IOTA/IOTA-ES occultation update for (1604) Tombaugh / TYC 1802-00439-1 event on 2008 Mar 28, 14:01 UT Visible from E Russia Summary ------- On 2008 Mar 28 UT, the 32 km diameter asteroid (1604) Tombaugh will occult a 10.4 mag star in the constellation Taurus for observers along a path across E Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.1 mag to 16.5 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: UCAC. The event at a glimpse ---------------------- * Rank: 37 * date and approx. time of event: 2008 Mar 28, 14:02 - 2008 Mar 28, 14:03 UT * midpoint of event [JD]: 2454554.08460417 * magnitude of target star: 10.4 * magnitude drop [mag]: 6.1 * estimated maximum duration [s]: 0.9 * Moon: 63 % sunlit, 154° distance * Sun: 50° distance * rough path description: E Russia The occultation path -------------------- * approximate projected width [km]: 48 * 1 sigma uncertainty interval [path widths]: +/- 1.78 * 1 sigma uncertainty interval [seconds]: +/- 1.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .030 +/- .023) * 1 sigma uncertainty ellipse (major, minor, PA): ( .030", .023", 86° ) * approx speed of asteroid's shadow [km/s]: 36.2338 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1802-00439-1 by 1604 Tombaugh 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 ' " Longitude Longitude Longitude Longitude Latitude Latitude Latitude Latitude 72 0 0 73 45 40 14 2 49 34 243 0 73 31 15 74 0 9 72 40 34 74 52 20 73 0 0 73 37 37 14 2 50 34 245 0 73 23 9 73 52 11 72 32 12 74 44 39 74 0 0 73 29 17 14 2 51 34 246 -1 73 14 44 73 43 55 72 23 32 74 36 40 75 0 0 73 20 40 14 2 51 34 247 -1 73 6 2 73 35 23 72 14 34 74 28 25 76 0 0 73 11 45 14 2 52 34 248 -1 72 57 2 73 26 32 72 5 18 74 19 52 77 0 0 73 2 31 14 2 53 33 249 -2 72 47 43 73 17 23 71 55 43 74 11 1 78 0 0 72 52 58 14 2 54 33 250 -2 72 38 6 73 7 55 71 45 49 74 1 52 79 0 0 72 43 6 14 2 55 33 251 -2 72 28 9 72 58 9 71 35 35 73 52 24 80 0 0 72 32 55 14 2 56 33 252 -3 72 17 53 72 48 2 71 25 1 73 42 37 81 0 0 72 22 23 14 2 57 33 254 -3 72 7 16 72 37 36 71 14 6 73 32 30 82 0 0 72 11 31 14 2 57 32 255 -3 71 56 18 72 26 49 71 2 51 73 22 3 83 0 0 72 0 18 14 2 58 32 256 -4 71 45 0 72 15 42 70 51 14 73 11 15 84 0 0 71 48 44 14 2 59 32 257 -4 71 33 20 72 4 13 70 39 16 73 0 6 85 0 0 71 36 47 14 3 0 32 258 -4 71 21 18 71 52 22 70 26 56 72 48 36 86 0 0 71 24 28 14 3 1 31 259 -5 71 8 54 71 40 8 70 14 12 72 36 43 87 0 0 71 11 46 14 3 2 31 260 -5 70 56 6 71 27 32 70 1 6 72 24 28 88 0 0 70 58 41 14 3 3 31 261 -6 70 42 56 71 14 33 69 47 36 72 11 50 89 0 0 70 45 12 14 3 4 30 262 -6 70 29 21 71 1 9 69 33 42 71 58 48 90 0 0 70 31 18 14 3 5 30 264 -6 70 15 22 70 47 21 69 19 23 71 45 22 91 0 0 70 17 0 14 3 6 30 265 -7 70 0 58 70 33 9 69 4 40 71 31 31 92 0 0 70 2 16 14 3 7 29 266 -7 69 46 8 70 18 31 68 49 31 71 17 14 93 0 0 69 47 6 14 3 8 29 267 -8 69 30 53 70 3 27 68 33 56 71 2 32 94 0 0 69 31 30 14 3 9 29 268 -8 69 15 11 69 47 57 68 17 55 70 47 24 95 0 0 69 15 27 14 3 10 28 269 -9 68 59 2 69 31 59 68 1 26 70 31 48 96 0 0 68 58 57 14 3 11 28 270 -9 68 42 26 69 15 35 67 44 31 70 15 45 97 0 0 68 41 58 14 3 12 28 271 -9 68 25 22 68 58 42 67 27 8 69 59 14 98 0 0 68 24 32 14 3 13 27 272 -10 68 7 50 68 41 21 67 9 17 69 42 15 99 0 0 68 6 36 14 3 14 27 273 -10 67 49 49 68 23 31 66 50 57 69 24 46 100 0 0 67 48 12 14 3 15 27 274 -11 67 31 18 68 5 12 66 32 8 69 6 48 101 0 0 67 29 17 14 3 16 26 275 -11 67 12 19 67 46 23 66 12 50 68 48 20 102 0 0 67 9 53 14 3 17 26 277 -12 66 52 49 67 27 4 65 53 2 68 29 21 103 0 0 66 49 58 14 3 18 25 278 -12 66 32 49 67 7 15 65 32 44 68 9 51 104 0 0 66 29 32 14 3 19 25 279 -13 66 12 18 66 46 54 65 11 56 67 49 50 105 0 0 66 8 35 14 3 20 24 280 -13 65 51 16 66 26 3 64 50 38 67 29 18 106 0 0 65 47 7 14 3 21 24 281 -14 65 29 43 66 4 39 64 28 49 67 8 13 107 0 0 65 25 7 14 3 22 23 282 -15 65 7 39 65 42 44 64 6 28 66 46 36 108 0 0 65 2 36 14 3 23 23 283 -15 64 45 3 65 20 17 63 43 37 66 24 26 109 0 0 64 39 32 14 3 24 22 284 -16 64 21 55 64 57 18 63 20 14 66 1 43 110 0 0 64 15 56 14 3 25 22 285 -16 63 58 15 64 33 46 62 56 21 65 38 27 111 0 0 63 51 48 14 3 26 21 286 -17 63 34 3 64 9 42 62 31 56 65 14 38 112 0 0 63 27 8 14 3 27 21 287 -17 63 9 19 63 45 5 62 6 59 64 50 15 113 0 0 63 1 55 14 3 28 20 288 -18 62 44 3 63 19 56 61 41 32 64 25 20 114 0 0 62 36 11 14 3 29 20 289 -19 62 18 15 62 54 15 61 15 33 63 59 50 115 0 0 62 9 54 14 3 30 19 290 -19 61 51 55 62 28 1 60 49 4 63 33 48 116 0 0 61 43 6 14 3 31 19 291 -20 61 25 4 62 1 16 60 22 4 63 7 13 117 0 0 61 15 46 14 3 32 18 292 -21 60 57 42 61 33 59 59 54 34 62 40 5 118 0 0 60 47 55 14 3 33 17 293 -21 60 29 50 61 6 10 59 26 34 62 12 24 119 0 0 60 19 34 14 3 34 17 294 -22 60 1 26 60 37 50 58 58 5 61 44 12 120 0 0 59 50 42 14 3 35 16 295 -23 59 32 33 60 9 0 58 29 7 61 15 28 121 0 0 59 21 21 14 3 36 15 295 -23 59 3 11 59 39 41 57 59 40 60 46 12 122 0 0 58 51 31 14 3 37 15 296 -24 58 33 20 59 9 51 57 29 46 60 16 27 123 0 0 58 21 13 14 3 38 14 297 -25 58 3 1 58 39 34 56 59 26 59 46 11 124 0 0 57 50 27 14 3 39 13 298 -25 57 32 15 58 8 48 56 28 39 59 15 27 125 0 0 57 19 15 14 3 39 13 299 -26 57 1 3 57 37 36 55 57 27 58 44 14 126 0 0 56 47 37 14 3 40 12 300 -27 56 29 26 57 5 58 55 25 50 58 12 35 127 0 0 56 15 34 14 3 41 11 301 -28 55 57 24 56 33 54 54 53 51 57 40 29 128 0 0 55 43 8 14 3 42 10 302 -28 55 24 58 56 1 27 54 21 29 57 7 58 129 0 0 55 10 20 14 3 42 10 303 -29 54 52 11 55 28 37 53 48 46 56 35 3 130 0 0 54 37 10 14 3 43 9 303 -30 54 19 3 54 55 26 53 15 43 56 1 45 131 0 0 54 3 40 14 3 43 8 304 -31 53 45 35 54 21 54 52 42 21 55 28 6 132 0 0 53 29 51 14 3 44 7 305 -31 53 11 48 53 48 3 52 8 42 54 54 6 133 0 0 52 55 45 14 3 44 6 306 -32 52 37 44 53 13 54 51 34 47 54 19 48 134 0 0 52 21 22 14 3 45 5 307 -33 52 3 25 52 39 29 .. .. .. 53 45 12 135 0 0 51 46 45 14 3 45 5 307 -34 51 28 51 52 4 49 .. .. .. 53 10 21 136 0 0 51 11 55 14 3 45 4 308 -34 50 54 4 51 29 55 .. .. .. 52 35 15 137 0 0 50 36 54 14 3 46 3 309 -35 50 19 6 50 54 50 .. .. .. 51 59 56 138 0 0 50 1 42 14 3 46 2 310 -36 49 43 57 50 19 34 .. .. .. 51 24 26 139 0 0 49 26 21 14 3 46 1 311 -36 49 8 41 49 44 10 .. .. .. 50 48 46 140 0 0 48 50 53 14 3 46 0 311 -37 48 33 17 49 8 38 .. .. .. 50 12 58 Uncertainty in time = +/- 2 secs [Prediction of 2008 Feb 14.0] Data for the target star ------------------------ * name: TYC 1802-00439-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 35 27.4509 DE: +26 07 15.897 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .023, .019 ) * V mag [mag]: 10.4 * B mag [mag]: 11.1 * Apparent position with proper motion RA(deg): 53.9861808444 DE(deg): 26.1501323442 * Equation of equinoxes (radians) : 0.000040945825167 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1604) Tombaugh approx. diameter [km]: 32 approx. diameter ["]: .013 distance from Earth [AU]: 3.52500 * orbital information: orbit source: Preston date of fit: 2008 Feb 13 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 856 number of rejected observations: 45 time covered by the observations: 1920 Mar 10 - 2007 Dec 16 1 sigma uncertainty ellipse (major, minor, PA): 0.019, 0.014, 80° remarks: * orbital elements for (1604) Tombaugh : Mean anomaly = 75.93536828 deg Arg. of pericenter = 36.21106276 deg Long. of node = 309.25325091 deg Inclination = 9.37943714 deg Eccentricity = 0.09629305 Semimajor axis = 3.02616728 AU Perihelion dist = 2.73476840 AU Mag: H = 10.35, G = 0.15 Epoch of elements : MJD 54553.58500000 TDT (2008 Mar 28.585) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 28 1604 Tombaugh 14h 1.8m UT 10.4 3 35 27.451 26 7 15.90TYC 1802-00439-1 11.1 16.5 32 0.9 3.525 3.753 6.98 17.0480 26.120 -29.22 3.28 14.0305 -0.10266 0.74202 20.25925 2.79658 0.00422 0.00147 2000 75.2641652008 325.00000 36.211063309.253251 9.3794370.09629305 3.0261673 2.734768410.5 5.00.15 RATE 1.8722540 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.030 0.023 86 2.78 0.023 0 54510.5020080328_0439-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 14, 20:04 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org