IOTA/IOTA-ES occultation update for (644) Cosima / TYC 1357-01260-1 event on 2008 Oct 13, 08:25 UT Visible from Venezuela, Colombia Summary ------- On 2008 Oct 13 UT, the 20 km diameter asteroid (644) Cosima will occult a 9.8 mag star in the constellation Gemini for observers along a path across Venezuela, Colombia. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.9 mag to 15.7 mag (the magnitude of the asteroid) for at most 1.4 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: 36 * date and approx. time of event: 2008 Oct 13, 08:18 - 2008 Oct 13, 08:25 UT * midpoint of event [JD]: 2454752.85075417 * magnitude of target star: 9.8 * magnitude drop [mag]: 5.9 * estimated maximum duration [s]: 1.4 * Moon: 97 % sunlit, 105° distance * Sun: 94° distance * rough path description: Venezuela, Colombia The occultation path -------------------- * approximate projected width [km]: 21 * 1 sigma uncertainty interval [path widths]: +/- 1.86 * 1 sigma uncertainty interval [seconds]: +/- 3.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .036 +/- .024) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .024", 94° ) * approx speed of asteroid's shadow [km/s]: 14.4634 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1357-01260-1 by 644 Cosima on 2008 Oct 13 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 -125 0 0 - 8 38 21 8 18 1 1 68 -73 - 8 44 25 - 8 32 16 - 9 7 2 .. .. .. -124 0 0 - 8 14 12 8 18 1 2 68 -73 - 8 20 16 - 8 8 8 - 8 42 51 - 7 45 36 -123 0 0 - 7 50 12 8 18 1 3 67 -73 - 7 56 16 - 7 44 9 - 8 18 50 - 7 21 39 -122 0 0 - 7 26 23 8 18 2 4 67 -74 - 7 32 26 - 7 20 20 - 7 54 59 - 6 57 51 -121 0 0 - 7 2 44 8 18 2 5 67 -74 - 7 8 47 - 6 56 41 - 7 31 18 - 6 34 14 -120 0 0 - 6 39 16 8 18 3 6 67 -73 - 6 45 19 - 6 33 14 - 7 7 48 - 6 10 48 -119 0 0 - 6 16 0 8 18 4 7 67 -73 - 6 22 2 - 6 9 59 - 6 44 30 - 5 47 35 -118 0 0 - 5 52 57 8 18 5 8 67 -73 - 5 58 58 - 5 46 55 - 6 21 24 - 5 24 33 -117 0 0 - 5 30 6 8 18 7 9 67 -73 - 5 36 7 - 5 24 5 - 5 58 31 - 5 1 44 -116 0 0 - 5 7 28 8 18 8 10 67 -72 - 5 13 29 - 5 1 28 - 5 35 52 - 4 39 9 -115 0 0 - 4 45 5 8 18 10 11 67 -72 - 4 51 5 - 4 39 5 - 5 13 26 - 4 16 48 -114 0 0 - 4 22 56 8 18 11 12 66 -71 - 4 28 55 - 4 16 56 - 4 51 15 - 3 54 41 -113 0 0 - 4 1 2 8 18 13 14 66 -71 - 4 7 1 - 3 55 3 - 4 29 18 - 3 32 49 -112 0 0 - 3 39 23 8 18 15 15 66 -70 - 3 45 22 - 3 33 25 - 4 7 37 - 3 11 13 -111 0 0 - 3 18 0 8 18 18 16 66 -70 - 3 23 58 - 3 12 2 - 3 46 12 - 2 49 52 -110 0 0 - 2 56 54 8 18 20 17 66 -69 - 3 2 52 - 2 50 57 - 3 25 3 - 2 28 49 -109 0 0 - 2 36 5 8 18 22 18 66 -68 - 2 42 2 - 2 30 8 - 3 4 12 - 2 8 2 -108 0 0 - 2 15 33 8 18 25 19 66 -68 - 2 21 29 - 2 9 36 - 2 43 37 - 1 47 32 -107 0 0 - 1 55 18 8 18 28 20 66 -67 - 2 1 14 - 1 49 22 - 2 23 20 - 1 27 20 -106 0 0 - 1 35 22 8 18 31 21 66 -66 - 1 41 18 - 1 29 27 - 2 3 22 - 1 7 27 -105 0 0 - 1 15 45 8 18 34 22 66 -65 - 1 21 40 - 1 9 50 - 1 43 42 - 0 47 52 -104 0 0 - 0 56 26 8 18 37 23 66 -64 - 1 2 21 - 0 50 32 - 1 24 21 - 0 28 36 -103 0 0 - 0 37 27 8 18 41 24 66 -64 - 0 43 21 - 0 31 34 - 1 5 19 - 0 9 39 -102 0 0 - 0 18 48 8 18 44 25 66 -63 - 0 24 42 - 0 12 55 - 0 46 38 0 8 57 -101 0 0 - 0 0 29 8 18 48 26 65 -62 - 0 6 22 0 5 23 - 0 28 16 0 27 14 -100 0 0 0 17 29 8 18 52 27 65 -61 0 11 37 0 23 21 - 0 10 15 0 45 10 - 99 0 0 0 35 7 8 18 56 28 65 -60 0 29 15 0 40 58 0 7 25 1 2 45 - 98 0 0 0 52 23 8 19 0 29 65 -59 0 46 32 0 58 14 0 24 44 1 19 59 - 97 0 0 1 9 18 8 19 4 30 65 -58 1 3 28 1 15 9 0 41 41 1 36 51 - 96 0 0 1 25 51 8 19 8 31 65 -57 1 20 1 1 31 41 0 58 17 1 53 22 - 95 0 0 1 42 2 8 19 13 32 65 -56 1 36 13 1 47 52 1 14 30 2 9 31 - 94 0 0 1 57 51 8 19 17 33 65 -55 1 52 2 2 3 40 1 30 22 2 25 17 - 93 0 0 2 13 17 8 19 22 35 65 -54 2 7 28 2 19 6 1 45 50 2 40 41 - 92 0 0 2 28 20 8 19 27 36 65 -53 2 22 32 2 34 8 2 0 55 2 55 41 - 91 0 0 2 43 0 8 19 32 37 65 -52 2 37 12 2 48 48 2 15 38 3 10 19 - 90 0 0 2 57 17 8 19 37 38 64 -52 2 51 29 3 3 4 2 29 56 3 24 33 - 89 0 0 3 11 10 8 19 42 39 64 -51 3 5 23 3 16 56 2 43 52 3 38 24 - 88 0 0 3 24 39 8 19 47 40 64 -50 3 18 52 3 30 25 2 57 23 3 51 51 - 87 0 0 3 37 44 8 19 53 41 64 -49 3 31 58 3 43 29 3 10 30 4 4 54 - 86 0 0 3 50 24 8 19 58 42 64 -48 3 44 39 3 56 10 3 23 13 4 17 32 - 85 0 0 4 2 41 8 20 4 43 64 -47 3 56 56 4 8 26 3 35 31 4 29 47 - 84 0 0 4 14 33 8 20 9 44 63 -46 4 8 48 4 20 17 3 47 25 4 41 36 - 83 0 0 4 25 59 8 20 15 45 63 -45 4 20 15 4 31 43 3 58 54 4 53 1 - 82 0 0 4 37 1 8 20 21 46 63 -44 4 31 18 4 42 45 4 9 58 5 4 1 - 81 0 0 4 47 38 8 20 27 47 63 -43 4 41 55 4 53 22 4 20 37 5 14 36 - 80 0 0 4 57 50 8 20 33 48 63 -42 4 52 7 5 3 33 4 30 50 5 24 46 - 79 0 0 5 7 36 8 20 39 49 62 -41 5 1 54 5 13 19 4 40 38 5 34 31 - 78 0 0 5 16 57 8 20 46 50 62 -40 5 11 15 5 22 39 4 50 1 5 43 50 - 77 0 0 5 25 52 8 20 52 51 62 -39 5 20 11 5 31 34 4 58 57 5 52 44 - 76 0 0 5 34 22 8 20 58 52 61 -38 5 28 40 5 40 3 5 7 28 6 1 12 - 75 0 0 5 42 25 8 21 5 52 61 -37 5 36 44 5 48 6 5 15 33 6 9 14 - 74 0 0 5 50 3 8 21 11 53 61 -36 5 44 22 5 55 44 5 23 12 6 16 50 - 73 0 0 5 57 15 8 21 18 54 60 -35 5 51 34 6 2 55 5 30 25 6 24 0 - 72 0 0 6 4 0 8 21 25 55 60 -34 5 58 20 6 9 40 5 37 12 6 30 45 - 71 0 0 6 10 19 8 21 32 56 59 -33 6 4 39 6 15 59 5 43 32 6 37 3 - 70 0 0 6 16 12 8 21 38 57 58 -32 6 10 32 6 21 52 5 49 26 6 42 54 - 69 0 0 6 21 39 8 21 45 58 58 -31 6 15 59 6 27 18 5 54 54 6 48 20 - 68 0 0 6 26 39 8 21 52 59 57 -30 6 20 59 6 32 18 5 59 55 6 53 19 - 67 0 0 6 31 13 8 22 0 60 56 -29 6 25 33 6 36 52 6 4 29 6 57 52 - 66 0 0 6 35 20 8 22 7 61 56 -28 6 29 40 6 40 59 6 8 37 7 1 58 - 65 0 0 6 39 0 8 22 14 62 55 -27 6 33 21 6 44 39 6 12 18 7 5 38 - 64 0 0 6 42 14 8 22 21 63 54 -26 6 36 35 6 47 53 6 15 33 7 8 51 - 63 0 0 6 45 1 8 22 28 63 53 -25 6 39 22 6 50 40 6 18 20 7 11 38 - 62 0 0 6 47 21 8 22 36 64 52 -24 6 41 43 6 53 0 6 20 41 7 13 58 - 61 0 0 6 49 15 8 22 43 65 51 -23 6 43 36 6 54 53 6 22 35 7 15 51 - 60 0 0 6 50 42 8 22 51 66 49 -21 6 45 3 6 56 20 6 24 2 7 17 18 - 59 0 0 6 51 41 8 22 58 67 48 -20 6 46 3 6 57 20 6 25 2 7 18 17 - 58 0 0 6 52 14 8 23 6 67 46 -19 6 46 36 6 57 53 6 25 35 7 18 50 - 57 0 0 6 52 21 8 23 13 68 45 -18 6 46 42 6 57 59 6 25 41 7 18 56 - 56 0 0 6 52 0 8 23 21 69 43 -17 6 46 21 6 57 38 6 25 21 7 18 36 - 55 0 0 6 51 12 8 23 29 69 41 -16 6 45 34 6 56 51 6 24 33 7 17 48 - 54 0 0 6 49 58 8 23 36 70 39 -15 6 44 19 6 55 36 6 23 18 7 16 34 - 53 0 0 6 48 16 8 23 44 71 37 -14 6 42 38 6 53 55 6 21 36 7 14 53 - 52 0 0 6 46 8 8 23 52 71 35 -13 6 40 29 6 51 47 6 19 27 7 12 45 - 51 0 0 6 43 33 8 24 0 72 32 -12 6 37 54 6 49 12 6 16 52 7 10 10 - 50 0 0 6 40 31 8 24 7 72 29 -11 6 34 52 6 46 10 6 13 49 7 7 9 - 49 0 0 6 37 2 8 24 15 73 27 -10 6 31 22 6 42 41 6 10 19 7 3 41 - 48 0 0 6 33 6 8 24 23 73 24 -9 6 27 26 6 38 45 6 6 23 6 59 46 - 47 0 0 6 28 43 8 24 31 73 20 -8 6 23 4 6 34 23 6 1 59 6 55 24 - 46 0 0 6 23 54 8 24 39 74 17 -7 6 18 14 6 29 33 5 57 9 6 50 35 - 45 0 0 6 18 37 8 24 47 74 14 -6 6 12 57 6 24 17 5 51 51 6 45 20 - 44 0 0 6 12 54 8 24 55 74 10 -5 6 7 14 6 18 35 5 46 7 6 39 38 - 43 0 0 6 6 45 8 25 3 74 7 -4 6 1 4 6 12 25 5 39 56 6 33 30 - 42 0 0 6 0 9 8 25 11 74 3 -3 5 54 28 6 5 49 5 33 19 6 26 55 - 41 0 0 5 53 6 8 25 19 74 360 -2 5 47 25 5 58 47 5 26 15 6 19 53 - 40 0 0 5 45 36 8 25 27 74 356 -1 5 39 55 5 51 18 5 18 44 6 12 25 Uncertainty in time = +/- 4 secs [Prediction of 2008 Sep 11.0] Data for the target star ------------------------ * name: TYC 1357-01260-1 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 09 38.8437 DE: +21 54 04.144 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .014, .015 ) * V mag [mag]: 9.8 * B mag [mag]: 10.0 * Apparent position with proper motion RA(deg): 107.5471153732 DE(deg): 21.8879769702 * Equation of equinoxes (radians) : 0.000048025252067 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (644) Cosima approx. diameter [km]: 20 approx. diameter ["]: .013 distance from Earth [AU]: 2.07700 * orbital information: orbit source: Preston date of fit: 2008 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1165 number of rejected observations: 62 time covered by the observations: 1907 Sep 14 - 2007 Dec 20 1 sigma uncertainty ellipse (major, minor, PA): 0.033, 0.019, 95° remarks: * orbital elements for (644) Cosima : Mean anomaly = 47.42700372 deg Arg. of pericenter = 269.07832518 deg Long. of node = 109.95261475 deg Inclination = 1.04067319 deg Eccentricity = 0.15444010 Semimajor axis = 2.59973897 AU Perihelion dist = 2.19823502 AU Mag: H = 10.64, G = 0.15 Epoch of elements : MJD 54752.35100000 TDT (2008 Oct 13.351) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 13 644 Cosima 8h 25.1m UT 9.8 7 9 38.844 21 54 4.14TYC 1357-01260-1 10.0 15.7 20 1.4 2.077 2.468 -3.85 -41.1323 21.902 50.28 -7.96 8.4181 -0.02925 -0.27295 8.11266 -0.91019 -0.00551 0.00066 2000 46.87421220081011.00000269.078325109.952615 1.0406730.15444010 2.5997390 2.198235011.1 5.00.15 RATE 2.3513070 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.024 94 2.86 0.024 0 54720.5020081013_1260-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Sep 11, 17:04 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org