IOTA/IOTA-ES occultation update for (224) Oceana / TYC 5817-00421-1 event on 2008 May 09, 05:07 UT Visible from W Africa Summary ------- On 2008 May 09 UT, the 58 km diameter asteroid (224) Oceana will occult a 8.8 mag star in the constellation Aquarius for observers along a path across W Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.0 mag to 13.8 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: 70 * date and approx. time of event: 2008 May 09, 05:04 - 2008 May 09, 05:06 UT * midpoint of event [JD]: 2454595.71338333 * magnitude of target star: 8.8 * magnitude drop [mag]: 5.0 * estimated maximum duration [s]: 2.2 * Moon: 19 % sunlit, 125° distance * Sun: 73° distance * rough path description: W Africa The occultation path -------------------- * approximate projected width [km]: 100 * 1 sigma uncertainty interval [path widths]: +/- 0.84 * 1 sigma uncertainty interval [seconds]: +/- 2.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .028 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .025", 80° ) * approx speed of asteroid's shadow [km/s]: 26.3507 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5817-00421-1 by 224 Oceana on 2008 May 9 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 Latitude Latitude Latitude Latitude 0 0 0 33 23 28 5 6 31 33 138 0 32 54 40 33 52 37 32 7 5 34 42 29 - 1 0 0 33 5 34 5 6 27 33 137 -1 32 36 54 33 34 36 31 49 31 34 24 13 - 2 0 0 32 48 20 5 6 24 32 136 -2 32 19 48 33 17 14 31 32 36 34 6 38 - 3 0 0 32 31 46 5 6 20 32 135 -3 32 3 21 33 0 33 31 16 20 33 49 44 - 4 0 0 32 15 53 5 6 17 32 133 -4 31 47 34 32 44 33 31 0 44 33 33 32 - 5 0 0 32 0 40 5 6 13 31 132 -5 31 32 27 32 29 13 30 45 48 33 18 0 - 6 0 0 31 46 7 5 6 10 31 131 -6 31 18 1 32 14 34 30 31 31 33 3 10 - 7 0 0 31 32 16 5 6 7 30 131 -7 31 4 15 32 0 36 30 17 54 32 49 2 - 8 0 0 31 19 5 5 6 4 30 130 -8 30 51 10 31 47 20 30 4 58 32 35 35 - 9 0 0 31 6 35 5 6 0 29 129 -8 30 38 45 31 34 45 29 52 42 32 22 51 - 10 0 0 30 54 47 5 5 57 29 128 -9 30 27 2 31 22 51 29 41 7 32 10 48 - 11 0 0 30 43 40 5 5 54 28 127 -10 30 15 59 31 11 40 29 30 12 31 59 28 - 12 0 0 30 33 14 5 5 51 27 126 -11 30 5 38 31 1 9 29 19 58 31 48 49 - 13 0 0 30 23 30 5 5 48 27 125 -12 29 55 58 30 51 21 29 10 24 31 38 53 - 14 0 0 30 14 27 5 5 45 26 124 -13 29 46 59 30 42 14 29 1 32 31 29 40 - 15 0 0 30 6 6 5 5 42 25 124 -14 29 38 42 30 33 50 28 53 20 31 21 9 - 16 0 0 29 58 27 5 5 40 25 123 -14 29 31 6 30 26 7 28 45 49 31 13 20 - 17 0 0 29 51 29 5 5 37 24 122 -15 29 24 11 30 19 6 28 38 59 31 6 14 - 18 0 0 29 45 14 5 5 34 23 121 -16 29 17 58 30 12 48 28 32 50 30 59 51 - 19 0 0 29 39 40 5 5 32 23 121 -17 29 12 26 30 7 11 28 27 23 30 54 10 - 20 0 0 29 34 47 5 5 29 22 120 -18 29 7 36 30 2 17 28 22 36 30 49 11 - 21 0 0 29 30 37 5 5 27 21 119 -18 29 3 28 29 58 4 28 18 30 30 44 55 - 22 0 0 29 27 8 5 5 25 21 118 -19 29 0 0 29 54 34 28 15 6 30 41 22 - 23 0 0 29 24 21 5 5 23 20 118 -20 28 57 15 29 51 45 28 12 22 30 38 31 - 24 0 0 29 22 16 5 5 20 19 117 -21 28 55 11 29 49 39 28 10 20 30 36 23 - 25 0 0 29 20 52 5 5 18 18 117 -21 28 53 48 29 48 15 28 8 58 30 34 57 - 26 0 0 29 20 10 5 5 16 17 116 -22 28 53 6 29 47 32 28 8 17 30 34 14 - 27 0 0 29 20 10 5 5 15 17 115 -23 28 53 6 29 47 32 28 8 18 30 34 13 - 28 0 0 29 20 51 5 5 13 16 115 -23 28 53 48 29 48 13 28 8 59 30 34 54 - 29 0 0 29 22 14 5 5 11 15 114 -24 28 55 10 29 49 36 28 10 21 30 36 18 - 30 0 0 29 24 19 5 5 9 14 114 -25 28 57 14 29 51 41 28 12 24 30 38 24 - 31 0 0 29 27 5 5 5 8 13 113 -25 28 59 59 29 54 28 28 15 8 30 41 13 - 32 0 0 29 30 32 5 5 6 13 112 -26 29 3 25 29 57 57 28 18 32 30 44 43 - 33 0 0 29 34 40 5 5 5 12 112 -27 29 7 32 30 2 6 28 22 37 30 48 55 - 34 0 0 29 39 30 5 5 4 11 111 -27 29 12 20 30 6 58 28 27 22 30 53 50 - 35 0 0 29 45 1 5 5 3 10 111 -28 29 17 49 30 12 31 28 32 48 30 59 26 - 36 0 0 29 51 13 5 5 2 9 110 -28 29 23 59 30 18 45 28 38 54 31 5 44 - 37 0 0 29 58 5 5 5 1 8 110 -29 29 30 49 30 25 40 28 45 40 31 12 44 - 38 0 0 30 5 39 5 5 0 8 109 -29 29 38 20 30 33 17 28 53 7 31 20 26 - 39 0 0 30 13 53 5 4 59 7 109 -30 29 46 31 30 41 34 29 1 13 31 28 49 - 40 0 0 30 22 48 5 4 58 6 108 -30 29 55 23 30 50 32 29 9 59 31 37 53 - 41 0 0 30 32 23 5 4 58 5 108 -31 30 4 54 31 0 11 .. .. .. 31 47 38 - 42 0 0 30 42 39 5 4 57 4 107 -31 30 15 6 31 10 31 .. .. .. 31 58 5 - 43 0 0 30 53 34 5 4 57 3 107 -32 30 25 57 31 21 30 .. .. .. 32 9 12 - 44 0 0 31 5 10 5 4 56 2 106 -32 30 37 29 31 33 11 .. .. .. 32 21 0 - 45 0 0 31 17 25 5 4 56 1 106 -32 30 49 39 31 45 31 .. .. .. 32 33 29 - 46 0 0 31 30 20 5 4 56 1 105 -33 31 2 29 31 58 31 .. .. .. 32 46 38 Uncertainty in time = +/- 2 secs [Prediction of 2008 Feb 17.0] Data for the target star ------------------------ * name: TYC 5817-00421-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 22 36 19.8831 DE: -12 37 41.572 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .023, .023 ) * V mag [mag]: 8.8 * B mag [mag]: 10.4 * Apparent position with proper motion RA(deg): 339.1945942450 DE(deg): -12.5848723241 * Equation of equinoxes (radians) : 0.000040254317021 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (224) Oceana approx. diameter [km]: 58 approx. diameter ["]: .030 distance from Earth [AU]: 2.65500 * orbital information: orbit source: Preston date of fit: 2008 Feb 16 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 649 number of rejected observations: 116 time covered by the observations: 1910 Dec 21 - 2007 Oct 04 1 sigma uncertainty ellipse (major, minor, PA): 0.017, 0.010, 61° remarks: * orbital elements for (224) Oceana : Mean anomaly = 34.81015201 deg Arg. of pericenter = 282.61701601 deg Long. of node = 352.92438168 deg Inclination = 5.83754799 deg Eccentricity = 0.04601274 Semimajor axis = 2.64535288 AU Perihelion dist = 2.52363296 AU Mag: H = 8.47, G = 0.15 Epoch of elements : MJD 54595.21300000 TDT (2008 May 09.213) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 9 224 Oceana 5h 7.3m UT 8.8 22 36 19.883-12 37 41.57TYC 5817-00421-1 10.4 13.8 58 2.2 2.655 3.115 18.68 34.8748 -12.633 102.30 17.46 5.1212 -0.30821 0.75392 13.76263 5.63898 -0.00491 -0.00208 2000 33.6159812008 5 4.00000282.617016352.924382 5.8375480.04601274 2.6453529 2.5236329 8.6 5.00.15 RATE 2.2907550 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.025 80 1.84 0.025 0 54513.5020080509_0421-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 31, 04:20 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org