IOTA/IOTA-ES occultation update for (3169) Ostro / HIP 51695 event on 2009 Apr 01, 02:30 UT Visible from Canada, USA, Mexico, Central America Summary ------- On 2009 Apr 01 UT, the 9 km diameter asteroid (3169) Ostro will occult a 8.7 mag star in the constellation Ursa Major for observers along a path across Canada, USA, Mexico, Central America. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.8 mag to 15.5 mag (the magnitude of the asteroid) for at most 1.6 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: 17 * date and approx. time of event: 2009 Apr 01, 02:19 - 2009 Apr 01, 02:45 UT * midpoint of event [JD]: 2454922.60254583 * magnitude of target star: 8.7 * magnitude drop [mag]: 6.8 * estimated maximum duration [s]: 1.6 * Moon: 33 % sunlit, 61° distance * Sun: 116° distance * rough path description: Canada, USA, Mexico, Central America The occultation path -------------------- * approximate projected width [km]: 9 * 1 sigma uncertainty interval [path widths]: +/- 4.05 * 1 sigma uncertainty interval [seconds]: +/- 5.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .046 +/- .041) * 1 sigma uncertainty ellipse (major, minor, PA): ( .047", .040", 72° ) * approx speed of asteroid's shadow [km/s]: 5.7047 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 51695 by 3169 Ostro on 2009 Apr 1 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude - 96 30 0 78 35 14 2 19 53 62 139 -1 - 96 17 51 78 35 49 - 96 42 7 78 34 37 - 94 38 54 78 40 21 - 98 19 37 78 29 28 - 94 21 34 77 7 9 2 20 21 64 140 -2 - 94 10 43 77 7 39 - 94 32 25 77 6 39 - 92 42 21 77 11 29 - 95 59 51 77 2 15 - 92 43 33 75 39 5 2 20 48 65 140 -3 - 92 33 44 75 39 32 - 92 53 22 75 38 39 - 91 13 57 75 42 49 - 94 12 32 75 34 52 - 91 27 12 74 11 15 2 21 16 66 140 -4 - 91 18 15 74 11 38 - 91 36 9 74 10 52 - 90 5 30 74 14 30 - 92 48 29 74 7 33 - 90 26 48 72 43 46 2 21 43 68 139 -5 - 90 18 34 72 44 6 - 90 35 2 72 43 25 - 89 11 41 72 46 38 - 91 41 37 72 40 29 - 89 38 27 71 16 39 2 22 11 69 138 -6 - 89 30 49 71 16 57 - 89 46 5 71 16 21 - 88 28 54 71 19 13 - 90 47 48 71 13 43 - 88 59 25 69 49 57 2 22 38 70 137 -7 - 88 52 18 69 50 14 - 89 6 32 69 49 41 - 87 54 36 69 52 15 - 90 4 5 69 47 18 - 88 27 44 68 23 39 2 23 5 71 135 -8 - 88 21 4 68 23 54 - 88 34 24 68 23 25 - 87 27 1 68 25 44 - 89 28 20 68 21 15 - 88 1 56 66 57 44 2 23 33 72 133 -9 - 87 55 40 66 57 58 - 88 8 13 66 57 30 - 87 4 47 66 59 38 - 88 59 1 66 55 31 - 87 40 57 65 32 10 2 24 0 73 130 -10 - 87 35 1 65 32 22 - 87 46 53 65 31 57 - 86 46 55 65 33 55 - 88 34 55 65 30 7 - 87 23 56 64 6 54 2 24 28 74 126 -11 - 87 18 18 64 7 5 - 87 29 34 64 6 42 - 86 32 40 64 8 31 - 88 15 9 64 5 0 - 87 10 13 62 41 54 2 24 55 75 123 -12 - 87 4 52 62 42 5 - 87 15 35 62 41 43 - 86 21 25 62 43 25 - 87 59 0 62 40 8 - 86 59 19 61 17 8 2 25 23 76 118 -13 - 86 54 12 61 17 18 - 87 4 26 61 16 58 - 86 12 43 61 18 33 - 87 45 54 61 15 28 - 86 50 48 59 52 34 2 25 50 77 113 -14 - 86 45 54 59 52 43 - 86 55 42 59 52 24 - 86 6 12 59 53 54 - 87 35 25 59 50 59 - 86 44 21 58 28 8 2 26 18 77 107 -15 - 86 39 39 58 28 17 - 86 49 4 58 27 59 - 86 1 32 58 29 24 - 87 27 10 58 26 38 - 86 39 41 57 3 47 2 26 45 78 101 -16 - 86 35 10 57 3 56 - 86 44 13 57 3 39 - 85 58 30 57 5 0 - 87 20 53 57 2 22 - 86 36 36 55 39 30 2 27 13 78 94 -17 - 86 32 14 55 39 39 - 86 40 58 55 39 22 - 85 56 53 55 40 40 - 87 16 19 55 38 8 - 86 34 53 54 15 13 2 27 40 78 87 -18 - 86 30 40 54 15 21 - 86 39 6 54 15 5 - 85 56 32 54 16 21 - 87 13 15 54 13 54 - 86 34 24 52 50 54 2 28 7 78 80 -19 - 86 30 20 52 51 2 - 86 38 29 52 50 46 - 85 57 18 52 51 59 - 87 11 31 52 49 37 - 86 35 2 51 26 29 2 28 35 78 73 -20 - 86 31 5 51 26 36 - 86 38 59 51 26 21 - 85 59 5 51 27 32 - 87 11 0 51 25 14 - 86 36 39 50 1 55 2 29 2 78 67 -20 - 86 32 49 50 2 3 - 86 40 29 50 1 48 - 86 1 46 50 2 57 - 87 11 33 50 0 42 - 86 39 10 48 37 10 2 29 30 77 61 -21 - 86 35 27 48 37 17 - 86 42 54 48 37 3 - 86 5 16 48 38 11 - 87 13 6 48 35 58 - 86 42 31 47 12 10 2 29 57 76 55 -22 - 86 38 54 47 12 18 - 86 46 9 47 12 3 - 86 9 31 47 13 11 - 87 15 33 47 11 0 - 86 46 38 45 46 53 2 30 25 76 51 -23 - 86 43 6 45 47 0 - 86 50 10 45 46 46 - 86 14 29 45 47 53 - 87 18 49 45 45 43 - 86 51 27 44 21 15 2 30 52 75 46 -24 - 86 48 0 44 21 22 - 86 54 54 44 21 7 - 86 20 5 44 22 14 - 87 22 50 44 20 5 - 86 56 55 42 55 11 2 31 20 74 43 -25 - 86 53 33 42 55 18 - 87 0 17 42 55 4 - 86 26 17 42 56 11 - 87 27 35 42 54 2 - 87 3 1 41 28 40 2 31 47 73 40 -25 - 86 59 43 41 28 47 - 87 6 19 41 28 33 - 86 33 4 41 29 40 - 87 33 0 41 27 31 - 87 9 42 40 1 37 2 32 15 72 37 -26 - 87 6 28 40 1 44 - 87 12 55 40 1 30 - 86 40 23 40 2 37 - 87 39 2 40 0 27 - 87 16 56 38 33 58 2 32 42 70 34 -27 - 87 13 47 38 34 5 - 87 20 6 38 33 51 - 86 48 13 38 34 59 - 87 45 41 38 32 48 - 87 24 43 37 5 39 2 33 9 69 32 -28 - 87 21 37 37 5 46 - 87 27 49 37 5 31 - 86 56 33 37 6 41 - 87 52 54 37 4 28 - 87 33 1 35 36 35 2 33 37 68 30 -28 - 87 29 58 35 36 42 - 87 36 3 35 36 28 - 87 5 22 35 37 38 - 88 0 41 35 35 23 - 87 41 49 34 6 42 2 34 4 67 28 -29 - 87 38 50 34 6 49 - 87 44 48 34 6 34 - 87 14 40 34 7 46 - 88 9 0 34 5 28 - 87 51 8 32 35 54 2 34 32 65 27 -30 - 87 48 11 32 36 2 - 87 54 4 32 35 46 - 87 24 26 32 37 0 - 88 17 51 32 34 39 - 88 0 56 31 4 6 2 34 59 64 25 -30 - 87 58 3 31 4 14 - 88 3 49 31 3 58 - 87 34 39 31 5 14 - 88 27 14 31 2 49 - 88 11 14 29 31 12 2 35 27 63 24 -31 - 88 8 23 29 31 20 - 88 14 5 29 31 4 - 87 45 21 29 32 22 - 88 37 8 29 29 53 - 88 22 2 27 57 5 2 35 54 61 23 -32 - 88 19 14 27 57 13 - 88 24 50 27 56 56 - 87 56 32 27 58 17 - 88 47 34 27 55 43 - 88 33 21 26 21 37 2 36 22 60 22 -32 - 88 30 35 26 21 46 - 88 36 7 26 21 28 - 88 8 11 26 22 52 - 88 58 32 26 20 13 - 88 45 11 24 44 41 2 36 49 58 21 -33 - 88 42 27 24 44 50 - 88 47 55 24 44 32 - 88 20 21 24 45 59 - 89 10 3 24 43 13 - 88 57 34 23 6 7 2 37 17 57 20 -33 - 88 54 52 23 6 17 - 89 0 16 23 5 58 - 88 33 2 23 7 29 - 89 22 9 23 4 36 - 89 10 32 21 25 46 2 37 44 55 20 -34 - 89 7 52 21 25 56 - 89 13 12 21 25 36 - 88 46 15 21 27 11 - 89 34 50 21 24 11 - 89 24 5 19 43 25 2 38 11 53 19 -34 - 89 21 27 19 43 35 - 89 26 44 19 43 14 - 89 0 4 19 44 55 - 89 48 8 19 41 45 - 89 38 17 17 58 51 2 38 39 52 18 -35 - 89 35 40 17 59 2 - 89 40 54 17 58 40 - 89 14 29 18 0 26 - 90 2 7 17 57 6 - 89 53 11 16 11 50 2 39 6 50 18 -35 - 89 50 35 16 12 1 - 89 55 46 16 11 38 - 89 29 35 16 13 31 - 90 16 48 16 9 59 - 90 8 49 14 22 2 2 39 34 48 17 -36 - 90 6 15 14 22 15 - 90 11 24 14 21 50 - 89 45 24 14 23 50 - 90 32 17 14 20 5 - 90 25 18 12 29 8 2 40 1 46 17 -36 - 90 22 45 12 29 22 - 90 27 52 12 28 55 - 90 2 2 12 31 3 - 90 48 37 12 27 3 - 90 42 42 10 32 43 2 40 29 45 16 -36 - 90 40 10 10 32 57 - 90 45 15 10 32 28 - 90 19 33 10 34 46 - 91 5 54 10 30 29 - 91 1 10 8 32 15 2 40 56 43 16 -37 - 90 58 38 8 32 30 - 91 3 42 8 32 0 - 90 38 6 8 34 28 - 91 24 16 8 29 51 - 91 20 49 6 27 8 2 41 24 40 16 -37 - 91 18 17 6 27 24 - 91 23 21 6 26 51 - 90 57 49 6 29 33 - 91 43 52 6 24 31 - 91 41 53 4 16 34 2 41 51 38 15 -37 - 91 39 21 4 16 52 - 91 44 24 4 16 16 - 91 18 54 4 19 13 - 92 4 54 4 13 43 - 92 4 36 1 59 34 2 42 19 36 15 -37 - 92 2 4 1 59 54 - 92 7 8 1 59 14 - 91 41 36 2 2 30 - 92 27 39 1 56 25 - 92 29 21 - 0 25 13 2 42 46 34 15 -37 - 92 26 49 - 0 24 50 - 92 31 53 - 0 25 35 - 92 6 16 - 0 21 56 - 92 52 29 - 0 28 43 - 92 56 38 - 2 59 36 2 43 13 31 15 -37 - 92 54 5 - 2 59 11 - 92 59 12 - 3 0 2 - 92 33 25 - 2 55 53 - 93 19 56 - 3 3 35 - 93 27 13 - 5 46 16 2 43 41 28 14 -37 - 93 24 38 - 5 45 47 - 93 29 48 - 5 46 46 - 93 3 45 - 5 41 57 - 93 50 46 - 5 50 52 - 94 2 17 - 8 49 16 2 44 8 25 14 -36 - 93 59 39 - 8 48 41 - 94 4 54 - 8 49 51 - 93 38 26 - 8 44 8 - 94 26 13 - 8 54 44 - 94 43 54 -12 15 32 2 44 36 22 14 -36 - 94 41 13 -12 14 48 - 94 46 36 -12 16 15 - 94 19 27 -12 9 9 - 95 8 29 -12 22 18 - 95 36 19 -16 18 38 2 45 3 18 14 -35 - 95 33 31 -16 17 40 - 95 39 8 -16 19 37 - 95 10 49 -16 10 6 - 96 2 1 -16 27 44 - 96 51 3 -21 34 30 2 45 31 12 15 -33 - 96 47 58 -21 32 57 - 96 54 8 -21 36 4 - 96 23 13 -21 20 50 - 97 19 18 -21 49 14 Uncertainty in time = +/- 7 secs Prediction of 2009 Mar 22.0 Data for the target star ------------------------ * name: HIP 51695 * constellation : Ursa Major * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 10 33 36.9437 DE: +53 13 00.306 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .016, .014 ) * V mag [mag]: 8.7 * B mag [mag]: 10.0 * Apparent position with proper motion RA(deg): 158.5611262097 DE(deg): 53.1690360697 * Equation of equinoxes (radians) : 0.000059033087729 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (3169) Ostro approx. diameter [km]: 9 approx. diameter ["]: .011 distance from Earth [AU]: 1.10700 * orbital information: orbit source: Preston date of fit: 2009 Mar 22 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 540 number of rejected observations: 8 time covered by the observations: 1953 Dec 31 - 2009 Mar 22 1 sigma uncertainty ellipse (major, minor, PA): 0.044, 0.038, 70° remarks: * orbital elements for (3169) Ostro : Mean anomaly = 34.73213506 deg Arg. of pericenter = 32.47319337 deg Long. of node = 96.43841197 deg Inclination = 24.90823805 deg Eccentricity = 0.06706368 Semimajor axis = 1.89188349 AU Perihelion dist = 1.76500683 AU Mag: H = 12.39, G = 0.15 Epoch of elements : MJD 54922.10400000 TDT (2009 Apr 01.104) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Apr 1 3169 Ostro 2h 27.7m UT 8.7 10 33 36.944 53 13 0.31HIP 51695 10.0 15.5 9 1.6 1.107 -0.586 -25.03 -68.1022 53.224 144.08 4.55 2.4611 -0.18710 0.04028 -0.66554 -3.15036 0.00267 -0.00361 2000 33.9352272009 330.00000 32.473193 96.438412 24.9082380.06706368 1.8918835 1.765006812.7 5.00.15 RATE 3.7875860 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.047 0.040 72 5.05 0.044 1 0 0 54912.0020090401__51695 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2009 Mar 22, 17:39 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org