IOTA/IOTA-ES occultation update for (99) Dike / TYC 1815-01949-1 event on 2009 Sep 08, 16:03 UT Visible from Summary ------- On 2009 Sep 08 UT, the 82 km diameter asteroid (99) Dike will occult a 9.6 mag star in the constellation Taurus for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 5.7 mag to 15.2 mag (the magnitude of the asteroid) for at most 8.6 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: 87 * date and approx. time of event: 2009 Sep 08, 15:53 - 2009 Sep 08, 16:04 UT * magnitude of target star: 9.6 * magnitude drop [mag]: 5.7 * estimated maximum duration [s]: 8.6 * Moon: 83 % sunlit, 33° distance * Sun: 99° distance * rough path description: Additional comments ------------------- close double star The occultation path -------------------- * approximate projected width [km]: 84 * 1 sigma uncertainty interval [path widths]: +/- 0.57 * 1 sigma uncertainty interval [seconds]: +/- 5.2 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .022) * 1 sigma uncertainty ellipse (major, minor, PA): ( .026", .022", 79° ) * approx speed of asteroid's shadow [km/s]: 9.5563 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1815-01949-1 by 99 Dike on 2009 Sep 8 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 134 34 35 -45 0 0 15 53 19 0 56 -49 135 30 52 ... .. .. 136 34 14 ... .. .. 136 34 58 -44 0 0 15 53 20 2 54 -49 137 28 56 135 40 24 138 29 44 134 37 24 Latitude Latitude Latitude Latitude 137 0 0 -43 47 6 15 53 20 3 54 -49 -44 15 0 -43 19 16 -44 46 53 -42 47 36 138 0 0 -43 15 36 15 53 20 3 53 -49 -43 43 40 -42 47 35 -44 15 45 -42 15 43 139 0 0 -42 43 14 15 53 21 4 53 -50 -43 11 29 -42 15 2 -43 43 46 -41 42 59 140 0 0 -42 10 0 15 53 22 5 52 -50 -42 38 25 -41 41 38 -43 10 54 -41 9 22 141 0 0 -41 35 53 15 53 23 6 51 -50 -42 4 29 -41 7 21 -42 37 11 -40 34 53 142 0 0 -41 0 53 15 53 24 7 51 -50 -41 29 40 -40 32 10 -42 2 33 -39 59 30 143 0 0 -40 24 59 15 53 26 8 50 -50 -40 53 56 -39 56 5 -41 27 2 -39 23 13 144 0 0 -39 48 10 15 53 28 9 49 -50 -40 17 18 -39 19 6 -40 50 37 -38 46 2 145 0 0 -39 10 26 15 53 30 10 49 -50 -39 39 45 -38 41 11 -40 13 16 -38 7 55 146 0 0 -38 31 47 15 53 32 11 48 -50 -39 1 17 -38 2 21 -39 35 0 -37 28 53 147 0 0 -37 52 12 15 53 34 12 47 -50 -38 21 52 -37 22 36 -38 55 47 -36 48 55 148 0 0 -37 11 41 15 53 37 13 47 -50 -37 41 32 -36 41 54 -38 15 39 -36 8 2 149 0 0 -36 30 13 15 53 40 14 46 -50 -37 0 14 -36 0 16 -37 34 34 -35 26 12 150 0 0 -35 47 49 15 53 43 15 45 -50 -36 18 1 -35 17 41 -36 52 32 -34 43 26 151 0 0 -35 4 28 15 53 47 16 45 -50 -35 34 50 -34 34 11 -36 9 33 -33 59 44 152 0 0 -34 20 11 15 53 51 18 44 -49 -34 50 43 -33 49 43 -35 25 37 -33 15 5 153 0 0 -33 34 58 15 53 55 19 44 -49 -34 5 40 -33 4 20 -34 40 45 -32 29 31 154 0 0 -32 48 49 15 53 59 20 43 -49 -33 19 40 -32 18 2 -33 54 57 -31 43 1 155 0 0 -32 1 44 15 54 4 21 42 -49 -32 32 45 -31 30 48 -33 8 12 -30 55 37 156 0 0 -31 13 44 15 54 9 22 42 -48 -31 44 54 -30 42 39 -32 20 32 -30 7 18 157 0 0 -30 24 51 15 54 15 23 41 -48 -30 56 9 -29 53 37 -31 31 57 -29 18 6 158 0 0 -29 35 4 15 54 21 25 41 -47 -30 6 31 -29 3 41 -30 42 29 -28 28 1 159 0 0 -28 44 25 15 54 27 26 40 -47 -29 16 0 -28 12 54 -29 52 7 -27 37 5 160 0 0 -27 52 55 15 54 34 27 40 -47 -28 24 38 -27 21 17 -29 0 53 -26 45 19 161 0 0 -27 0 35 15 54 41 28 39 -46 -27 32 26 -26 28 50 -28 8 50 -25 52 44 162 0 0 -26 7 28 15 54 48 30 39 -46 -26 39 25 -25 35 36 -27 15 57 -24 59 22 163 0 0 -25 13 34 15 54 56 31 38 -45 -25 45 38 -24 41 36 -26 22 17 -24 5 15 164 0 0 -24 18 56 15 55 4 32 37 -44 -24 51 6 -23 46 52 -25 27 51 -23 10 25 165 0 0 -23 23 36 15 55 12 33 37 -44 -23 55 51 -22 51 27 -24 32 43 -22 14 53 166 0 0 -22 27 36 15 55 21 35 36 -43 -22 59 56 -21 55 22 -23 36 53 -21 18 43 167 0 0 -21 30 59 15 55 31 36 36 -42 -22 3 22 -20 58 41 -22 40 24 -20 21 57 168 0 0 -20 33 47 15 55 40 37 35 -42 -21 6 14 -20 1 25 -21 43 20 -19 24 38 169 0 0 -19 36 3 15 55 50 39 35 -41 -20 8 32 -19 3 38 -20 45 42 -18 26 48 170 0 0 -18 37 50 15 56 1 40 34 -40 -19 10 22 -18 5 23 -19 47 34 -17 28 30 171 0 0 -17 39 10 15 56 12 41 34 -39 -18 11 44 -17 6 42 -18 48 58 -16 29 47 172 0 0 -16 40 9 15 56 23 43 33 -38 -17 12 43 -16 7 40 -17 49 58 -15 30 44 173 0 0 -15 40 48 15 56 35 44 32 -37 -16 13 22 -15 8 18 -16 50 38 -14 31 22 174 0 0 -14 41 11 15 56 47 46 32 -36 -15 13 45 -14 8 42 -15 51 0 -13 31 46 175 0 0 -13 41 21 15 56 59 47 31 -35 -14 13 55 -13 8 54 -14 51 8 -12 32 0 176 0 0 -12 41 24 15 57 11 48 31 -34 -13 13 55 -12 8 58 -13 51 6 -11 32 6 177 0 0 -11 41 21 15 57 24 50 30 -33 -12 13 49 -11 8 57 -12 50 58 -10 32 8 178 0 0 -10 41 16 15 57 38 51 29 -32 -11 13 42 -10 8 56 -11 50 47 - 9 32 11 179 0 0 - 9 41 15 15 57 51 52 28 -31 -10 13 36 - 9 8 58 -10 50 37 - 8 32 17 180 0 0 - 8 41 19 15 58 5 54 28 -30 - 9 13 36 - 8 9 7 - 9 50 31 - 7 32 32 -179 0 0 - 7 41 33 15 58 19 55 27 -29 - 8 13 45 - 7 9 27 - 8 50 34 - 6 32 57 -178 0 0 - 6 42 1 15 58 33 57 26 -28 - 7 14 7 - 6 10 0 - 7 50 49 - 5 33 37 -177 0 0 - 5 42 45 15 58 48 58 25 -27 - 6 14 45 - 5 10 51 - 6 51 20 - 4 34 36 -176 0 0 - 4 43 51 15 59 2 59 24 -26 - 5 15 43 - 4 12 4 - 5 52 10 - 3 35 56 -175 0 0 - 3 45 20 15 59 17 61 23 -25 - 4 17 5 - 3 13 40 - 4 53 23 - 2 37 41 -174 0 0 - 2 47 16 15 59 32 62 22 -24 - 3 18 53 - 2 15 45 - 3 55 2 - 1 39 55 -173 0 0 - 1 49 43 15 59 47 63 20 -23 - 2 21 11 - 1 18 20 - 2 57 10 - 0 42 40 -172 0 0 - 0 52 43 16 0 3 64 19 -21 - 1 24 3 - 0 21 30 - 1 59 51 0 14 0 -171 0 0 0 3 40 16 0 18 66 17 -20 - 0 27 30 0 34 44 - 1 3 7 1 10 4 -170 0 0 0 59 24 16 0 34 67 16 -19 0 28 25 1 30 19 - 0 7 2 2 5 27 -169 0 0 1 54 27 16 0 49 68 14 -18 1 23 38 2 25 12 0 48 23 3 0 8 -168 0 0 2 48 46 16 1 4 69 12 -17 2 18 7 3 19 20 1 43 5 3 54 4 -167 0 0 3 42 19 16 1 20 70 10 -16 3 11 51 4 12 42 2 37 1 4 47 14 -166 0 0 4 35 4 16 1 36 71 7 -14 4 4 47 5 5 16 3 30 10 5 39 35 -165 0 0 5 26 59 16 1 51 72 4 -13 4 56 53 5 56 59 4 22 29 6 31 6 -164 0 0 6 18 2 16 2 7 73 1 -12 5 48 8 6 47 51 5 13 57 7 21 45 -163 0 0 7 8 12 16 2 22 74 358 -11 6 38 29 7 37 49 6 4 32 8 11 30 -162 0 0 7 57 27 16 2 37 74 354 -10 7 27 57 8 26 53 6 54 12 9 0 21 -161 0 0 8 45 47 16 2 53 75 350 -9 8 16 28 9 15 1 7 42 58 9 48 15 -160 0 0 9 33 10 16 3 8 76 345 -8 9 4 4 10 2 13 8 30 47 10 35 13 -159 0 0 10 19 36 16 3 23 76 341 -6 9 50 41 10 48 26 9 17 38 11 21 14 -158 0 0 11 5 4 16 3 38 76 336 -5 10 36 21 11 33 42 10 3 31 12 6 16 -157 0 0 11 49 32 16 3 53 77 331 -4 11 21 2 12 17 59 10 48 26 12 50 19 -156 0 0 12 33 2 16 4 7 77 325 -3 12 4 43 13 1 17 11 32 21 13 33 23 -155 0 0 13 15 32 16 4 22 77 320 -2 12 47 25 13 43 35 12 15 16 14 15 28 -154 0 0 13 57 2 16 4 36 76 316 -1 13 29 6 14 24 53 12 57 11 14 56 34 Uncertainty in time = +/- 6 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: TYC 1815-01949-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 04 18 10.8556 DE: +23 17 04.375 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .020, .019 ) * V mag [mag]: 9.6 * B mag [mag]: 10.4 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (99) Dike approx. diameter [km]: 82 approx. diameter ["]: .040 distance from Earth [AU]: 2.85800 * orbital information: orbit source: Preston date of fit: 2008 Mar 20 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 706 number of rejected observations: 66 time covered by the observations: 1915 Jan 20 - 2007 Aug 14 1 sigma uncertainty ellipse (major, minor, PA): 0.017, 0.012, 64° remarks: * orbital elements for (99) Dike : Mean anomaly = 167.26360098 deg Arg. of pericenter = 195.79641618 deg Long. of node = 41.64118712 deg Inclination = 13.85445543 deg Eccentricity = 0.19712581 Semimajor axis = 2.66316042 AU Perihelion dist = 2.13818277 AU Mag: H = 9.48, G = 0.15 Epoch of elements : MJD 55082.66900000 TDT (2009 Sep 08.669) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Sep 8 99 Dike 16h 4.1m UT 9.6 4 18 10.856 23 17 4.38TYC 1815-01949-1 10.4 15.2 82 8.6 2.858 0.961 10.00 -164.3387 23.282 -61.64 5.47 16.0688 0.13938 -0.18384 4.30510 3.24952 -0.00557 -0.00100 2000 166.6583212009 9 6.00000195.796416 41.641187 13.8544550.19712581 2.6631604 2.1381828 9.4 5.00.15 RATE 2.2678170 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.026 0.022 79 1.57 0.022 0 54545.5020090908_1949-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 13:01 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org