IOTA/IOTA-ES occultation update for (16) Psyche / HIP 22112 event on 2010 Aug 21, 09:54 UT Visible from S USA, Mexico Summary ------- On 2010 Aug 21 UT, the 253 km diameter asteroid (16) Psyche will occult a 8.5 mag star in the constellation Taurus for observers along a path across S USA, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.7 mag to 11.1 mag (the magnitude of the asteroid) for at most 10.3 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: 100 * date and approx. time of event: 2010 Aug 21, 09:50 - 2010 Aug 21, 09:53 UT * midpoint of event [JD]: 2455429.91257917 * magnitude of target star: 8.5 * magnitude drop [mag]: 2.7 * estimated maximum duration [s]: 10.3 * Moon: 90 % sunlit, 141° distance * Sun: 76° distance * rough path description: S USA, Mexico Additional comments ------------------- pm issue, possible double star The occultation path -------------------- * approximate projected width [km]: 274 * 1 sigma uncertainty interval [path widths]: +/- 0.12 * 1 sigma uncertainty interval [seconds]: +/- 1.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .019 +/- .016) * 1 sigma uncertainty ellipse (major, minor, PA): ( .019", .016", 88° ) * approx speed of asteroid's shadow [km/s]: 24.6247 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 22112 by 16 Psyche on 2010 Aug 21 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 -141 0 0 17 37 18 9 50 9 1 70 -60 16 18 12 18 57 13 15 59 19 19 16 31 -140 0 0 17 58 46 9 50 9 2 70 -59 16 39 36 19 18 45 16 20 43 19 38 5 -139 0 0 18 20 20 9 50 9 3 71 -59 17 1 7 19 40 23 16 42 13 19 59 43 -138 0 0 18 42 0 9 50 10 4 71 -58 17 22 43 20 2 6 17 3 48 20 21 27 -137 0 0 19 3 44 9 50 10 5 71 -57 17 44 24 20 23 53 17 25 28 20 43 16 -136 0 0 19 25 32 9 50 10 6 72 -57 18 6 9 20 45 45 17 47 13 21 5 8 -135 0 0 19 47 24 9 50 11 7 72 -56 18 27 58 21 7 40 18 9 1 21 27 4 -134 0 0 20 9 19 9 50 12 8 72 -55 18 49 51 21 29 38 18 30 53 21 49 2 -133 0 0 20 31 17 9 50 12 9 73 -55 19 11 46 21 51 38 18 52 48 22 11 3 -132 0 0 20 53 17 9 50 13 10 73 -54 19 33 43 22 13 40 19 14 45 22 33 5 -131 0 0 21 15 18 9 50 14 11 73 -53 19 55 43 22 35 43 19 36 44 22 55 9 -130 0 0 21 37 20 9 50 15 12 74 -53 20 17 43 22 57 47 19 58 44 23 17 14 -129 0 0 21 59 23 9 50 16 13 74 -52 20 39 44 23 19 52 20 20 44 23 39 18 -128 0 0 22 21 25 9 50 17 14 75 -51 21 1 45 23 41 55 20 42 45 24 1 22 -127 0 0 22 43 27 9 50 18 15 75 -50 21 23 46 24 3 58 21 4 46 24 23 26 -126 0 0 23 5 28 9 50 20 16 75 -49 21 45 46 24 26 0 21 26 46 24 45 27 -125 0 0 23 27 27 9 50 21 17 76 -49 22 7 44 24 47 59 21 48 44 25 7 27 -124 0 0 23 49 23 9 50 23 18 76 -48 22 29 41 25 9 56 22 10 40 25 29 24 -123 0 0 24 11 17 9 50 24 19 77 -47 22 51 35 25 31 50 22 32 34 25 51 18 -122 0 0 24 33 8 9 50 26 20 77 -46 23 13 25 25 53 41 22 54 24 26 13 8 -121 0 0 24 54 55 9 50 27 21 78 -45 23 35 12 26 15 27 23 16 12 26 34 54 -120 0 0 25 16 37 9 50 29 22 78 -44 23 56 55 26 37 8 23 37 55 26 56 36 -119 0 0 25 38 14 9 50 31 23 79 -44 24 18 34 26 58 45 23 59 33 27 18 12 -118 0 0 25 59 46 9 50 33 24 79 -43 24 40 7 27 20 16 24 21 7 27 39 43 -117 0 0 26 21 13 9 50 35 25 80 -42 25 1 34 27 41 41 24 42 35 28 1 7 -116 0 0 26 42 33 9 50 37 26 80 -41 25 22 56 28 2 59 25 3 57 28 22 25 -115 0 0 27 3 46 9 50 39 27 81 -40 25 44 11 28 24 10 25 25 12 28 43 36 -114 0 0 27 24 52 9 50 41 28 81 -39 26 5 19 28 45 14 25 46 20 29 4 39 -113 0 0 27 45 50 9 50 43 28 82 -38 26 26 19 29 6 10 26 7 21 29 25 34 -112 0 0 28 6 39 9 50 46 29 82 -38 26 47 11 29 26 57 26 28 14 29 46 21 -111 0 0 28 27 21 9 50 48 30 83 -37 27 7 55 29 47 35 26 48 59 30 6 58 -110 0 0 28 47 53 9 50 50 31 84 -36 27 28 31 30 8 4 27 9 34 30 27 27 -109 0 0 29 8 15 9 50 53 32 84 -35 27 48 56 30 28 24 27 30 1 30 47 45 -108 0 0 29 28 28 9 50 55 33 85 -34 28 9 12 30 48 33 27 50 18 31 7 54 -107 0 0 29 48 31 9 50 58 34 86 -33 28 29 18 31 8 31 28 10 25 31 27 51 -106 0 0 30 8 22 9 51 0 35 86 -32 28 49 14 31 28 19 28 30 21 31 47 38 -105 0 0 30 28 3 9 51 3 36 87 -31 29 8 59 31 47 56 28 50 7 32 7 14 -104 0 0 30 47 32 9 51 6 37 88 -31 29 28 32 32 7 21 29 9 41 32 26 38 -103 0 0 31 6 50 9 51 8 37 88 -30 29 47 54 32 26 34 29 29 4 32 45 49 -102 0 0 31 25 55 9 51 11 38 89 -29 30 7 4 32 45 34 29 48 15 33 4 49 -101 0 0 31 44 48 9 51 14 39 90 -28 30 26 1 33 4 22 30 7 13 33 23 36 -100 0 0 32 3 28 9 51 17 40 91 -27 30 44 46 33 22 57 30 25 59 33 42 9 - 99 0 0 32 21 55 9 51 20 41 92 -26 31 3 18 33 41 19 30 44 32 34 0 30 - 98 0 0 32 40 8 9 51 23 42 92 -25 31 21 37 33 59 27 31 2 52 34 18 37 - 97 0 0 32 58 8 9 51 26 43 93 -24 31 39 42 34 17 22 31 20 59 34 36 30 - 96 0 0 33 15 54 9 51 29 43 94 -24 31 57 33 34 35 2 31 38 51 34 54 9 - 95 0 0 33 33 26 9 51 32 44 95 -23 32 15 10 34 52 28 31 56 30 35 11 34 - 94 0 0 33 50 43 9 51 35 45 96 -22 32 32 33 35 9 40 32 13 54 35 28 44 - 93 0 0 34 7 46 9 51 38 46 97 -21 32 49 42 35 26 36 32 31 4 35 45 39 - 92 0 0 34 24 33 9 51 41 47 98 -20 33 6 35 35 43 18 32 47 59 36 2 19 - 91 0 0 34 41 6 9 51 44 47 99 -19 33 23 14 35 59 45 33 4 39 36 18 44 - 90 0 0 34 57 23 9 51 47 48 100 -18 33 39 37 36 15 56 33 21 3 36 34 54 - 89 0 0 35 13 25 9 51 51 49 101 -18 33 55 45 36 31 51 33 37 13 36 50 48 - 88 0 0 35 29 11 9 51 54 50 102 -17 34 11 37 36 47 31 33 53 6 37 6 26 - 87 0 0 35 44 41 9 51 57 50 103 -16 34 27 13 37 2 55 34 8 44 37 21 48 - 86 0 0 35 59 55 9 52 0 51 104 -15 34 42 33 37 18 2 34 24 6 37 36 54 - 85 0 0 36 14 53 9 52 4 52 105 -14 34 57 38 37 32 54 34 39 11 37 51 44 - 84 0 0 36 29 35 9 52 7 53 107 -13 35 12 25 37 47 29 34 54 1 38 6 18 - 83 0 0 36 44 0 9 52 10 53 108 -13 35 26 57 38 1 47 35 8 34 38 20 35 - 82 0 0 36 58 8 9 52 14 54 109 -12 35 41 12 38 15 49 35 22 50 38 34 35 - 81 0 0 37 12 0 9 52 17 55 110 -11 35 55 10 38 29 35 35 36 50 38 48 19 - 80 0 0 37 25 35 9 52 20 55 112 -10 36 8 51 38 43 3 35 50 32 39 1 46 - 79 0 0 37 38 53 9 52 24 56 113 -9 36 22 15 38 56 15 36 3 58 39 14 56 - 78 0 0 37 51 54 9 52 27 57 115 -8 36 35 23 39 9 10 36 17 7 39 27 49 - 77 0 0 38 4 38 9 52 31 57 116 -8 36 48 13 39 21 47 36 29 59 39 40 25 - 76 0 0 38 17 5 9 52 34 58 118 -7 37 0 46 39 34 7 36 42 33 39 52 44 - 75 0 0 38 29 15 9 52 37 59 119 -6 37 13 2 39 46 11 36 54 50 40 4 45 - 74 0 0 38 41 7 9 52 41 59 121 -5 37 25 0 39 57 57 37 6 50 40 16 30 - 73 0 0 38 52 42 9 52 44 60 122 -4 37 36 41 40 9 25 37 18 32 40 27 57 - 72 0 0 39 3 59 9 52 48 60 124 -3 37 48 4 40 20 37 37 29 57 40 39 7 - 71 0 0 39 14 59 9 52 51 61 126 -3 37 59 10 40 31 31 37 41 5 40 49 59 - 70 0 0 39 25 42 9 52 55 61 127 -2 38 9 59 40 42 7 37 51 54 41 0 34 - 69 0 0 39 36 7 9 52 58 62 129 -1 38 20 29 40 52 26 38 2 26 41 10 52 - 68 0 0 39 46 14 9 53 2 62 131 0 38 30 42 41 2 28 38 12 41 41 20 52 Uncertainty in time = +/- 1 secs Prediction of 2010 Jul 19.0 Data for the target star ------------------------ * name: HIP 22112 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 04 45 34.6850 DE: +19 19 41.879 * position source: Pos: PPMXL, pm: , pi: * standard error: RA,DE ["]: ( .016, .015 ) * V mag [mag]: 8.5 * B mag [mag]: 8.7 * Apparent position with proper motion RA(deg): 71.5543250111 DE(deg): 19.3483305469 * Equation of equinoxes (radians) : 0.000080956005638 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (16) Psyche approx. diameter [km]: 253 approx. diameter ["]: .133 distance from Earth [AU]: 2.62500 * orbital information: orbit source: Preston date of fit: 2010 Jun 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 2046 number of rejected observations: 253 time covered by the observations: 1903 May 04 - 2009 Nov 18 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.006, 82° remarks: * orbital elements for (16) Psyche : Mean anomaly = 24.96395248 deg Arg. of pericenter = 226.88939046 deg Long. of node = 150.29830925 deg Inclination = 3.09936433 deg Eccentricity = 0.13767845 Semimajor axis = 2.92070404 AU Perihelion dist = 2.51858604 AU Mag: H = 5.97, G = 0.20 Epoch of elements : MJD 55429.41300000 TDT (2010 Aug 21.413) ------ occelmnt file for Occult BEGIN ----------------------------------- 2010 Aug 21 16 Psyche 9h 54.1m UT 8.5 4 45 34.685 19 19 41.88HIP 22112 8.8 11.1 253 10.3 2.625 3.281 3.48 -46.7534 19.328 32.27 12.08 9.9019 -0.03323 0.38224 13.85992 1.03969 -0.00528 -0.00075 2000 23.1052882010 812.00000226.889390150.298309 3.0993640.13767845 2.9207040 2.5185860 5.9 5.00.20 RATE 1.9745710 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.019 0.016 88 1.12 0.016 0 0 0-1 455396.0020100821__22112 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2010 Aug 13, 22:54 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org