IOTA/IOTA-ES occultation update for (1832) Mrkos / TYC 7346-00845-1 event on 2008 Oct 14, 10:30 UT Visible from SE Australia Summary ------- On 2008 Oct 14 UT, the 31 km diameter asteroid (1832) Mrkos will occult a 9.3 mag star in the constellation Scorpius for observers along a path across SE Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 8.1 mag to 17.4 mag (the magnitude of the asteroid) for at most 0.9 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: 17 * date and approx. time of event: 2008 Oct 14, 10:31 - 2008 Oct 14, 10:33 UT * midpoint of event [JD]: 2454753.93777083 * magnitude of target star: 9.3 * magnitude drop [mag]: 8.1 * estimated maximum duration [s]: 0.9 * Moon: 100 % sunlit, 122° distance * Sun: 52° distance * rough path description: SE Australia The occultation path -------------------- * approximate projected width [km]: 34 * 1 sigma uncertainty interval [path widths]: +/- 3.98 * 1 sigma uncertainty interval [seconds]: +/- 3.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .053 +/- .044) * 1 sigma uncertainty ellipse (major, minor, PA): ( .053", .044", 89° ) * approx speed of asteroid's shadow [km/s]: 34.2554 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 7346-00845-1 by 1832 Mrkos on 2008 Oct 14 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 117 0 0 -45 19 57 10 31 58 50 275 0 -45 30 7 -45 9 48 -46 51 33 -43 49 29 118 0 0 -44 59 4 10 32 0 49 274 -1 -45 9 16 -44 48 53 -46 30 58 -43 28 18 119 0 0 -44 37 42 10 32 2 48 273 -2 -44 47 56 -44 27 29 -46 9 55 -43 6 38 120 0 0 -44 15 51 10 32 5 48 271 -2 -44 26 7 -44 5 36 -45 48 23 -42 44 30 121 0 0 -43 53 33 10 32 7 47 270 -3 -44 3 51 -43 43 15 -45 26 22 -42 21 54 122 0 0 -43 30 45 10 32 9 46 269 -4 -43 41 5 -43 20 26 -45 3 53 -41 58 49 123 0 0 -43 7 29 10 32 11 46 268 -5 -43 17 51 -42 57 8 -44 40 55 -41 35 15 124 0 0 -42 43 44 10 32 13 45 267 -6 -42 54 8 -42 33 21 -44 17 28 -41 11 13 125 0 0 -42 19 31 10 32 15 44 266 -6 -42 29 57 -42 9 6 -43 53 33 -40 46 43 126 0 0 -41 54 49 10 32 17 43 265 -7 -42 5 17 -41 44 23 -43 29 9 -40 21 44 127 0 0 -41 29 39 10 32 19 42 264 -8 -41 40 9 -41 19 11 -43 4 16 -39 56 18 128 0 0 -41 4 1 10 32 21 42 263 -9 -41 14 33 -40 53 30 -42 38 55 -39 30 23 129 0 0 -40 37 54 10 32 23 41 262 -10 -40 48 28 -40 27 22 -42 13 5 -39 4 0 130 0 0 -40 11 20 10 32 26 40 261 -11 -40 21 55 -40 0 46 -41 46 47 -38 37 10 131 0 0 -39 44 18 10 32 28 39 260 -12 -39 54 55 -39 33 42 -41 20 1 -38 9 52 132 0 0 -39 16 48 10 32 30 38 259 -12 -39 27 27 -39 6 10 -40 52 47 -37 42 8 133 0 0 -38 48 51 10 32 32 37 259 -13 -38 59 32 -38 38 12 -40 25 5 -37 13 56 134 0 0 -38 20 27 10 32 34 37 258 -14 -38 31 9 -38 9 46 -39 56 56 -36 45 18 135 0 0 -37 51 37 10 32 35 36 257 -15 -38 2 21 -37 40 55 -39 28 20 -36 16 14 136 0 0 -37 22 21 10 32 37 35 256 -16 -37 33 6 -37 11 37 -38 59 18 -35 46 44 137 0 0 -36 52 38 10 32 39 34 255 -17 -37 3 25 -36 41 53 -38 29 49 -35 16 49 138 0 0 -36 22 31 10 32 41 33 254 -18 -36 33 19 -36 11 44 -37 59 54 -34 46 30 139 0 0 -35 51 59 10 32 43 32 254 -19 -36 2 48 -35 41 10 -37 29 34 -34 15 46 140 0 0 -35 21 2 10 32 45 31 253 -20 -35 31 53 -35 10 13 -36 58 49 -33 44 38 141 0 0 -34 49 42 10 32 47 30 252 -21 -35 0 34 -34 38 52 -36 27 40 -33 13 8 142 0 0 -34 17 59 10 32 48 29 252 -22 -34 28 52 -34 7 8 -35 56 7 -32 41 15 143 0 0 -33 45 54 10 32 50 28 251 -23 -33 56 48 -33 35 1 -35 24 11 -32 9 1 144 0 0 -33 13 27 10 32 52 27 250 -24 -33 24 22 -33 2 33 -34 51 53 -31 36 26 145 0 0 -32 40 40 10 32 53 26 250 -25 -32 51 35 -32 29 45 -34 19 14 -31 3 31 146 0 0 -32 7 32 10 32 55 25 249 -26 -32 18 29 -31 56 37 -33 46 13 -30 30 16 147 0 0 -31 34 5 10 32 56 24 248 -27 -31 45 2 -31 23 9 -33 12 53 -29 56 43 148 0 0 -31 0 20 10 32 58 23 248 -28 -31 11 18 -30 49 23 -32 39 14 -29 22 53 149 0 0 -30 26 18 10 32 59 22 247 -29 -30 37 16 -30 15 21 -32 5 16 -28 48 46 150 0 0 -29 51 59 10 33 1 21 246 -30 -30 2 58 -29 41 1 -31 31 1 -28 14 23 151 0 0 -29 17 25 10 33 2 20 246 -31 -29 28 24 -29 6 27 -30 56 30 -27 39 46 152 0 0 -28 42 36 10 33 3 19 245 -32 -28 53 35 -28 31 38 -30 21 44 -27 4 55 153 0 0 -28 7 34 10 33 4 18 245 -33 -28 18 33 -27 56 35 -29 46 44 -26 29 51 154 0 0 -27 32 20 10 33 6 17 244 -34 -27 43 19 -27 21 21 -29 11 30 -25 54 36 155 0 0 -26 56 54 10 33 7 16 244 -35 -27 7 54 -26 45 55 -28 36 4 -25 19 10 156 0 0 -26 21 18 10 33 8 15 243 -36 -26 32 18 -26 10 20 -28 0 28 -24 43 36 157 0 0 -25 45 34 10 33 9 14 243 -37 -25 56 33 -25 34 36 -27 24 42 -24 7 53 158 0 0 -25 9 42 10 33 9 13 242 -39 -25 20 41 -24 58 44 -26 48 47 -23 32 3 159 0 0 -24 33 43 10 33 10 12 242 -40 -24 44 41 -24 22 45 -26 12 45 -22 56 8 160 0 0 -23 57 39 10 33 11 11 242 -41 -24 8 37 -23 46 41 -25 36 36 -22 20 8 161 0 0 -23 21 30 10 33 12 10 241 -42 -23 32 28 -23 10 34 -25 0 23 -21 44 4 162 0 0 -22 45 19 10 33 12 8 241 -43 -22 56 16 -22 34 23 -24 24 6 -21 7 58 163 0 0 -22 9 6 10 33 13 7 240 -44 -22 20 2 -21 58 11 -23 47 46 -20 31 52 164 0 0 -21 32 53 10 33 13 6 240 -45 -21 43 48 -21 21 58 -23 11 26 .. .. .. 165 0 0 -20 56 40 10 33 14 5 240 -46 -21 7 35 -20 45 47 -22 35 5 .. .. .. 166 0 0 -20 20 30 10 33 14 4 239 -47 -20 31 23 -20 9 37 -21 58 46 .. .. .. 167 0 0 -19 44 22 10 33 14 3 239 -48 -19 55 15 -19 33 31 -21 22 29 .. .. .. 168 0 0 -19 8 20 10 33 15 2 239 -50 -19 19 11 -18 57 29 -20 46 16 .. .. .. 169 0 0 -18 32 22 10 33 15 1 238 -51 -18 43 13 -18 21 33 -20 10 8 .. .. .. Uncertainty in time = +/- 4 secs [Prediction of 2008 Sep 11.0] Data for the target star ------------------------ * name: TYC 7346-00845-1 * constellation : Scorpius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 16 40 54.6016 DE: -30 11 51.561 * position source: mpos:TYC pm:TYC * standard error: RA,DE ["]: ( .038, .038 ) * V mag [mag]: 9.3 * B mag [mag]: 9.6 * Apparent position with proper motion RA(deg): 250.3656086459 DE(deg): -30.2164957288 * Equation of equinoxes (radians) : 0.000047390137311 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1832) Mrkos approx. diameter [km]: 31 approx. diameter ["]: .011 distance from Earth [AU]: 3.88400 * orbital information: orbit source: Preston date of fit: 2008 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 685 number of rejected observations: 12 time covered by the observations: 1937 Feb 05 - 2008 Jun 24 1 sigma uncertainty ellipse (major, minor, PA): 0.036, 0.021, 87° remarks: * orbital elements for (1832) Mrkos : Mean anomaly = 250.42352644 deg Arg. of pericenter = 82.74255325 deg Long. of node = 303.54965773 deg Inclination = 14.97554426 deg Eccentricity = 0.10960457 Semimajor axis = 3.21250682 AU Perihelion dist = 2.86040138 AU Mag: H = 11.24, G = 0.15 Epoch of elements : MJD 54753.43800000 TDT (2008 Oct 14.438) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 14 1832 Mrkos 10h 30.4m UT 9.3 16 40 54.602-30 11 51.56TYC 7346-00845-1 9.6 17.4 31 0.9 3.884 3.374 1.70 69.2855 -30.198 18.89 -8.37 10.5065 0.01422 -0.39401 19.32012 0.75108 0.00448 -0.00113 2000 249.83503020081011.00000 82.742553303.549658 14.9755440.10960457 3.2125068 2.860401411.0 5.00.15 RATE 1.7117400 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.053 0.044 89 4.98 0.044 0 54720.5020081014_0845-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Sep 11, 19:16 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org