IOTA/IOTA-ES occultation update for (210) Isabella / TYC 6839-00648-1 event on 2008 May 20, 16:31 UT Visible from Philippines, SE Asia Summary ------- On 2008 May 20 UT, the 87 km diameter asteroid (210) Isabella will occult a 10.7 mag star in the constellation Ophiuchus for observers along a path across Philippines, SE Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.3 mag to 13.9 mag (the magnitude of the asteroid) for at most 8.3 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 92 * date and approx. time of event: 2008 May 20, 16:25 - 2008 May 20, 16:39 UT * magnitude of target star: 10.7 * magnitude drop [mag]: 3.3 * estimated maximum duration [s]: 8.3 * Moon: 100 % sunlit, 19° distance * Sun: 154° distance * rough path description: Philippines, SE Asia The occultation path -------------------- * approximate projected width [km]: 124 * 1 sigma uncertainty interval [path widths]: +/- 0.49 * 1 sigma uncertainty interval [seconds]: +/- 3.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .031 +/- .028) * 1 sigma uncertainty ellipse (major, minor, PA): ( .031", .028", 93° ) * approx speed of asteroid's shadow [km/s]: 10.4735 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6839-00648-1 by 210 Isabella 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 66 0 0 30 57 27 16 39 21 1 124 -24 31 38 49 30 16 41 .. .. .. .. .. .. 67 0 0 30 23 4 16 39 20 2 125 -25 31 4 9 29 42 34 31 45 1 .. .. .. 68 0 0 29 49 14 16 39 20 3 125 -26 30 30 2 29 9 0 31 10 37 .. .. .. 69 0 0 29 15 57 16 39 19 4 126 -27 29 56 29 28 35 59 30 36 47 27 57 21 70 0 0 28 43 14 16 39 18 5 126 -28 29 23 30 28 3 32 30 3 32 27 25 8 71 0 0 28 11 7 16 39 16 6 127 -29 28 51 7 27 31 40 29 30 53 26 53 31 72 0 0 27 39 36 16 39 14 7 127 -30 28 19 20 27 0 24 28 58 50 26 22 28 73 0 0 27 8 41 16 39 12 8 128 -31 27 48 10 26 29 43 28 27 24 25 52 2 74 0 0 26 38 22 16 39 10 9 128 -32 27 17 37 25 59 39 27 56 36 25 22 12 75 0 0 26 8 42 16 39 8 10 129 -33 26 47 41 25 30 13 27 26 25 24 52 58 76 0 0 25 39 39 16 39 5 11 129 -34 26 18 24 25 1 24 26 56 54 24 24 22 77 0 0 25 11 14 16 39 2 12 130 -35 25 49 46 24 33 12 26 28 1 23 56 24 78 0 0 24 43 28 16 38 59 13 130 -36 25 21 46 24 5 40 25 59 47 23 29 3 79 0 0 24 16 21 16 38 55 14 131 -37 24 54 26 23 38 46 25 32 13 23 2 22 80 0 0 23 49 54 16 38 52 15 131 -38 24 27 45 23 12 31 25 5 20 22 36 18 81 0 0 23 24 6 16 38 48 16 132 -38 24 1 45 22 46 55 24 39 6 22 10 54 82 0 0 22 58 58 16 38 43 17 132 -39 23 36 24 22 21 59 24 13 33 21 46 9 83 0 0 22 34 30 16 38 39 18 133 -40 23 11 44 21 57 42 23 48 41 21 22 4 84 0 0 22 10 42 16 38 34 19 133 -41 22 47 45 21 34 6 23 24 30 20 58 38 85 0 0 21 47 35 16 38 29 20 134 -42 22 24 26 21 11 9 23 1 0 20 35 51 86 0 0 21 25 8 16 38 24 20 134 -43 22 1 49 20 48 53 22 38 11 20 13 45 87 0 0 21 3 22 16 38 19 21 135 -43 21 39 52 20 27 17 22 16 4 19 52 19 88 0 0 20 42 17 16 38 14 22 135 -44 21 18 36 20 6 22 21 54 38 19 31 33 89 0 0 20 21 52 16 38 8 23 136 -45 20 58 2 19 46 7 21 33 53 19 11 27 90 0 0 20 2 9 16 38 2 24 136 -46 20 38 9 19 26 32 21 13 51 18 52 1 91 0 0 19 43 6 16 37 56 25 137 -46 20 18 57 19 7 39 20 54 30 18 33 16 92 0 0 19 24 44 16 37 50 26 137 -47 20 0 27 18 49 26 20 35 50 18 15 11 93 0 0 19 7 4 16 37 43 27 138 -48 19 42 38 18 31 53 20 17 53 17 57 46 94 0 0 18 50 4 16 37 37 27 138 -48 19 25 30 18 15 2 20 0 37 17 41 2 95 0 0 18 33 46 16 37 30 28 139 -49 19 9 4 17 58 51 19 44 2 17 24 59 96 0 0 18 18 8 16 37 23 29 139 -49 18 53 19 17 43 20 19 28 10 17 9 35 97 0 0 18 3 12 16 37 16 30 140 -50 18 38 15 17 28 31 19 12 59 16 54 52 98 0 0 17 48 57 16 37 9 31 141 -50 18 23 53 17 14 22 18 58 30 16 40 50 99 0 0 17 35 22 16 37 1 31 141 -51 18 10 12 17 0 54 18 44 42 16 27 28 100 0 0 17 22 29 16 36 54 32 142 -51 17 57 12 16 48 6 18 31 37 16 14 46 101 0 0 17 10 16 16 36 46 33 143 -52 17 44 54 16 36 0 18 19 12 16 2 44 102 0 0 16 58 44 16 36 38 33 143 -52 17 33 17 16 24 33 18 7 29 15 51 23 103 0 0 16 47 53 16 36 30 34 144 -52 17 22 21 16 13 47 17 56 28 15 40 42 104 0 0 16 37 43 16 36 22 35 145 -53 17 12 6 16 3 42 17 46 8 15 30 41 105 0 0 16 28 14 16 36 14 35 145 -53 17 2 32 15 54 17 17 36 29 15 21 20 106 0 0 16 19 25 16 36 6 36 146 -53 16 53 39 15 45 32 17 27 32 15 12 39 107 0 0 16 11 17 16 35 58 37 147 -54 16 45 27 15 37 28 17 19 16 15 4 38 108 0 0 16 3 49 16 35 49 37 148 -54 16 37 55 15 30 4 17 11 41 14 57 18 109 0 0 15 57 2 16 35 40 38 149 -54 16 31 5 15 23 20 17 4 48 14 50 37 110 0 0 15 50 56 16 35 32 39 150 -54 16 24 55 15 17 16 16 58 35 14 44 36 111 0 0 15 45 29 16 35 23 39 150 -54 16 19 27 15 11 52 16 53 3 14 39 15 112 0 0 15 40 44 16 35 14 40 151 -54 16 14 38 15 7 9 16 48 13 14 34 33 113 0 0 15 36 38 16 35 5 40 152 -54 16 10 31 15 3 5 16 44 3 14 30 32 114 0 0 15 33 13 16 34 56 41 153 -54 16 7 4 14 59 42 16 40 34 14 27 10 115 0 0 15 30 28 16 34 47 41 154 -54 16 4 17 14 56 58 16 37 47 14 24 28 116 0 0 15 28 23 16 34 37 41 155 -54 16 2 11 14 54 55 16 35 40 14 22 25 117 0 0 15 26 58 16 34 28 42 156 -54 16 0 46 14 53 31 16 34 13 14 21 2 118 0 0 15 26 14 16 34 19 42 157 -54 16 0 1 14 52 47 16 33 28 14 20 18 119 0 0 15 26 9 16 34 9 43 158 -54 15 59 56 14 52 43 16 33 23 14 20 14 120 0 0 15 26 45 16 34 0 43 159 -53 16 0 32 14 53 18 16 33 58 14 20 50 121 0 0 15 28 1 16 33 50 43 160 -53 16 1 48 14 54 33 16 35 15 14 22 5 122 0 0 15 29 56 16 33 41 43 161 -53 16 3 44 14 56 28 16 37 12 14 23 59 123 0 0 15 32 32 16 33 31 44 162 -52 16 6 21 14 59 3 16 39 49 14 26 33 124 0 0 15 35 48 16 33 21 44 164 -52 16 9 38 15 2 17 16 43 8 14 29 46 125 0 0 15 39 43 16 33 12 44 165 -52 16 13 35 15 6 11 16 47 6 14 33 39 126 0 0 15 44 18 16 33 2 44 166 -51 16 18 12 15 10 45 16 51 45 14 38 11 127 0 0 15 49 34 16 32 52 44 167 -51 16 23 30 15 15 58 16 57 5 14 43 22 128 0 0 15 55 29 16 32 42 45 168 -50 16 29 27 15 21 51 17 3 5 14 49 12 129 0 0 16 2 4 16 32 32 45 169 -50 16 36 5 15 28 23 17 9 46 14 55 42 130 0 0 16 9 19 16 32 22 45 171 -49 16 43 23 15 35 35 17 17 7 15 2 51 131 0 0 16 17 14 16 32 13 45 172 -49 16 51 21 15 43 27 17 25 8 15 10 39 132 0 0 16 25 48 16 32 3 45 173 -48 16 59 59 15 51 57 17 33 50 15 19 7 133 0 0 16 35 2 16 31 53 45 174 -48 17 9 18 16 1 8 17 43 13 15 28 14 134 0 0 16 44 56 16 31 43 45 175 -47 17 19 16 16 10 58 17 53 15 15 37 59 135 0 0 16 55 30 16 31 33 44 176 -46 17 29 55 16 21 27 18 3 59 15 48 25 136 0 0 17 6 44 16 31 23 44 178 -46 17 41 13 16 32 36 18 15 22 15 59 29 137 0 0 17 18 37 16 31 13 44 179 -45 17 53 12 16 44 25 18 27 26 16 11 13 138 0 0 17 31 11 16 31 3 44 180 -44 18 5 50 16 56 52 18 40 10 16 23 35 139 0 0 17 44 23 16 30 53 44 181 -44 18 19 9 17 9 59 18 53 35 16 36 37 140 0 0 17 58 16 16 30 44 43 182 -43 18 33 8 17 23 46 19 7 40 16 50 18 141 0 0 18 12 48 16 30 34 43 183 -42 18 47 47 17 38 12 19 22 25 17 4 38 142 0 0 18 28 0 16 30 24 43 185 -41 19 3 5 17 53 17 19 37 51 17 19 37 143 0 0 18 43 51 16 30 14 42 186 -40 19 19 4 18 9 2 19 53 57 17 35 15 144 0 0 19 0 22 16 30 5 42 187 -40 19 35 42 18 25 25 20 10 42 17 51 32 145 0 0 19 17 33 16 29 55 42 188 -39 19 53 0 18 42 28 20 28 8 18 8 27 146 0 0 19 35 22 16 29 46 41 189 -38 20 10 58 19 0 10 20 46 15 18 26 2 147 0 0 19 53 52 16 29 36 41 190 -37 20 29 36 19 18 31 21 5 1 18 44 15 148 0 0 20 13 0 16 29 27 40 191 -36 20 48 53 19 37 31 21 24 27 19 3 7 149 0 0 20 32 48 16 29 17 40 192 -35 21 8 49 19 57 10 21 44 32 19 22 38 150 0 0 20 53 14 16 29 8 39 193 -35 21 29 25 20 17 28 22 5 18 19 42 47 151 0 0 21 14 20 16 28 59 39 194 -34 21 50 41 20 38 24 22 26 43 20 3 34 152 0 0 21 36 4 16 28 50 38 195 -33 22 12 35 20 59 58 22 48 48 20 24 59 153 0 0 21 58 27 16 28 41 38 196 -32 22 35 8 21 22 11 23 11 32 20 47 3 154 0 0 22 21 29 16 28 32 37 197 -31 22 58 20 21 45 3 23 34 55 21 9 44 155 0 0 22 45 8 16 28 23 36 198 -30 23 22 11 22 8 32 23 58 57 21 33 4 156 0 0 23 9 26 16 28 15 36 199 -29 23 46 41 22 32 39 24 23 37 21 57 0 157 0 0 23 34 22 16 28 6 35 200 -28 24 11 48 22 57 23 24 48 57 22 21 34 158 0 0 23 59 55 16 27 58 34 200 -27 24 37 33 23 22 45 25 14 54 22 46 45 159 0 0 24 26 6 16 27 49 34 201 -26 25 3 56 23 48 44 25 41 30 23 12 33 160 0 0 24 52 54 16 27 41 33 202 -25 25 30 57 24 15 19 26 8 43 23 38 57 161 0 0 25 20 18 16 27 33 32 203 -24 25 58 34 24 42 32 26 36 34 24 5 57 162 0 0 25 48 19 16 27 25 31 204 -23 26 26 48 25 10 20 27 5 2 24 33 33 163 0 0 26 16 56 16 27 18 30 205 -22 26 55 39 25 38 43 27 34 6 25 1 44 164 0 0 26 46 8 16 27 10 30 205 -21 27 25 5 26 7 42 28 3 46 25 30 31 165 0 0 27 15 56 16 27 3 29 206 -20 27 55 7 26 37 16 28 34 2 25 59 52 166 0 0 27 46 18 16 26 56 28 207 -20 28 25 43 27 7 24 29 4 54 26 29 47 167 0 0 28 17 14 16 26 49 27 208 -19 28 56 54 27 38 6 29 36 20 27 0 15 168 0 0 28 48 44 16 26 42 26 208 -18 29 28 39 28 9 21 30 8 20 27 31 17 169 0 0 29 20 46 16 26 35 25 209 -17 30 0 57 28 41 9 30 40 53 28 2 51 170 0 0 29 53 21 16 26 29 25 210 -16 30 33 47 29 13 29 31 14 0 28 34 56 171 0 0 30 26 27 16 26 23 24 210 -14 31 7 9 29 46 20 31 47 38 29 7 33 172 0 0 31 0 4 16 26 17 23 211 -13 31 41 2 30 19 41 32 21 47 29 40 40 173 0 0 31 34 11 16 26 11 22 212 -12 32 15 25 30 53 32 32 56 27 30 14 17 174 0 0 32 8 47 16 26 5 21 212 -11 32 50 17 31 27 53 33 31 36 30 48 22 175 0 0 32 43 51 16 26 0 20 213 -10 33 25 38 32 2 41 34 7 14 31 22 55 176 0 0 33 19 22 16 25 55 19 214 -9 34 1 26 32 37 56 34 43 20 31 57 55 177 0 0 33 55 19 16 25 50 18 214 -8 34 37 41 33 13 37 35 19 52 32 33 21 178 0 0 34 31 42 16 25 45 17 215 -7 35 14 21 33 49 44 35 56 49 33 9 12 179 0 0 35 8 29 16 25 41 16 216 -6 35 51 25 34 26 14 36 34 11 33 45 27 180 0 0 35 45 38 16 25 37 15 216 -5 36 28 51 35 3 7 37 11 55 34 22 4 -179 0 0 36 23 9 16 25 33 14 217 -4 37 6 40 35 40 21 37 50 2 34 59 3 -178 0 0 37 1 0 16 25 29 13 218 -3 37 44 48 36 17 56 38 28 28 35 36 22 -177 0 0 37 39 11 16 25 26 12 218 -2 38 23 16 36 55 49 39 7 14 36 14 1 -176 0 0 38 17 38 16 25 23 11 219 -1 39 2 1 37 34 0 39 46 16 36 51 56 -175 0 0 38 56 22 16 25 20 10 220 0 39 41 2 38 12 28 40 25 35 37 30 8 Uncertainty in time = +/- 4 secs [Prediction of 2008 May 8.0] Data for the target star ------------------------ * name: TYC 6839-00648-1 * constellation : Ophiuchus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 17 37 19.9232 DE: -28 40 40.706 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .024 ) * V mag [mag]: 10.7 * B mag [mag]: 10.9 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (210) Isabella approx. diameter [km]: 87 approx. diameter ["]: .058 distance from Earth [AU]: 2.05600 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 869 number of rejected observations: 73 time covered by the observations: 1915 Nov 02 - 2008 May 01 1 sigma uncertainty ellipse (major, minor, PA): 0.022, 0.015, 95° remarks: * orbital elements for (210) Isabella : Mean anomaly = 218.14207586 deg Arg. of pericenter = 13.66076110 deg Long. of node = 32.83519443 deg Inclination = 5.25763889 deg Eccentricity = 0.12320137 Semimajor axis = 2.72293222 AU Perihelion dist = 2.38746323 AU Mag: H = 9.36, G = 0.15 Epoch of elements : MJD 54606.68900000 TDT (2008 May 20.689) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 20 210 Isabella 16h 32.2m UT 10.7 17 37 19.923-28 40 40.71TYC 6839-00648-1 11.0 13.9 87 8.3 2.056 -1.898 -4.03 137.5773 -28.676 -68.91 20.16 16.5369 -0.11290 0.70204 -5.83580 -0.94308 -0.00237 0.00057 2000 216.6748062008 514.00000 13.660761 32.835194 5.2576390.12320137 2.7229322 2.3874632 9.3 5.00.15 RATE 2.1935570 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.031 0.028 93 1.49 0.028 0 54594.5020080520_0648-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 08, 03:46 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org