IOTA/IOTA-ES occultation update for (2105) Gudy / TYC 6650-00157-1 event on 2012 Nov 30, 03:13 UT Visible from Africa Summary ------- On 2012 Nov 30 UT, the 24 km diameter asteroid (2105) Gudy will occult a 10.5 mag star in the constellation Crater for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.5 mag to 16.0 mag (the magnitude of the asteroid) for at most 0.8 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: 21 * date and approx. time of event: 2012 Nov 30, 03:10 - 2012 Nov 30, 03:13 UT * geocentric midpoint of event [JD]: 2456261.63455 * magnitude of target star: 10.5 * magnitude drop [mag]: 5.5 * estimated maximum duration [s]: 0.8 * Moon: 98 % sunlit, 95° distance * Sun: 68° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 26 * 1 sigma uncertainty interval [path widths]: +/- 3.19 * 1 sigma uncertainty interval [seconds]: +/- 2.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .044 +/- .041) * 1 sigma uncertainty ellipse (major, minor, PA): ( .044", .041", 107° ) * approx speed of asteroid's shadow [km/s]: 31.4170 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6650-00157-1 by 2105 Gudy on 2012 Nov 30 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 - 23 27 36 25 0 0 3 10 37 0 116 -65 - 23 45 8 - 23 10 14 ... .. .. ... .. .. - 21 19 16 24 0 0 3 10 37 3 117 -63 - 21 35 37 - 21 3 2 - 23 23 0 ... .. .. Latitude Latitude Latitude Latitude - 21 0 0 23 50 33 3 10 37 3 117 -63 23 42 35 23 58 31 22 51 33 .. .. .. - 20 0 0 23 20 22 3 10 37 4 117 -62 23 12 20 23 28 23 22 20 53 .. .. .. - 19 0 0 22 49 1 3 10 38 5 118 -61 22 40 55 22 57 6 21 49 2 23 48 30 - 18 0 0 22 16 29 3 10 38 6 118 -60 22 8 19 22 24 38 21 15 59 23 16 28 - 17 0 0 21 42 44 3 10 39 7 119 -59 21 34 29 21 50 58 20 41 41 22 43 15 - 16 0 0 21 7 44 3 10 39 8 119 -58 20 59 26 21 16 3 20 6 8 22 8 48 - 15 0 0 20 31 29 3 10 40 9 119 -57 20 23 6 20 39 52 19 29 18 21 33 7 - 14 0 0 19 53 56 3 10 41 11 120 -56 19 45 28 20 2 24 18 51 10 20 56 9 - 13 0 0 19 15 5 3 10 41 12 120 -55 19 6 31 19 23 37 18 11 40 20 17 53 - 12 0 0 18 34 52 3 10 42 13 120 -54 18 26 13 18 43 30 17 30 49 19 38 18 - 11 0 0 17 53 17 3 10 43 14 120 -53 17 44 33 18 2 0 16 48 34 18 57 22 - 10 0 0 17 10 18 3 10 45 15 121 -52 17 1 28 17 19 7 16 4 54 18 15 3 - 9 0 0 16 25 53 3 10 46 16 121 -50 16 16 58 16 34 47 15 19 46 17 31 20 - 8 0 0 15 40 1 3 10 47 18 121 -49 15 31 0 15 49 1 14 33 9 16 46 11 - 7 0 0 14 52 39 3 10 49 19 121 -48 14 43 32 15 1 46 13 45 2 15 59 34 - 6 0 0 14 3 47 3 10 50 20 122 -47 13 54 34 14 13 0 12 55 23 15 11 27 - 5 0 0 13 13 23 3 10 52 21 122 -46 13 4 3 13 22 42 12 4 10 14 21 50 - 4 0 0 12 21 24 3 10 54 23 122 -45 12 11 58 12 30 50 11 11 21 13 30 40 - 3 0 0 11 27 50 3 10 56 24 122 -43 11 18 17 11 37 23 10 16 56 12 37 56 - 2 0 0 10 32 40 3 10 58 25 122 -42 10 22 59 10 42 20 9 20 52 11 43 37 - 1 0 0 9 35 51 3 11 0 27 122 -41 9 26 3 9 45 38 8 23 8 10 47 42 0 0 0 8 37 23 3 11 3 28 122 -40 8 27 27 8 47 17 7 23 43 9 50 8 1 0 0 7 37 14 3 11 5 29 122 -38 7 27 11 7 47 17 6 22 37 8 50 55 2 0 0 6 35 24 3 11 8 31 122 -37 6 25 13 6 45 34 5 19 47 7 50 2 3 0 0 5 31 52 3 11 11 32 122 -36 5 21 33 5 42 10 4 15 14 6 47 29 4 0 0 4 26 37 3 11 14 34 122 -34 4 16 10 4 37 4 3 8 57 5 43 14 5 0 0 3 19 40 3 11 17 35 122 -33 3 9 4 3 30 15 2 0 55 4 37 18 6 0 0 2 10 59 3 11 21 37 121 -32 2 0 14 2 21 43 0 51 9 3 29 40 7 0 0 1 0 36 3 11 24 38 121 -30 0 49 42 1 11 29 - 0 20 20 2 20 21 8 0 0 - 0 11 29 3 11 28 40 121 -29 - 0 22 32 - 0 0 27 - 1 33 33 1 9 21 9 0 0 - 1 25 15 3 11 32 41 120 -27 - 1 36 27 - 1 14 4 - 2 48 28 - 0 3 19 10 0 0 - 2 40 40 3 11 36 42 120 -26 - 2 52 1 - 2 29 20 - 4 5 4 - 1 17 37 11 0 0 - 3 57 43 3 11 40 44 119 -24 - 4 9 14 - 3 46 14 - 5 23 17 - 2 33 33 12 0 0 - 5 16 21 3 11 45 46 118 -23 - 5 28 1 - 5 4 43 - 6 43 7 - 3 51 2 13 0 0 - 6 36 31 3 11 49 47 117 -21 - 6 48 21 - 6 24 43 - 8 4 29 - 5 10 4 14 0 0 - 7 58 10 3 11 54 49 116 -20 - 8 10 9 - 7 46 13 - 9 27 21 - 6 30 34 15 0 0 - 9 21 14 3 11 59 50 115 -18 - 9 33 23 - 9 9 7 -10 51 36 - 7 52 29 16 0 0 -10 45 37 3 12 4 52 114 -17 -10 57 55 -10 33 20 -12 17 12 - 9 15 44 17 0 0 -12 11 15 3 12 9 53 113 -15 -12 23 43 -11 58 49 -13 44 1 -10 40 14 18 0 0 -13 38 1 3 12 15 54 111 -14 -13 50 39 -13 25 26 -15 11 59 -12 5 53 19 0 0 -15 5 50 3 12 20 56 109 -12 -15 18 36 -14 53 5 -16 40 57 -13 32 36 20 0 0 -16 34 33 3 12 26 57 108 -11 -16 47 28 -16 21 40 -18 10 48 -15 0 14 21 0 0 -18 4 3 3 12 32 59 105 -9 -18 17 7 -17 51 1 -19 41 23 -16 28 42 22 0 0 -19 34 10 3 12 38 60 103 -8 -19 47 23 -19 21 0 -21 12 35 -17 57 49 23 0 0 -21 4 47 3 12 44 61 100 -6 -21 18 8 -20 51 29 -22 44 13 -19 27 29 24 0 0 -22 35 44 3 12 50 62 98 -5 -22 49 12 -22 22 18 -24 16 7 -20 57 31 25 0 0 -24 6 50 3 12 56 63 94 -3 -24 20 25 -23 53 17 -25 48 7 -22 27 47 26 0 0 -25 37 56 3 13 2 64 91 -2 -25 51 37 -25 24 16 -27 20 2 -23 58 5 27 0 0 -27 8 50 3 13 8 65 87 0 -27 22 38 -26 55 5 -28 51 42 -25 28 17 Uncertainty in time = +/- 3 secs Prediction of 2012 Nov 16.0 Data for the target star ------------------------ * name: TYC 6650-00157-1 * constellation : Crater * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 11 25 36.6671 DE: -23 10 30.292 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .027, .035 ) * V mag [mag]: 10.5 * B mag [mag]: 11.6 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2105) Gudy approx. diameter [km]: 24 approx. diameter ["]: .013 distance from Earth [AU]: 2.50700 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 571 number of rejected observations: 18 time covered by the observations: 1976 Feb 25 - 2012 Feb 19 1 sigma uncertainty ellipse (major, minor, PA): 0.035, 0.021, 117° remarks: * orbital elements for (2105) Gudy : Mean anomaly = 72.63329262 deg Arg. of pericenter = 155.90375191 deg Long. of node = 273.66409157 deg Inclination = 29.34354679 deg Eccentricity = 0.15058580 Semimajor axis = 2.38811546 AU Perihelion dist = 2.02849917 AU Mag: H = 11.18, G = 0.15 Epoch of elements : MJD 56261.13500000 TDT (2012 Nov 30.135) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 30 2105 Gudy 3h 13.8m UT 10.5 11 25 36.667-23 10 30.29TYC 6650-00157-1 11.6 16.0 24 0.8 2.507 2.939 -47.19 53.5621 -23.162 128.74 -21.69 3.2292 -0.28287 -0.24267 11.55482-13.45114 -0.00511 0.00139 2000 72.33017120121129.00000155.903752273.664092 29.3435470.15058580 2.3881155 2.028499211.1 5.00.15 RATE 2.6706760 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.044 0.041 107 4.19 0.042 0 0 1-2 056247.0020121130_0157-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 10, 03:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org