IOTA/IOTA-ES occultation update for (426) Hippo / TYC 5490-01153-1 event on 2008 May 20, 02:31 UT Visible from Brazil, Argentina, Chile Summary ------- On 2008 May 20 UT, the 127 km diameter asteroid (426) Hippo will occult a 11.8 mag star in the constellation Sextans for observers along a path across Brazil, Argentina, Chile. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.7 mag to 13.3 mag (the magnitude of the asteroid) for at most 10.2 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: 99 * date and approx. time of event: 2008 May 20, 02:29 - 2008 May 20, 02:39 UT * magnitude of target star: 11.8 * magnitude drop [mag]: 1.7 * estimated maximum duration [s]: 10.2 * Moon: 100 % sunlit, 81° distance * Sun: 98° distance * rough path description: Brazil, Argentina, Chile The occultation path -------------------- * approximate projected width [km]: 132 * 1 sigma uncertainty interval [path widths]: +/- 0.31 * 1 sigma uncertainty interval [seconds]: +/- 2.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .022 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .026", .021", 160° ) * approx speed of asteroid's shadow [km/s]: 12.5061 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5490-01153-1 by 426 Hippo on 2008 May 20 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 -136 0 0 -20 43 9 2 29 34 72 48 0 -21 19 55 -20 6 29 -21 42 46 -19 43 49 -135 0 0 -20 56 39 2 29 43 72 45 -1 -21 33 24 -20 20 1 -21 56 15 -19 57 21 -134 0 0 -21 10 2 2 29 52 73 42 -2 -21 46 46 -20 33 25 -22 9 36 -20 10 45 -133 0 0 -21 23 17 2 30 0 73 39 -3 -22 0 0 -20 46 41 -22 22 49 -20 24 2 -132 0 0 -21 36 25 2 30 9 73 36 -4 -22 13 6 -20 59 49 -22 35 55 -20 37 11 -131 0 0 -21 49 23 2 30 18 74 32 -5 -22 26 4 -21 12 49 -22 48 52 -20 50 12 -130 0 0 -22 2 14 2 30 27 74 29 -6 -22 38 53 -21 25 41 -23 1 40 -21 3 4 -129 0 0 -22 14 55 2 30 35 74 25 -7 -22 51 33 -21 38 23 -23 14 19 -21 15 48 -128 0 0 -22 27 28 2 30 44 75 21 -8 -23 4 5 -21 50 57 -23 26 50 -21 28 22 -127 0 0 -22 39 51 2 30 53 75 17 -9 -23 16 27 -22 3 22 -23 39 11 -21 40 47 -126 0 0 -22 52 5 2 31 1 75 13 -10 -23 28 39 -22 15 37 -23 51 23 -21 53 3 -125 0 0 -23 4 9 2 31 10 75 9 -11 -23 40 42 -22 27 42 -24 3 25 -22 5 10 -124 0 0 -23 16 3 2 31 19 75 5 -12 -23 52 35 -22 39 38 -24 15 17 -22 17 6 -123 0 0 -23 27 48 2 31 27 74 1 -13 -24 4 18 -22 51 24 -24 26 59 -22 28 53 -122 0 0 -23 39 22 2 31 36 74 357 -14 -24 15 51 -23 2 59 -24 38 31 -22 40 29 -121 0 0 -23 50 45 2 31 45 74 354 -15 -24 27 13 -23 14 24 -24 49 53 -22 51 55 -120 0 0 -24 1 58 2 31 53 74 350 -16 -24 38 24 -23 25 38 -25 1 3 -23 3 10 -119 0 0 -24 13 0 2 32 2 73 347 -17 -24 49 25 -23 36 42 -25 12 3 -23 14 14 -118 0 0 -24 23 51 2 32 10 73 343 -18 -25 0 15 -23 47 34 -25 22 52 -23 25 7 -117 0 0 -24 34 31 2 32 19 72 340 -19 -25 10 54 -23 58 16 -25 33 30 -23 35 49 -116 0 0 -24 45 0 2 32 27 72 337 -20 -25 21 21 -24 8 46 -25 43 56 -23 46 20 -115 0 0 -24 55 17 2 32 35 71 334 -20 -25 31 37 -24 19 4 -25 54 11 -23 56 40 -114 0 0 -25 5 23 2 32 44 71 332 -21 -25 41 41 -24 29 11 -26 4 14 -24 6 47 -113 0 0 -25 15 17 2 32 52 70 329 -22 -25 51 33 -24 39 6 -26 14 6 -24 16 43 -112 0 0 -25 24 58 2 33 0 70 327 -23 -26 1 14 -24 48 49 -26 23 46 -24 26 27 -111 0 0 -25 34 28 2 33 8 69 325 -24 -26 10 42 -24 58 20 -26 33 13 -24 35 59 -110 0 0 -25 43 46 2 33 17 68 322 -25 -26 19 58 -25 7 39 -26 42 29 -24 45 19 -109 0 0 -25 52 51 2 33 25 68 320 -26 -26 29 2 -25 16 46 -26 51 32 -24 54 27 -108 0 0 -26 1 44 2 33 33 67 318 -27 -26 37 54 -25 25 40 -27 0 22 -25 3 22 -107 0 0 -26 10 24 2 33 41 66 317 -28 -26 46 33 -25 34 22 -27 9 1 -25 12 4 -106 0 0 -26 18 52 2 33 48 65 315 -29 -26 55 0 -25 42 51 -27 17 26 -25 20 34 -105 0 0 -26 27 7 2 33 56 65 313 -30 -27 3 13 -25 51 7 -27 25 39 -25 28 51 -104 0 0 -26 35 9 2 34 4 64 312 -31 -27 11 14 -25 59 11 -27 33 40 -25 36 55 -103 0 0 -26 42 59 2 34 12 63 310 -32 -27 19 2 -26 7 1 -27 41 27 -25 44 47 -102 0 0 -26 50 35 2 34 19 62 309 -33 -27 26 37 -26 14 39 -27 49 1 -25 52 25 -101 0 0 -26 57 58 2 34 27 61 308 -34 -27 33 59 -26 22 3 -27 56 22 -25 59 50 -100 0 0 -27 5 8 2 34 34 61 306 -35 -27 41 8 -26 29 14 -28 3 30 -26 7 2 - 99 0 0 -27 12 5 2 34 42 60 305 -35 -27 48 4 -26 36 12 -28 10 25 -26 14 0 - 98 0 0 -27 18 48 2 34 49 59 304 -36 -27 54 46 -26 42 56 -28 17 7 -26 20 45 - 97 0 0 -27 25 18 2 34 56 58 303 -37 -28 1 15 -26 49 28 -28 23 35 -26 27 17 - 96 0 0 -27 31 35 2 35 4 57 302 -38 -28 7 30 -26 55 45 -28 29 50 -26 33 35 - 95 0 0 -27 37 38 2 35 11 57 300 -39 -28 13 32 -27 1 49 -28 35 51 -26 39 40 - 94 0 0 -27 43 27 2 35 18 56 299 -40 -28 19 21 -27 7 39 -28 41 39 -26 45 31 - 93 0 0 -27 49 3 2 35 25 55 298 -41 -28 24 56 -27 13 16 -28 47 13 -26 51 8 - 92 0 0 -27 54 25 2 35 32 54 297 -42 -28 30 17 -27 18 39 -28 52 34 -26 56 32 - 91 0 0 -27 59 34 2 35 38 53 297 -43 -28 35 24 -27 23 49 -28 57 41 -27 1 42 - 90 0 0 -28 4 28 2 35 45 52 296 -44 -28 40 18 -27 28 44 -29 2 34 -27 6 38 - 89 0 0 -28 9 9 2 35 52 51 295 -45 -28 44 58 -27 33 26 -29 7 14 -27 11 20 - 88 0 0 -28 13 36 2 35 58 51 294 -46 -28 49 25 -27 37 54 -29 11 40 -27 15 48 - 87 0 0 -28 17 49 2 36 5 50 293 -46 -28 53 37 -27 42 7 -29 15 52 -27 20 2 - 86 0 0 -28 21 49 2 36 11 49 292 -47 -28 57 36 -27 46 7 -29 19 50 -27 24 3 - 85 0 0 -28 25 34 2 36 17 48 291 -48 -29 1 20 -27 49 53 -29 23 34 -27 27 49 - 84 0 0 -28 29 5 2 36 23 47 291 -49 -29 4 51 -27 53 26 -29 27 5 -27 31 22 - 83 0 0 -28 32 23 2 36 29 46 290 -50 -29 8 8 -27 56 44 -29 30 21 -27 34 40 - 82 0 0 -28 35 26 2 36 35 45 289 -51 -29 11 11 -27 59 48 -29 33 24 -27 37 44 - 81 0 0 -28 38 16 2 36 41 45 288 -52 -29 14 0 -28 2 38 -29 36 13 -27 40 35 - 80 0 0 -28 40 52 2 36 47 44 288 -53 -29 16 35 -28 5 14 -29 38 48 -27 43 11 - 79 0 0 -28 43 13 2 36 53 43 287 -54 -29 18 57 -28 7 35 -29 41 9 -27 45 33 - 78 0 0 -28 45 21 2 36 58 42 286 -55 -29 21 4 -28 9 43 -29 43 16 -27 47 41 - 77 0 0 -28 47 14 2 37 4 41 286 -55 -29 22 57 -28 11 37 -29 45 9 -27 49 35 - 76 0 0 -28 48 54 2 37 9 40 285 -56 -29 24 36 -28 13 17 -29 46 48 -27 51 15 - 75 0 0 -28 50 19 2 37 15 39 284 -57 -29 26 2 -28 14 43 -29 48 13 -27 52 41 - 74 0 0 -28 51 31 2 37 20 38 284 -58 -29 27 13 -28 15 54 -29 49 24 -27 53 53 - 73 0 0 -28 52 28 2 37 25 38 283 -59 -29 28 10 -28 16 52 -29 50 21 -27 54 50 - 72 0 0 -28 53 12 2 37 30 37 282 -60 -29 28 54 -28 17 35 -29 51 5 -27 55 34 - 71 0 0 -28 53 41 2 37 35 36 282 -61 -29 29 23 -28 18 5 -29 51 34 -27 56 3 - 70 0 0 -28 53 57 2 37 39 35 281 -62 -29 29 39 -28 18 20 -29 51 50 -27 56 19 - 69 0 0 -28 53 58 2 37 44 34 281 -62 -29 29 40 -28 18 22 -29 51 52 -27 56 20 - 68 0 0 -28 53 46 2 37 49 33 280 -63 -29 29 28 -28 18 10 -29 51 39 -27 56 8 - 67 0 0 -28 53 20 2 37 53 32 279 -64 -29 29 2 -28 17 43 -29 51 13 -27 55 41 - 66 0 0 -28 52 39 2 37 58 31 279 -65 -29 28 22 -28 17 3 -29 50 33 -27 55 1 - 65 0 0 -28 51 45 2 38 2 31 278 -66 -29 27 28 -28 16 9 -29 49 40 -27 54 7 - 64 0 0 -28 50 38 2 38 6 30 278 -67 -29 26 21 -28 15 0 -29 48 32 -27 52 58 - 63 0 0 -28 49 16 2 38 10 29 277 -68 -29 24 59 -28 13 38 -29 47 11 -27 51 36 - 62 0 0 -28 47 40 2 38 14 28 276 -68 -29 23 24 -28 12 3 -29 45 36 -27 50 0 - 61 0 0 -28 45 51 2 38 18 27 276 -69 -29 21 35 -28 10 13 -29 43 48 -27 48 10 - 60 0 0 -28 43 48 2 38 21 26 275 -70 -29 19 33 -28 8 10 -29 41 46 -27 46 7 - 59 0 0 -28 41 32 2 38 25 25 275 -71 -29 17 17 -28 5 53 -29 39 30 -27 43 49 - 58 0 0 -28 39 1 2 38 28 24 274 -72 -29 14 47 -28 3 22 -29 37 0 -27 41 18 - 57 0 0 -28 36 18 2 38 32 24 274 -73 -29 12 4 -28 0 37 -29 34 18 -27 38 33 - 56 0 0 -28 33 20 2 38 35 23 273 -73 -29 9 7 -27 57 39 -29 31 21 -27 35 35 - 55 0 0 -28 30 9 2 38 38 22 273 -74 -29 5 57 -27 54 28 -29 28 11 -27 32 23 - 54 0 0 -28 26 45 2 38 41 21 272 -75 -29 2 33 -27 51 3 -29 24 48 -27 28 58 - 53 0 0 -28 23 7 2 38 44 20 272 -76 -28 58 56 -27 47 25 -29 21 12 -27 25 19 - 52 0 0 -28 19 16 2 38 47 19 271 -77 -28 55 6 -27 43 33 -29 17 22 -27 21 27 - 51 0 0 -28 15 12 2 38 49 18 271 -77 -28 51 2 -27 39 28 -29 13 19 -27 17 21 - 50 0 0 -28 10 54 2 38 52 17 270 -78 -28 46 46 -27 35 9 -29 9 2 -27 13 2 - 49 0 0 -28 6 24 2 38 54 16 270 -79 -28 42 16 -27 30 38 -29 4 33 -27 8 30 - 48 0 0 -28 1 40 2 38 56 16 269 -79 -28 37 33 -27 25 53 -28 59 51 -27 3 45 - 47 0 0 -27 56 43 2 38 59 15 269 -80 -28 32 37 -27 20 55 -28 54 55 -26 58 47 - 46 0 0 -27 51 33 2 39 1 14 268 -81 -28 27 28 -27 15 45 -28 49 47 -26 53 35 - 45 0 0 -27 46 11 2 39 3 13 268 -81 -28 22 6 -27 10 21 -28 44 26 -26 48 11 - 44 0 0 -27 40 35 2 39 4 12 267 -82 -28 16 32 -27 4 45 -28 38 52 -26 42 34 - 43 0 0 -27 34 47 2 39 6 11 267 -82 -28 10 44 -26 58 55 -28 33 5 -26 36 44 - 42 0 0 -27 28 46 2 39 8 10 266 -82 -28 4 45 -26 52 53 -28 27 6 -26 30 42 - 41 0 0 -27 22 33 2 39 9 9 266 -83 -27 58 32 -26 46 39 -28 20 54 -26 24 27 - 40 0 0 -27 16 7 2 39 10 8 265 -83 -27 52 7 -26 40 12 -28 14 30 -26 17 59 - 39 0 0 -27 9 28 2 39 11 7 265 -83 -27 45 30 -26 33 33 -28 7 54 -26 11 19 - 38 0 0 -27 2 38 2 39 12 7 264 -82 -27 38 41 -26 26 41 -28 1 5 -26 4 27 - 37 0 0 -26 55 35 2 39 13 6 264 -82 -27 31 39 -26 19 37 -27 54 4 -25 57 22 - 36 0 0 -26 48 20 2 39 14 5 264 -82 -27 24 25 -26 12 21 -27 46 51 -25 50 5 - 35 0 0 -26 40 53 2 39 15 4 263 -81 -27 16 59 -26 4 53 -27 39 26 -25 42 37 - 34 0 0 -26 33 14 2 39 15 3 263 -81 -27 9 22 -25 57 13 -27 31 49 -25 34 56 - 33 0 0 -26 25 24 2 39 15 2 262 -80 -27 1 32 -25 49 21 -27 24 0 -25 27 3 - 32 0 0 -26 17 21 2 39 16 1 262 -80 -26 53 31 -25 41 18 -27 16 0 -25 18 59 - 31 0 0 -26 9 8 2 39 16 0 261 -79 -26 45 19 -25 33 3 -27 7 48 -25 10 44 Uncertainty in time = +/- 3 secs [Prediction of 2008 May 8.0] Data for the target star ------------------------ * name: TYC 5490-01153-1 * constellation : Sextans * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 10 12 47.9066 DE: -07 50 28.003 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .019, .020 ) * V mag [mag]: 11.8 * B mag [mag]: 12.1 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (426) Hippo approx. diameter [km]: 127 approx. diameter ["]: .078 distance from Earth [AU]: 2.24300 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 694 number of rejected observations: 76 time covered by the observations: 1907 Sep 14 - 2008 Apr 30 1 sigma uncertainty ellipse (major, minor, PA): 0.018, 0.010, 136° remarks: * orbital elements for (426) Hippo : Mean anomaly = 10.10837926 deg Arg. of pericenter = 219.11449908 deg Long. of node = 311.70807078 deg Inclination = 19.53890858 deg Eccentricity = 0.10426682 Semimajor axis = 2.88704286 AU Perihelion dist = 2.58602008 AU Mag: H = 8.59, G = 0.15 Epoch of elements : MJD 54606.10500000 TDT (2008 May 20.105) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 20 426 Hippo 2h 31.1m UT 11.8 10 12 47.907- 7 50 28.00TYC 5490-01153-1 12.1 13.3 127 10.2 2.243 1.828 -5.30 -122.6897 -7.840 141.37 20.04 2.5176 -0.05146 -0.25702 6.92840 -1.35034 0.00514 -0.00179 2000 8.8817592008 514.00000219.114499311.708071 19.5389090.10426682 2.8870429 2.5860201 8.4 5.00.15 RATE 2.0092050 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.026 0.021 160 1.31 0.025 0 54594.5020080520_1153-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 08, 03:42 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org