IOTA/IOTA-ES occultation update for (1031) Arctica / UCAC2 30530549 event on 2012 Nov 23, 04:33 UT Visible from W Africa, E Canada Summary ------- On 2012 Nov 23 UT, the 77 km diameter asteroid (1031) Arctica will occult a 11.0 mag star in the constellation Hydra for observers along a path across W Africa, E Canada. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.9 mag to 14.9 mag (the magnitude of the asteroid) for at most 5.9 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: 52 * date and approx. time of event: 2012 Nov 23, 04:25 - 2012 Nov 23, 04:36 UT * geocentric midpoint of event [JD]: 2456254.68988333 * magnitude of target star: 11.0 * magnitude drop [mag]: 3.9 * estimated maximum duration [s]: 5.9 * Moon: 75 % sunlit, 135° distance * Sun: 103° distance * rough path description: W Africa, E Canada The occultation path -------------------- * approximate projected width [km]: 77 * 1 sigma uncertainty interval [path widths]: +/- 1.23 * 1 sigma uncertainty interval [seconds]: +/- 8.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .047 +/- .064) * 1 sigma uncertainty ellipse (major, minor, PA): ( .064", .047", 0° ) * approx speed of asteroid's shadow [km/s]: 13.1084 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 30530549 by 1031 Arctica on 2012 Nov 23 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 - 77 10 54 55 0 0 4 25 23 1 98 -55 ... .. .. - 73 40 59 ... .. .. - 67 35 27 - 69 4 42 54 0 0 4 25 26 6 105 -56 - 71 26 23 - 66 59 21 ... .. .. - 62 34 50 Latitude Latitude Latitude Latitude - 69 0 0 53 59 14 4 25 26 6 105 -56 53 37 35 54 20 52 52 44 16 55 14 1 - 68 0 0 53 49 4 4 25 27 7 106 -57 53 27 20 54 10 48 52 33 46 55 4 12 - 67 0 0 53 38 17 4 25 27 8 107 -57 53 16 27 54 0 7 52 22 38 54 53 46 - 66 0 0 53 26 52 4 25 28 8 107 -57 53 4 54 53 48 48 52 10 50 54 42 42 - 65 0 0 53 14 46 4 25 29 9 108 -57 52 52 42 53 36 49 51 58 21 54 31 0 - 64 0 0 53 2 1 4 25 30 9 109 -57 52 39 50 53 24 11 51 45 10 54 18 40 - 63 0 0 52 48 34 4 25 31 10 110 -57 52 26 16 53 10 52 51 31 17 54 5 39 - 62 0 0 52 34 26 4 25 32 11 111 -57 52 11 59 52 56 52 51 16 41 53 51 58 - 61 0 0 52 19 34 4 25 33 11 111 -57 51 56 59 52 42 8 51 1 20 53 37 35 - 60 0 0 52 3 58 4 25 34 12 112 -57 51 41 14 52 26 41 50 45 14 53 22 29 - 59 0 0 51 47 37 4 25 35 13 113 -58 51 24 43 52 10 29 50 28 20 53 6 39 - 58 0 0 51 30 28 4 25 37 13 114 -58 51 7 26 51 53 30 50 10 39 52 50 4 - 57 0 0 51 12 32 4 25 38 14 114 -58 50 49 20 51 35 44 49 52 8 52 32 43 - 56 0 0 50 53 47 4 25 40 15 115 -58 50 30 24 51 17 9 49 32 46 52 14 34 - 55 0 0 50 34 11 4 25 41 16 116 -58 50 10 37 50 57 44 49 12 32 51 55 36 - 54 0 0 50 13 43 4 25 43 16 117 -58 49 49 57 50 37 28 48 51 24 51 35 47 - 53 0 0 49 52 21 4 25 45 17 118 -58 49 28 24 50 16 18 48 29 21 51 15 6 - 52 0 0 49 30 4 4 25 47 18 118 -58 49 5 54 49 54 13 48 6 20 50 53 31 - 51 0 0 49 6 49 4 25 49 19 119 -58 48 42 26 49 31 11 47 42 20 50 31 1 - 50 0 0 48 42 36 4 25 51 19 120 -58 48 17 59 49 7 11 47 17 20 50 7 34 - 49 0 0 48 17 21 4 25 53 20 121 -57 47 52 30 48 42 10 46 51 16 49 43 7 - 48 0 0 47 51 3 4 25 55 21 121 -57 47 25 58 48 16 7 46 24 8 49 17 40 - 47 0 0 47 23 40 4 25 58 22 122 -57 46 58 20 47 48 59 45 55 52 48 51 9 - 46 0 0 46 55 10 4 26 1 23 123 -57 46 29 34 47 20 44 45 26 27 48 23 32 - 45 0 0 46 25 30 4 26 3 23 123 -57 45 59 37 46 51 20 44 55 50 47 54 48 - 44 0 0 45 54 37 4 26 6 24 124 -57 45 28 28 46 20 45 44 23 59 47 24 54 - 43 0 0 45 22 30 4 26 10 25 125 -57 44 56 3 45 48 55 43 50 50 46 53 47 - 42 0 0 44 49 5 4 26 13 26 126 -56 44 22 20 45 15 48 43 16 22 46 21 25 - 41 0 0 44 14 20 4 26 17 27 126 -56 43 47 15 44 41 22 42 40 31 45 47 44 - 40 0 0 43 38 11 4 26 20 28 127 -56 43 10 47 44 5 33 42 3 14 45 12 43 - 39 0 0 43 0 36 4 26 24 29 128 -56 42 32 52 43 28 18 41 24 28 44 36 17 - 38 0 0 42 21 31 4 26 28 30 128 -55 41 53 26 42 49 34 40 44 9 43 58 25 - 37 0 0 41 40 53 4 26 33 31 129 -55 41 12 26 42 9 18 40 2 16 43 19 2 - 36 0 0 40 58 39 4 26 37 32 130 -55 40 29 49 41 27 26 39 18 43 42 38 5 - 35 0 0 40 14 45 4 26 42 33 130 -54 39 45 32 40 43 55 38 33 27 41 55 31 - 34 0 0 39 29 7 4 26 47 34 131 -54 38 59 29 39 58 41 37 46 24 41 11 16 - 33 0 0 38 41 41 4 26 53 35 131 -53 38 11 38 39 11 40 36 57 31 40 25 16 - 32 0 0 37 52 23 4 26 58 36 132 -53 37 21 55 38 22 48 36 6 44 39 37 27 - 31 0 0 37 1 10 4 27 5 38 132 -52 36 30 15 37 32 2 35 13 57 38 47 45 - 30 0 0 36 7 57 4 27 11 39 133 -52 35 36 35 36 39 16 34 19 8 37 56 6 - 29 0 0 35 12 40 4 27 18 40 134 -51 34 40 49 35 44 28 33 22 12 37 2 26 - 28 0 0 34 15 15 4 27 25 41 134 -50 33 42 54 34 47 31 32 23 4 36 6 41 - 27 0 0 33 15 37 4 27 32 43 135 -50 32 42 46 33 48 23 31 21 41 35 8 46 - 26 0 0 32 13 42 4 27 40 44 135 -49 31 40 20 32 46 59 30 17 58 34 8 37 - 25 0 0 31 9 25 4 27 48 45 135 -48 30 35 32 31 43 14 29 11 51 33 6 9 - 24 0 0 30 2 43 4 27 57 47 136 -47 29 28 17 30 37 5 28 3 15 32 1 19 - 23 0 0 28 53 32 4 28 6 48 136 -46 28 18 33 29 28 27 26 52 7 30 54 2 - 22 0 0 27 41 48 4 28 16 50 136 -45 27 6 14 28 17 17 25 38 23 29 44 14 - 21 0 0 26 27 26 4 28 26 51 137 -44 25 51 18 27 3 30 24 22 0 28 31 52 - 20 0 0 25 10 25 4 28 37 53 137 -43 24 33 41 25 47 4 23 2 55 27 16 51 - 19 0 0 23 50 41 4 28 48 54 137 -42 23 13 21 24 27 55 21 41 6 25 59 10 - 18 0 0 22 28 12 4 29 0 56 137 -41 21 50 16 23 6 2 20 16 30 24 38 45 - 17 0 0 21 2 56 4 29 12 58 137 -40 20 24 24 21 41 23 18 49 7 23 15 34 - 16 0 0 19 34 54 4 29 25 60 137 -39 18 55 44 20 13 57 17 18 56 21 49 37 - 15 0 0 18 4 4 4 29 38 61 137 -37 17 24 18 18 43 44 15 45 59 20 20 53 - 14 0 0 16 30 29 4 29 52 63 137 -36 15 50 7 17 10 45 14 10 17 18 49 22 - 13 0 0 14 54 11 4 30 7 65 136 -35 14 13 13 15 35 3 12 31 54 17 15 7 - 12 0 0 13 15 14 4 30 22 67 135 -33 12 33 41 13 56 41 10 50 55 15 38 11 - 11 0 0 11 33 44 4 30 37 69 135 -32 10 51 36 12 15 45 9 7 25 13 58 37 - 10 0 0 9 49 47 4 30 53 71 133 -30 9 7 6 10 32 20 7 21 34 12 16 33 - 9 0 0 8 3 32 4 31 10 73 132 -29 7 20 20 8 46 36 5 33 31 10 32 5 - 8 0 0 6 15 10 4 31 27 75 130 -27 5 31 29 6 58 44 3 43 27 8 45 24 - 7 0 0 4 24 53 4 31 45 77 127 -26 3 40 45 5 8 53 1 51 37 6 56 40 - 6 0 0 2 32 54 4 32 2 79 123 -24 1 48 22 3 17 19 - 0 1 46 5 6 6 - 5 0 0 0 39 31 4 32 21 81 117 -22 - 0 5 23 1 24 17 - 1 56 24 3 13 57 - 4 0 0 - 1 15 2 4 32 39 82 108 -21 - 2 0 14 - 0 29 57 - 3 51 59 1 20 29 - 3 0 0 - 3 10 24 4 32 58 84 94 -19 - 3 55 51 - 2 25 4 - 5 48 12 - 0 34 0 - 2 0 0 - 5 6 16 4 33 16 85 74 -17 - 5 51 55 - 4 20 45 - 7 44 42 - 2 29 13 - 1 0 0 - 7 2 20 4 33 35 85 50 -15 - 7 48 5 - 6 16 41 - 9 41 10 - 4 24 49 0 0 0 - 8 58 13 4 33 54 84 30 -14 - 9 44 2 - 8 12 31 -11 37 15 - 6 20 29 1 0 0 -10 53 36 4 34 12 82 15 -12 -11 39 25 -10 7 54 -13 32 36 - 8 15 51 2 0 0 -12 48 9 4 34 30 81 6 -10 -13 33 54 -12 2 31 -15 26 53 -10 10 37 3 0 0 -14 41 33 4 34 48 79 359 -8 -15 27 9 -13 56 3 -17 19 47 -12 4 27 4 0 0 -16 33 29 4 35 6 77 354 -7 -17 18 53 -15 48 10 -19 11 1 -13 57 2 5 0 0 -18 23 41 4 35 23 75 351 -5 -19 8 50 -17 38 37 -21 0 18 -15 48 4 6 0 0 -20 11 53 4 35 40 73 348 -3 -20 56 43 -19 27 7 -22 47 25 -17 37 18 7 0 0 -21 57 52 4 35 57 71 346 -2 -22 42 21 -21 13 27 -24 32 8 -19 24 29 8 0 0 -23 41 26 4 36 13 69 344 0 -24 25 31 -22 57 25 -26 14 18 -21 9 25 Uncertainty in time = +/- 9 secs Prediction of 2012 Nov 16.0 Data for the target star ------------------------ * name: UCAC2 30530549 * constellation : Hydra * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 08 55 41.2417 DE: -03 30 02.865 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .040, .063 ) * V mag [mag]: 11.0 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1031) Arctica approx. diameter [km]: 77 approx. diameter ["]: .042 distance from Earth [AU]: 2.54400 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1078 number of rejected observations: 71 time covered by the observations: 1913 May 09 - 2012 Feb 23 1 sigma uncertainty ellipse (major, minor, PA): 0.024, 0.012, 104° remarks: * orbital elements for (1031) Arctica : Mean anomaly = 317.61197865 deg Arg. of pericenter = 305.92947271 deg Long. of node = 218.94650377 deg Inclination = 17.63569192 deg Eccentricity = 0.05635440 Semimajor axis = 3.04744373 AU Perihelion dist = 2.87570686 AU Mag: H = 9.48, G = 0.15 Epoch of elements : MJD 56254.19000000 TDT (2012 Nov 23.190) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 23 1031 Arctica 4h 33.4m UT 11.0 8 55 41.242- 3 30 2.87UCAC2 30530549 0.0 14.9 77 5.9 2.544 0.842 -22.25 3.0069 -3.495 108.26 -20.42 4.5572 -0.08069 -0.04413 3.64826 -6.43677 -0.00536 0.00215 2000 316.83570620121119.00000305.929473218.946504 17.6356920.05635440 3.0474437 2.8757069 9.6 5.00.15 RATE 1.8526800 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.064 0.047 0 2.23 0.051 0 0-3 5 056247.0020121123_530549 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 10, 03:05 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org