IOTA/IOTA-ES occultation update for (546) Herodias / TYC 6940-00503-1 event on 2008 Dec 06, 12:02 UT Visible from Australia Summary ------- On 2008 Dec 06 UT, the 66 km diameter asteroid (546) Herodias will occult a 10.0 mag star in the constellation Capricornus 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 5.4 mag to 15.4 mag (the magnitude of the asteroid) for at most 2.2 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: 69 * date and approx. time of event: 2008 Dec 06, 12:03 - 2008 Dec 06, 12:05 UT * magnitude of target star: 10.0 * magnitude drop [mag]: 5.4 * estimated maximum duration [s]: 2.2 * Moon: 57 % sunlit, 36° distance * Sun: 65° distance * rough path description: Australia The occultation path -------------------- * approximate projected width [km]: 81 * 1 sigma uncertainty interval [path widths]: +/- 0.85 * 1 sigma uncertainty interval [seconds]: +/- 1.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .026", .024", 81° ) * approx speed of asteroid's shadow [km/s]: 29.6207 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6940-00503-1 by 546 Herodias on 2008 Dec 6 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 158 49 18 - 3 0 0 12 5 23 0 246 -59 ... .. .. 157 56 45 ... .. .. ... .. .. 156 42 11 - 4 0 0 12 5 23 2 246 -57 157 33 1 155 52 26 159 2 13 154 30 11 Latitude Latitude Latitude Latitude 155 0 0 - 4 51 16 12 5 22 4 246 -55 - 5 16 10 - 4 26 31 - 5 58 51 .. .. .. 154 0 0 - 5 22 39 12 5 22 5 246 -54 - 5 47 43 - 4 57 43 - 6 30 42 - 4 15 41 153 0 0 - 5 54 58 12 5 21 7 246 -53 - 6 20 13 - 5 29 52 - 7 3 30 - 4 47 33 152 0 0 - 6 28 14 12 5 21 8 246 -52 - 6 53 40 - 6 2 58 - 7 37 15 - 5 20 21 151 0 0 - 7 2 27 12 5 20 9 246 -51 - 7 28 4 - 6 37 0 - 8 11 59 - 5 54 5 150 0 0 - 7 37 38 12 5 19 10 247 -50 - 8 3 26 - 7 11 59 - 8 47 40 - 6 28 45 149 0 0 - 8 13 45 12 5 18 11 247 -49 - 8 39 45 - 7 47 55 - 9 24 20 - 7 4 22 148 0 0 - 8 50 49 12 5 17 12 247 -48 - 9 17 1 - 8 24 47 -10 1 57 - 7 40 55 147 0 0 - 9 28 50 12 5 16 13 247 -47 - 9 55 14 - 9 2 36 -10 40 32 - 8 18 23 146 0 0 -10 7 48 12 5 14 15 247 -46 -10 34 25 - 9 41 22 -11 20 5 - 8 56 48 145 0 0 -10 47 43 12 5 13 16 248 -45 -11 14 33 -10 21 4 -12 0 35 - 9 36 9 144 0 0 -11 28 34 12 5 11 17 248 -43 -11 55 37 -11 1 41 -12 42 3 -10 16 25 143 0 0 -12 10 21 12 5 10 18 248 -42 -12 37 37 -11 43 15 -13 24 27 -10 57 37 142 0 0 -12 53 3 12 5 8 19 248 -41 -13 20 34 -12 25 44 -14 7 48 -11 39 43 141 0 0 -13 36 41 12 5 6 21 249 -40 -14 4 26 -13 9 8 -14 52 5 -12 22 44 140 0 0 -14 21 13 12 5 4 22 249 -39 -14 49 12 -13 53 26 -15 37 17 -13 6 39 139 0 0 -15 6 39 12 5 2 23 250 -37 -15 34 53 -14 38 37 -16 23 24 -13 51 27 138 0 0 -15 52 58 12 4 59 24 250 -36 -16 21 27 -15 24 42 -17 10 24 -14 37 7 137 0 0 -16 40 9 12 4 57 25 251 -35 -17 8 54 -16 11 38 -17 58 17 -15 23 38 136 0 0 -17 28 11 12 4 54 26 251 -34 -17 57 11 -16 59 25 -18 47 2 -16 11 0 135 0 0 -18 17 3 12 4 52 28 252 -32 -18 46 19 -17 48 2 -19 36 37 -16 59 12 134 0 0 -19 6 44 12 4 49 29 252 -31 -19 36 16 -18 37 27 -20 27 2 -17 48 11 133 0 0 -19 57 12 12 4 46 30 253 -30 -20 27 0 -19 27 39 -21 18 14 -18 37 58 132 0 0 -20 48 26 12 4 43 31 253 -29 -21 18 30 -20 18 37 -22 10 12 -19 28 29 131 0 0 -21 40 23 12 4 40 32 254 -27 -22 10 43 -21 10 18 -23 2 55 -20 19 45 130 0 0 -22 33 3 12 4 37 33 255 -26 -23 3 39 -22 2 42 -23 56 20 -21 11 42 129 0 0 -23 26 22 12 4 34 34 256 -25 -23 57 16 -22 55 45 -24 50 25 -22 4 19 128 0 0 -24 20 20 12 4 30 36 257 -23 -24 51 30 -23 49 27 -25 45 9 -22 57 34 127 0 0 -25 14 53 12 4 27 37 257 -22 -25 46 19 -24 43 44 -26 40 28 -23 51 24 126 0 0 -26 9 59 12 4 23 38 258 -21 -26 41 42 -25 38 34 -27 36 19 -24 45 48 125 0 0 -27 5 36 12 4 19 39 259 -20 -27 37 35 -26 33 55 -28 32 42 -25 40 43 124 0 0 -28 1 40 12 4 16 40 261 -18 -28 33 56 -27 29 43 -29 29 31 -26 36 5 123 0 0 -28 58 10 12 4 12 41 262 -17 -29 30 41 -28 25 57 -30 26 45 -27 31 53 122 0 0 -29 55 1 12 4 8 42 263 -16 -30 27 48 -29 22 33 -31 24 20 -28 28 4 121 0 0 -30 52 10 12 4 4 43 264 -14 -31 25 14 -30 19 27 -32 22 13 -29 24 33 120 0 0 -31 49 35 12 4 0 44 266 -13 -32 22 54 -31 16 37 -33 20 20 -30 21 19 119 0 0 -32 47 12 12 3 55 45 267 -12 -33 20 45 -32 13 59 -34 18 38 -31 18 17 118 0 0 -33 44 56 12 3 51 46 268 -11 -34 18 44 -33 11 30 -35 17 3 -32 15 25 117 0 0 -34 42 45 12 3 47 46 270 -9 -35 16 47 -34 9 5 -36 15 31 -33 12 38 116 0 0 -35 40 35 12 3 43 47 272 -8 -36 14 51 -35 6 42 -37 13 58 -34 9 54 115 0 0 -36 38 22 12 3 38 48 273 -7 -37 12 50 -36 4 17 -38 12 20 -35 7 8 114 0 0 -37 36 2 12 3 34 49 275 -6 -38 10 43 -37 1 45 -39 10 34 -36 4 18 113 0 0 -38 33 32 12 3 30 49 277 -5 -39 8 23 -37 59 4 -40 8 35 -37 1 18 112 0 0 -39 30 47 12 3 25 50 279 -3 -40 5 49 -38 56 8 -41 6 20 -37 58 6 111 0 0 -40 27 44 12 3 21 51 281 -2 -41 2 55 -39 52 56 -42 3 43 -38 54 38 110 0 0 -41 24 18 12 3 16 51 283 -1 -41 59 39 -40 49 21 -43 0 43 -39 50 50 Uncertainty in time = +/- 2 secs [Prediction of 2008 Nov 26.0] Data for the target star ------------------------ * name: TYC 6940-00503-1 * constellation : Capricornus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 37 51.2586 DE: -24 18 09.091 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .022 ) * V mag [mag]: 10.0 * B mag [mag]: 11.2 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (546) Herodias approx. diameter [km]: 66 approx. diameter ["]: .029 distance from Earth [AU]: 3.14200 * orbital information: orbit source: Preston date of fit: 2008 Oct 29 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 605 number of rejected observations: 49 time covered by the observations: 1904 Oct 13 - 2008 Oct 19 1 sigma uncertainty ellipse (major, minor, PA): 0.015, 0.011, 63° remarks: * orbital elements for (546) Herodias : Mean anomaly = 211.38408240 deg Arg. of pericenter = 109.02106782 deg Long. of node = 21.86512097 deg Inclination = 14.84788590 deg Eccentricity = 0.11459905 Semimajor axis = 2.59825939 AU Perihelion dist = 2.30050133 AU Mag: H = 9.69, G = 0.15 Epoch of elements : MJD 54806.50200000 TDT (2008 Dec 06.502) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Dec 6 546 Herodias 12h 2.5m UT 10.0 21 37 51.259-24 18 9.09TYC 6940-00503-1 11.2 15.4 66 2.2 3.142 2.895 24.98 68.2013 -24.310 -2.81 -22.57 12.0410 0.30961 -0.49103 14.13698 8.92536 0.00519 0.00134 2000 209.85395620081130.00000109.021068 21.865121 14.8478860.11459905 2.5982594 2.3005013 9.7 5.00.15 RATE 2.3533160 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.026 0.024 81 1.85 0.025 0 54796.5020081206_0503-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Nov 26, 23:46 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org