IOTA/IOTA-ES occultation update for (308) Polyxo / UCAC2 26686366 event on 2010 Jan 04, 06:11 UT Visible from Europe Summary ------- On 2010 Jan 04 UT, the 141 km diameter asteroid (308) Polyxo will occult a 11.7 mag star in the constellation Libra for observers along a path across Europe. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 13.7 mag (the magnitude of the asteroid) for at most 4.4 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: 91 * date and approx. time of event: 2010 Jan 04, 06:09 - 2010 Jan 04, 06:10 UT * magnitude of target star: 11.7 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 4.4 * Moon: 83 % sunlit, 71° distance * Sun: 61° distance * rough path description: Europe The occultation path -------------------- * approximate projected width [km]: 251 * 1 sigma uncertainty interval [path widths]: +/- 0.51 * 1 sigma uncertainty interval [seconds]: +/- 2.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .034 +/- .032) * 1 sigma uncertainty ellipse (major, minor, PA): ( .034", .032", 91° ) * approx speed of asteroid's shadow [km/s]: 32.1506 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 26686366 by 308 Polyxo on 2010 Jan 4 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 - 27 23 14 65 0 0 6 9 33 2 130 -31 - 31 47 29 - 23 1 59 ... .. .. - 18 36 56 - 24 23 59 64 0 0 6 9 33 3 132 -30 - 28 36 32 - 20 13 12 ... .. .. - 15 57 48 Latitude Latitude Latitude Latitude - 24 0 0 63 51 46 6 9 33 3 133 -30 62 27 33 65 20 3 .. .. .. 66 55 5 - 23 0 0 63 30 56 6 9 33 4 134 -30 62 6 39 64 59 19 60 44 19 66 34 26 - 22 0 0 63 9 49 6 9 34 5 135 -29 61 45 29 64 38 15 60 23 6 66 13 27 - 21 0 0 62 48 24 6 9 34 5 136 -29 61 24 1 64 16 53 60 1 36 65 52 8 - 20 0 0 62 26 42 6 9 34 6 136 -29 61 2 18 63 55 12 59 39 51 65 30 29 - 19 0 0 62 4 43 6 9 35 6 137 -28 60 40 19 63 33 14 59 17 51 65 8 32 - 18 0 0 61 42 28 6 9 35 7 138 -28 60 18 4 63 10 59 58 55 37 64 46 16 - 17 0 0 61 19 57 6 9 35 7 139 -27 59 55 34 62 48 27 58 33 8 64 23 42 - 16 0 0 60 57 12 6 9 36 8 140 -27 59 32 51 62 25 38 58 10 26 64 0 51 - 15 0 0 60 34 11 6 9 36 9 141 -26 59 9 53 62 2 35 57 47 32 63 37 43 - 14 0 0 60 10 57 6 9 37 9 142 -26 58 46 43 61 39 16 57 24 25 63 14 18 - 13 0 0 59 47 30 6 9 38 10 143 -25 58 23 20 61 15 43 57 1 6 62 50 39 - 12 0 0 59 23 50 6 9 38 11 144 -25 57 59 46 60 51 57 56 37 36 62 26 45 - 11 0 0 58 59 58 6 9 39 11 144 -24 57 36 0 60 27 57 56 13 56 62 2 36 - 10 0 0 58 35 55 6 9 40 12 145 -24 57 12 4 60 3 46 55 50 7 61 38 15 - 9 0 0 58 11 41 6 9 41 12 146 -23 56 47 58 59 39 23 55 26 8 61 13 41 - 8 0 0 57 47 18 6 9 42 13 147 -23 56 23 44 59 14 50 55 2 2 60 48 55 - 7 0 0 57 22 46 6 9 43 14 148 -22 55 59 22 58 50 7 54 37 48 60 23 59 - 6 0 0 56 58 6 6 9 44 14 149 -21 55 34 52 58 25 15 54 13 27 59 58 53 - 5 0 0 56 33 19 6 9 45 15 150 -21 55 10 16 58 0 15 53 49 0 59 33 38 - 4 0 0 56 8 25 6 9 46 16 151 -20 54 45 34 57 35 8 53 24 29 59 8 16 - 3 0 0 55 43 26 6 9 47 16 152 -20 54 20 47 57 9 55 52 59 53 58 42 46 - 2 0 0 55 18 23 6 9 48 17 153 -19 53 55 56 56 44 37 52 35 14 58 17 10 - 1 0 0 54 53 16 6 9 50 18 154 -18 53 31 3 56 19 15 52 10 33 57 51 29 0 0 0 54 28 6 6 9 51 18 155 -18 53 6 7 55 53 49 51 45 50 57 25 44 1 0 0 54 2 55 6 9 52 19 155 -17 52 41 10 55 28 21 51 21 6 56 59 56 2 0 0 53 37 42 6 9 54 19 156 -16 52 16 13 55 2 51 50 56 22 56 34 6 3 0 0 53 12 30 6 9 55 20 157 -15 51 51 16 54 37 21 50 31 39 56 8 15 4 0 0 52 47 18 6 9 57 21 158 -15 51 26 20 54 11 52 50 6 57 55 42 24 5 0 0 52 22 9 6 9 59 21 159 -14 51 1 27 53 46 24 49 42 19 55 16 34 6 0 0 51 57 2 6 10 0 22 160 -13 50 36 37 53 20 58 49 17 44 54 50 46 7 0 0 51 32 0 6 10 2 22 161 -13 50 11 51 52 55 36 48 53 13 54 25 1 8 0 0 51 7 2 6 10 4 23 162 -12 49 47 10 52 30 18 48 28 48 53 59 21 9 0 0 50 42 9 6 10 6 24 163 -11 49 22 36 52 5 6 48 4 29 53 33 45 10 0 0 50 17 24 6 10 8 24 164 -10 48 58 8 51 40 0 47 40 17 53 8 16 11 0 0 49 52 45 6 10 10 25 165 -10 48 33 47 51 15 2 47 16 13 52 42 53 12 0 0 49 28 15 6 10 12 25 166 -9 48 9 35 50 50 11 46 52 18 52 17 39 13 0 0 49 3 55 6 10 14 26 167 -8 47 45 33 50 25 30 46 28 32 51 52 34 14 0 0 48 39 45 6 10 16 26 168 -7 47 21 41 50 0 59 46 4 57 51 27 38 15 0 0 48 15 45 6 10 18 27 169 -7 46 58 0 49 36 39 45 41 32 51 2 54 16 0 0 47 51 58 6 10 20 27 170 -6 46 34 31 49 12 31 45 18 20 50 38 22 17 0 0 47 28 23 6 10 23 28 171 -5 46 11 15 48 48 36 44 55 21 50 14 2 18 0 0 47 5 2 6 10 25 28 173 -4 45 48 12 48 24 54 44 32 35 49 49 56 19 0 0 46 41 55 6 10 27 29 174 -3 45 25 24 48 1 26 44 10 3 49 26 5 20 0 0 46 19 4 6 10 30 29 175 -3 45 2 50 47 38 14 43 47 47 49 2 28 21 0 0 45 56 28 6 10 32 30 176 -2 44 40 33 47 15 18 43 25 46 48 39 9 22 0 0 45 34 9 6 10 34 30 177 -1 44 18 32 46 52 39 43 4 2 48 16 6 23 0 0 45 12 8 6 10 37 31 178 0 43 56 49 46 30 17 42 42 35 47 53 21 Uncertainty in time = +/- 2 secs Prediction of 2009 Nov 15.0 Data for the target star ------------------------ * name: UCAC2 26686366 * constellation : Libra * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 14 43 53.9242 DE: -14 17 20.278 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .032, .031 ) * V mag [mag]: 11.7 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (308) Polyxo approx. diameter [km]: 141 approx. diameter ["]: .063 distance from Earth [AU]: 3.08900 * orbital information: orbit source: Preston date of fit: 2009 Nov 14 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1251 number of rejected observations: 161 time covered by the observations: 1902 Oct 07 - 2009 May 26 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.006, 104° remarks: * orbital elements for (308) Polyxo : Mean anomaly = 274.90774243 deg Arg. of pericenter = 112.23667613 deg Long. of node = 181.89491461 deg Inclination = 4.36423736 deg Eccentricity = 0.03695281 Semimajor axis = 2.74950644 AU Perihelion dist = 2.64790444 AU Mag: H = 8.09, G = 0.21 Epoch of elements : MJD 55200.25800000 TDT (2010 Jan 04.258) ------ occelmnt file for Occult BEGIN ----------------------------------- 2010 Jan 4 308 Polyxo 6h 11.4m UT 11.7 14 43 53.924-14 17 20.28UCAC2 26686366 0.0 13.7 141 4.4 3.089 3.445 -12.73 24.3760 -14.285 88.36 -22.73 6.1897 0.20361 0.80158 17.58703 -4.47205 -0.00489 0.00162 2000 274.8519672010 1 4.00000112.236676181.894915 4.3642370.03695281 2.7495064 2.6479045 8.2 5.00.21 RATE 2.1618320 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.034 0.032 91 1.51 0.032 0 055150.0020100104_686366 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2009 Nov 14, 22:20 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org