IOTA/IOTA-ES occultation update for (426) Hippo / TYC 0837-00365-1 event on 2012 Oct 16, 11:09 UT Visible from W USA Summary ------- On 2012 Oct 16 UT, the 121 km diameter asteroid (426) Hippo will occult a 12.4 mag star in the constellation Leo for observers along a path across W USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.7 mag to 13.9 mag (the magnitude of the asteroid) for at most 3.3 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: UCAC. The event at a glimpse ---------------------- * Rank: 83 * date and approx. time of event: 2012 Oct 16, 11:06 - 2012 Oct 16, 11:07 UT * geocentric midpoint of event [JD]: 2456216.96492083 * magnitude of target star: 12.4 * magnitude drop [mag]: 1.7 * estimated maximum duration [s]: 3.3 * Moon: 1 % sunlit, 62° distance * Sun: 50° distance * rough path description: W USA The occultation path -------------------- * approximate projected width [km]: 121 * 1 sigma uncertainty interval [path widths]: +/- 0.64 * 1 sigma uncertainty interval [seconds]: +/- 2.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .038 +/- .032) * 1 sigma uncertainty ellipse (major, minor, PA): ( .038", .032", 95° ) * approx speed of asteroid's shadow [km/s]: 37.2477 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0837-00365-1 by 426 Hippo on 2012 Oct 16 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 -132 0 0 35 44 13 11 6 39 1 80 -46 35 10 54 36 17 33 34 28 17 37 0 15 -131 0 0 35 52 37 11 6 39 2 81 -45 35 19 22 36 25 54 34 36 49 37 8 32 -130 0 0 36 0 33 11 6 39 2 81 -45 35 27 21 36 33 47 34 44 52 37 16 21 -129 0 0 36 8 1 11 6 39 3 82 -44 35 34 51 36 41 12 34 52 26 37 23 43 -128 0 0 36 15 1 11 6 39 4 82 -43 35 41 54 36 48 9 34 59 32 37 30 36 -127 0 0 36 21 32 11 6 39 5 83 -42 35 48 28 36 54 38 35 6 9 37 37 2 -126 0 0 36 27 36 11 6 39 6 84 -42 35 54 34 37 0 39 35 12 18 37 43 0 -125 0 0 36 33 12 11 6 40 7 84 -41 36 0 12 37 6 13 35 17 59 37 48 31 -124 0 0 36 38 19 11 6 40 7 85 -40 36 5 22 37 11 19 35 23 11 37 53 34 -123 0 0 36 43 0 11 6 40 8 85 -39 36 10 4 37 15 57 35 27 56 37 58 10 -122 0 0 36 47 12 11 6 41 9 86 -38 36 14 18 37 20 8 35 32 12 38 2 19 -121 0 0 36 50 57 11 6 41 10 87 -38 36 18 4 37 23 51 35 36 0 38 6 0 -120 0 0 36 54 14 11 6 42 11 87 -37 36 21 23 37 27 7 35 39 20 38 9 15 -119 0 0 36 57 4 11 6 42 11 88 -36 36 24 13 37 29 56 35 42 13 38 12 2 -118 0 0 36 59 26 11 6 42 12 88 -35 36 26 37 37 32 17 35 44 37 38 14 22 -117 0 0 37 1 21 11 6 43 13 89 -35 36 28 32 37 34 11 35 46 34 38 16 15 -116 0 0 37 2 48 11 6 44 14 90 -34 36 30 0 37 35 38 35 48 2 38 17 41 -115 0 0 37 3 48 11 6 44 15 90 -33 36 31 0 37 36 37 35 49 3 38 18 40 -114 0 0 37 4 20 11 6 45 15 91 -32 36 31 33 37 37 9 35 49 36 38 19 12 -113 0 0 37 4 25 11 6 45 16 91 -31 36 31 38 37 37 14 35 49 41 38 19 16 -112 0 0 37 4 3 11 6 46 17 92 -31 36 31 15 37 36 52 35 49 18 38 18 54 -111 0 0 37 3 13 11 6 47 18 93 -30 36 30 25 37 36 2 35 48 27 38 18 5 -110 0 0 37 1 55 11 6 48 19 93 -29 36 29 7 37 34 45 35 47 9 38 16 48 -109 0 0 37 0 10 11 6 48 19 94 -28 36 27 21 37 33 1 35 45 22 38 15 5 -108 0 0 36 57 58 11 6 49 20 94 -27 36 25 8 37 30 49 35 43 7 38 12 54 -107 0 0 36 55 17 11 6 50 21 95 -27 36 22 26 37 28 10 35 40 25 38 10 16 -106 0 0 36 52 9 11 6 51 22 96 -26 36 19 17 37 25 3 35 37 14 38 7 11 -105 0 0 36 48 34 11 6 52 23 96 -25 36 15 40 37 21 29 35 33 35 38 3 39 -104 0 0 36 44 30 11 6 53 23 97 -24 36 11 35 37 17 27 35 29 28 37 59 39 -103 0 0 36 39 59 11 6 54 24 97 -24 36 7 2 37 12 57 35 24 53 37 55 12 -102 0 0 36 35 0 11 6 55 25 98 -23 36 2 1 37 8 0 35 19 49 37 50 17 -101 0 0 36 29 32 11 6 56 26 99 -22 35 56 31 37 2 35 35 14 17 37 44 54 -100 0 0 36 23 37 11 6 57 27 99 -21 35 50 34 36 56 42 35 8 16 37 39 4 - 99 0 0 36 17 13 11 6 58 27 100 -20 35 44 7 36 50 20 35 1 47 37 32 46 - 98 0 0 36 10 21 11 6 59 28 100 -20 35 37 13 36 43 31 34 54 49 37 26 0 - 97 0 0 36 3 1 11 7 0 29 101 -19 35 29 49 36 36 13 34 47 22 37 18 46 - 96 0 0 35 55 11 11 7 2 30 102 -18 35 21 57 36 28 27 34 39 26 37 11 4 - 95 0 0 35 46 54 11 7 3 31 102 -17 35 13 36 36 20 12 34 31 1 37 2 53 - 94 0 0 35 38 7 11 7 4 32 103 -16 35 4 46 36 11 29 34 22 6 36 54 14 - 93 0 0 35 28 51 11 7 5 32 104 -15 34 55 27 36 2 17 34 12 43 36 45 6 - 92 0 0 35 19 6 11 7 7 33 104 -15 34 45 38 35 52 36 34 2 50 36 35 30 - 91 0 0 35 8 52 11 7 8 34 105 -14 34 35 21 35 42 26 33 52 27 36 25 25 - 90 0 0 34 58 9 11 7 10 35 105 -13 34 24 33 35 31 46 33 41 34 36 14 50 - 89 0 0 34 46 56 11 7 11 36 106 -12 34 13 16 35 20 37 33 30 12 36 3 47 - 88 0 0 34 35 13 11 7 13 37 107 -11 34 1 29 35 8 59 33 18 19 35 52 14 - 87 0 0 34 23 1 11 7 14 37 107 -11 33 49 12 34 56 51 33 5 56 35 40 12 - 86 0 0 34 10 18 11 7 16 38 108 -10 33 36 24 34 44 13 32 53 3 35 27 40 - 85 0 0 33 57 5 11 7 17 39 108 -9 33 23 7 34 31 5 32 39 39 35 14 38 - 84 0 0 33 43 22 11 7 19 40 109 -8 33 9 19 34 17 27 32 25 45 35 1 6 - 83 0 0 33 29 8 11 7 21 41 110 -7 32 55 0 34 3 18 32 11 20 34 47 4 - 82 0 0 33 14 24 11 7 22 42 110 -6 32 40 10 33 48 39 31 56 23 34 32 32 - 81 0 0 32 59 9 11 7 24 43 111 -5 32 24 50 33 33 29 31 40 56 34 17 29 - 80 0 0 32 43 22 11 7 26 44 111 -4 32 8 58 33 17 48 31 24 57 34 1 55 - 79 0 0 32 27 5 11 7 28 44 112 -4 31 52 35 33 1 37 31 8 27 33 45 51 - 78 0 0 32 10 16 11 7 30 45 113 -3 31 35 40 32 44 54 30 51 25 33 29 15 - 77 0 0 31 52 56 11 7 32 46 113 -2 31 18 14 32 27 40 30 33 51 33 12 9 - 76 0 0 31 35 5 11 7 34 47 114 -1 31 0 17 32 9 54 30 15 46 32 54 31 - 75 0 0 31 16 41 11 7 36 48 114 0 30 41 47 31 51 37 29 57 9 32 36 21 Uncertainty in time = +/- 2 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 0837-00365-1 * constellation : Leo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 10 20 07.5871 DE: +08 37 30.065 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .036, .032 ) * V mag [mag]: 12.4 * B mag [mag]: 12.5 * Apparent position with proper motion RA(deg): 155.1999777340 DE(deg): 8.5599842864 * Equation of equinoxes (radians) : 0.000059373603754 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (426) Hippo approx. diameter [km]: 121 approx. diameter ["]: .053 distance from Earth [AU]: 3.17200 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 905 number of rejected observations: 78 time covered by the observations: 1907 Sep 14 - 2012 Mar 12 1 sigma uncertainty ellipse (major, minor, PA): 0.014, 0.008, 130° remarks: * orbital elements for (426) Hippo : Mean anomaly = 330.54184670 deg Arg. of pericenter = 221.87299220 deg Long. of node = 311.43920198 deg Inclination = 19.47872894 deg Eccentricity = 0.10312813 Semimajor axis = 2.88851462 AU Perihelion dist = 2.59062750 AU Mag: H = 8.57, G = 0.15 Epoch of elements : MJD 56216.46500000 TDT (2012 Oct 16.465) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 16 426 Hippo 11h 9.5m UT 12.4 10 20 7.587 8 37 30.06TYC 0837-00365-1 12.5 13.9 121 3.3 3.172 3.343 -30.65 -37.7141 8.634 9.00 -9.13 11.1581 0.03793 0.06156 17.88335-11.05347 -0.00414 0.00149 2000 329.24388920121010.00000221.872992311.439202 19.4787290.10312813 2.8885146 2.5906275 8.4 5.00.15 RATE 2.0076690 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.038 0.032 95 1.64 0.034 0 0 1 5 056165.0020121016_0365-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 26, 04:27 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org