IOTA/IOTA-ES occultation update for (3812) Lidaksum / TYC 6308-01950-1 event on 2012 Nov 24, 02:21 UT Visible from Mexico Summary ------- On 2012 Nov 24 UT, the 38 km diameter asteroid (3812) Lidaksum will occult a 9.9 mag star in the constellation Sagittarius for observers along a path across Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.7 mag to 17.6 mag (the magnitude of the asteroid) for at most 1.1 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: 20 * date and approx. time of event: 2012 Nov 24, 02:23 - 2012 Nov 24, 02:24 UT * geocentric midpoint of event [JD]: 2456255.59862083 * magnitude of target star: 9.9 * magnitude drop [mag]: 7.7 * estimated maximum duration [s]: 1.1 * Moon: 83 % sunlit, 85° distance * Sun: 46° distance * rough path description: Mexico The occultation path -------------------- * approximate projected width [km]: 44 * 1 sigma uncertainty interval [path widths]: +/- 3.37 * 1 sigma uncertainty interval [seconds]: +/- 4.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .055 +/- .044) * 1 sigma uncertainty ellipse (major, minor, PA): ( .055", .044", 97° ) * approx speed of asteroid's shadow [km/s]: 36.0215 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6308-01950-1 by 3812 Lidaksum on 2012 Nov 24 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 -134 0 0 14 15 33 2 23 40 40 225 -1 14 3 8 14 28 0 12 40 9 15 52 38 -133 0 0 14 30 23 2 23 42 39 226 -2 14 17 57 14 42 51 12 54 50 16 7 38 -132 0 0 14 45 36 2 23 45 38 227 -3 14 33 8 14 58 5 13 9 53 16 23 0 -131 0 0 15 1 11 2 23 47 37 227 -4 14 48 42 15 13 41 13 25 19 16 38 44 -130 0 0 15 17 8 2 23 49 37 228 -5 15 4 38 15 29 39 13 41 7 16 54 51 -129 0 0 15 33 27 2 23 51 36 228 -6 15 20 56 15 46 0 13 57 17 17 11 20 -128 0 0 15 50 7 2 23 53 35 229 -7 15 37 35 16 2 41 14 13 48 17 28 10 -127 0 0 16 7 8 2 23 55 34 230 -8 15 54 35 16 19 44 14 30 40 17 45 22 -126 0 0 16 24 31 2 23 57 33 230 -9 16 11 56 16 37 7 14 47 52 18 2 54 -125 0 0 16 42 13 2 23 59 32 231 -10 16 29 37 16 54 51 15 5 25 18 20 46 -124 0 0 17 0 16 2 24 1 31 231 -11 16 47 38 17 12 55 15 23 18 18 38 59 -123 0 0 17 18 38 2 24 3 30 232 -12 17 5 59 17 31 18 15 41 30 18 57 31 -122 0 0 17 37 19 2 24 5 29 232 -13 17 24 39 17 50 0 16 0 1 19 16 23 -121 0 0 17 56 19 2 24 7 28 233 -14 17 43 37 18 9 2 16 18 51 19 35 33 -120 0 0 18 15 37 2 24 8 27 233 -15 18 2 54 18 28 21 16 37 59 19 55 2 -119 0 0 18 35 13 2 24 10 26 234 -16 18 22 29 18 47 58 16 57 25 20 14 48 -118 0 0 18 55 6 2 24 12 25 234 -17 18 42 21 19 7 53 17 17 9 20 34 52 -117 0 0 19 15 16 2 24 13 24 235 -18 19 2 30 19 28 4 17 37 9 20 55 12 -116 0 0 19 35 43 2 24 15 23 235 -19 19 22 55 19 48 32 17 57 26 21 15 49 -115 0 0 19 56 25 2 24 16 22 235 -20 19 43 36 20 9 16 18 17 59 21 36 42 -114 0 0 20 17 23 2 24 17 21 236 -21 20 4 33 20 30 15 18 38 47 21 57 50 -113 0 0 20 38 36 2 24 19 20 236 -22 20 25 44 20 51 30 18 59 50 22 19 13 -112 0 0 21 0 3 2 24 20 19 237 -23 20 47 10 21 12 58 19 21 8 22 40 50 -111 0 0 21 21 44 2 24 21 19 237 -24 21 8 50 21 34 40 19 42 40 23 2 41 -110 0 0 21 43 38 2 24 22 18 238 -25 21 30 43 21 56 35 20 4 25 23 24 45 -109 0 0 22 5 45 2 24 23 17 238 -26 21 52 49 22 18 43 20 26 22 23 47 2 -108 0 0 22 28 4 2 24 24 16 238 -27 22 15 6 22 41 4 20 48 32 24 9 30 -107 0 0 22 50 34 2 24 25 15 239 -28 22 37 36 23 3 35 21 10 54 24 32 10 -106 0 0 23 13 16 2 24 26 14 239 -29 23 0 16 23 26 18 21 33 27 24 55 0 -105 0 0 23 36 7 2 24 27 13 240 -30 23 23 6 23 49 10 21 56 10 25 18 1 -104 0 0 23 59 9 2 24 28 12 240 -31 23 46 6 24 12 13 22 19 3 25 41 11 -103 0 0 24 22 19 2 24 28 11 241 -32 24 9 16 24 35 24 22 42 5 26 4 30 -102 0 0 24 45 38 2 24 29 10 241 -33 24 32 34 24 58 44 23 5 17 26 27 57 -101 0 0 25 9 5 2 24 29 9 241 -34 24 55 59 25 22 12 23 28 36 26 51 32 -100 0 0 25 32 39 2 24 30 8 242 -34 25 19 32 25 45 47 23 52 2 27 15 13 - 99 0 0 25 56 19 2 24 30 7 242 -35 25 43 12 26 9 28 24 15 36 27 39 1 - 98 0 0 26 20 6 2 24 31 6 243 -36 26 6 58 26 33 16 .. .. .. 28 2 55 - 97 0 0 26 43 57 2 24 31 5 243 -37 26 30 48 26 57 8 .. .. .. 28 26 54 - 96 0 0 27 7 54 2 24 31 4 244 -38 26 54 44 27 21 6 .. .. .. 28 50 56 - 95 0 0 27 31 54 2 24 32 3 244 -39 27 18 43 27 45 7 .. .. .. 29 15 3 - 94 0 0 27 55 58 2 24 32 2 245 -40 27 42 46 28 9 11 .. .. .. 29 39 13 - 93 0 0 28 20 4 2 24 32 1 245 -41 28 6 52 28 33 18 .. .. .. 30 3 24 Uncertainty in time = +/- 4 secs Prediction of 2012 Nov 16.0 Data for the target star ------------------------ * name: TYC 6308-01950-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 18 06.6141 DE: -21 23 13.509 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .037, .033 ) * V mag [mag]: 9.9 * B mag [mag]: 10.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (3812) Lidaksum approx. diameter [km]: 38 approx. diameter ["]: .013 distance from Earth [AU]: 4.04900 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 776 number of rejected observations: 15 time covered by the observations: 1965 Jan 11 - 2012 Jul 27 1 sigma uncertainty ellipse (major, minor, PA): 0.041, 0.029, 103° remarks: * orbital elements for (3812) Lidaksum : Mean anomaly = 130.56058119 deg Arg. of pericenter = 37.06883746 deg Long. of node = 123.01553475 deg Inclination = 18.41755697 deg Eccentricity = 0.11723680 Semimajor axis = 3.17468519 AU Perihelion dist = 2.80249524 AU Mag: H = 11.18, G = 0.15 Epoch of elements : MJD 56255.09900000 TDT (2012 Nov 24.099) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 24 3812 Lidaksum 2h 22.0m UT 9.9 19 18 6.614-21 23 13.51TYC 6308-01950-1 10.3 17.6 38 1.1 4.049 3.162 -0.38 -169.4293 -21.387 141.18 -20.60 2.3669 0.00527 0.51968 20.33078 -0.17662 0.00427 0.00063 2000 129.67212120121119.00000 37.068837123.015535 18.4175570.11723680 3.1746852 2.802495311.2 5.00.15 RATE 1.7424200 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.055 0.044 97 4.37 0.044 0 0 1 1 056247.0020121124_1950-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 20:22 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org