IOTA/IOTA-ES occultation update for (721) Tabora / UCAC2 27109217 event on 2009 Jan 10, 23:50 UT Visible from Summary ------- On 2009 Jan 10 UT, the 76 km diameter asteroid (721) Tabora will occult a 11.2 mag star in the constellation Libra for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 4.9 mag to 16.1 mag (the magnitude of the asteroid) for at most 3.2 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: 44 * date and approx. time of event: 2009 Jan 10, 23:46 - 2009 Jan 10, 23:49 UT * magnitude of target star: 11.2 * magnitude drop [mag]: 4.9 * estimated maximum duration [s]: 3.2 * Moon: 100 % sunlit, 112° distance * Sun: 70° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 79 * 1 sigma uncertainty interval [path widths]: +/- 1.47 * 1 sigma uncertainty interval [seconds]: +/- 5.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .047 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .047", .036", 94° ) * approx speed of asteroid's shadow [km/s]: 23.8959 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 27109217 by 721 Tabora on 2009 Jan 10 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 32 0 0 35 22 35 23 46 31 1 107 -63 35 0 21 35 44 51 33 55 12 36 50 35 33 0 0 35 7 30 23 46 31 1 108 -62 34 45 14 35 29 49 33 39 58 36 35 40 34 0 0 34 52 4 23 46 31 2 108 -62 34 29 45 35 14 25 33 24 21 36 20 24 35 0 0 34 36 15 23 46 31 3 109 -61 34 13 53 34 58 39 33 8 22 36 4 45 36 0 0 34 20 4 23 46 31 4 109 -60 33 57 40 34 42 30 32 52 1 35 48 44 37 0 0 34 3 30 23 46 32 5 110 -60 33 41 4 34 25 59 32 35 18 35 32 21 38 0 0 33 46 35 23 46 32 6 110 -59 33 24 6 34 9 7 32 18 13 35 15 35 39 0 0 33 29 17 23 46 33 7 111 -58 33 6 45 33 51 52 32 0 45 34 58 28 40 0 0 33 11 38 23 46 33 8 111 -57 32 49 3 33 34 15 31 42 55 34 40 59 41 0 0 32 53 36 23 46 34 8 112 -57 32 30 59 33 16 15 31 24 43 34 23 8 42 0 0 32 35 12 23 46 34 9 113 -56 32 12 33 32 57 55 31 6 10 34 4 55 43 0 0 32 16 27 23 46 35 10 113 -55 31 53 45 32 39 12 30 47 14 33 46 20 44 0 0 31 57 20 23 46 36 11 114 -54 31 34 35 32 20 7 30 27 57 33 27 23 45 0 0 31 37 51 23 46 37 12 114 -53 31 15 4 32 0 41 30 8 18 33 8 5 46 0 0 31 18 1 23 46 38 13 115 -53 30 55 11 31 40 54 29 48 18 32 48 25 47 0 0 30 57 50 23 46 39 14 115 -52 30 34 58 31 20 45 29 27 57 32 28 24 48 0 0 30 37 18 23 46 40 15 116 -51 30 14 22 31 0 15 29 7 14 32 8 1 49 0 0 30 16 24 23 46 41 16 116 -50 29 53 27 30 39 24 28 46 11 31 47 18 50 0 0 29 55 10 23 46 42 17 117 -49 29 32 10 30 18 13 28 24 47 31 26 14 51 0 0 29 33 35 23 46 44 18 117 -48 29 10 33 29 56 40 28 3 2 31 4 49 52 0 0 29 11 40 23 46 45 19 118 -47 28 48 35 29 34 48 27 40 58 30 43 4 53 0 0 28 49 25 23 46 47 20 118 -47 28 26 18 29 12 35 27 18 33 30 20 58 54 0 0 28 26 50 23 46 48 21 119 -46 28 3 40 28 50 3 26 55 49 29 58 33 55 0 0 28 3 56 23 46 50 21 119 -45 27 40 44 28 27 11 26 32 46 29 35 48 56 0 0 27 40 42 23 46 52 22 120 -44 27 17 28 28 3 59 26 9 23 29 12 44 57 0 0 27 17 10 23 46 54 23 120 -43 26 53 53 27 40 29 25 45 42 28 49 20 58 0 0 26 53 19 23 46 55 24 121 -42 26 30 0 27 16 40 25 21 42 28 25 38 59 0 0 26 29 10 23 46 58 25 121 -41 26 5 49 26 52 34 24 57 25 28 1 37 60 0 0 26 4 43 23 47 0 26 122 -40 25 41 20 26 28 9 24 32 50 27 37 19 61 0 0 25 39 59 23 47 2 27 122 -39 25 16 34 26 3 26 24 7 58 27 12 42 62 0 0 25 14 58 23 47 4 28 123 -38 24 51 31 25 38 27 23 42 49 26 47 49 63 0 0 24 49 40 23 47 6 29 124 -37 24 26 11 25 13 11 23 17 24 26 22 39 64 0 0 24 24 6 23 47 9 30 124 -36 24 0 36 24 47 40 22 51 44 25 57 12 65 0 0 23 58 17 23 47 11 31 125 -35 23 34 45 24 21 52 22 25 48 25 31 30 66 0 0 23 32 13 23 47 14 32 125 -34 23 8 39 23 55 50 21 59 37 25 5 32 67 0 0 23 5 54 23 47 17 33 126 -33 22 42 19 23 29 33 21 33 13 24 39 20 68 0 0 22 39 22 23 47 19 34 126 -32 22 15 45 23 3 1 21 6 34 24 12 53 69 0 0 22 12 36 23 47 22 35 127 -31 21 48 57 22 36 17 20 39 43 23 46 12 70 0 0 21 45 37 23 47 25 36 127 -30 21 21 57 22 9 20 20 12 40 23 19 19 71 0 0 21 18 26 23 47 28 37 128 -29 20 54 45 21 42 10 19 45 24 22 52 13 72 0 0 20 51 4 23 47 31 38 128 -28 20 27 22 21 14 49 19 17 58 22 24 55 73 0 0 20 23 31 23 47 34 39 129 -27 19 59 48 20 47 17 18 50 21 21 57 26 74 0 0 19 55 48 23 47 38 41 129 -26 19 32 4 20 19 34 18 22 34 21 29 46 75 0 0 19 27 55 23 47 41 42 130 -25 19 4 10 19 51 42 17 54 38 21 1 56 76 0 0 18 59 53 23 47 45 43 130 -24 18 36 8 19 23 41 17 26 34 20 33 57 77 0 0 18 31 43 23 47 48 44 131 -23 18 7 58 18 55 32 16 58 22 20 5 50 78 0 0 18 3 26 23 47 52 45 132 -22 17 39 40 18 27 16 16 30 3 19 37 35 79 0 0 17 35 3 23 47 55 46 132 -21 17 11 16 17 58 52 16 1 38 19 9 13 80 0 0 17 6 34 23 47 59 47 133 -20 16 42 47 17 30 23 15 33 8 18 40 44 81 0 0 16 37 59 23 48 3 48 133 -19 16 14 12 17 1 49 15 4 33 18 12 11 82 0 0 16 9 20 23 48 7 49 134 -18 15 45 33 16 33 10 14 35 54 17 43 32 83 0 0 15 40 38 23 48 11 50 135 -17 15 16 51 16 4 28 14 7 12 17 14 49 84 0 0 15 11 53 23 48 15 51 136 -15 14 48 7 15 35 43 13 38 28 16 46 4 85 0 0 14 43 7 23 48 19 52 136 -14 14 19 20 15 6 56 13 9 43 16 17 16 86 0 0 14 14 19 23 48 23 53 137 -13 13 50 33 14 38 8 12 40 57 15 48 26 87 0 0 13 45 31 23 48 27 54 138 -12 13 21 45 14 9 19 12 12 11 15 19 36 88 0 0 13 16 43 23 48 32 55 139 -11 12 52 59 13 40 31 11 43 26 14 50 46 89 0 0 12 47 58 23 48 36 56 139 -10 12 24 13 13 11 45 11 14 43 14 21 58 90 0 0 12 19 14 23 48 41 57 140 -9 11 55 31 12 43 0 10 46 2 13 53 10 91 0 0 11 50 33 23 48 45 58 141 -8 11 26 51 12 14 18 10 17 25 13 24 26 92 0 0 11 21 56 23 48 50 59 142 -7 10 58 15 11 45 41 9 48 53 12 55 45 93 0 0 10 53 24 23 48 54 60 143 -6 10 29 44 11 17 7 9 20 25 12 27 8 94 0 0 10 24 58 23 48 59 61 145 -4 10 1 19 10 48 40 8 52 4 11 58 37 95 0 0 9 56 38 23 49 4 62 146 -3 9 33 0 10 20 18 8 23 49 11 30 11 96 0 0 9 28 25 23 49 8 63 147 -2 9 4 49 9 52 4 7 55 42 11 1 53 97 0 0 9 0 20 23 49 13 64 148 -1 8 36 45 9 23 57 7 27 43 10 33 41 98 0 0 8 32 23 23 49 18 65 150 0 8 8 50 8 55 59 6 59 53 10 5 39 Uncertainty in time = +/- 6 secs [Prediction of 2008 Nov 4.0] Data for the target star ------------------------ * name: UCAC2 27109217 * constellation : Libra * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 14 34 28.1389 DE: -13 25 04.053 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .044, .034 ) * V mag [mag]: 11.2 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (721) Tabora approx. diameter [km]: 76 approx. diameter ["]: .025 distance from Earth [AU]: 4.16100 * orbital information: orbit source: Preston date of fit: 2008 Nov 03 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 970 number of rejected observations: 55 time covered by the observations: 1911 Oct 29 - 2008 Jun 29 1 sigma uncertainty ellipse (major, minor, PA): 0.018, 0.012, 116° remarks: * orbital elements for (721) Tabora : Mean anomaly = 170.70096332 deg Arg. of pericenter = 355.51900601 deg Long. of node = 38.79117847 deg Inclination = 8.34577118 deg Eccentricity = 0.10904215 Semimajor axis = 3.55512601 AU Perihelion dist = 3.16746744 AU Mag: H = 9.24, G = 0.15 Epoch of elements : MJD 54841.99400000 TDT (2009 Jan 10.994) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Jan 10 721 Tabora 23h 50.8m UT 11.2 14 34 28.139-13 25 4.05UCAC2 27109217 0.0 16.1 76 3.2 4.161 1.821 -10.32 110.2867 -13.415 -175.74 -21.82 23.8467 0.09609 0.24562 12.57293 -4.88205 -0.00543 0.00184 2000 170.4077752009 1 9.00000355.519006 38.791178 8.3457710.10904215 3.5551260 3.1674674 9.3 5.00.15 RATE 1.4703530 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.047 0.036 94 2.47 0.037 0 54774.5020090110_109217 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Nov 04, 05:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org