IOTA/IOTA-ES occultation update for (2060) Chiron / TYC 5775-01429-1 event on 2008 Oct 18, 07:27 UT Visible from Alaska Summary ------- On 2008 Oct 18 UT, the 269 km diameter asteroid (2060) Chiron will occult a 11.7 mag star in the constellation Aquarius for observers along a path across Alaska. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.0 mag to 18.7 mag (the magnitude of the asteroid) for at most 54.8 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: 34 * date and approx. time of event: 2008 Oct 18, 06:52 - 2008 Oct 18, 07:11 UT * midpoint of event [JD]: 2454757.79954583 * magnitude of target star: 11.7 * magnitude drop [mag]: 7.0 * estimated maximum duration [s]: 54.8 * Moon: 83 % sunlit, 116° distance * Sun: 111° distance * rough path description: Alaska The occultation path -------------------- * approximate projected width [km]: 300 * 1 sigma uncertainty interval [path widths]: +/- 1.94 * 1 sigma uncertainty interval [seconds]: +/- 103.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .053 +/- .041) * 1 sigma uncertainty ellipse (major, minor, PA): ( .053", .041", 77° ) * approx speed of asteroid's shadow [km/s]: 4.9112 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5775-01429-1 by 2060 Chiron on 2008 Oct 18 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 -165 59 37 80 0 0 6 52 0 0 188 -15 -173 51 54 -158 4 35 ... .. .. ... .. .. -166 43 22 79 0 0 6 52 0 1 187 -15 -173 53 32 -159 31 38 ... .. .. ... .. .. -167 22 32 78 0 0 6 52 1 2 186 -15 -173 57 40 -160 46 36 158 49 12 ... .. .. -167 58 14 77 0 0 6 52 2 3 186 -16 -174 3 47 -161 52 24 160 56 34 ... .. .. -168 31 13 76 0 0 6 52 4 4 185 -16 -174 11 28 -162 51 3 162 40 40 ... .. .. -169 2 4 75 0 0 6 52 6 5 185 -16 -174 20 26 -163 44 2 164 6 47 ... .. .. -169 31 14 74 0 0 6 52 9 6 184 -17 -174 30 30 -164 32 29 165 18 41 ... .. .. -169 59 2 73 0 0 6 52 12 7 184 -17 -174 41 28 -165 17 13 166 19 7 ... .. .. -170 25 43 72 0 0 6 52 15 8 183 -17 -174 53 15 -165 58 54 167 10 6 ... .. .. -170 51 29 71 0 0 6 52 19 9 183 -18 -175 5 43 -166 38 3 167 53 15 ... .. .. -171 16 31 70 0 0 6 52 23 10 182 -18 -175 18 48 -167 15 4 168 29 46 ... .. .. -171 40 56 69 0 0 6 52 28 11 182 -18 -175 32 27 -167 50 17 169 0 38 ... .. .. -172 4 51 68 0 0 6 52 33 12 182 -18 -175 46 36 -168 23 59 169 26 39 ... .. .. -172 28 21 67 0 0 6 52 39 13 181 -18 -176 1 14 -168 56 23 169 48 27 -155 8 10 -172 51 31 66 0 0 6 52 45 14 181 -19 -176 16 17 -169 27 40 170 6 33 -156 12 41 -173 14 24 65 0 0 6 52 52 15 181 -19 -176 31 44 -169 58 0 170 21 23 -157 13 18 -173 37 5 64 0 0 6 52 59 16 180 -19 -176 47 34 -170 27 30 170 33 19 -158 10 30 -173 59 34 63 0 0 6 53 6 17 180 -19 -177 3 46 -170 56 18 170 42 41 -159 4 44 -174 21 56 62 0 0 6 53 14 18 180 -19 -177 20 18 -171 24 29 170 49 43 -159 56 21 -174 44 13 61 0 0 6 53 22 19 179 -19 -177 37 11 -171 52 9 170 54 39 -160 45 39 -175 6 25 60 0 0 6 53 31 20 179 -19 -177 54 22 -172 19 22 170 57 40 -161 32 53 -175 28 35 59 0 0 6 53 40 21 178 -19 -178 11 52 -172 46 12 170 58 56 -162 18 18 -175 50 44 58 0 0 6 53 50 22 178 -19 -178 29 40 -173 12 42 170 58 37 -163 2 5 -176 12 54 57 0 0 6 54 0 23 178 -20 -178 47 47 -173 38 55 170 56 49 -163 44 25 -176 35 5 56 0 0 6 54 10 24 177 -20 -179 6 10 -174 4 54 170 53 40 -164 25 27 -176 57 20 55 0 0 6 54 21 25 177 -20 -179 24 51 -174 30 41 170 49 14 -165 5 18 -177 19 38 54 0 0 6 54 32 26 177 -20 -179 43 48 -174 56 19 170 43 37 -165 44 7 -177 42 0 53 0 0 6 54 44 27 176 -20 179 56 57 -175 21 49 170 36 54 -166 21 59 -178 4 28 52 0 0 6 54 56 28 176 -20 179 37 26 -175 47 14 170 29 8 -166 58 59 -178 27 2 51 0 0 6 55 8 29 175 -20 179 17 38 -176 12 34 170 20 24 -167 35 15 -178 49 44 50 0 0 6 55 21 30 175 -19 178 57 34 -176 37 52 170 10 43 -168 10 48 -179 12 32 49 0 0 6 55 34 31 175 -19 178 37 13 -177 3 8 170 0 10 -168 45 45 -179 35 29 48 0 0 6 55 48 32 174 -19 178 16 35 -177 28 24 169 48 46 -169 20 8 -179 58 35 47 0 0 6 56 2 33 174 -19 177 55 41 -177 53 41 169 36 34 -169 54 2 179 38 10 46 0 0 6 56 16 34 173 -19 177 34 30 -178 19 0 169 23 36 -170 27 29 179 14 45 45 0 0 6 56 31 35 173 -19 177 13 2 -178 44 23 169 9 53 -171 0 32 178 51 9 44 0 0 6 56 46 36 172 -19 176 51 17 -179 9 49 168 55 27 -171 33 13 178 27 22 43 0 0 6 57 1 37 172 -19 176 29 15 -179 35 20 168 40 19 -172 5 36 178 3 24 42 0 0 6 57 17 38 171 -18 176 6 57 179 59 3 168 24 32 -172 37 42 177 39 14 41 0 0 6 57 33 39 171 -18 175 44 20 179 33 19 168 8 5 -173 9 34 177 14 52 40 0 0 6 57 50 40 170 -18 175 21 26 179 7 28 167 51 0 -173 41 13 176 50 17 39 0 0 6 58 7 41 170 -18 174 58 15 178 41 29 167 33 17 -174 12 41 176 25 28 38 0 0 6 58 24 42 169 -18 174 34 45 178 15 21 167 14 58 -174 44 1 176 0 25 37 0 0 6 58 41 43 168 -17 174 10 57 177 49 4 166 56 3 -175 15 13 175 35 9 36 0 0 6 58 59 44 168 -17 173 46 51 177 22 37 166 36 33 -175 46 18 175 9 37 35 0 0 6 59 18 45 167 -17 173 22 26 176 55 58 166 16 28 -176 17 20 174 43 50 34 0 0 6 59 36 46 166 -16 172 57 42 176 29 9 165 55 48 -176 48 18 174 17 48 33 0 0 6 59 55 46 165 -16 172 32 39 176 2 7 165 34 34 -177 19 13 173 51 29 32 0 0 7 0 14 47 165 -16 172 7 16 175 34 53 165 12 46 -177 50 9 173 24 54 31 0 0 7 0 34 48 164 -15 171 41 32 175 7 25 164 50 24 -178 21 4 172 58 2 30 0 0 7 0 53 49 163 -15 171 15 29 174 39 44 164 27 28 -178 52 1 172 30 52 29 0 0 7 1 13 50 162 -15 170 49 4 174 11 48 164 3 59 -179 23 1 172 3 23 28 0 0 7 1 34 51 161 -14 170 22 19 173 43 36 163 39 56 -179 54 4 171 35 36 27 0 0 7 1 54 52 160 -14 169 55 11 173 15 9 163 15 19 179 34 48 171 7 30 26 0 0 7 2 15 52 159 -14 169 27 41 172 46 26 162 50 8 179 3 35 170 39 4 25 0 0 7 2 37 53 158 -13 168 59 49 172 17 25 162 24 22 178 32 15 170 10 17 24 0 0 7 2 58 54 157 -13 168 31 34 171 48 7 161 58 3 178 0 48 169 41 10 23 0 0 7 3 20 55 156 -12 168 2 54 171 18 30 161 31 8 177 29 12 169 11 40 22 0 0 7 3 42 55 155 -12 167 33 51 170 48 35 161 3 38 176 57 27 168 41 49 21 0 0 7 4 4 56 153 -11 167 4 22 170 18 19 160 35 32 176 25 32 168 11 34 20 0 0 7 4 26 57 152 -11 166 34 28 169 47 43 160 6 50 175 53 26 167 40 55 19 0 0 7 4 49 58 151 -10 166 4 8 169 16 46 159 37 31 175 21 7 167 9 52 18 0 0 7 5 12 58 149 -10 165 33 20 168 45 26 159 7 35 174 48 36 166 38 24 17 0 0 7 5 35 59 148 -9 165 2 5 168 13 44 158 37 0 174 15 51 166 6 30 16 0 0 7 5 59 60 146 -9 164 30 21 167 41 38 158 5 46 173 42 51 165 34 8 15 0 0 7 6 22 60 144 -8 163 58 8 167 9 7 157 33 52 173 9 35 165 1 19 14 0 0 7 6 46 61 142 -8 163 25 24 166 36 11 157 1 17 172 36 3 164 28 1 13 0 0 7 7 10 61 141 -7 162 52 9 166 2 49 156 28 0 172 2 13 163 54 13 12 0 0 7 7 34 62 139 -6 162 18 21 165 28 59 155 53 59 171 28 4 163 19 54 11 0 0 7 7 59 62 137 -6 161 44 0 164 54 41 155 19 14 170 53 36 162 45 3 10 0 0 7 8 23 62 135 -5 161 9 5 164 19 53 154 43 44 170 18 47 162 9 39 9 0 0 7 8 48 63 133 -5 160 33 33 163 44 34 154 7 26 169 43 37 161 33 40 8 0 0 7 9 13 63 130 -4 159 57 25 163 8 44 153 30 19 169 8 3 160 57 6 7 0 0 7 9 38 63 128 -3 159 20 38 162 32 20 152 52 22 168 32 6 160 19 54 6 0 0 7 10 3 63 126 -3 158 43 11 161 55 22 152 13 32 167 55 43 159 42 4 5 0 0 7 10 29 64 124 -2 158 5 2 161 17 48 151 33 47 167 18 54 159 3 33 4 0 0 7 10 54 64 121 -1 157 26 11 160 39 36 150 53 6 166 41 38 158 24 21 3 0 0 7 11 20 64 119 0 156 46 34 160 0 45 150 11 26 166 3 52 Uncertainty in time = +/- 118 secs [Prediction of 2008 Aug 6.0] Data for the target star ------------------------ * name: TYC 5775-01429-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 05 32.1758 DE: -09 40 35.380 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .022 ) * V mag [mag]: 11.7 * B mag [mag]: 13.0 * Apparent position with proper motion RA(deg): 316.5073015828 DE(deg): -9.6402783106 * Equation of equinoxes (radians) : 0.000047509001039 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2060) Chiron approx. diameter [km]: 269 approx. diameter ["]: .025 distance from Earth [AU]: 15.13700 * orbital information: orbit source: Preston date of fit: 2008 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1038 number of rejected observations: 22 time covered by the observations: 1941 Jan 23 - 2007 Oct 22 1 sigma uncertainty ellipse (major, minor, PA): 0.049, 0.034, 75° remarks: * orbital elements for (2060) Chiron : Mean anomaly = 89.90744969 deg Arg. of pericenter = 340.03125975 deg Long. of node = 209.28085139 deg Inclination = 6.93266350 deg Eccentricity = 0.37968959 Semimajor axis = 13.71020692 AU Perihelion dist = 8.50458402 AU Mag: H = 6.30, G = 0.15 Epoch of elements : MJD 54757.31100000 TDT (2008 Oct 18.311) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 18 2060 Chiron 7h 11.3m UT 11.7 21 5 32.176- 9 40 35.38TYC 5775-01429-1 13.0 18.7 269 54.8 15.137 -0.050 -1.43 -178.6039 -9.676 68.44 -9.78 7.1891 -0.39238 0.20448 -1.28670 -2.45531 0.00547 0.00139 2000 89.76550720081011.00000340.031260209.280851 6.9326630.3796895913.7102069 8.5045841 6.5 5.00.15 RATE 0.1941500 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.053 0.041 77 2.94 0.047 0 54684.5020081018_1429-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Sep 12, 18:20 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org