IOTA/IOTA-ES occultation update for (972) Cohnia / UCAC2 41686323 event on 2012 Sep 20, 21:38 UT Visible from Russia, SW Asia Summary ------- On 2012 Sep 20 UT, the 80 km diameter asteroid (972) Cohnia will occult a 12.0 mag star in the constellation Auriga for observers along a path across Russia, SW Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.6 mag to 14.5 mag (the magnitude of the asteroid) for at most 4.3 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: UCAC. The event at a glimpse ---------------------- * Rank: 88 * date and approx. time of event: 2012 Sep 20, 21:33 - 2012 Sep 20, 21:37 UT * geocentric midpoint of event [JD]: 2456191.40160833 * magnitude of target star: 12.0 * magnitude drop [mag]: 2.6 * estimated maximum duration [s]: 4.3 * Moon: 29 % sunlit, 150° distance * Sun: 86° distance * rough path description: Russia, SW Asia The occultation path -------------------- * approximate projected width [km]: 94 * 1 sigma uncertainty interval [path widths]: +/- 0.55 * 1 sigma uncertainty interval [seconds]: +/- 3.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .038 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .038", .025", 94° ) * approx speed of asteroid's shadow [km/s]: 18.6745 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 41686323 by 972 Cohnia on 2012 Sep 20 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 22 0 0 30 39 49 21 33 29 1 57 -56 30 9 19 31 10 31 .. .. .. 31 44 33 23 0 0 31 13 44 21 33 29 2 58 -56 30 43 11 31 44 29 30 9 48 32 18 34 24 0 0 31 47 37 21 33 30 3 58 -56 31 17 2 32 18 25 30 43 36 32 52 32 25 0 0 32 21 27 21 33 30 4 59 -56 31 50 49 32 52 17 31 17 21 33 26 26 26 0 0 32 55 12 21 33 30 5 59 -55 32 24 32 33 26 4 31 51 2 34 0 16 27 0 0 33 28 51 21 33 31 6 60 -55 32 58 10 33 59 45 32 24 38 34 33 59 28 0 0 34 2 24 21 33 32 7 60 -55 33 31 41 34 33 19 32 58 7 35 7 34 29 0 0 34 35 48 21 33 33 8 61 -54 34 5 4 35 6 44 33 31 29 35 41 1 30 0 0 35 9 4 21 33 34 9 62 -54 34 38 19 35 40 1 34 4 43 36 14 19 31 0 0 35 42 9 21 33 35 10 62 -54 35 11 23 36 13 7 34 37 47 36 47 25 32 0 0 36 15 3 21 33 36 11 63 -53 35 44 17 36 46 1 35 10 40 37 20 20 33 0 0 36 47 45 21 33 37 12 63 -53 36 16 59 37 18 43 35 43 22 37 53 2 34 0 0 37 20 14 21 33 39 12 64 -52 36 49 28 37 51 12 36 15 51 38 25 31 35 0 0 37 52 28 21 33 40 13 65 -52 37 21 43 38 23 26 36 48 6 38 57 44 36 0 0 38 24 28 21 33 42 14 65 -51 37 53 43 38 55 25 37 20 7 39 29 42 37 0 0 38 56 11 21 33 44 15 66 -50 38 25 27 39 27 7 37 51 52 40 1 23 38 0 0 39 27 37 21 33 45 16 67 -50 38 56 55 39 58 32 38 23 21 40 32 47 39 0 0 39 58 46 21 33 47 17 67 -49 39 28 5 40 29 39 38 54 33 41 3 52 40 0 0 40 29 36 21 33 49 18 68 -49 39 58 56 41 0 27 39 25 27 41 34 38 41 0 0 41 0 6 21 33 51 19 69 -48 40 29 29 41 30 56 39 56 2 42 5 5 42 0 0 41 30 17 21 33 54 20 70 -47 40 59 42 42 1 4 40 26 17 42 35 10 43 0 0 42 0 7 21 33 56 21 70 -47 41 29 34 42 30 51 40 56 12 43 4 54 44 0 0 42 29 35 21 33 58 22 71 -46 41 59 5 43 0 16 41 25 46 43 34 16 45 0 0 42 58 41 21 34 0 22 72 -45 42 28 14 43 29 20 41 54 58 44 3 16 46 0 0 43 27 25 21 34 3 23 73 -45 42 57 1 43 58 0 42 23 48 44 31 53 47 0 0 43 55 45 21 34 5 24 73 -44 43 25 25 44 26 17 42 52 16 45 0 6 48 0 0 44 23 42 21 34 8 25 74 -44 43 53 25 44 54 10 43 20 20 45 27 54 49 0 0 44 51 14 21 34 10 26 75 -43 44 21 2 45 21 38 43 48 1 45 55 18 50 0 0 45 18 22 21 34 13 27 76 -42 44 48 14 45 48 42 44 15 17 46 22 18 51 0 0 45 45 5 21 34 16 27 77 -41 45 15 1 46 15 21 44 42 9 46 48 52 52 0 0 46 11 23 21 34 18 28 78 -41 45 41 23 46 41 34 45 8 36 47 15 0 53 0 0 46 37 15 21 34 21 29 78 -40 46 7 20 47 7 22 45 34 38 47 40 42 54 0 0 47 2 42 21 34 24 30 79 -39 46 32 51 47 32 43 46 0 14 48 5 58 55 0 0 47 27 42 21 34 27 30 80 -39 46 57 57 47 57 39 46 25 25 48 30 48 56 0 0 47 52 16 21 34 30 31 81 -38 47 22 36 48 22 8 46 50 10 48 55 11 57 0 0 48 16 24 21 34 32 32 82 -37 47 46 49 48 46 10 47 14 28 49 19 8 58 0 0 48 40 5 21 34 35 33 83 -37 48 10 35 49 9 46 47 38 20 49 42 38 59 0 0 49 3 20 21 34 38 33 84 -36 48 33 55 49 32 55 48 1 46 50 5 41 60 0 0 49 26 8 21 34 41 34 85 -35 48 56 48 49 55 37 48 24 45 50 28 17 61 0 0 49 48 29 21 34 44 35 86 -35 49 19 15 50 17 53 48 47 18 50 50 26 62 0 0 50 10 23 21 34 47 35 87 -34 49 41 15 50 39 41 49 9 24 51 12 8 63 0 0 50 31 50 21 34 50 36 88 -33 50 2 48 51 1 3 49 31 3 51 33 23 64 0 0 50 52 51 21 34 53 37 89 -33 50 23 55 51 21 58 49 52 16 51 54 11 65 0 0 51 13 25 21 34 56 37 90 -32 50 44 35 51 42 26 50 13 2 52 14 33 66 0 0 51 33 33 21 35 0 38 91 -31 51 4 48 52 2 28 50 33 22 52 34 28 67 0 0 51 53 14 21 35 3 39 92 -31 51 24 35 52 22 3 50 53 15 52 53 56 68 0 0 52 12 28 21 35 6 39 93 -30 51 43 55 52 41 11 51 12 42 53 12 58 69 0 0 52 31 17 21 35 9 40 94 -30 52 2 50 52 59 53 51 31 42 53 31 33 70 0 0 52 49 39 21 35 12 40 95 -29 52 21 18 53 18 10 51 50 17 53 49 43 71 0 0 53 7 35 21 35 15 41 97 -28 52 39 20 53 36 0 52 8 25 54 7 26 72 0 0 53 25 5 21 35 18 41 98 -28 52 56 56 53 53 24 52 26 8 54 24 44 73 0 0 53 42 10 21 35 21 42 99 -27 53 14 6 54 10 23 52 43 25 54 41 36 74 0 0 53 58 49 21 35 24 43 100 -26 53 30 51 54 26 56 53 0 16 54 58 2 75 0 0 54 15 3 21 35 28 43 101 -26 53 47 11 54 43 4 53 16 42 55 14 4 76 0 0 54 30 52 21 35 31 44 102 -25 54 3 6 54 58 47 53 32 43 55 29 40 77 0 0 54 46 16 21 35 34 44 104 -25 54 18 36 55 14 5 53 48 19 55 44 52 78 0 0 55 1 16 21 35 37 45 105 -24 54 33 41 55 28 59 54 3 31 55 59 39 79 0 0 55 15 51 21 35 40 45 106 -23 54 48 21 55 43 28 54 18 17 56 14 2 80 0 0 55 30 1 21 35 43 46 107 -23 55 2 38 55 57 34 54 32 40 56 28 1 81 0 0 55 43 48 21 35 46 46 108 -22 55 16 30 56 11 15 54 46 38 56 41 36 82 0 0 55 57 12 21 35 49 47 110 -22 55 29 59 56 24 33 55 0 12 56 54 48 83 0 0 56 10 11 21 35 52 47 111 -21 55 43 4 56 37 27 55 13 23 57 7 36 84 0 0 56 22 48 21 35 56 47 112 -20 55 55 45 56 49 58 55 26 10 57 20 2 85 0 0 56 35 1 21 35 59 48 114 -20 56 8 4 57 2 6 55 38 34 57 32 4 86 0 0 56 46 52 21 36 2 48 115 -19 56 20 0 57 13 52 55 50 35 57 43 44 87 0 0 56 58 20 21 36 5 49 116 -19 56 31 33 57 25 15 56 2 14 57 55 1 88 0 0 57 9 25 21 36 8 49 117 -18 56 42 43 57 36 16 56 13 29 58 5 57 89 0 0 57 20 9 21 36 11 50 119 -18 56 53 31 57 46 54 56 24 23 58 16 30 90 0 0 57 30 31 21 36 14 50 120 -17 57 3 58 57 57 11 56 34 54 58 26 42 91 0 0 57 40 31 21 36 17 50 122 -16 57 14 2 58 7 7 56 45 3 58 36 32 92 0 0 57 50 9 21 36 20 51 123 -16 57 23 45 58 16 41 56 54 51 58 46 1 93 0 0 57 59 26 21 36 23 51 124 -15 57 33 7 58 25 54 57 4 17 58 55 10 94 0 0 58 8 23 21 36 26 51 126 -15 57 42 7 58 34 46 57 13 22 59 3 57 95 0 0 58 16 58 21 36 29 52 127 -14 57 50 46 58 43 17 57 22 6 59 12 24 96 0 0 58 25 13 21 36 32 52 129 -14 57 59 5 58 51 28 57 30 29 59 20 30 97 0 0 58 33 7 21 36 35 52 130 -13 58 7 3 58 59 19 57 38 31 59 28 17 98 0 0 58 40 41 21 36 38 53 131 -13 58 14 40 59 6 49 57 46 12 59 35 43 99 0 0 58 47 55 21 36 41 53 133 -12 58 21 58 59 14 0 57 53 33 59 42 49 100 0 0 58 54 49 21 36 45 53 134 -12 58 28 55 59 20 50 58 0 34 59 49 36 101 0 0 59 1 23 21 36 48 54 136 -11 58 35 33 59 27 21 58 7 15 59 56 4 102 0 0 59 7 38 21 36 51 54 137 -11 58 41 50 59 33 33 58 13 36 60 2 12 103 0 0 59 13 33 21 36 54 54 139 -10 58 47 48 59 39 25 58 19 37 60 8 1 104 0 0 59 19 9 21 36 57 54 140 -10 58 53 27 59 44 58 58 25 19 60 13 31 105 0 0 59 24 26 21 37 0 55 142 -9 58 58 47 59 50 12 58 30 41 60 18 42 106 0 0 59 29 24 21 37 3 55 143 -8 59 3 47 59 55 8 58 35 44 60 23 34 107 0 0 59 34 2 21 37 6 55 145 -8 59 8 28 59 59 44 58 40 28 60 28 8 108 0 0 59 38 22 21 37 9 55 146 -7 59 12 50 60 4 2 58 44 52 60 32 24 109 0 0 59 42 24 21 37 12 56 148 -7 59 16 54 60 8 1 58 48 58 60 36 21 110 0 0 59 46 7 21 37 15 56 150 -6 59 20 38 60 11 42 58 52 45 60 39 59 111 0 0 59 49 31 21 37 18 56 151 -6 59 24 4 60 15 5 58 56 13 60 43 20 112 0 0 59 52 37 21 37 20 56 153 -5 59 27 12 60 18 9 58 59 22 60 46 23 113 0 0 59 55 25 21 37 23 56 154 -5 59 30 1 60 20 55 59 2 13 60 49 7 114 0 0 59 57 54 21 37 26 57 156 -4 59 32 32 60 23 23 59 4 45 60 51 34 115 0 0 60 0 5 21 37 29 57 158 -4 59 34 44 60 25 33 59 6 58 60 53 43 116 0 0 60 1 58 21 37 32 57 159 -3 59 36 38 60 27 26 59 8 54 60 55 34 117 0 0 60 3 33 21 37 35 57 161 -3 59 38 14 60 29 0 59 10 30 60 57 7 118 0 0 60 4 51 21 37 38 57 162 -2 59 39 32 60 30 16 59 11 49 60 58 23 119 0 0 60 5 50 21 37 41 57 164 -2 59 40 31 60 31 15 59 12 49 60 59 21 120 0 0 60 6 31 21 37 44 57 166 -1 59 41 13 60 31 56 59 13 31 61 0 1 121 0 0 60 6 54 21 37 47 58 167 -1 59 41 36 60 32 18 59 13 54 61 0 24 122 0 0 60 6 59 21 37 50 58 169 0 59 41 41 60 32 24 59 14 0 61 0 29 Uncertainty in time = +/- 4 secs Prediction of 2012 Aug 7.0 Data for the target star ------------------------ * name: UCAC2 41686323 * constellation : Auriga * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 11 51.8623 DE: +28 08 09.031 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .031, .024 ) * V mag [mag]: 12.0 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (972) Cohnia approx. diameter [km]: 80 approx. diameter ["]: .046 distance from Earth [AU]: 2.40800 * orbital information: orbit source: Preston date of fit: 2012 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1091 number of rejected observations: 59 time covered by the observations: 1906 Jan 22 - 2012 Jan 03 1 sigma uncertainty ellipse (major, minor, PA): 0.022, 0.009, 102° remarks: * orbital elements for (972) Cohnia : Mean anomaly = 33.77205189 deg Arg. of pericenter = 94.43834075 deg Long. of node = 281.54133301 deg Inclination = 8.36516403 deg Eccentricity = 0.23437358 Semimajor axis = 3.06130859 AU Perihelion dist = 2.34381873 AU Mag: H = 9.54, G = 0.15 Epoch of elements : MJD 56190.90200000 TDT (2012 Sep 20.902) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 20 972 Cohnia 21h 38.3m UT 12.0 6 11 51.862 28 8 9.03UCAC2 41686323 0.0 14.5 80 4.3 2.408 2.905 -2.14 128.2091 28.137 -146.29 0.67 21.6386 0.02670 0.52279 10.52407 -0.58688 -0.00561 0.00015 2000 33.6060742012 920.00000 94.438341281.541333 8.3651640.23437358 3.0613086 2.3438187 9.5 5.00.15 RATE 1.8401090 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.038 0.025 94 1.55 0.025 0 0 3 1 056146.0020120920_686323 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 20:35 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org