IOTA/IOTA-ES occultation update for (999) Zachia / HIP 13496 event on 2008 Jul 08, 17:49 UT Visible from E Russia Summary ------- On 2008 Jul 08 UT, the 18 km diameter asteroid (999) Zachia will occult a 9.1 mag star in the constellation Aries for observers along a path across E Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.7 mag to 15.8 mag (the magnitude of the asteroid) for at most 0.5 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: . The event at a glimpse ---------------------- * Rank: 24 * date and approx. time of event: 2008 Jul 08, 17:47 - 2008 Jul 08, 17:48 UT * midpoint of event [JD]: 2454656.24251667 * magnitude of target star: 9.1 * magnitude drop [mag]: 6.7 * estimated maximum duration [s]: 0.5 * Moon: 36 % sunlit, 134° distance * Sun: 60° distance * rough path description: E Russia The occultation path -------------------- * approximate projected width [km]: 31 * 1 sigma uncertainty interval [path widths]: +/- 2.76 * 1 sigma uncertainty interval [seconds]: +/- 2.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .046 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .046", .027", 87° ) * approx speed of asteroid's shadow [km/s]: 33.2627 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 13496 by 999 Zachia on 2008 Jul 8 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 104 4 43 41 0 0 17 47 23 1 66 -26 104 30 32 103 38 40 ... .. .. ... .. .. 106 46 9 42 0 0 17 47 23 3 68 -25 107 11 5 106 21 1 ... .. .. 103 58 42 Latitude Latitude Latitude Latitude 107 0 0 42 5 17 17 47 23 3 68 -25 41 55 46 42 14 50 .. .. .. 43 8 22 108 0 0 42 28 23 17 47 24 4 69 -24 42 18 49 42 37 59 .. .. .. 43 31 46 109 0 0 42 51 51 17 47 24 5 69 -24 42 42 14 43 1 29 .. .. .. 43 55 32 110 0 0 43 15 40 17 47 24 6 70 -23 43 6 1 43 25 21 42 13 31 44 19 40 111 0 0 43 39 49 17 47 25 7 71 -22 43 30 8 43 49 34 42 37 23 44 44 9 112 0 0 44 4 19 17 47 26 8 71 -22 43 54 34 44 14 6 43 1 35 45 8 58 113 0 0 44 29 7 17 47 26 8 72 -21 44 19 20 44 38 57 43 26 6 45 34 6 114 0 0 44 54 14 17 47 27 9 73 -21 44 44 24 45 4 7 43 50 55 45 59 32 115 0 0 45 19 38 17 47 28 10 73 -20 45 9 45 45 29 34 44 16 1 46 25 16 116 0 0 45 45 19 17 47 29 11 74 -19 45 35 23 45 55 17 44 41 23 46 51 16 117 0 0 46 11 15 17 47 30 12 75 -19 46 1 16 46 21 17 45 7 2 47 17 32 118 0 0 46 37 26 17 47 31 12 76 -18 46 27 25 46 47 31 45 32 55 47 44 3 119 0 0 47 3 51 17 47 32 13 77 -17 46 53 47 47 13 59 45 59 2 48 10 48 120 0 0 47 30 29 17 47 33 14 77 -17 47 20 22 47 40 40 46 25 22 48 37 46 121 0 0 47 57 19 17 47 34 15 78 -16 47 47 9 48 7 33 46 51 54 49 4 56 122 0 0 48 24 20 17 47 35 15 79 -15 48 14 7 48 34 37 47 18 37 49 32 17 123 0 0 48 51 31 17 47 36 16 80 -14 48 41 15 49 1 50 47 45 30 49 59 47 124 0 0 49 18 51 17 47 38 17 81 -14 49 8 33 49 29 13 48 12 33 50 27 27 125 0 0 49 46 19 17 47 39 18 82 -13 49 35 58 49 56 44 48 39 43 50 55 14 126 0 0 50 13 54 17 47 41 18 82 -12 50 3 30 50 24 21 49 7 1 51 23 8 127 0 0 50 41 35 17 47 42 19 83 -12 50 31 8 50 52 5 49 34 25 51 51 7 128 0 0 51 9 20 17 47 44 20 84 -11 50 58 50 51 19 53 50 1 53 52 19 10 129 0 0 51 37 9 17 47 45 20 85 -10 51 26 37 51 47 44 50 29 26 52 47 17 130 0 0 52 5 0 17 47 47 21 86 -9 51 54 25 52 15 38 50 57 2 53 15 27 131 0 0 52 32 53 17 47 48 22 87 -9 52 22 16 52 43 34 51 24 39 53 43 37 132 0 0 53 0 46 17 47 50 22 88 -8 52 50 7 53 11 29 51 52 17 54 11 46 133 0 0 53 28 39 17 47 52 23 89 -7 53 17 57 53 39 24 52 19 55 54 39 55 134 0 0 53 56 29 17 47 53 23 90 -7 53 45 45 54 7 17 52 47 31 55 8 1 135 0 0 54 24 17 17 47 55 24 91 -6 54 13 30 54 35 7 53 15 6 55 36 4 136 0 0 54 52 0 17 47 57 25 92 -5 54 41 12 55 2 52 53 42 36 56 4 1 137 0 0 55 19 38 17 47 59 25 93 -4 55 8 48 55 30 32 54 10 2 56 31 53 138 0 0 55 47 10 17 48 1 26 94 -4 55 36 18 55 58 6 54 37 22 56 59 38 139 0 0 56 14 35 17 48 2 26 95 -3 56 3 41 56 25 32 55 4 36 57 27 15 140 0 0 56 41 51 17 48 4 27 96 -2 56 30 55 56 52 50 55 31 42 57 54 43 141 0 0 57 8 58 17 48 6 27 98 -2 56 58 1 57 19 59 55 58 40 58 22 0 142 0 0 57 35 54 17 48 8 28 99 -1 57 24 56 57 46 57 56 25 27 58 49 6 143 0 0 58 2 39 17 48 10 28 100 0 57 51 40 58 13 43 56 52 5 59 16 0 Uncertainty in time = +/- 2 secs [Prediction of 2008 Jun 6.0] Data for the target star ------------------------ * name: HIP 13496 * constellation : Aries * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 02 53 46.8143 DE: +18 38 03.083 * position source: mpos:HIP pm:HIP plx:HIP * standard error: RA,DE ["]: ( .026, .022 ) * V mag [mag]: 9.1 * B mag [mag]: 9.5 * Apparent position with proper motion RA(deg): 43.5652621726 DE(deg): 18.6698395936 * Equation of equinoxes (radians) : 0.000051440490251 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (999) Zachia approx. diameter [km]: 18 approx. diameter ["]: .010 distance from Earth [AU]: 2.44900 * orbital information: orbit source: Preston date of fit: 2008 Jun 04 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 657 number of rejected observations: 41 time covered by the observations: 1923 Aug 09 - 2007 Sep 22 1 sigma uncertainty ellipse (major, minor, PA): 0.038, 0.016, 85° remarks: * orbital elements for (999) Zachia : Mean anomaly = 25.38585780 deg Arg. of pericenter = 127.62440378 deg Long. of node = 215.16135362 deg Inclination = 9.76148797 deg Eccentricity = 0.21449310 Semimajor axis = 2.61278040 AU Perihelion dist = 2.05235704 AU Mag: H = 10.78, G = 0.15 Epoch of elements : MJD 54655.74200000 TDT (2008 Jul 08.742) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Jul 8 999 Zachia 17h 49.2m UT 9.1 2 53 46.814 18 38 3.08HIP 13496 9.6 15.8 18 0.5 2.449 4.647 13.47 -150.9128 18.631 -86.01 22.37 17.8204 -0.16229 0.79868 18.39563 3.75214 -0.00437 -0.00123 2000 24.0458332008 7 3.00000127.624404215.161354 9.7614880.21449310 2.6127804 2.052357011.1 5.00.15 RATE 2.3337250 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.046 0.027 87 3.76 0.028 0 54623.5020080708__13496 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Jun 06, 21:48 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org