IOTA/IOTA-ES occultation update for (895) Helio / UCAC2 36631668 event on 2012 Dec 01, 16:07 UT Visible from Russia, China, SE Asia Summary ------- On 2012 Dec 01 UT, the 128 km diameter asteroid (895) Helio will occult a 11.8 mag star in the constellation Gemini for observers along a path across Russia, China, SE Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.3 mag to 12.7 mag (the magnitude of the asteroid) for at most 10.5 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: 96 * date and approx. time of event: 2012 Dec 01, 16:02 - 2012 Dec 01, 16:12 UT * geocentric midpoint of event [JD]: 2456263.17172083 * magnitude of target star: 11.8 * magnitude drop [mag]: 1.3 * estimated maximum duration [s]: 10.5 * Moon: 92 % sunlit, 8° distance * Sun: 139° distance * rough path description: Russia, China, SE Asia The occultation path -------------------- * approximate projected width [km]: 208 * 1 sigma uncertainty interval [path widths]: +/- 0.42 * 1 sigma uncertainty interval [seconds]: +/- 3.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .041 +/- .030) * 1 sigma uncertainty ellipse (major, minor, PA): ( .041", .030", 102° ) * approx speed of asteroid's shadow [km/s]: 12.1608 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 36631668 by 895 Helio on 2012 Dec 1 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude 41 28 34 74 52 40 16 2 2 6 60 -25 52 45 34 76 32 33 ... .. .. .. .. .. 61 8 53 77 21 24 ... .. .. .. .. .. 56 4 3 75 40 45 16 2 10 10 74 -28 65 15 9 76 28 58 45 34 48 74 15 29 72 21 42 76 52 35 33 1 44 71 35 7 67 4 17 75 27 35 16 2 19 13 85 -31 74 50 34 75 51 16 58 31 7 74 44 39 80 52 31 76 0 39 50 24 10 73 44 37 75 33 2 74 46 44 16 2 27 15 93 -33 82 10 52 74 56 10 68 18 16 74 25 1 87 19 47 74 56 53 61 37 47 73 53 31 82 6 43 73 51 25 16 2 35 17 99 -35 87 49 24 73 51 56 75 53 27 73 42 19 92 15 58 73 47 11 70 12 38 73 25 59 87 13 44 72 48 18 16 2 44 19 103 -37 92 12 24 72 43 3 81 49 32 72 47 15 96 5 26 72 34 45 76 54 57 72 40 11 91 15 40 71 41 4 16 2 52 20 107 -38 95 39 12 71 31 59 86 30 43 71 45 22 99 5 36 71 21 20 82 12 53 71 44 21 94 28 29 70 31 51 16 3 0 21 110 -40 98 23 48 70 20 10 90 15 6 70 39 46 101 28 48 70 7 56 86 26 44 70 42 51 97 3 46 69 21 52 16 3 8 23 112 -41 100 36 10 69 8 23 93 15 58 69 32 18 103 23 47 68 55 5 89 51 29 69 38 14 99 9 59 68 11 51 16 3 17 24 113 -42 102 23 35 67 57 8 95 43 10 68 24 4 104 56 54 67 43 7 92 38 12 68 32 0 100 53 22 67 2 14 16 3 25 25 115 -44 103 51 20 66 46 39 97 43 56 67 15 42 106 12 44 66 32 10 94 55 5 67 25 5 102 18 32 65 53 17 16 3 33 26 116 -45 105 3 22 65 37 6 99 23 41 66 7 38 107 14 44 65 22 18 96 48 18 66 18 3 103 29 0 64 45 7 16 3 41 27 116 -46 106 2 41 64 28 33 100 46 28 65 0 6 108 5 30 64 13 34 98 22 28 65 11 17 104 27 26 63 37 50 16 3 50 28 117 -48 106 51 34 63 21 0 101 55 26 63 53 16 108 47 1 63 5 56 99 41 6 64 4 59 105 15 54 62 31 26 16 3 58 29 117 -49 107 31 46 62 14 28 102 52 58 62 47 10 109 20 51 61 59 22 100 46 58 62 59 18 105 56 2 61 25 58 16 4 6 29 117 -50 108 4 41 61 8 55 103 40 59 61 41 54 109 48 12 60 53 51 101 42 12 61 54 17 106 29 6 60 21 23 16 4 15 30 117 -51 108 31 26 60 4 19 104 20 58 60 37 25 110 10 2 59 49 18 102 28 29 60 50 1 106 56 10 59 17 40 16 4 23 31 117 -52 108 52 54 59 0 39 104 54 7 59 33 46 110 27 9 58 45 42 103 7 10 59 46 29 107 18 2 58 14 48 16 4 31 32 117 -53 109 9 49 57 57 50 105 21 23 58 30 54 110 40 11 57 43 0 103 39 20 58 43 41 107 35 26 57 12 44 16 4 39 32 117 -54 109 22 45 56 55 51 105 43 35 57 28 48 110 49 40 56 41 8 104 5 54 57 41 37 107 48 53 56 11 25 16 4 48 33 117 -55 109 32 14 55 54 40 106 1 21 56 27 26 110 56 1 55 40 5 104 27 33 56 40 15 107 58 53 55 10 51 16 4 56 33 116 -56 109 38 38 54 54 13 106 15 14 55 26 47 110 59 35 54 39 46 104 44 56 55 39 34 108 5 49 54 10 59 16 5 4 34 116 -57 109 42 18 53 54 29 106 25 40 54 26 49 111 0 42 53 40 10 104 58 31 54 39 33 108 10 0 53 11 46 16 5 13 34 115 -58 109 43 32 52 55 25 106 33 2 53 27 29 110 59 37 52 41 14 105 8 44 53 40 9 108 11 44 52 13 10 16 5 21 35 115 -59 109 42 34 51 56 58 106 37 39 52 28 46 110 56 31 51 42 57 105 15 57 52 41 21 108 11 15 51 15 9 16 5 29 35 114 -60 109 39 37 50 59 7 106 39 48 51 30 37 110 51 37 50 45 15 105 20 27 51 43 8 108 8 44 50 17 42 16 5 37 36 113 -61 109 34 51 50 1 49 106 39 42 50 33 2 110 45 4 49 48 6 105 22 30 50 45 26 108 4 22 49 20 46 16 5 46 36 113 -62 109 28 25 49 5 4 106 37 33 49 35 57 110 36 59 48 51 29 105 22 19 49 48 16 107 58 18 48 24 20 16 5 54 36 112 -63 109 20 27 48 8 47 106 33 31 48 39 22 110 27 30 47 55 22 105 20 5 48 51 34 107 50 40 47 28 22 16 6 2 37 111 -64 109 11 3 47 12 59 106 27 44 47 43 15 110 16 43 46 59 42 105 15 59 47 55 20 107 41 35 46 32 50 16 6 10 37 111 -64 109 0 20 46 17 37 106 20 22 46 47 34 110 4 43 46 4 29 105 10 8 46 59 32 107 31 7 45 37 42 16 6 19 37 110 -65 108 48 23 45 22 39 106 11 29 45 52 17 109 51 34 45 9 41 105 2 39 46 4 7 107 19 22 44 42 57 16 6 27 37 109 -66 108 35 15 44 28 4 106 1 12 44 57 22 109 37 20 44 15 15 104 53 40 45 9 6 107 6 24 43 48 34 16 6 35 37 108 -67 108 21 1 43 33 51 105 49 35 44 2 50 109 22 5 43 21 11 104 43 15 44 14 26 106 52 17 42 54 31 16 6 44 38 107 -68 108 5 43 42 39 58 105 36 43 43 8 37 109 5 50 42 27 26 104 31 28 43 20 5 106 37 4 42 0 46 16 6 52 38 107 -69 107 49 25 41 46 24 105 22 39 42 14 43 108 48 39 41 34 1 104 18 25 42 26 3 106 20 47 41 7 19 16 7 0 38 106 -69 107 32 8 40 53 7 105 7 25 41 21 6 108 30 34 40 40 52 104 4 8 41 32 18 106 3 30 40 14 8 16 7 8 38 105 -70 107 13 54 40 0 5 104 51 6 40 27 44 108 11 36 39 48 0 103 48 40 40 38 49 105 45 12 39 21 11 16 7 17 38 104 -71 106 54 45 39 7 19 104 33 42 39 34 38 107 51 46 38 55 22 103 32 3 39 45 34 105 25 57 38 28 28 16 7 25 38 103 -71 106 34 43 38 14 46 104 15 16 38 41 45 107 31 6 38 2 57 103 14 20 38 52 33 105 5 44 37 35 57 16 7 33 38 102 -72 106 13 48 37 22 25 103 55 49 37 49 3 107 9 35 37 10 45 102 55 32 37 59 43 104 44 36 36 43 36 16 7 42 38 101 -72 105 52 0 36 30 15 103 35 22 36 56 33 106 47 16 36 18 44 102 35 41 37 7 4 104 22 33 35 51 26 16 7 50 38 100 -73 105 29 21 35 38 15 103 13 55 36 4 12 106 24 8 35 26 53 102 14 46 36 14 35 103 59 34 34 59 24 16 7 58 37 100 -74 105 5 50 34 46 23 102 51 30 35 12 0 106 0 11 34 35 10 101 52 49 35 22 14 103 35 40 34 7 29 16 8 6 37 99 -74 104 41 27 33 54 39 102 28 5 34 19 54 105 35 25 33 43 35 101 29 51 34 29 59 103 10 51 33 15 41 16 8 15 37 98 -74 104 16 13 33 3 2 102 3 42 33 27 55 105 9 50 32 52 6 101 5 50 33 37 51 102 45 6 32 23 57 16 8 23 37 97 -75 103 50 6 32 11 29 101 38 20 32 36 0 104 43 25 32 0 42 100 40 47 32 45 47 102 18 25 31 32 17 16 8 31 37 96 -75 103 23 6 31 20 0 101 11 57 31 44 9 104 16 9 31 9 23 100 14 40 31 53 46 101 50 46 30 40 40 16 8 39 36 95 -75 102 55 12 30 28 34 100 44 34 30 52 20 103 48 2 30 18 6 99 47 29 31 1 47 101 22 8 29 49 4 16 8 48 36 94 -75 102 26 22 29 37 10 100 16 8 30 0 32 103 19 2 29 26 51 99 19 13 30 9 49 100 52 30 28 57 28 16 8 56 36 93 -75 101 56 35 28 45 45 99 46 38 29 8 44 102 49 7 28 35 36 98 49 50 29 17 49 100 21 50 28 5 50 16 9 4 35 93 -75 101 25 49 27 54 20 99 16 3 28 16 53 102 18 16 27 44 21 98 19 17 28 25 48 99 50 6 27 14 9 16 9 13 35 92 -75 100 54 3 27 2 52 98 44 19 27 25 0 101 46 27 26 53 3 97 47 32 27 33 43 99 17 14 26 22 25 16 9 21 35 91 -75 100 21 13 26 11 20 98 11 24 26 33 1 101 13 38 26 1 42 97 14 33 26 41 33 98 43 12 25 30 34 16 9 29 34 90 -75 99 47 17 25 19 44 97 37 15 25 40 56 100 39 45 25 10 16 96 40 16 25 49 15 98 7 57 24 38 36 16 9 37 34 89 -74 99 12 12 24 28 0 97 1 48 24 48 44 100 4 46 24 18 44 96 4 37 24 56 49 97 31 25 23 46 29 16 9 46 33 88 -74 98 35 53 23 36 8 96 24 59 23 56 21 99 28 38 23 27 4 95 27 31 24 4 12 96 53 31 22 54 12 16 9 54 32 88 -73 97 58 18 22 44 6 95 46 42 23 3 46 98 51 15 22 35 14 94 48 53 23 11 22 96 14 10 22 1 41 16 10 2 32 87 -73 97 19 20 21 51 51 95 6 53 22 10 57 98 12 35 21 43 13 94 8 37 22 18 17 95 33 15 21 8 55 16 10 10 31 86 -72 96 38 55 20 59 23 94 25 25 21 17 52 97 32 32 20 50 59 93 26 35 21 24 55 94 50 41 20 15 51 16 10 19 30 85 -71 95 56 56 20 6 39 93 42 9 20 24 28 96 50 59 19 58 29 92 42 40 20 31 12 94 6 18 19 22 27 16 10 27 30 85 -70 95 13 16 19 13 35 92 56 57 19 30 42 96 7 50 19 5 42 91 56 40 19 37 5 93 19 58 18 28 40 16 10 35 29 84 -70 94 27 46 18 20 10 92 9 39 18 36 30 95 22 58 18 12 34 91 8 25 18 42 31 92 31 29 17 34 26 16 10 44 28 83 -69 93 40 17 17 26 20 91 20 0 17 41 49 94 36 13 17 19 3 90 17 40 17 47 25 91 40 38 16 39 41 16 10 52 27 83 -68 92 50 37 16 32 2 90 27 47 16 46 35 93 47 25 16 25 5 89 24 7 16 51 43 90 47 9 15 44 21 16 11 0 26 82 -67 91 58 31 15 37 11 89 32 40 15 50 41 92 56 21 15 30 37 88 27 25 15 55 18 89 50 42 14 48 19 16 11 8 25 81 -65 91 3 44 14 41 44 88 34 18 14 54 2 92 2 46 14 35 35 87 27 8 14 58 2 88 50 54 13 51 30 16 11 17 24 81 -64 90 5 54 13 45 33 87 32 10 13 56 29 91 6 21 13 39 52 86 22 41 13 59 48 87 47 14 12 53 45 16 11 25 23 80 -63 89 4 36 12 48 31 86 25 40 12 57 53 90 6 46 12 43 23 85 13 21 13 0 22 86 39 4 11 54 54 16 11 33 22 80 -62 87 59 18 11 50 31 85 14 0 11 58 1 89 3 31 11 46 0 83 58 6 11 59 29 85 25 30 10 54 42 16 11 42 21 79 -60 86 49 18 10 51 21 83 56 3 10 56 35 87 56 2 10 47 35 82 35 33 10 56 47 84 5 23 9 52 52 16 11 50 19 79 -59 85 33 41 9 50 46 82 30 14 9 53 11 86 43 32 9 47 53 81 3 35 9 51 43 82 37 0 8 48 56 16 11 58 17 78 -57 84 11 10 8 48 26 80 54 8 8 47 11 85 25 0 8 46 39 79 18 49 8 43 26 80 57 42 7 42 15 16 12 6 16 78 -55 82 39 53 7 43 53 79 3 47 7 37 35 83 58 56 7 43 30 77 15 6 7 30 22 79 3 4 6 31 40 16 12 15 14 77 -53 80 56 54 6 36 21 76 51 37 6 22 29 82 23 10 6 37 53 74 38 43 6 9 5 76 44 24 5 15 0 16 12 23 11 77 -50 78 57 10 5 24 33 73 59 9 4 57 14 80 34 11 5 28 53 70 38 57 4 26 55 73 38 56 3 46 32 16 12 31 8 77 -47 76 30 23 4 5 54 68 45 55 2 56 47 78 25 38 4 14 55 ... .. .. .. .. .. Uncertainty in time = +/- 5 secs Prediction of 2012 Nov 16.0 Data for the target star ------------------------ * name: UCAC2 36631668 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 21 33.9994 DE: +13 52 43.488 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .033, .027 ) * V mag [mag]: 11.8 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (895) Helio approx. diameter [km]: 128 approx. diameter ["]: .092 distance from Earth [AU]: 1.92200 * orbital information: orbit source: Preston date of fit: 2012 Nov 16 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 1033 number of rejected observations: 56 time covered by the observations: 1906 Jun 21 - 2012 Nov 08 1 sigma uncertainty ellipse (major, minor, PA): 0.026, 0.014, 122° remarks: * orbital elements for (895) Helio : Mean anomaly = 10.96354845 deg Arg. of pericenter = 178.20153136 deg Long. of node = 264.70437298 deg Inclination = 26.08511027 deg Eccentricity = 0.14711572 Semimajor axis = 3.20284814 AU Perihelion dist = 2.73165882 AU Mag: H = 8.31, G = 0.15 Epoch of elements : MJD 56262.67200000 TDT (2012 Dec 01.672) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 1 895 Helio 16h 7.3m UT 11.8 7 21 33.999 13 52 43.49UCAC2 36631668 0.0 12.7 128 10.5 1.922 -1.365 -24.33 157.6553 13.886 -64.50 -21.93 16.1213 -0.61092 0.49847 -4.34033 -5.31737 -0.00369 0.00117 2000 10.50410020121129.00000178.201531264.704373 26.0851100.14711572 3.2028481 2.7316588 8.3 5.00.15 RATE 1.7194900 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.041 0.030 102 1.42 0.039 0 0 4-2 056247.0020121201_631668 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Nov 16, 09:17 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org