IOTA/IOTA-ES occultation update for (3144) Brosche / HIP 60745 event on 2012 Dec 20, 19:01 UT Visible from Australia Summary ------- On 2012 Dec 20 UT, the 28 km diameter asteroid (3144) Brosche will occult a 7.9 mag star in the constellation Virgo for observers along a path across Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 11.2 mag to 19.1 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: . The event at a glimpse ---------------------- * Rank: 37 * date and approx. time of event: 2012 Dec 20, 18:57 - 2012 Dec 20, 19:00 UT * geocentric midpoint of event [JD]: 2456282.29264583 * magnitude of target star: 7.9 * magnitude drop [mag]: 11.2 * estimated maximum duration [s]: 1.4 * Moon: 56 % sunlit, 176° distance * Sun: 79° distance * rough path description: Australia The occultation path -------------------- * approximate projected width [km]: 34 * 1 sigma uncertainty interval [path widths]: +/- 1.80 * 1 sigma uncertainty interval [seconds]: +/- 3.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .034 +/- .026) * 1 sigma uncertainty ellipse (major, minor, PA): ( .035", .025", 109° ) * approx speed of asteroid's shadow [km/s]: 20.6752 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 60745 by 3144 Brosche on 2012 Dec 20 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 82 0 0 - 6 19 40 18 57 13 0 99 -60 - 6 29 8 - 6 10 14 - 7 3 19 .. .. .. 83 0 0 - 6 29 33 18 57 13 1 99 -59 - 6 39 1 - 6 20 5 - 7 13 17 .. .. .. 84 0 0 - 6 40 4 18 57 13 2 99 -59 - 6 49 34 - 6 30 36 - 7 23 54 .. .. .. 85 0 0 - 6 51 15 18 57 13 3 99 -58 - 7 0 46 - 6 41 46 - 7 35 10 .. .. .. 86 0 0 - 7 3 5 18 57 14 4 98 -58 - 7 12 37 - 6 53 34 - 7 47 6 .. .. .. 87 0 0 - 7 15 34 18 57 14 5 98 -57 - 7 25 7 - 7 6 2 - 7 59 41 - 6 31 51 88 0 0 - 7 28 42 18 57 15 6 98 -57 - 7 38 17 - 7 19 8 - 8 12 56 - 6 44 53 89 0 0 - 7 42 29 18 57 16 7 98 -56 - 7 52 5 - 7 32 54 - 8 26 50 - 6 58 33 90 0 0 - 7 56 55 18 57 17 8 98 -55 - 8 6 33 - 7 47 19 - 8 41 23 - 7 12 53 91 0 0 - 8 12 1 18 57 18 9 98 -55 - 8 21 40 - 8 2 22 - 8 56 36 - 7 27 51 92 0 0 - 8 27 45 18 57 19 10 98 -54 - 8 37 26 - 8 18 5 - 9 12 28 - 7 43 28 93 0 0 - 8 44 8 18 57 20 11 97 -53 - 8 53 51 - 8 34 27 - 9 28 59 - 7 59 43 94 0 0 - 9 1 11 18 57 22 12 97 -53 - 9 10 55 - 8 51 27 - 9 46 10 - 8 16 38 95 0 0 - 9 18 52 18 57 23 13 97 -52 - 9 28 38 - 9 9 7 -10 4 0 - 8 34 11 96 0 0 - 9 37 12 18 57 25 14 97 -51 - 9 47 0 - 9 27 25 -10 22 29 - 8 52 22 97 0 0 - 9 56 11 18 57 27 15 97 -50 -10 6 1 - 9 46 22 -10 41 37 - 9 11 12 98 0 0 -10 15 49 18 57 28 16 96 -50 -10 25 41 -10 5 58 -11 1 24 - 9 30 41 99 0 0 -10 36 5 18 57 30 17 96 -49 -10 45 59 -10 26 12 -11 21 50 - 9 50 48 100 0 0 -10 57 0 18 57 33 18 96 -48 -11 6 56 -10 47 5 -11 42 54 -10 11 33 101 0 0 -11 18 32 18 57 35 19 96 -47 -11 28 31 -11 8 35 -12 4 37 -10 32 56 102 0 0 -11 40 43 18 57 37 20 95 -46 -11 50 44 -11 30 44 -12 26 59 -10 54 56 103 0 0 -12 3 32 18 57 40 22 95 -45 -12 13 35 -11 53 30 -12 49 58 -11 17 35 104 0 0 -12 26 59 18 57 42 23 95 -44 -12 37 4 -12 16 54 -13 13 36 -11 40 50 105 0 0 -12 51 2 18 57 45 24 94 -43 -13 1 10 -12 40 56 -13 37 51 -12 4 43 106 0 0 -13 15 43 18 57 48 25 94 -42 -13 25 54 -13 5 34 -14 2 43 -12 29 13 107 0 0 -13 41 1 18 57 51 26 93 -42 -13 51 14 -13 30 49 -14 28 12 -12 54 20 108 0 0 -14 6 55 18 57 54 27 93 -41 -14 17 11 -13 56 41 -14 54 18 -13 20 2 109 0 0 -14 33 25 18 57 57 28 93 -40 -14 43 43 -14 23 9 -15 21 0 -13 46 21 110 0 0 -15 0 31 18 58 1 29 92 -39 -15 10 52 -14 50 12 -15 48 18 -14 13 15 111 0 0 -15 28 12 18 58 4 30 92 -38 -15 38 35 -15 17 50 -16 16 12 -14 40 44 112 0 0 -15 56 28 18 58 8 31 91 -37 -16 6 54 -15 46 3 -16 44 40 -15 8 47 113 0 0 -16 25 18 18 58 11 32 91 -36 -16 35 47 -16 14 51 -17 13 43 -15 37 25 114 0 0 -16 54 42 18 58 15 33 90 -35 -17 5 13 -16 44 12 -17 43 20 -16 6 36 115 0 0 -17 24 38 18 58 19 33 89 -33 -17 35 13 -17 14 6 -18 13 30 -16 36 20 116 0 0 -17 55 8 18 58 23 34 89 -32 -18 5 45 -17 44 32 -18 44 12 -17 6 37 117 0 0 -18 26 9 18 58 27 35 88 -31 -18 36 49 -18 15 30 -19 15 26 -17 37 25 118 0 0 -18 57 41 18 58 32 36 87 -30 -19 8 23 -18 46 59 -19 47 11 -18 8 44 119 0 0 -19 29 43 18 58 36 37 86 -29 -19 40 29 -19 18 59 -20 19 27 -18 40 34 120 0 0 -20 2 15 18 58 40 38 86 -28 -20 13 3 -19 51 28 -20 52 12 -19 12 52 121 0 0 -20 35 15 18 58 45 39 85 -27 -20 46 6 -20 24 25 -21 25 26 -19 45 40 122 0 0 -21 8 43 18 58 50 40 84 -26 -21 19 37 -20 57 50 -21 59 7 -20 18 55 123 0 0 -21 42 38 18 58 54 41 83 -25 -21 53 35 -21 31 42 -22 33 15 -20 52 36 124 0 0 -22 16 58 18 58 59 42 82 -24 -22 27 58 -22 6 0 -23 7 49 -21 26 44 125 0 0 -22 51 43 18 59 4 43 81 -23 -23 2 46 -22 40 42 -23 42 48 -22 1 16 126 0 0 -23 26 52 18 59 9 43 80 -22 -23 37 58 -23 15 48 -24 18 9 -22 36 12 127 0 0 -24 2 23 18 59 14 44 79 -21 -24 13 32 -23 51 16 -24 53 54 -23 11 31 128 0 0 -24 38 15 18 59 19 45 78 -19 -24 49 27 -24 27 6 -25 29 59 -23 47 11 129 0 0 -25 14 28 18 59 24 46 76 -18 -25 25 42 -25 3 16 -26 6 24 -24 23 11 130 0 0 -25 50 59 18 59 30 46 75 -17 -26 2 16 -25 39 44 -26 43 8 -24 59 30 131 0 0 -26 27 48 18 59 35 47 74 -16 -26 39 7 -26 16 30 -27 20 9 -25 36 7 132 0 0 -27 4 52 18 59 40 48 72 -15 -27 16 14 -26 53 32 -27 57 26 -26 13 0 133 0 0 -27 42 12 18 59 46 49 71 -14 -27 53 36 -27 30 49 -28 34 57 -26 50 8 134 0 0 -28 19 45 18 59 51 49 69 -13 -28 31 12 -28 8 20 -29 12 42 -27 27 29 135 0 0 -28 57 29 18 59 57 50 68 -12 -29 8 58 -28 46 2 -29 50 37 -28 5 3 136 0 0 -29 35 24 19 0 2 50 66 -11 -29 46 56 -29 23 54 -30 28 43 -28 42 47 137 0 0 -30 13 27 19 0 8 51 65 -10 -30 25 1 -30 1 55 -31 6 57 -29 20 41 138 0 0 -30 51 38 19 0 13 51 63 -9 -31 3 15 -30 40 4 -31 45 18 -29 58 42 139 0 0 -31 29 55 19 0 19 52 61 -7 -31 41 33 -31 18 19 -32 23 44 -30 36 49 140 0 0 -32 8 16 19 0 25 52 59 -6 -32 19 56 -31 56 38 -33 2 14 -31 15 1 141 0 0 -32 46 39 19 0 30 53 57 -5 -32 58 21 -32 34 59 -33 40 46 -31 53 16 142 0 0 -33 25 3 19 0 36 53 56 -4 -33 36 47 -33 13 21 -34 19 19 -32 31 32 143 0 0 -34 3 27 19 0 42 53 54 -3 -34 15 12 -33 51 43 -34 57 50 -33 9 48 144 0 0 -34 41 48 19 0 47 54 52 -2 -34 53 35 -34 30 3 -35 36 18 -33 48 3 145 0 0 -35 20 6 19 0 53 54 50 -1 -35 31 54 -35 8 19 -36 14 42 -34 26 14 146 0 0 -35 58 18 19 0 58 54 48 0 -36 10 7 -35 46 30 -36 53 0 -35 4 20 Uncertainty in time = +/- 3 secs Prediction of 2012 Dec 17.0 Data for the target star ------------------------ * name: HIP 60745 * constellation : Virgo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 12 26 58.8048 DE: -08 49 46.441 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .010, .007 ) * V mag [mag]: 7.9 * B mag [mag]: 8.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (3144) Brosche approx. diameter [km]: 28 approx. diameter ["]: .014 distance from Earth [AU]: 2.69000 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 806 number of rejected observations: 10 time covered by the observations: 1931 Oct 19 - 2012 Apr 16 1 sigma uncertainty ellipse (major, minor, PA): 0.034, 0.024, 110° remarks: * orbital elements for (3144) Brosche : Mean anomaly = 186.18485454 deg Arg. of pericenter = 95.48584791 deg Long. of node = 248.85611693 deg Inclination = 5.50967672 deg Eccentricity = 0.20991776 Semimajor axis = 2.22456381 AU Perihelion dist = 1.75758836 AU Mag: H = 13.73, G = 0.15 Epoch of elements : MJD 56281.79300000 TDT (2012 Dec 20.793) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 20 3144 Brosche 19h 1.4m UT 7.9 12 26 58.805- 8 49 46.44HIP 60745 8.3 19.1 28 1.4 2.690 2.252 -18.47 171.6290 -8.825 -105.86 -23.43 19.0235 -0.27959 -0.50549 10.21180 -5.64804 -0.00539 0.00222 2000 185.65223620121219.00000 95.485848248.856117 5.5096770.20991776 2.2245638 1.757588413.8 5.00.15 RATE 2.9705490 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.035 0.025 109 2.80 0.026 0 0-2-1 056278.0020121220__60745 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 10, 06:10 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org