IOTA/IOTA-ES occultation update for (7875) 1991 ES1 / TYC 0827-00874-1 event on 2008 May 10, 10:51 UT Visible from New Guinea Summary ------- On 2008 May 10 UT, the 35 km diameter asteroid (7875) 1991 ES1 will occult a 10.0 mag star in the constellation Leo for observers along a path across New Guinea. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.3 mag to 17.3 mag (the magnitude of the asteroid) for at most 2.1 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: 39 * date and approx. time of event: 2008 May 10, 10:50 - 2008 May 10, 10:57 UT * magnitude of target star: 10.0 * magnitude drop [mag]: 7.3 * estimated maximum duration [s]: 2.1 * Moon: 32 % sunlit, 24° distance * Sun: 92° distance * rough path description: New Guinea The occultation path -------------------- * approximate projected width [km]: 36 * 1 sigma uncertainty interval [path widths]: +/- 1.70 * 1 sigma uncertainty interval [seconds]: +/- 4.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .050 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .050", .036", 93° ) * approx speed of asteroid's shadow [km/s]: 16.7846 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0827-00874-1 by 7875 1991 ES1 on 2008 May 10 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 108 0 0 1 51 10 10 50 52 77 23 -1 1 41 26 2 0 53 1 8 18 2 33 54 109 0 0 1 48 50 10 50 59 77 19 -2 1 39 6 1 58 34 1 5 58 2 31 35 110 0 0 1 46 14 10 51 6 77 15 -3 1 36 30 1 55 57 1 3 21 2 28 59 111 0 0 1 43 21 10 51 13 78 10 -4 1 33 36 1 53 4 1 0 28 2 26 7 112 0 0 1 40 11 10 51 20 78 6 -5 1 30 26 1 49 55 0 57 17 2 22 57 113 0 0 1 36 44 10 51 26 78 1 -6 1 27 0 1 46 28 0 53 50 2 19 32 114 0 0 1 33 1 10 51 33 78 356 -7 1 23 17 1 42 46 0 50 6 2 15 49 115 0 0 1 29 2 10 51 40 77 352 -8 1 19 17 1 38 46 0 46 6 2 11 50 116 0 0 1 24 46 10 51 47 77 347 -9 1 15 1 1 34 30 0 41 49 2 7 35 117 0 0 1 20 13 10 51 54 77 343 -10 1 10 28 1 29 58 0 37 16 2 3 4 118 0 0 1 15 24 10 52 0 76 339 -11 1 5 39 1 25 9 0 32 26 1 58 16 119 0 0 1 10 19 10 52 7 76 336 -12 1 0 34 1 20 5 0 27 20 1 53 12 120 0 0 1 4 58 10 52 14 75 332 -13 0 55 13 1 14 44 0 21 58 1 47 51 121 0 0 0 59 21 10 52 21 75 329 -14 0 49 35 1 9 7 0 16 20 1 42 15 122 0 0 0 53 28 10 52 28 74 326 -15 0 43 42 1 3 14 0 10 26 1 36 23 123 0 0 0 47 19 10 52 34 73 323 -16 0 37 32 0 57 5 0 4 15 1 30 15 124 0 0 0 40 54 10 52 41 73 321 -17 0 31 7 0 50 40 - 0 2 11 1 23 52 125 0 0 0 34 14 10 52 48 72 319 -18 0 24 27 0 44 0 - 0 8 52 1 17 12 126 0 0 0 27 18 10 52 54 71 317 -19 0 17 30 0 37 5 - 0 15 49 1 10 17 127 0 0 0 20 6 10 53 1 70 315 -20 0 10 19 0 29 53 - 0 23 2 1 3 7 128 0 0 0 12 40 10 53 8 70 313 -21 0 2 52 0 22 27 - 0 30 30 0 55 42 129 0 0 0 4 58 10 53 14 69 312 -22 - 0 4 50 0 14 45 - 0 38 13 0 48 1 130 0 0 - 0 2 59 10 53 21 68 310 -23 - 0 12 48 0 6 49 - 0 46 11 0 40 6 131 0 0 - 0 11 11 10 53 27 67 309 -24 - 0 21 0 - 0 1 22 - 0 54 24 0 31 56 132 0 0 - 0 19 37 10 53 34 66 308 -25 - 0 29 26 - 0 9 48 - 1 2 52 0 23 31 133 0 0 - 0 28 18 10 53 40 65 306 -26 - 0 38 7 - 0 18 29 - 1 11 34 0 14 51 134 0 0 - 0 37 13 10 53 46 64 305 -27 - 0 47 3 - 0 27 24 - 1 20 31 0 5 57 135 0 0 - 0 46 23 10 53 53 63 304 -28 - 0 56 13 - 0 36 33 - 1 29 42 - 0 3 11 136 0 0 - 0 55 46 10 53 59 62 304 -29 - 1 5 37 - 0 45 56 - 1 39 7 - 0 12 33 137 0 0 - 1 5 24 10 54 5 62 303 -30 - 1 15 14 - 0 55 33 - 1 48 46 - 0 22 9 138 0 0 - 1 15 15 10 54 11 61 302 -31 - 1 25 6 - 1 5 24 - 1 58 38 - 0 31 58 139 0 0 - 1 25 19 10 54 18 60 301 -32 - 1 35 11 - 1 15 28 - 2 8 44 - 0 42 1 140 0 0 - 1 35 37 10 54 24 59 301 -33 - 1 45 29 - 1 25 46 - 2 19 4 - 0 52 18 141 0 0 - 1 46 8 10 54 30 58 300 -34 - 1 56 0 - 1 36 16 - 2 29 36 - 1 2 47 142 0 0 - 1 56 52 10 54 36 57 299 -35 - 2 6 44 - 1 47 0 - 2 40 21 - 1 13 29 143 0 0 - 2 7 48 10 54 41 56 299 -36 - 2 17 41 - 1 57 56 - 2 51 19 - 1 24 24 144 0 0 - 2 18 57 10 54 47 55 298 -37 - 2 28 50 - 2 9 4 - 3 2 30 - 1 35 31 145 0 0 - 2 30 18 10 54 53 54 298 -38 - 2 40 11 - 2 20 25 - 3 13 52 - 1 46 51 146 0 0 - 2 41 51 10 54 59 53 297 -39 - 2 51 45 - 2 31 57 - 3 25 27 - 1 58 22 147 0 0 - 2 53 35 10 55 4 52 297 -40 - 3 3 30 - 2 43 42 - 3 37 13 - 2 10 5 148 0 0 - 3 5 32 10 55 10 51 297 -41 - 3 15 26 - 2 55 37 - 3 49 10 - 2 22 0 149 0 0 - 3 17 39 10 55 15 50 296 -42 - 3 27 34 - 3 7 45 - 4 1 19 - 2 34 6 150 0 0 - 3 29 57 10 55 20 49 296 -43 - 3 39 53 - 3 20 3 - 4 13 39 - 2 46 23 151 0 0 - 3 42 27 10 55 26 48 295 -44 - 3 52 22 - 3 32 31 - 4 26 10 - 2 58 50 152 0 0 - 3 55 6 10 55 31 47 295 -45 - 4 5 2 - 3 45 11 - 4 38 51 - 3 11 29 153 0 0 - 4 7 56 10 55 36 46 295 -47 - 4 17 52 - 3 58 0 - 4 51 42 - 3 24 17 154 0 0 - 4 20 56 10 55 41 45 294 -48 - 4 30 52 - 4 10 59 - 5 4 43 - 3 37 15 155 0 0 - 4 34 5 10 55 46 44 294 -49 - 4 44 2 - 4 24 8 - 5 17 54 - 3 50 23 156 0 0 - 4 47 24 10 55 51 43 294 -50 - 4 57 21 - 4 37 27 - 5 31 14 - 4 3 40 157 0 0 - 5 0 51 10 55 56 42 294 -51 - 5 10 49 - 4 50 54 - 5 44 43 - 4 17 7 158 0 0 - 5 14 28 10 56 0 41 293 -52 - 5 24 26 - 5 4 31 - 5 58 21 - 4 30 42 159 0 0 - 5 28 13 10 56 5 40 293 -53 - 5 38 11 - 5 18 15 - 6 12 7 - 4 44 26 160 0 0 - 5 42 6 10 56 9 39 293 -54 - 5 52 5 - 5 32 8 - 6 26 2 - 4 58 18 161 0 0 - 5 56 7 10 56 13 38 293 -55 - 6 6 6 - 5 46 9 - 6 40 4 - 5 12 18 162 0 0 - 6 10 16 10 56 18 36 292 -56 - 6 20 15 - 6 0 17 - 6 54 14 - 5 26 25 163 0 0 - 6 24 32 10 56 22 35 292 -57 - 6 34 31 - 6 14 33 - 7 8 31 - 5 40 40 164 0 0 - 6 38 55 10 56 26 34 292 -58 - 6 48 54 - 6 28 56 - 7 22 55 - 5 55 2 165 0 0 - 6 53 24 10 56 30 33 292 -59 - 7 3 24 - 6 43 25 - 7 37 26 - 6 9 30 166 0 0 - 7 8 0 10 56 34 32 292 -60 - 7 18 0 - 6 58 1 - 7 52 3 - 6 24 5 167 0 0 - 7 22 42 10 56 37 31 291 -61 - 7 32 42 - 7 12 42 - 8 6 46 - 6 38 46 168 0 0 - 7 37 30 10 56 41 30 291 -62 - 7 47 30 - 7 27 30 - 8 21 34 - 6 53 32 169 0 0 - 7 52 22 10 56 44 29 291 -63 - 8 2 23 - 7 42 22 - 8 36 28 - 7 8 24 170 0 0 - 8 7 20 10 56 48 28 291 -64 - 8 17 21 - 7 57 20 - 8 51 27 - 7 23 21 171 0 0 - 8 22 23 10 56 51 27 290 -65 - 8 32 24 - 8 12 22 - 9 6 30 - 7 38 23 172 0 0 - 8 37 30 10 56 54 26 290 -66 - 8 47 31 - 8 27 29 - 9 21 38 - 7 53 29 173 0 0 - 8 52 41 10 56 57 25 290 -67 - 9 2 42 - 8 42 40 - 9 36 49 - 8 8 39 174 0 0 - 9 7 55 10 57 0 24 290 -68 - 9 17 57 - 8 57 54 - 9 52 5 - 8 23 53 175 0 0 - 9 23 13 10 57 3 23 290 -69 - 9 33 15 - 9 13 12 -10 7 23 - 8 39 11 176 0 0 - 9 38 34 10 57 6 22 289 -70 - 9 48 36 - 9 28 33 -10 22 45 - 8 54 31 177 0 0 - 9 53 58 10 57 8 21 289 -71 -10 4 0 - 9 43 56 -10 38 9 - 9 9 54 178 0 0 -10 9 24 10 57 11 20 289 -72 -10 19 26 - 9 59 22 -10 53 35 - 9 25 20 179 0 0 -10 24 52 10 57 13 19 289 -73 -10 34 54 -10 14 50 -11 9 4 - 9 40 47 180 0 0 -10 40 21 10 57 15 18 289 -74 -10 50 24 -10 30 20 -11 24 34 - 9 56 16 -179 0 0 -10 55 52 10 57 17 17 288 -75 -11 5 55 -10 45 51 -11 40 5 -10 11 47 -178 0 0 -11 11 24 10 57 19 16 288 -76 -11 21 27 -11 1 22 -11 55 37 -10 27 19 -177 0 0 -11 26 57 10 57 21 15 288 -77 -11 36 59 -11 16 55 -12 11 10 -10 42 51 -176 0 0 -11 42 30 10 57 23 14 288 -78 -11 52 32 -11 32 28 -12 26 43 -10 58 24 -175 0 0 -11 58 3 10 57 25 13 288 -79 -12 8 5 -11 48 1 -12 42 16 -11 13 57 -174 0 0 -12 13 35 10 57 26 12 287 -80 -12 23 38 -12 3 33 -12 57 49 -11 29 29 -173 0 0 -12 29 7 10 57 27 11 287 -81 -12 39 10 -12 19 5 -13 13 21 -11 45 1 -172 0 0 -12 44 38 10 57 29 10 287 -82 -12 54 40 -12 34 36 -13 28 51 -12 0 32 -171 0 0 -13 0 8 10 57 30 9 287 -83 -13 10 10 -12 50 6 -13 44 21 -12 16 2 -170 0 0 -13 15 36 10 57 31 8 286 -83 -13 25 38 -13 5 34 -13 59 49 -12 31 30 -169 0 0 -13 31 2 10 57 32 7 286 -84 -13 41 4 -13 21 0 -14 15 14 -12 46 56 -168 0 0 -13 46 25 10 57 32 6 286 -85 -13 56 28 -13 36 24 -14 30 38 -13 2 20 -167 0 0 -14 1 47 10 57 33 5 286 -86 -14 11 49 -13 51 45 -14 45 59 -13 17 42 -166 0 0 -14 17 5 10 57 33 4 285 -86 -14 27 7 -14 7 3 -15 1 16 -13 33 0 -165 0 0 -14 32 20 10 57 34 3 285 -86 -14 42 22 -14 22 18 -15 16 31 -13 48 16 -164 0 0 -14 47 31 10 57 34 2 285 -86 -14 57 33 -14 37 30 -15 31 42 -14 3 28 -163 0 0 -15 2 39 10 57 34 1 285 -86 -15 12 41 -14 52 38 -15 46 49 -14 18 36 Uncertainty in time = +/- 5 secs [Prediction of 2008 May 8.0] Data for the target star ------------------------ * name: TYC 0827-00874-1 * constellation : Leo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 09 38 21.0701 DE: +13 59 35.778 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .024, .021 ) * V mag [mag]: 10.0 * B mag [mag]: 10.6 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (7875) 1991 ES1 approx. diameter [km]: 35 approx. diameter ["]: .021 distance from Earth [AU]: 2.35200 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 703 number of rejected observations: 8 time covered by the observations: 1989 Sep 30 - 2008 Mar 12 1 sigma uncertainty ellipse (major, minor, PA): 0.044, 0.029, 94° remarks: * orbital elements for (7875) 1991 ES1 : Mean anomaly = 74.04955267 deg Arg. of pericenter = 264.86931899 deg Long. of node = 165.50674632 deg Inclination = 14.15125376 deg Eccentricity = 0.18023758 Semimajor axis = 2.64331454 AU Perihelion dist = 2.16688992 AU Mag: H = 12.19, G = 0.15 Epoch of elements : MJD 54596.45200000 TDT (2008 May 10.452) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 10 7875 1991 ES1 10h 51.4m UT 10.0 9 38 21.070 13 59 35.78TYC 0827-00874-1 10.6 17.3 35 2.1 2.352 2.430 -2.03 113.1307 13.994 16.26 17.78 10.8564 -0.01279 -0.21345 9.45818 -0.54180 0.00527 -0.00181 2000 72.5698482008 5 4.00000264.869319165.506746 14.1512540.18023758 2.6433145 2.166889912.3 5.00.15 RATE 2.2934050 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.050 0.036 93 2.70 0.035 0 54594.5020080510_0874-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 08, 02:55 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org