IOTA/IOTA-ES occultation update for (679) Pax / HIP 47375 event on 2012 Oct 18, 10:09 UT Visible from Caribbean, Mexico Summary ------- On 2012 Oct 18 UT, the 61 km diameter asteroid (679) Pax will occult a 8.6 mag star in the constellation Leo for observers along a path across Caribbean, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.6 mag to 14.2 mag (the magnitude of the asteroid) for at most 2.2 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: . The event at a glimpse ---------------------- * Rank: 86 * date and approx. time of event: 2012 Oct 18, 10:05 - 2012 Oct 18, 10:07 UT * geocentric midpoint of event [JD]: 2456218.92334167 * magnitude of target star: 8.6 * magnitude drop [mag]: 5.6 * estimated maximum duration [s]: 2.2 * Moon: 12 % sunlit, 104° distance * Sun: 64° distance * rough path description: Caribbean, Mexico The occultation path -------------------- * approximate projected width [km]: 62 * 1 sigma uncertainty interval [path widths]: +/- 0.59 * 1 sigma uncertainty interval [seconds]: +/- 2.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .029 +/- .018) * 1 sigma uncertainty ellipse (major, minor, PA): ( .029", .018", 87° ) * approx speed of asteroid's shadow [km/s]: 27.6661 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 47375 by 679 Pax on 2012 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 ' " Latitude Latitude Latitude Latitude -126 0 0 9 13 16 10 5 49 1 72 -61 8 55 42 9 30 52 8 34 58 9 51 38 -125 0 0 9 32 13 10 5 49 2 73 -60 9 14 39 9 49 49 8 53 55 10 10 35 -124 0 0 9 51 9 10 5 49 3 73 -59 9 33 34 10 8 44 9 12 51 10 29 31 -123 0 0 10 10 3 10 5 49 4 73 -58 9 52 29 10 27 39 9 31 46 10 48 25 -122 0 0 10 28 56 10 5 50 5 73 -57 10 11 21 10 46 31 9 50 38 11 7 17 -121 0 0 10 47 46 10 5 50 6 73 -56 10 30 12 11 5 21 10 9 29 11 26 7 -120 0 0 11 6 33 10 5 51 7 74 -55 10 48 59 11 24 8 10 28 17 11 44 54 -119 0 0 11 25 18 10 5 51 8 74 -54 11 7 44 11 42 53 10 47 1 12 3 38 -118 0 0 11 43 59 10 5 52 9 74 -53 11 26 25 12 1 33 11 5 43 12 22 19 -117 0 0 12 2 36 10 5 52 10 74 -52 11 45 2 12 20 10 11 24 20 12 40 55 -116 0 0 12 21 8 10 5 53 11 74 -51 12 3 35 12 38 42 11 42 53 12 59 27 -115 0 0 12 39 36 10 5 54 12 75 -51 12 22 3 12 57 10 12 1 22 13 17 54 -114 0 0 12 57 59 10 5 55 13 75 -50 12 40 26 13 15 32 12 19 46 13 36 16 -113 0 0 13 16 16 10 5 56 14 75 -49 12 58 44 13 33 49 12 38 4 13 54 32 -112 0 0 13 34 27 10 5 57 15 75 -48 13 16 56 13 52 0 12 56 16 14 12 43 -111 0 0 13 52 32 10 5 58 16 76 -47 13 35 1 14 10 4 13 14 22 14 30 47 -110 0 0 14 10 31 10 5 59 17 76 -46 13 53 0 14 28 2 13 32 21 14 48 44 -109 0 0 14 28 22 10 6 1 18 76 -45 14 10 52 14 45 53 13 50 14 15 6 35 -108 0 0 14 46 6 10 6 2 19 76 -44 14 28 37 15 3 37 14 7 59 15 24 17 -107 0 0 15 3 43 10 6 3 20 77 -43 14 46 14 15 21 12 14 25 37 15 41 52 -106 0 0 15 21 11 10 6 5 21 77 -42 15 3 42 15 38 40 14 43 6 15 59 19 -105 0 0 15 38 31 10 6 6 22 77 -41 15 21 3 15 55 59 15 0 27 16 16 38 -104 0 0 15 55 42 10 6 8 23 77 -40 15 38 14 16 13 10 15 17 40 16 33 47 -103 0 0 16 12 43 10 6 9 24 78 -39 15 55 17 16 30 11 15 34 43 16 50 48 -102 0 0 16 29 36 10 6 11 25 78 -38 16 12 10 16 47 3 15 51 37 17 7 39 -101 0 0 16 46 19 10 6 13 26 78 -37 16 28 53 17 3 44 16 8 21 17 24 20 -100 0 0 17 2 51 10 6 15 27 79 -36 16 45 27 17 20 16 16 24 55 17 40 51 - 99 0 0 17 19 13 10 6 17 28 79 -35 17 1 50 17 36 38 16 41 19 17 57 11 - 98 0 0 17 35 25 10 6 19 29 79 -34 17 18 2 17 52 49 16 57 33 18 13 21 - 97 0 0 17 51 26 10 6 21 30 80 -33 17 34 3 18 8 48 17 13 35 18 29 20 - 96 0 0 18 7 15 10 6 23 31 80 -32 17 49 54 18 24 37 17 29 26 18 45 8 - 95 0 0 18 22 53 10 6 25 32 81 -31 18 5 32 18 40 14 17 45 6 19 0 44 - 94 0 0 18 38 19 10 6 27 33 81 -30 18 20 59 18 55 39 18 0 33 19 16 8 - 93 0 0 18 53 33 10 6 29 34 81 -29 18 36 14 19 10 52 18 15 49 19 31 20 - 92 0 0 19 8 34 10 6 32 35 82 -28 18 51 16 19 25 53 18 30 53 19 46 20 - 91 0 0 19 23 23 10 6 34 36 82 -27 19 6 6 19 40 41 18 45 44 20 1 7 - 90 0 0 19 37 59 10 6 36 37 83 -26 19 20 43 19 55 16 19 0 22 20 15 41 - 89 0 0 19 52 23 10 6 39 38 83 -25 19 35 7 20 9 39 19 14 47 20 30 2 - 88 0 0 20 6 32 10 6 41 39 83 -24 19 49 18 20 23 48 19 28 59 20 44 10 - 87 0 0 20 20 29 10 6 44 40 84 -24 20 3 15 20 37 43 19 42 57 20 58 5 - 86 0 0 20 34 12 10 6 46 41 84 -23 20 16 59 20 51 25 19 56 42 21 11 45 - 85 0 0 20 47 40 10 6 49 42 85 -22 20 30 29 21 4 53 20 10 13 21 25 12 - 84 0 0 21 0 55 10 6 52 43 85 -21 20 43 44 21 18 7 20 23 29 21 38 25 - 83 0 0 21 13 56 10 6 54 44 86 -20 20 56 46 21 31 6 20 36 32 21 51 23 - 82 0 0 21 26 42 10 6 57 45 86 -19 21 9 33 21 43 51 20 49 20 22 4 7 - 81 0 0 21 39 13 10 7 0 46 87 -18 21 22 5 21 56 22 21 1 53 22 16 36 - 80 0 0 21 51 29 10 7 3 47 87 -17 21 34 22 22 8 37 21 14 11 22 28 51 - 79 0 0 22 3 31 10 7 6 48 88 -16 21 46 25 22 20 38 21 26 15 22 40 50 - 78 0 0 22 15 17 10 7 8 49 88 -15 21 58 12 22 32 23 21 38 3 22 52 35 - 77 0 0 22 26 48 10 7 11 49 89 -14 22 9 44 22 43 53 21 49 36 23 4 4 - 76 0 0 22 38 4 10 7 14 50 90 -13 22 21 0 22 55 8 22 0 54 23 15 17 - 75 0 0 22 49 4 10 7 17 51 90 -12 22 32 1 23 6 7 22 11 56 23 26 16 - 74 0 0 22 59 48 10 7 20 52 91 -12 22 42 47 23 16 51 22 22 42 23 36 58 - 73 0 0 23 10 17 10 7 23 53 91 -11 22 53 16 23 27 18 22 33 13 23 47 25 - 72 0 0 23 20 29 10 7 27 54 92 -10 23 3 29 23 37 30 22 43 27 23 57 35 - 71 0 0 23 30 26 10 7 30 55 93 -9 23 13 27 23 47 26 22 53 25 24 7 30 - 70 0 0 23 40 6 10 7 33 56 94 -8 23 23 8 23 57 5 23 3 7 24 17 8 - 69 0 0 23 49 30 10 7 36 57 94 -7 23 32 33 24 6 28 23 12 33 24 26 31 - 68 0 0 23 58 38 10 7 39 58 95 -6 23 41 41 24 15 35 23 21 43 24 35 37 - 67 0 0 24 7 29 10 7 43 59 96 -5 23 50 33 24 24 26 23 30 36 24 44 26 - 66 0 0 24 16 4 10 7 46 60 97 -4 23 59 9 24 32 59 23 39 12 24 52 59 - 65 0 0 24 24 22 10 7 49 61 98 -3 24 7 27 24 41 17 23 47 32 25 1 15 - 64 0 0 24 32 23 10 7 52 61 98 -3 24 15 29 24 49 17 23 55 34 25 9 15 - 63 0 0 24 40 7 10 7 56 62 99 -2 24 23 15 24 57 1 24 3 20 25 16 58 - 62 0 0 24 47 35 10 7 59 63 100 -1 24 30 43 25 4 28 24 10 50 25 24 24 Uncertainty in time = +/- 2 secs Prediction of 2012 Jul 10.0 Data for the target star ------------------------ * name: HIP 47375 * constellation : Leo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 09 39 08.2862 DE: +17 28 04.502 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .022, .014 ) * V mag [mag]: 8.6 * B mag [mag]: 9.1 * Apparent position with proper motion RA(deg): 144.9622094909 DE(deg): 17.4082162650 * Equation of equinoxes (radians) : 0.000059570412175 * Diameter [mas]: 0 * remarks:slight pm issue Data for the minor planet ------------------------- * general information: (number) name: (679) Pax approx. diameter [km]: 61 approx. diameter ["]: .030 distance from Earth [AU]: 2.76500 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 927 number of rejected observations: 66 time covered by the observations: 1909 Jan 29 - 2011 Dec 01 1 sigma uncertainty ellipse (major, minor, PA): 0.019, 0.011, 82° remarks: * orbital elements for (679) Pax : Mean anomaly = 65.72746197 deg Arg. of pericenter = 266.85650210 deg Long. of node = 112.26810717 deg Inclination = 24.38755119 deg Eccentricity = 0.31204481 Semimajor axis = 2.58543086 AU Perihelion dist = 1.77866058 AU Mag: H = 9.00, G = 0.15 Epoch of elements : MJD 56218.42300000 TDT (2012 Oct 18.423) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 18 679 Pax 10h 9.6m UT 8.6 9 39 8.286 17 28 4.50HIP 47375 9.1 14.2 61 2.2 2.765 3.471 -0.55 -34.9224 17.468 23.88 -9.84 10.1602 0.00150 0.15229 15.61455 -0.17341 -0.00482 0.00181 2000 63.73049220121010.00000266.856502112.268107 24.3875510.31204481 2.5854309 1.7786606 9.0 5.00.15 RATE 2.3708540 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.029 0.018 87 1.59 0.018 0 0 2 2 056118.0020121018__47375 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 26, 04:34 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org