IOTA/IOTA-ES occultation update for (17) Thetis / TYC 6891-00510-1 event on 2008 Oct 13, 10:54 UT Visible from Philippines Summary ------- On 2008 Oct 13 UT, the 90 km diameter asteroid (17) Thetis will occult a 11.0 mag star in the constellation Sagittarius for observers along a path across Philippines. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.5 mag to 12.2 mag (the magnitude of the asteroid) for at most 5.2 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: 97 * date and approx. time of event: 2008 Oct 13, 10:53 - 2008 Oct 13, 10:58 UT * magnitude of target star: 11.0 * magnitude drop [mag]: 1.5 * estimated maximum duration [s]: 5.2 * Moon: 97 % sunlit, 66° distance * Sun: 95° distance * rough path description: Philippines The occultation path -------------------- * approximate projected width [km]: 115 * 1 sigma uncertainty interval [path widths]: +/- 0.40 * 1 sigma uncertainty interval [seconds]: +/- 1.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .024 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .025", .024", 0° ) * approx speed of asteroid's shadow [km/s]: 17.2018 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6891-00510-1 by 17 Thetis on 2008 Oct 13 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 102 0 0 15 5 57 10 53 25 51 165 -1 14 34 49 15 37 19 14 10 3 16 2 35 103 0 0 15 9 30 10 53 32 51 167 -2 14 38 21 15 40 53 14 13 34 16 6 10 104 0 0 15 13 36 10 53 38 51 168 -3 14 42 25 15 45 0 14 17 38 16 10 18 105 0 0 15 18 14 10 53 45 51 170 -4 14 47 2 15 49 40 14 22 14 16 14 59 106 0 0 15 23 26 10 53 51 51 171 -5 14 52 12 15 54 53 14 27 22 16 20 13 107 0 0 15 29 10 10 53 58 52 173 -6 14 57 54 16 0 39 14 33 3 16 26 0 108 0 0 15 35 26 10 54 4 52 174 -7 15 4 9 16 6 57 14 39 17 16 32 20 109 0 0 15 42 15 10 54 10 51 176 -8 15 10 56 16 13 48 14 46 2 16 39 13 110 0 0 15 49 37 10 54 17 51 177 -9 15 18 16 16 21 12 14 53 20 16 46 38 111 0 0 15 57 31 10 54 23 51 179 -10 15 26 7 16 29 8 15 1 10 16 54 36 112 0 0 16 5 57 10 54 30 51 180 -11 15 34 31 16 37 36 15 9 32 17 3 6 113 0 0 16 14 55 10 54 36 51 182 -12 15 43 26 16 46 37 15 18 26 17 12 9 114 0 0 16 24 25 10 54 43 51 183 -13 15 52 54 16 56 10 15 27 51 17 21 44 115 0 0 16 34 27 10 54 49 51 185 -14 16 2 53 17 6 15 15 37 48 17 31 51 116 0 0 16 45 0 10 54 55 50 186 -15 16 13 24 17 16 51 15 48 16 17 42 30 117 0 0 16 56 5 10 55 2 50 188 -16 16 24 26 17 27 59 15 59 16 17 53 41 118 0 0 17 7 42 10 55 8 50 189 -17 16 35 59 17 39 39 16 10 46 18 5 23 119 0 0 17 19 49 10 55 14 49 191 -18 16 48 3 17 51 50 16 22 48 18 17 37 120 0 0 17 32 27 10 55 21 49 192 -19 17 0 38 18 4 31 16 35 20 18 30 21 121 0 0 17 45 36 10 55 27 48 193 -20 17 13 43 18 17 44 16 48 23 18 43 37 122 0 0 17 59 16 10 55 33 48 195 -21 17 27 19 18 31 27 17 1 56 18 57 23 123 0 0 18 13 26 10 55 39 48 196 -22 17 41 25 18 45 41 17 15 59 19 11 40 124 0 0 18 28 5 10 55 45 47 197 -23 17 56 1 19 0 24 17 30 31 19 26 27 125 0 0 18 43 14 10 55 51 47 198 -24 18 11 6 19 15 38 17 45 33 19 41 43 126 0 0 18 58 53 10 55 57 46 200 -25 18 26 40 19 31 20 18 1 5 19 57 29 127 0 0 19 15 0 10 56 3 45 201 -26 18 42 44 19 47 32 18 17 5 20 13 45 128 0 0 19 31 37 10 56 9 45 202 -27 18 59 16 20 4 13 18 33 34 20 30 29 129 0 0 19 48 41 10 56 15 44 203 -28 19 16 16 20 21 22 18 50 30 20 47 42 130 0 0 20 6 14 10 56 21 43 204 -29 19 33 44 20 38 59 19 7 55 21 5 23 131 0 0 20 24 14 10 56 26 43 205 -29 19 51 40 20 57 4 19 25 47 21 23 32 132 0 0 20 42 42 10 56 32 42 206 -30 20 10 3 21 15 37 19 44 6 21 42 8 133 0 0 21 1 36 10 56 37 41 207 -31 20 28 53 21 34 36 20 2 52 22 1 11 134 0 0 21 20 57 10 56 43 41 208 -32 20 48 8 21 54 1 20 22 5 22 20 41 135 0 0 21 40 44 10 56 48 40 209 -33 21 7 50 22 13 53 20 41 43 22 40 36 136 0 0 22 0 56 10 56 54 39 210 -34 21 27 57 22 34 10 21 1 46 23 0 57 137 0 0 22 21 33 10 56 59 38 211 -35 21 48 30 22 54 52 21 22 14 23 21 44 138 0 0 22 42 34 10 57 4 38 212 -36 22 9 26 23 15 59 21 43 7 23 42 54 139 0 0 23 4 0 10 57 9 37 213 -37 22 30 46 23 37 29 22 4 23 24 4 29 140 0 0 23 25 49 10 57 14 36 213 -38 22 52 30 23 59 23 22 26 3 24 26 28 141 0 0 23 48 0 10 57 19 35 214 -39 23 14 37 24 21 40 22 48 5 24 48 49 142 0 0 24 10 34 10 57 23 34 215 -39 23 37 5 24 44 19 23 10 30 25 11 32 143 0 0 24 33 29 10 57 28 33 216 -40 23 59 56 25 7 20 23 33 16 25 34 37 144 0 0 24 56 46 10 57 33 33 217 -41 24 23 7 25 30 42 23 56 24 25 58 3 145 0 0 25 20 23 10 57 37 32 217 -42 24 46 39 25 54 24 24 19 51 26 21 50 146 0 0 25 44 19 10 57 41 31 218 -43 25 10 30 26 18 26 24 43 39 26 45 56 147 0 0 26 8 35 10 57 45 30 219 -44 25 34 40 26 42 46 25 7 45 27 10 21 148 0 0 26 33 9 10 57 50 29 220 -44 25 59 9 27 7 26 25 32 10 27 35 4 149 0 0 26 58 0 10 57 53 28 220 -45 26 23 55 27 32 22 25 56 52 28 0 5 150 0 0 27 23 8 10 57 57 27 221 -46 26 48 59 27 57 36 26 21 51 28 25 23 151 0 0 27 48 33 10 58 1 26 222 -47 27 14 18 28 23 5 26 47 7 28 50 57 152 0 0 28 14 12 10 58 5 25 222 -47 27 39 53 28 48 50 27 12 38 29 16 46 153 0 0 28 40 7 10 58 8 25 223 -48 28 5 42 29 14 50 27 38 23 29 42 49 154 0 0 29 6 15 10 58 11 24 224 -49 28 31 46 29 41 3 28 4 23 30 9 6 155 0 0 29 32 36 10 58 15 23 224 -49 28 58 2 30 7 29 28 30 35 30 35 37 156 0 0 29 59 9 10 58 18 22 225 -50 29 24 31 30 34 7 28 57 0 31 2 19 157 0 0 30 25 54 10 58 21 21 225 -50 29 51 11 31 0 56 29 23 37 31 29 12 158 0 0 30 52 49 10 58 23 20 226 -51 30 18 1 31 27 56 29 50 24 31 56 15 159 0 0 31 19 54 10 58 26 19 227 -51 30 45 1 31 55 5 30 17 21 32 23 28 160 0 0 31 47 7 10 58 29 18 227 -52 31 12 11 32 22 23 30 44 27 32 50 50 161 0 0 32 14 29 10 58 31 17 228 -52 31 39 28 32 49 49 31 11 41 33 18 19 162 0 0 32 41 57 10 58 33 16 229 -53 32 6 52 33 17 22 31 39 2 33 45 56 163 0 0 33 9 32 10 58 35 15 229 -53 32 34 23 33 45 0 32 6 29 34 13 38 164 0 0 33 37 12 10 58 37 14 230 -54 33 1 59 34 12 44 32 34 3 34 41 25 165 0 0 34 4 56 10 58 39 13 230 -54 33 29 40 34 40 32 33 1 41 35 9 16 166 0 0 34 32 44 10 58 41 12 231 -54 33 57 24 35 8 24 33 29 22 35 37 10 167 0 0 35 0 35 10 58 43 11 232 -55 34 25 12 35 36 18 33 57 7 36 5 7 168 0 0 35 28 27 10 58 44 11 232 -55 34 53 1 36 4 14 34 24 54 36 33 6 169 0 0 35 56 21 10 58 45 10 233 -55 35 20 51 36 32 10 34 52 41 37 1 5 170 0 0 36 24 14 10 58 47 9 233 -55 35 48 42 37 0 6 35 20 30 37 29 3 171 0 0 36 52 6 10 58 48 8 234 -56 36 16 31 37 28 1 35 48 17 37 57 1 172 0 0 37 19 57 10 58 49 7 235 -56 36 44 20 37 55 55 36 16 4 38 24 56 173 0 0 37 47 45 10 58 50 6 235 -56 37 12 5 38 23 45 36 43 48 38 52 49 174 0 0 38 15 30 10 58 50 5 236 -56 37 39 48 38 51 32 37 11 29 39 20 37 175 0 0 38 43 11 10 58 51 4 236 -56 38 7 27 39 19 15 37 39 6 39 48 22 176 0 0 39 10 46 10 58 51 3 237 -56 38 35 1 39 46 52 38 6 39 40 16 0 177 0 0 39 38 16 10 58 52 2 238 -56 39 2 29 40 14 23 38 34 6 40 43 33 178 0 0 40 5 39 10 58 52 1 238 -56 39 29 51 40 41 48 39 1 27 41 10 58 179 0 0 40 32 55 10 58 52 0 239 -56 39 57 5 41 9 5 39 28 40 .. .. .. Uncertainty in time = +/- 2 secs [Prediction of 2008 Oct 1.0] Data for the target star ------------------------ * name: TYC 6891-00510-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 50 26.4671 DE: -22 48 13.603 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .023, .024 ) * V mag [mag]: 11.0 * B mag [mag]: 11.7 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (17) Thetis approx. diameter [km]: 90 approx. diameter ["]: .063 distance from Earth [AU]: 1.95600 * orbital information: orbit source: Preston date of fit: 2008 Sep 30 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1669 number of rejected observations: 233 time covered by the observations: 1900 Oct 03 - 2008 Sep 30 1 sigma uncertainty ellipse (major, minor, PA): 0.008, 0.007, 93° remarks: * orbital elements for (17) Thetis : Mean anomaly = 47.16082647 deg Arg. of pericenter = 135.88115655 deg Long. of node = 125.59920003 deg Inclination = 5.58885659 deg Eccentricity = 0.13495213 Semimajor axis = 2.47041235 AU Perihelion dist = 2.13702494 AU Mag: H = 7.67, G = 0.15 Epoch of elements : MJD 54752.45400000 TDT (2008 Oct 13.454) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 13 17 Thetis 10h 54.0m UT 11.0 19 50 26.467-22 48 13.60TYC 6891-00510-1 11.7 12.2 90 5.2 1.956 3.137 4.86 111.7260 -22.804 13.03 -8.00 10.9006 -0.06961 0.61788 9.64879 1.08094 0.00539 0.00102 2000 46.53791720081011.00000135.881157125.599200 5.5888570.13495213 2.4704124 2.1370249 7.8 5.00.15 RATE 2.5383410 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.025 0.024 0 1.40 0.025 0 54740.5020081013_0510-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Oct 01, 04:46 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org