IOTA/IOTA-ES occultation update for (4834) Thoas / TYC 6429-01392-1 event on 2009 Sep 04, 04:25 UT Visible from Summary ------- On 2009 Sep 04 UT, the 87 km diameter asteroid (4834) Thoas will occult a 12.0 mag star in the constellation Cetus for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 4.3 mag to 16.2 mag (the magnitude of the asteroid) for at most 7.2 seconds. This update is based on historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 24 * date and approx. time of event: 2009 Sep 04, 04:21 - 2009 Sep 04, 04:30 UT * magnitude of target star: 12.0 * magnitude drop [mag]: 4.3 * estimated maximum duration [s]: 7.2 * Moon: 100 % sunlit, 53° distance * Sun: 134° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 164 * 1 sigma uncertainty interval [path widths]: +/- 2.76 * 1 sigma uncertainty interval [seconds]: +/- 56.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .199 +/- .157) * 1 sigma uncertainty ellipse (major, minor, PA): ( .244", .068", 53° ) * approx speed of asteroid's shadow [km/s]: 11.9731 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6429-01392-1 by 4834 Thoas on 2009 Sep 4 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 - 61 19 52 60 0 0 4 21 28 1 143 -23 - 63 13 11 - 59 32 12 ... .. .. ... .. .. - 59 59 24 59 0 0 4 21 29 2 144 -24 - 61 45 9 - 58 18 20 ... .. .. ... .. .. - 58 49 48 58 0 0 4 21 29 3 145 -25 - 60 29 19 - 57 14 16 ... .. .. ... .. .. - 57 49 24 57 0 0 4 21 31 4 146 -26 - 59 23 40 - 56 18 36 - 69 38 17 ... .. .. - 56 56 56 56 0 0 4 21 32 5 147 -27 - 58 26 43 - 55 30 12 - 68 2 14 ... .. .. - 56 11 22 55 0 0 4 21 34 7 147 -27 - 57 37 16 - 54 48 12 - 66 40 38 ... .. .. - 55 31 55 54 0 0 4 21 37 8 148 -28 - 56 54 25 - 54 11 52 - 65 30 46 ... .. .. - 54 57 53 53 0 0 4 21 39 9 148 -29 - 56 17 23 - 53 40 36 - 64 30 41 ... .. .. - 54 28 43 52 0 0 4 21 42 10 149 -30 - 55 45 34 - 53 13 56 - 63 38 58 ... .. .. - 54 3 59 51 0 0 4 21 45 11 149 -31 - 55 18 27 - 52 51 24 - 62 54 29 ... .. .. - 53 43 15 50 0 0 4 21 49 12 149 -32 - 54 55 36 - 52 32 41 - 62 16 22 - 46 29 0 - 53 26 13 49 0 0 4 21 52 13 149 -33 - 54 36 39 - 52 17 27 - 61 43 55 - 46 22 16 - 53 12 35 48 0 0 4 21 56 14 149 -34 - 54 21 18 - 52 5 27 - 61 16 33 - 46 18 2 - 53 2 7 47 0 0 4 22 1 14 149 -35 - 54 9 16 - 51 56 27 - 60 53 48 - 46 16 8 - 52 54 35 46 0 0 4 22 5 15 149 -36 - 54 0 19 - 51 50 16 - 60 35 17 - 46 16 25 - 52 49 49 45 0 0 4 22 10 16 149 -37 - 53 54 16 - 51 46 43 - 60 20 39 - 46 18 48 - 52 47 39 44 0 0 4 22 15 17 149 -38 - 53 50 57 - 51 45 39 - 60 9 38 - 46 23 9 - 52 47 57 43 0 0 4 22 20 18 149 -39 - 53 50 11 - 51 46 57 - 60 1 59 - 46 29 24 - 52 50 35 42 0 0 4 22 25 19 149 -40 - 53 51 53 - 51 50 30 - 59 57 30 - 46 37 28 - 52 55 27 41 0 0 4 22 31 20 149 -41 - 53 55 54 - 51 56 12 - 59 56 2 - 46 47 15 - 53 2 29 40 0 0 4 22 37 20 148 -42 - 54 2 10 - 52 3 58 - 59 57 24 - 46 58 44 - 53 11 35 39 0 0 4 22 43 21 148 -42 - 54 10 34 - 52 13 44 - 60 1 30 - 47 11 51 - 53 22 41 38 0 0 4 22 50 22 148 -43 - 54 21 4 - 52 25 25 - 60 8 14 - 47 26 32 - 53 35 44 37 0 0 4 22 57 23 147 -44 - 54 33 35 - 52 39 0 - 60 17 30 - 47 42 47 - 53 50 42 36 0 0 4 23 4 24 147 -45 - 54 48 6 - 52 54 24 - 60 29 14 - 48 0 33 - 54 7 32 35 0 0 4 23 11 24 146 -46 - 55 4 32 - 53 11 37 - 60 43 24 - 48 19 49 - 54 26 13 34 0 0 4 23 18 25 146 -48 - 55 22 54 - 53 30 38 - 60 59 56 - 48 40 33 - 54 46 43 33 0 0 4 23 26 26 145 -49 - 55 43 9 - 53 51 24 - 61 18 50 - 49 2 46 - 55 9 3 32 0 0 4 23 34 26 145 -50 - 56 5 17 - 54 13 55 - 61 40 4 - 49 26 26 - 55 33 12 31 0 0 4 23 42 27 144 -51 - 56 29 19 - 54 38 11 - 62 3 39 - 49 51 34 - 55 59 10 30 0 0 4 23 50 28 143 -52 - 56 55 13 - 55 4 14 - 62 29 36 - 50 18 9 - 56 26 58 29 0 0 4 23 59 28 143 -53 - 57 23 2 - 55 32 2 - 62 57 57 - 50 46 13 - 56 56 38 28 0 0 4 24 8 29 142 -54 - 57 52 48 - 56 1 38 - 63 28 44 - 51 15 47 - 57 28 12 27 0 0 4 24 17 29 141 -55 - 58 24 31 - 56 33 4 - 64 2 1 - 51 46 51 - 58 1 42 26 0 0 4 24 27 30 141 -56 - 58 58 15 - 57 6 22 - 64 37 54 - 52 19 27 - 58 37 12 25 0 0 4 24 36 30 140 -57 - 59 34 4 - 57 41 35 - 65 16 28 - 52 53 39 - 59 14 45 24 0 0 4 24 46 31 139 -58 - 60 12 1 - 58 18 46 - 65 57 52 - 53 29 27 - 59 54 26 23 0 0 4 24 57 31 138 -59 - 60 52 13 - 58 58 1 - 66 42 15 - 54 6 54 - 60 36 21 22 0 0 4 25 7 31 137 -60 - 61 34 44 - 59 39 23 - 67 29 48 - 54 46 6 - 61 20 36 21 0 0 4 25 18 32 136 -61 - 62 19 43 - 60 22 59 - 68 20 47 - 55 27 4 - 62 7 20 20 0 0 4 25 29 32 135 -63 - 63 7 18 - 61 8 57 - 69 15 28 - 56 9 55 - 62 56 41 19 0 0 4 25 40 32 134 -64 - 63 57 39 - 61 57 24 - 70 14 14 - 56 54 43 - 63 48 51 18 0 0 4 25 52 32 133 -65 - 64 51 0 - 62 48 31 - 71 17 34 - 57 41 34 - 64 44 3 17 0 0 4 26 4 32 132 -66 - 65 47 34 - 63 42 30 - 72 26 1 - 58 30 37 - 65 42 33 16 0 0 4 26 16 32 131 -67 - 66 47 39 - 64 39 34 - 73 40 24 - 59 21 58 - 66 44 39 15 0 0 4 26 29 32 130 -68 - 67 51 38 - 65 40 0 - 75 1 46 - 60 15 47 - 67 50 46 14 0 0 4 26 42 32 129 -69 - 68 59 59 - 66 44 10 - 76 31 35 - 61 12 16 - 69 1 23 13 0 0 4 26 56 32 127 -70 - 70 13 14 - 67 52 27 - 78 12 2 - 62 11 39 - 70 17 6 12 0 0 4 27 10 31 126 -71 - 71 32 10 - 69 5 24 - 80 6 36 - 63 14 9 - 71 38 44 11 0 0 4 27 25 31 125 -71 - 72 57 44 - 70 23 41 - 82 21 28 - 64 20 7 - 73 7 21 10 0 0 4 27 40 30 124 -72 - 74 31 18 - 71 48 9 - 85 10 0 - 65 29 55 - 74 44 26 9 0 0 4 27 56 30 123 -72 - 76 14 47 - 73 20 1 - 89 16 57 - 66 44 0 - 76 32 8 8 0 0 4 28 12 29 121 -72 - 78 11 10 - 75 0 53 ... .. .. - 68 2 58 - 78 33 51 7 0 0 4 28 30 27 120 -72 - 80 25 25 - 76 53 13 ... .. .. - 69 27 32 Latitude Latitude Latitude Latitude - 80 0 0 6 22 16 4 28 42 27 119 -72 7 10 38 5 35 3 12 3 13 1 31 30 - 81 0 0 5 58 14 4 28 50 26 119 -71 6 46 4 5 11 29 11 34 55 1 10 6 - 82 0 0 5 35 58 4 28 58 25 118 -71 6 23 20 4 49 39 11 8 49 0 50 14 - 83 0 0 5 15 26 4 29 6 25 118 -70 6 2 24 4 29 31 10 44 51 0 31 53 - 84 0 0 4 56 37 4 29 13 24 118 -70 5 43 12 4 11 4 10 22 58 0 15 1 - 85 0 0 4 39 29 4 29 20 23 117 -69 5 25 44 3 54 14 10 3 7 - 0 0 22 - 86 0 0 4 24 0 4 29 27 22 117 -68 5 9 57 3 39 2 9 45 14 - 0 14 19 - 87 0 0 4 10 9 4 29 33 22 117 -68 4 55 50 3 25 25 9 29 18 - 0 26 49 - 88 0 0 3 57 54 4 29 40 21 116 -67 4 43 22 3 13 22 9 15 16 - 0 37 53 - 89 0 0 3 47 15 4 29 46 20 116 -66 4 32 32 3 2 54 9 3 6 - 0 47 33 - 90 0 0 3 38 10 4 29 51 19 116 -65 4 23 18 2 53 58 8 52 48 - 0 55 49 - 91 0 0 3 30 39 4 29 57 18 115 -64 4 15 40 2 46 34 8 44 19 - 1 2 41 - 92 0 0 3 24 43 4 30 2 18 115 -64 4 9 38 2 40 42 8 37 40 - 1 8 10 - 93 0 0 3 20 19 4 30 7 17 115 -63 4 5 11 2 36 22 8 32 50 - 1 12 15 - 94 0 0 3 17 28 4 30 12 16 115 -62 4 2 19 2 33 33 8 29 48 - 1 14 58 - 95 0 0 3 16 11 4 30 17 15 115 -61 4 1 2 2 32 15 8 28 34 - 1 16 17 - 96 0 0 3 16 27 4 30 21 14 115 -60 4 1 20 2 32 28 8 29 10 - 1 16 14 - 97 0 0 3 18 16 4 30 25 13 114 -59 4 3 14 2 34 14 8 31 34 - 1 14 47 - 98 0 0 3 21 40 4 30 29 12 114 -58 4 6 44 2 37 31 8 35 48 - 1 11 56 - 99 0 0 3 26 38 4 30 32 11 114 -57 4 11 50 2 42 22 8 41 53 .. .. .. -100 0 0 3 33 12 4 30 35 10 114 -56 4 18 35 2 48 46 8 49 50 .. .. .. -101 0 0 3 41 22 4 30 38 9 114 -55 4 26 57 2 56 45 8 59 41 .. .. .. -102 0 0 3 51 11 4 30 41 8 114 -54 4 37 1 3 6 20 9 11 28 .. .. .. -103 0 0 4 2 39 4 30 44 7 114 -53 4 48 45 3 17 31 9 25 13 .. .. .. -104 0 0 4 15 47 4 30 46 6 114 -52 5 2 13 3 30 22 9 40 59 .. .. .. -105 0 0 4 30 38 4 30 48 5 113 -51 5 17 26 3 44 53 9 58 49 .. .. .. -106 0 0 4 47 15 4 30 49 4 113 -50 5 34 27 4 1 6 10 18 46 .. .. .. -107 0 0 5 5 38 4 30 50 3 113 -49 5 53 17 4 19 4 10 40 54 .. .. .. -108 0 0 5 25 51 4 30 51 2 113 -48 6 14 1 4 38 49 .. .. .. .. .. .. -109 0 0 5 47 57 4 30 52 1 113 -47 6 36 41 5 0 24 .. .. .. .. .. .. -110 0 0 6 11 59 4 30 52 0 113 -46 .. .. .. 5 23 52 .. .. .. .. .. .. Uncertainty in time = +/- 60 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: TYC 6429-01392-1 * constellation : Cetus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 01 52 38.2792 DE: -22 52 50.643 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .036, .024 ) * V mag [mag]: 12.0 * B mag [mag]: 12.6 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (4834) Thoas approx. diameter [km]: 87 approx. diameter ["]: .030 distance from Earth [AU]: 4.05100 * orbital information: orbit source: Preston date of fit: 2008 Mar 20 source of used astrometry: MPC (via Astdys) number of used observations: 464 number of rejected observations: 6 time covered by the observations: 1986 Dec 02 - 2007 Nov 11 1 sigma uncertainty ellipse (major, minor, PA): 0.242, 0.065, 52° remarks: * orbital elements for (4834) Thoas : Mean anomaly = 312.28241808 deg Arg. of pericenter = 351.21696503 deg Long. of node = 76.04445930 deg Inclination = 28.44938107 deg Eccentricity = 0.13772150 Semimajor axis = 5.22814591 AU Perihelion dist = 4.50811783 AU Mag: H = 9.21, G = 0.15 Epoch of elements : MJD 55078.18400000 TDT (2009 Sep 04.184) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Sep 4 4834 Thoas 4h 26.1m UT 12.0 1 52 38.279-22 52 50.64TYC 6429-01392-1 12.6 16.2 87 7.2 4.051 -0.668 -11.41 -21.8081 -22.877 113.24 7.14 4.4357 -0.65843 0.53238 -4.24588 -5.25757 -0.00410 0.00092 2000 311.6076602009 827.00000351.216965 76.044459 28.4493810.13772150 5.2281459 4.5081178 9.2 5.00.15 RATE 0.8244840 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.244 0.068 53 3.76 0.082 0 54545.5020090904_1392-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 12:51 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org