24 6 17 12 77 0 0 5 31 14 20 58 19 49 68 -56 5 23 57 5 38 31 4 34 18 6 28 0 78 0 0 5 41 45 20 58 27 50 67 -55 5 34 28 5 49 2 4 44 52 6 38 28 79 0 0 5 51 57 20 58 35 51 67 -54 5 44 40 5 59 13 4 55 6 6 48 36 80 0 0 6 1 47 20 58 43 52 67 -53 5 54 31 6 9 3 5 5 0 6 58 24 81 0 0 6 11 18 20 58 51 53 67 -52 6 4 2 6 18 33 5 14 33 7 7 52 82 0 0 6 20 28 20 58 59 54 67 -51 6 13 12 6 27 43 5 23 46 7 16 59 83 0 0 6 29 17 20 59 8 55 66 -50 6 22 1 6 36 32 5 32 37 7 25 45 84 0 0 6 37 45 20 59 16 56 66 -49 6 30 30 6 44 59 5 41 8 7 34 10 85 0 0 6 45 52 20 59 25 57 66 -48 6 38 37 6 53 6 5 49 18 7 42 15 86 0 0 6 53 38 20 59 33 58 65 -47 6 46 24 7 0 52 5 57 6 7 49 59 87 0 0 7 1 3 20 59 42 59 65 -46 6 53 49 7 8 16 6 4 33 7 57 21 88 0 0 7 8 6 20 59 51 60 65 -45 7 0 52 7 15 19 6 11 39 8 4 22 89 0 0 7 14 48 21 0 0 61 64 -44 7 7 34 7 22 1 6 18 23 8 11 2 90 0 0 7 21 8 21 0 9 61 64 -43 7 13 55 7 28 21 6 24 45 8 17 20 91 0 0 7 27 6 21 0 18 62 63 -41 7 19 54 7 34 19 6 30 46 8 23 17 92 0 0 7 32 43 21 0 27 63 62 -40 7 25 31 7 39 56 6 36 24 8 28 51 93 0 0 7 37 58 21 0 36 64 62 -39 7 30 46 7 45 10 6 41 41 8 34 5 94 0 0 7 42 51 21 0 45 65 61 -38 7 35 39 7 50 3 6 46 35 8 38 56 95 0 0 7 47 21 21 0 55 66 60 -37 7 40 10 7 54 33 6 51 7 8 43 25 96 0 0 7 51 30 21 1 4 67 59 -36 7 44 18 7 58 42 6 55 17 8 47 32 97 0 0 7 55 17 21 1 13 68 58 -35 7 48 5 8 2 28 6 59 5 8 51 18 98 0 0 7 58 41 21 1 23 69 57 -34 7 51 29 8 5 52 7 2 30 8 54 41 99 0 0 8 1 43 21 1 32 70 56 -33 7 54 31 8 8 54 7 5 33 8 57 42 100 0 0 8 4 22 21 1 42 71 54 -32 7 57 11 8 11 34 7 8 14 9 0 20 101 0 0 8 6 40 21 1 52 72 53 -31 7 59 29 8 13 51 7 10 32 9 2 37 102 0 0 8 8 34 21 2 1 72 51 -30 8 1 23 8 15 45 7 12 27 9 4 31 103 0 0 8 10 7 21 2 11 73 49 -29 8 2 56 8 17 18 7 14 0 9 6 3 104 0 0 8 11 17 21 2 21 74 47 -28 8 4 6 8 18 27 7 15 10 9 7 12 105 0 0 8 12 4 21 2 31 75 45 -27 8 4 53 8 19 15 7 15 58 9 8 0 106 0 0 8 12 29 21 2 40 75 42 -26 8 5 18 8 19 40 7 16 23 9 8 24 107 0 0 8 12 31 21 2 50 76 39 -25 8 5 20 8 19 42 7 16 25 9 8 27 108 0 0 8 12 11 21 3 0 77 36 -24 8 5 0 8 19 22 7 16 5 9 8 6 109 0 0 8 11 28 21 3 10 77 32 -23 8 4 17 8 18 39 7 15 22 9 7 24 110 0 0 8 10 23 21 3 20 78 28 -22 8 3 12 8 17 33 7 14 16 9 6 19 111 0 0 8 8 55 21 3 30 78 24 -21 8 1 44 8 16 6 7 12 47 9 4 51 112 0 0 8 7 4 21 3 40 79 19 -20 7 59 53 8 14 15 7 10 56 9 3 2 113 0 0 8 4 51 21 3 50 79 15 -19 7 57 40 8 12 2 7 8 42 9 0 49 114 0 0 8 2 16 21 4 0 79 9 -18 7 55 4 8 9 27 7 6 6 8 58 15 115 0 0 7 59 18 21 4 10 79 4 -17 7 52 6 8 6 29 7 3 7 8 55 18 116 0 0 7 55 57 21 4 20 79 359 -16 7 48 46 8 3 9 6 59 45 8 51 59 117 0 0 7 52 15 21 4 30 79 354 -15 7 45 3 7 59 26 6 56 1 8 48 17 118 0 0 7 48 9 21 4 40 79 349 -14 7 40 57 7 55 21 6 51 55 8 44 13 119 0 0 7 43 42 21 4 50 78 344 -13 7 36 30 7 50 54 6 47 26 8 39 47 120 0 0 7 38 52 21 5 0 78 340 -12 7 31 40 7 46 4 6 42 34 8 34 59 121 0 0 7 33 40 21 5 10 78 336 -11 7 26 28 7 40 53 6 37 21 8 29 49 122 0 0 7 28 6 21 5 20 77 332 -9 7 20 53 7 35 19 6 31 45 8 24 17 123 0 0 7 22 10 21 5 30 76 328 -8 7 14 57 7 29 23 6 25 47 8 18 23 124 0 0 7 15 52 21 5 40 76 325 -7 7 8 39 7 23 5 6 19 27 8 12 7 125 0 0 7 9 12 21 5 50 75 322 -6 7 1 58 7 16 25 6 12 44 8 5 29 126 0 0 7 2 10 21 6 0 74 320 -5 6 54 56 7 9 24 6 5 40 7 58 29 127 0 0 6 54 47 21 6 10 74 318 -4 6 47 32 7 2 1 5 58 14 7 51 8 128 0 0 6 47 1 21 6 20 73 315 -3 6 39 47 6 54 16 5 50 27 7 43 26 129 0 0 6 38 55 21 6 30 72 314 -2 6 31 40 6 46 10 5 42 17 7 35 21 130 0 0 6 30 27 21 6 40 71 312 -1 6 23 11 6 37 42 5 33 47 7 26 56 131 0 0 6 21 37 21 6 49 70 310 0 6 14 22 6 28 53 5 24 54 7 18 10 Uncertainty in time = +/- 8 secs Prediction of 2012 Aug 7.0 Data for the target star ------------------------ * name: TYC 1291-01004-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 05 18 57.8858 DE: +18 46 52.930 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .032, .071 ) * V mag [mag]: 9.4 * B mag [mag]: 10.2 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1076) Viola approx. diameter [km]: 26 approx. diameter ["]: .022 distance from Earth [AU]: 1.66400 * orbital information: orbit source: Preston date of fit: 2012 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1013 number of rejected observations: 68 time covered by the observations: 1926 Nov 04 - 2011 Nov 26 1 sigma uncertainty ellipse (major, minor, PA): 0.040, 0.024, 83° remarks: * orbital elements for (1076) Viola : Mean anomaly = 334.52656193 deg Arg. of pericenter = 304.00308883 deg Long. of node = 143.73844353 deg Inclination = 3.31858399 deg Eccentricity = 0.14574059 Semimajor axis = 2.47473803 AU Perihelion dist = 2.11406825 AU Mag: H = 12.09, G = 0.15 Epoch of elements : MJD 56198.87800000 TDT (2012 Sep 28.878) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 28 1076 Viola 21h 4.2m UT 9.4 5 18 57.886 18 46 52.93TYC 1291-01004-1 10.2 16.3 26 2.3 1.664 2.402 -1.86 115.6485 18.782 -138.45 -2.44 21.0702 -0.01031 -0.18857 6.45753 -0.35193 -0.00517 -0.00026 2000 332.2789292012 920.00000304.003089143.738444 3.3185840.14574059 2.4747380 2.114068212.3 5.00.15 RATE 2.5316880 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.075 0.051 359 4.40 0.073 0 0-2 0 056146.0020120928_1004-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 21:13 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org