IOTA/IOTA-ES occultation update for (691) Lehigh / TYC 6887-00937-1 event on 2012 Jul 16, 00:33 UT Visible from Atlantic Summary ------- On 2012 Jul 16 UT, the 86 km diameter asteroid (691) Lehigh will occult a 9.6 mag star in the constellation Sagittarius for observers along a path across Atlantic. In the case of an occultation, the combined light of the asteroid and the star will drop by 4.0 mag to 13.5 mag (the magnitude of the asteroid) for at most 6.6 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 92 * date and approx. time of event: 2012 Jul 16, 00:29 - 2012 Jul 16, 00:36 UT * geocentric midpoint of event [JD]: 2456124.52294167 * magnitude of target star: 9.6 * magnitude drop [mag]: 4.0 * estimated maximum duration [s]: 6.6 * Moon: 9 % sunlit, 149° distance * Sun: 171° distance * rough path description: Atlantic The occultation path -------------------- * approximate projected width [km]: 198 * 1 sigma uncertainty interval [path widths]: +/- 0.49 * 1 sigma uncertainty interval [seconds]: +/- 3.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .036 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .027", 92° ) * approx speed of asteroid's shadow [km/s]: 13.1615 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6887-00937-1 by 691 Lehigh on 2012 Jul 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 ' " Longitude Longitude Longitude Longitude - 5 11 50 60 0 0 0 29 34 1 185 -9 - 7 3 29 - 3 23 33 - 8 56 35 ... .. .. - 5 26 21 59 0 0 0 29 35 2 185 -10 - 7 15 12 - 3 40 44 - 9 5 25 ... .. .. - 5 44 24 58 0 0 0 29 35 3 185 -11 - 7 30 46 - 4 1 8 - 9 18 25 ... .. .. - 6 5 46 57 0 0 0 29 36 4 184 -12 - 7 49 56 - 4 24 37 - 9 35 19 ... .. .. - 6 30 16 56 0 0 0 29 38 5 184 -13 - 8 12 29 - 4 50 59 - 9 55 52 - 3 16 15 - 6 57 46 55 0 0 0 29 40 6 184 -14 - 8 38 16 - 5 20 9 - 10 19 55 - 3 46 59 - 7 28 9 54 0 0 0 29 42 7 183 -15 - 9 7 10 - 5 51 58 - 10 47 19 - 4 20 13 - 8 1 19 53 0 0 0 29 44 8 183 -16 - 9 39 4 - 6 26 25 - 11 17 56 - 4 55 51 - 8 37 14 52 0 0 0 29 47 9 182 -17 - 10 13 54 - 7 3 24 - 11 51 43 - 5 33 53 - 9 15 51 51 0 0 0 29 50 10 182 -18 - 10 51 38 - 7 42 53 - 12 28 35 - 6 14 15 - 9 57 8 50 0 0 0 29 54 11 181 -19 - 11 32 14 - 8 24 54 - 13 8 32 - 6 56 58 - 10 41 7 49 0 0 0 29 58 12 180 -20 - 12 15 43 - 9 9 24 - 13 51 35 - 7 42 2 - 11 27 48 48 0 0 0 30 3 13 180 -21 - 13 2 6 - 9 56 27 - 14 37 44 - 8 29 28 - 12 17 15 47 0 0 0 30 8 14 179 -22 - 13 51 27 - 10 46 4 - 15 27 4 - 9 19 19 - 13 9 31 46 0 0 0 30 13 15 178 -23 - 14 43 50 - 11 38 20 - 16 19 41 - 10 11 39 - 14 4 44 45 0 0 0 30 20 16 177 -23 - 15 39 23 - 12 33 20 - 17 15 42 - 11 6 32 - 15 3 1 44 0 0 0 30 26 17 177 -24 - 16 38 14 - 13 31 10 - 18 15 17 - 12 4 4 - 16 4 31 43 0 0 0 30 33 18 176 -25 - 17 40 34 - 14 32 1 - 19 18 40 - 13 4 24 - 17 9 26 42 0 0 0 30 41 19 175 -26 - 18 46 39 - 15 36 1 - 20 26 8 - 14 7 41 - 18 18 3 41 0 0 0 30 49 19 174 -27 - 19 56 45 - 16 43 25 - 21 38 1 - 15 14 7 - 19 30 40 40 0 0 0 30 58 20 173 -28 - 21 11 15 - 17 54 29 - 22 54 48 - 16 23 55 - 20 47 40 39 0 0 0 31 7 21 171 -28 - 22 30 37 - 19 9 32 - 24 17 1 - 17 37 23 - 22 9 33 38 0 0 0 31 18 22 170 -29 - 23 55 28 - 20 29 0 - 25 45 28 - 18 54 51 - 23 36 58 37 0 0 0 31 29 23 169 -30 - 25 26 35 - 21 53 23 - 27 21 8 - 20 16 47 - 25 10 42 36 0 0 0 31 41 23 167 -30 - 27 5 0 - 23 23 21 - 29 5 25 - 21 43 43 - 26 51 51 35 0 0 0 31 54 24 166 -31 - 28 52 11 - 24 59 45 - 31 0 19 - 23 16 21 - 28 41 58 34 0 0 0 32 8 25 164 -31 - 30 50 13 - 26 43 45 - 33 8 53 - 24 55 36 - 30 43 11 33 0 0 0 32 24 25 162 -31 - 33 2 17 - 28 36 57 - 35 36 9 - 26 42 40 Latitude Latitude Latitude Latitude - 32 0 0 32 25 8 0 32 34 25 161 -31 33 27 23 31 25 26 34 31 14 30 29 7 - 33 0 0 31 59 33 0 32 42 26 160 -31 33 0 59 31 0 34 34 3 55 30 4 53 - 34 0 0 31 35 22 0 32 50 26 159 -31 32 36 3 30 37 4 33 38 8 29 41 58 - 35 0 0 31 12 35 0 32 57 26 158 -31 32 12 34 30 14 53 33 13 53 29 20 20 - 36 0 0 30 51 10 0 33 5 26 157 -31 31 50 31 29 54 2 32 51 8 28 59 58 - 37 0 0 30 31 5 0 33 12 26 156 -31 31 29 51 29 34 28 32 29 49 28 40 52 - 38 0 0 30 12 20 0 33 20 26 155 -30 31 10 34 29 16 12 32 9 57 28 23 0 - 39 0 0 29 54 53 0 33 27 25 154 -30 30 52 38 28 59 11 31 51 29 28 6 23 - 40 0 0 29 38 44 0 33 35 25 153 -30 30 36 3 28 43 26 31 34 24 27 50 58 - 41 0 0 29 23 51 0 33 42 25 152 -30 30 20 46 28 28 55 31 18 42 27 36 46 - 42 0 0 29 10 15 0 33 49 25 151 -29 30 6 49 28 15 38 31 4 20 27 23 47 - 43 0 0 28 57 54 0 33 57 25 151 -29 29 54 9 28 3 34 30 51 19 27 11 58 - 44 0 0 28 46 48 0 34 4 24 150 -29 29 42 45 27 52 43 30 39 38 27 1 21 - 45 0 0 28 36 56 0 34 11 24 149 -28 29 32 39 27 43 4 30 29 15 26 51 54 - 46 0 0 28 28 18 0 34 18 24 148 -28 29 23 48 27 34 38 30 20 11 26 43 38 - 47 0 0 28 20 54 0 34 24 23 147 -27 29 16 14 27 27 23 30 12 24 26 36 32 - 48 0 0 28 14 43 0 34 31 23 146 -27 29 9 54 27 21 20 30 5 55 26 30 35 - 49 0 0 28 9 45 0 34 38 23 146 -26 29 4 49 27 16 28 30 0 44 26 25 49 - 50 0 0 28 6 0 0 34 44 22 145 -26 29 1 0 27 12 47 29 56 49 26 22 12 - 51 0 0 28 3 28 0 34 50 22 144 -25 28 58 25 27 10 18 29 54 11 26 19 45 - 52 0 0 28 2 9 0 34 56 21 143 -24 28 57 5 27 9 0 29 52 50 26 18 27 - 53 0 0 28 2 3 0 35 3 21 143 -24 28 57 0 27 8 52 29 52 46 26 18 19 - 54 0 0 28 3 10 0 35 8 20 142 -23 28 58 10 27 9 57 29 54 0 26 19 21 - 55 0 0 28 5 30 0 35 14 20 141 -23 29 0 35 27 12 12 29 56 30 26 21 33 - 56 0 0 28 9 4 0 35 20 19 141 -22 29 4 16 27 15 40 30 0 18 26 24 54 - 57 0 0 28 13 52 0 35 25 18 140 -21 29 9 12 27 20 20 30 5 24 26 29 27 - 58 0 0 28 19 53 0 35 30 18 139 -20 29 15 25 27 26 12 30 11 49 26 35 10 - 59 0 0 28 27 10 0 35 36 17 139 -20 29 22 55 27 33 16 30 19 33 26 42 4 - 60 0 0 28 35 42 0 35 41 17 138 -19 29 31 41 27 41 35 30 28 36 26 50 10 - 61 0 0 28 45 29 0 35 45 16 137 -18 29 41 46 27 51 7 30 39 0 26 59 29 - 62 0 0 28 56 34 0 35 50 15 137 -17 29 53 10 28 1 53 30 50 45 27 9 59 - 63 0 0 29 8 55 0 35 54 14 136 -17 30 5 54 28 13 55 31 3 53 27 21 44 - 64 0 0 29 22 35 0 35 58 14 136 -16 30 19 58 28 27 13 31 18 24 27 34 42 - 65 0 0 29 37 34 0 36 2 13 135 -15 30 35 24 28 41 47 31 34 19 27 48 55 - 66 0 0 29 53 53 0 36 6 12 134 -14 30 52 13 28 57 40 31 51 41 28 4 23 - 67 0 0 30 11 33 0 36 10 11 134 -13 31 10 26 29 14 51 32 10 30 28 21 9 - 68 0 0 30 30 36 0 36 13 10 133 -12 31 30 4 29 33 22 32 30 48 28 39 11 - 69 0 0 30 51 3 0 36 16 10 133 -11 31 51 10 29 53 14 32 52 38 28 58 33 - 70 0 0 31 12 56 0 36 19 9 132 -10 32 13 46 30 14 28 33 16 0 29 19 14 - 71 0 0 31 36 15 0 36 21 8 132 -10 32 37 52 30 37 7 33 40 58 29 41 16 - 72 0 0 32 1 4 0 36 24 7 131 -9 33 3 31 31 1 11 34 7 34 30 4 41 - 73 0 0 32 27 24 0 36 26 6 131 -8 33 30 45 31 26 42 34 35 51 30 29 30 - 74 0 0 32 55 16 0 36 28 5 130 -7 33 59 38 31 53 42 35 5 51 30 55 45 - 75 0 0 33 24 45 0 36 29 4 129 -6 34 30 12 32 22 14 35 37 39 31 23 27 - 76 0 0 33 55 52 0 36 30 3 129 -5 35 2 30 32 52 19 36 11 19 .. .. .. - 77 0 0 34 28 40 0 36 31 2 128 -4 35 36 36 33 24 0 36 46 54 .. .. .. - 78 0 0 35 3 12 0 36 32 1 128 -3 36 12 33 33 57 19 .. .. .. .. .. .. - 79 0 0 35 39 33 0 36 32 0 127 -2 .. .. .. 34 32 20 .. .. .. .. .. .. Uncertainty in time = +/- 4 secs Prediction of 2012 Jul 8.0 Data for the target star ------------------------ * name: TYC 6887-00937-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 21 22.8440 DE: -29 28 23.053 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .023 ) * V mag [mag]: 9.6 * B mag [mag]: 9.6 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (691) Lehigh approx. diameter [km]: 86 approx. diameter ["]: .058 distance from Earth [AU]: 2.03600 * orbital information: orbit source: Preston date of fit: 2012 Jul 07 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 886 number of rejected observations: 52 time covered by the observations: 1914 Nov 21 - 2012 Jun 21 1 sigma uncertainty ellipse (major, minor, PA): 0.025, 0.014, 95° remarks: * orbital elements for (691) Lehigh : Mean anomaly = 271.83945792 deg Arg. of pericenter = 303.80206782 deg Long. of node = 88.18701534 deg Inclination = 13.02690220 deg Eccentricity = 0.11886700 Semimajor axis = 3.01277871 AU Perihelion dist = 2.65465874 AU Mag: H = 9.16, G = 0.15 Epoch of elements : MJD 56124.02300000 TDT (2012 Jul 16.023) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Jul 16 691 Lehigh 0h 33.0m UT 9.6 19 21 22.844-29 28 23.05TYC 6887-00937-1 9.7 13.5 86 6.6 2.036 -2.269 -12.28 -12.1734 -29.469 173.26 21.32 0.5506 -0.34461 0.83196 -6.86284 -2.84377 0.00046 0.00078 2000 271.0812242012 712.00000303.802068 88.187015 13.0269020.11886700 3.0127787 2.6546587 9.2 5.00.15 RATE 1.8847480 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.027 92 1.49 0.029 0 0 0-3 056116.0020120716_0937-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 07, 21:47 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org