IOTA/IOTA-ES occultation update for (886) Washingtonia / TYC 1799-00974-1 event on 2008 Mar 28, 02:34 UT Visible from USA, Mexico Summary ------- On 2008 Mar 28 UT, the 93 km diameter asteroid (886) Washingtonia will occult a 10.3 mag star in the constellation Taurus for observers along a path across USA, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 4.1 mag to 14.4 mag (the magnitude of the asteroid) for at most 2.6 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: 82 * date and approx. time of event: 2008 Mar 28, 02:36 - 2008 Mar 28, 02:37 UT * midpoint of event [JD]: 2454553.60731667 * magnitude of target star: 10.3 * magnitude drop [mag]: 4.1 * estimated maximum duration [s]: 2.6 * Moon: 67 % sunlit, 162° distance * Sun: 52° distance * rough path description: USA, Mexico The occultation path -------------------- * approximate projected width [km]: 93 * 1 sigma uncertainty interval [path widths]: +/- 0.65 * 1 sigma uncertainty interval [seconds]: +/- 2.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .038 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .038", .025", 83° ) * approx speed of asteroid's shadow [km/s]: 36.2745 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1799-00974-1 by 886 Washingtonia on 2008 Mar 28 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 -125 0 0 32 44 57 2 36 22 51 269 -1 32 19 46 33 10 9 31 47 1 33 42 56 -124 0 0 32 43 5 2 36 24 50 269 -2 32 17 53 33 8 17 31 45 7 33 41 5 -123 0 0 32 40 45 2 36 26 49 270 -2 32 15 33 33 5 59 31 42 46 33 38 46 -122 0 0 32 37 59 2 36 28 48 271 -3 32 12 45 33 3 13 31 39 58 33 36 1 -121 0 0 32 34 45 2 36 30 48 271 -4 32 9 30 32 59 59 31 36 42 33 32 49 -120 0 0 32 31 3 2 36 32 47 272 -5 32 5 48 32 56 19 31 32 58 33 29 10 -119 0 0 32 26 55 2 36 34 46 272 -6 32 1 38 32 52 11 31 28 47 33 25 4 -118 0 0 32 22 19 2 36 36 45 273 -7 31 57 1 32 47 37 31 24 8 33 20 31 -117 0 0 32 17 15 2 36 38 44 274 -8 31 51 56 32 42 35 31 19 2 33 15 31 -116 0 0 32 11 44 2 36 40 43 274 -8 31 46 24 32 37 5 31 13 27 33 10 3 -115 0 0 32 5 46 2 36 42 43 275 -9 31 40 24 32 31 8 31 7 25 33 4 8 -114 0 0 31 59 20 2 36 43 42 275 -10 31 33 56 32 24 44 31 0 56 32 57 47 -113 0 0 31 52 26 2 36 45 41 276 -11 31 27 1 32 17 53 30 53 58 32 50 57 -112 0 0 31 45 5 2 36 47 40 276 -12 31 19 38 32 10 33 30 46 32 32 43 40 -111 0 0 31 37 16 2 36 48 39 277 -13 31 11 47 32 2 46 30 38 39 32 35 56 -110 0 0 31 29 0 2 36 50 38 277 -14 31 3 28 31 54 32 30 30 17 32 27 45 -109 0 0 31 20 15 2 36 52 37 278 -14 30 54 41 31 45 50 30 21 28 32 19 5 -108 0 0 31 11 3 2 36 53 36 279 -15 30 45 27 31 36 40 30 12 10 32 9 58 -107 0 0 31 1 23 2 36 55 36 279 -16 30 35 44 31 27 2 30 2 24 32 0 24 -106 0 0 30 51 14 2 36 57 35 280 -17 30 25 33 31 16 56 29 52 10 31 50 21 -105 0 0 30 40 38 2 36 58 34 280 -18 30 14 54 31 6 22 29 41 27 31 39 51 -104 0 0 30 29 33 2 37 0 33 281 -19 30 3 46 30 55 21 29 30 16 31 28 53 -103 0 0 30 18 0 2 37 1 32 281 -20 29 52 11 30 43 51 29 18 37 31 17 27 -102 0 0 30 5 59 2 37 2 31 282 -21 29 40 7 30 31 53 29 6 29 31 5 33 -101 0 0 29 53 30 2 37 4 30 282 -22 29 27 34 30 19 26 28 53 52 30 53 10 -100 0 0 29 40 32 2 37 5 29 283 -22 29 14 33 30 6 31 28 40 47 30 40 19 - 99 0 0 29 27 6 2 37 7 28 283 -23 29 1 3 29 53 8 28 27 13 30 27 1 - 98 0 0 29 13 11 2 37 8 28 284 -24 28 47 5 29 39 17 28 13 11 30 13 13 - 97 0 0 28 58 47 2 37 9 27 284 -25 28 32 38 29 24 57 27 58 39 29 58 58 - 96 0 0 28 43 55 2 37 10 26 285 -26 28 17 43 29 10 8 27 43 39 29 44 14 - 95 0 0 28 28 34 2 37 12 25 285 -27 28 2 18 28 54 51 27 28 10 29 29 1 - 94 0 0 28 12 45 2 37 13 24 286 -28 27 46 25 28 39 5 27 12 12 29 13 20 - 93 0 0 27 56 26 2 37 14 23 286 -29 27 30 3 28 22 50 26 55 45 28 57 10 - 92 0 0 27 39 39 2 37 15 22 287 -30 27 13 12 28 6 7 26 38 50 28 40 32 - 91 0 0 27 22 23 2 37 16 21 287 -31 26 55 53 27 48 55 26 21 25 28 23 25 - 90 0 0 27 4 39 2 37 17 20 288 -32 26 38 4 27 31 14 26 3 31 28 5 49 - 89 0 0 26 46 25 2 37 18 19 288 -33 26 19 47 27 13 5 25 45 9 27 47 45 - 88 0 0 26 27 43 2 37 19 18 288 -33 26 1 0 26 54 27 25 26 17 27 29 12 - 87 0 0 26 8 32 2 37 20 17 289 -34 25 41 45 26 35 20 25 6 57 27 10 10 - 86 0 0 25 48 53 2 37 21 16 289 -35 25 22 2 26 15 44 24 47 8 26 50 40 - 85 0 0 25 28 44 2 37 22 15 290 -36 25 1 49 25 55 40 24 26 50 26 30 41 - 84 0 0 25 8 7 2 37 22 14 290 -37 24 41 8 25 35 7 24 6 4 26 10 14 - 83 0 0 24 47 2 2 37 23 13 291 -38 24 19 58 25 14 6 23 44 49 25 49 18 - 82 0 0 24 25 28 2 37 24 12 291 -39 23 58 20 24 52 36 23 23 5 25 27 54 - 81 0 0 24 3 26 2 37 24 11 291 -40 23 36 14 24 30 38 23 0 53 25 6 1 - 80 0 0 23 40 55 2 37 25 10 292 -41 23 13 39 24 8 12 22 38 13 24 43 41 - 79 0 0 23 17 57 2 37 26 9 292 -42 22 50 36 23 45 18 22 15 5 24 20 52 - 78 0 0 22 54 31 2 37 26 8 293 -43 22 27 6 23 21 56 21 51 29 23 57 36 - 77 0 0 22 30 37 2 37 26 7 293 -44 22 3 8 22 58 6 21 27 25 23 33 52 - 76 0 0 22 6 15 2 37 27 6 293 -45 21 38 42 22 33 49 21 2 54 23 9 40 - 75 0 0 21 41 26 2 37 27 5 294 -46 21 13 49 22 9 4 20 37 55 22 45 1 - 74 0 0 21 16 11 2 37 27 4 294 -47 20 48 29 21 43 53 20 12 30 22 19 55 - 73 0 0 20 50 28 2 37 28 3 295 -48 20 22 43 21 18 15 19 46 38 21 54 22 - 72 0 0 20 24 20 2 37 28 2 295 -49 19 56 30 20 52 10 19 20 20 21 28 23 - 71 0 0 19 57 45 2 37 28 1 295 -50 19 29 51 20 25 40 18 53 35 21 1 58 - 70 0 0 19 30 44 2 37 28 0 296 -51 19 2 46 19 58 43 .. .. .. 20 35 7 Uncertainty in time = +/- 2 secs [Prediction of 2008 Feb 14.0] Data for the target star ------------------------ * name: TYC 1799-00974-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 45 35.4116 DE: +24 04 59.205 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .034, .022 ) * V mag [mag]: 10.3 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 56.5185921884 DE(deg): 24.1104323726 * Equation of equinoxes (radians) : 0.000040832533714 * remarks:no mean pos in Tycho2 Data for the minor planet ------------------------- * general information: (number) name: (886) Washingtonia approx. diameter [km]: 93 approx. diameter ["]: .039 distance from Earth [AU]: 3.28900 * orbital information: orbit source: Preston date of fit: 2008 Feb 13 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 588 number of rejected observations: 62 time covered by the observations: 1910 Jun 03 - 2007 Dec 05 1 sigma uncertainty ellipse (major, minor, PA): 0.018, 0.012, 58° remarks: * orbital elements for (886) Washingtonia : Mean anomaly = 48.83157084 deg Arg. of pericenter = 300.43613074 deg Long. of node = 59.63629332 deg Inclination = 16.83285944 deg Eccentricity = 0.26348730 Semimajor axis = 3.17901976 AU Perihelion dist = 2.34138841 AU Mag: H = 9.22, G = 0.15 Epoch of elements : MJD 54553.10700000 TDT (2008 Mar 28.107) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 28 886 Washingtonia 2h 34.5m UT 10.3 3 45 35.412 24 4 59.20TYC 1799-00974-1 0.0 14.4 93 2.6 3.289 3.784 17.64 -168.1247 24.078 142.64 3.09 2.5756 -0.01452 0.03925 19.38207 6.59809 0.00438 0.00125 2000 48.2913082008 325.00000300.436131 59.636293 16.8328590.26348730 3.1790198 2.3413884 8.7 5.00.15 RATE 1.7388580 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.038 0.025 83 1.65 0.025 0 54510.5020080328_0974-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 14, 20:00 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org