IOTA/IOTA-ES occultation update for (2621) Goto / HIP 45671 event on 2012 Oct 28, 08:00 UT Visible from Central America Summary ------- On 2012 Oct 28 UT, the 47 km diameter asteroid (2621) Goto will occult a 8.6 mag star in the constellation Cancer for observers along a path across Central America. In the case of an occultation, the combined light of the asteroid and the star will drop by 8.2 mag to 16.8 mag (the magnitude of the asteroid) for at most 2.3 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: . The event at a glimpse ---------------------- * Rank: 50 * date and approx. time of event: 2012 Oct 28, 07:55 - 2012 Oct 28, 07:59 UT * geocentric midpoint of event [JD]: 2456228.83382917 * magnitude of target star: 8.6 * magnitude drop [mag]: 8.2 * estimated maximum duration [s]: 2.3 * Moon: 98 % sunlit, 116° distance * Sun: 80° distance * rough path description: Central America Additional comments ------------------- close double star The occultation path -------------------- * approximate projected width [km]: 47 * 1 sigma uncertainty interval [path widths]: +/- 1.29 * 1 sigma uncertainty interval [seconds]: +/- 4.2 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .039 +/- .026) * 1 sigma uncertainty ellipse (major, minor, PA): ( .039", .026", 93° ) * approx speed of asteroid's shadow [km/s]: 20.0889 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 45671 by 2621 Goto on 2012 Oct 28 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 -105 0 0 - 1 55 41 7 55 26 0 69 -67 - 2 9 21 - 1 42 1 - 2 44 37 - 1 6 47 -104 0 0 - 1 32 49 7 55 26 1 69 -66 - 1 46 29 - 1 19 9 - 2 21 44 - 0 43 56 -103 0 0 - 1 9 59 7 55 26 2 69 -66 - 1 23 39 - 0 56 20 - 1 58 54 - 0 21 7 -102 0 0 - 0 47 13 7 55 27 4 69 -65 - 1 0 52 - 0 33 34 - 1 36 7 0 1 38 -101 0 0 - 0 24 30 7 55 27 5 69 -64 - 0 38 9 - 0 10 51 - 1 13 23 0 24 20 -100 0 0 - 0 1 51 7 55 28 6 69 -64 - 0 15 30 0 11 47 - 0 50 43 0 46 57 - 99 0 0 0 20 43 7 55 28 7 69 -63 0 7 4 0 34 21 - 0 28 8 1 9 30 - 98 0 0 0 43 11 7 55 29 8 69 -62 0 29 34 0 56 49 - 0 5 37 1 31 57 - 97 0 0 1 5 34 7 55 30 9 69 -62 0 51 57 1 19 12 0 16 47 1 54 19 - 96 0 0 1 27 51 7 55 31 10 69 -61 1 14 14 1 41 28 0 39 6 2 16 34 - 95 0 0 1 50 1 7 55 32 11 69 -60 1 36 25 2 3 37 1 1 17 2 38 42 - 94 0 0 2 12 4 7 55 33 12 69 -59 1 58 28 2 25 39 1 23 22 3 0 43 - 93 0 0 2 33 59 7 55 34 13 69 -59 2 20 23 2 47 34 1 45 19 3 22 36 - 92 0 0 2 55 45 7 55 36 14 69 -58 2 42 10 3 9 20 2 7 7 3 44 20 - 91 0 0 3 17 23 7 55 37 15 69 -57 3 3 49 3 30 57 2 28 47 4 5 56 - 90 0 0 3 38 51 7 55 39 16 69 -56 3 25 18 3 52 24 2 50 18 4 27 22 - 89 0 0 4 0 10 7 55 41 17 69 -55 3 46 37 4 13 42 3 11 39 4 48 38 - 88 0 0 4 21 18 7 55 43 19 70 -54 4 7 46 4 34 50 3 32 50 5 9 44 - 87 0 0 4 42 16 7 55 45 20 70 -53 4 28 45 4 55 47 3 53 50 5 30 39 - 86 0 0 5 3 2 7 55 47 21 70 -53 4 49 32 5 16 33 4 14 39 5 51 23 - 85 0 0 5 23 37 7 55 49 22 70 -52 5 10 7 5 37 7 4 35 17 6 11 55 - 84 0 0 5 44 0 7 55 51 23 70 -51 5 30 31 5 57 29 4 55 43 6 32 15 - 83 0 0 6 4 10 7 55 53 24 70 -50 5 50 42 6 17 38 5 15 56 6 52 22 - 82 0 0 6 24 8 7 55 56 25 70 -49 6 10 40 6 37 35 5 35 56 7 12 17 - 81 0 0 6 43 52 7 55 58 26 70 -48 6 30 25 6 57 18 5 55 43 7 31 58 - 80 0 0 7 3 22 7 56 1 27 70 -47 6 49 56 7 16 48 6 15 17 7 51 25 - 79 0 0 7 22 38 7 56 3 28 70 -46 7 9 14 7 36 3 6 34 36 8 10 38 - 78 0 0 7 41 40 7 56 6 29 70 -45 7 28 16 7 55 4 6 53 41 8 29 36 - 77 0 0 8 0 27 7 56 9 30 71 -44 7 47 4 8 13 50 7 12 31 8 48 20 - 76 0 0 8 18 59 7 56 12 31 71 -44 8 5 37 8 32 20 7 31 6 9 6 48 - 75 0 0 8 37 15 7 56 15 32 71 -43 8 23 54 8 50 36 7 49 26 9 25 1 - 74 0 0 8 55 15 7 56 18 33 71 -42 8 41 55 9 8 35 8 7 29 9 42 58 - 73 0 0 9 12 59 7 56 22 34 71 -41 8 59 39 9 26 18 8 25 16 10 0 38 - 72 0 0 9 30 26 7 56 25 35 71 -40 9 17 8 9 43 44 8 42 47 10 18 2 - 71 0 0 9 47 37 7 56 28 36 71 -39 9 34 19 10 0 54 9 0 1 10 35 9 - 70 0 0 10 4 30 7 56 32 37 71 -38 9 51 14 10 17 46 9 16 58 10 51 59 - 69 0 0 10 21 6 7 56 35 38 72 -37 10 7 50 10 34 21 9 33 37 11 8 31 - 68 0 0 10 37 24 7 56 39 39 72 -36 10 24 10 10 50 38 9 49 59 11 24 46 - 67 0 0 10 53 24 7 56 43 41 72 -35 10 40 11 11 6 37 10 6 3 11 40 43 - 66 0 0 11 9 6 7 56 46 42 72 -34 10 55 54 11 22 18 10 21 48 11 56 21 - 65 0 0 11 24 29 7 56 50 43 72 -33 11 11 18 11 37 41 10 37 15 12 11 41 - 64 0 0 11 39 34 7 56 54 44 72 -32 11 26 24 11 52 44 10 52 23 12 26 42 - 63 0 0 11 54 20 7 56 58 45 72 -31 11 41 10 12 7 29 11 7 12 12 41 25 - 62 0 0 12 8 47 7 57 2 46 73 -30 11 55 38 12 21 55 11 21 42 12 55 48 - 61 0 0 12 22 54 7 57 6 47 73 -29 12 9 46 12 36 1 11 35 53 13 9 52 - 60 0 0 12 36 41 7 57 10 48 73 -28 12 23 35 12 49 48 11 49 44 13 23 36 - 59 0 0 12 50 9 7 57 14 49 73 -27 12 37 4 13 3 15 12 3 15 13 37 1 - 58 0 0 13 3 17 7 57 19 50 73 -27 12 50 12 13 16 22 12 16 27 13 50 5 - 57 0 0 13 16 5 7 57 23 51 73 -26 13 3 1 13 29 9 12 29 18 14 2 50 - 56 0 0 13 28 33 7 57 27 52 73 -25 13 15 30 13 41 35 12 41 48 14 15 14 - 55 0 0 13 40 40 7 57 32 53 73 -24 13 27 38 13 53 42 12 53 59 14 27 18 - 54 0 0 13 52 26 7 57 36 54 74 -23 13 39 25 14 5 27 13 5 48 14 39 1 - 53 0 0 14 3 52 7 57 41 55 74 -22 13 50 52 14 16 52 13 17 17 14 50 24 - 52 0 0 14 14 57 7 57 45 56 74 -21 14 1 57 14 27 56 13 28 25 15 1 26 - 51 0 0 14 25 41 7 57 50 57 74 -20 14 12 42 14 38 40 13 39 12 15 12 7 - 50 0 0 14 36 4 7 57 55 58 74 -19 14 23 6 14 49 2 13 49 38 15 22 27 - 49 0 0 14 46 5 7 58 0 59 74 -18 14 33 8 14 59 2 13 59 42 15 32 26 - 48 0 0 14 55 46 7 58 4 60 74 -17 14 42 49 15 8 42 14 9 25 15 42 4 - 47 0 0 15 5 5 7 58 9 61 74 -16 14 52 9 15 18 0 14 18 47 15 51 20 - 46 0 0 15 14 2 7 58 14 62 74 -15 15 1 7 15 26 57 14 27 47 16 0 15 - 45 0 0 15 22 38 7 58 19 63 74 -14 15 9 43 15 35 32 14 36 25 16 8 48 - 44 0 0 15 30 52 7 58 24 64 74 -13 15 17 58 15 43 45 14 44 41 16 17 0 - 43 0 0 15 38 44 7 58 29 65 74 -12 15 25 51 15 51 37 14 52 36 16 24 50 - 42 0 0 15 46 14 7 58 34 66 74 -11 15 33 22 15 59 7 15 0 8 16 32 18 - 41 0 0 15 53 23 7 58 39 67 74 -10 15 40 31 16 6 15 15 7 19 16 39 24 - 40 0 0 16 0 9 7 58 44 68 74 -10 15 47 18 16 13 0 15 14 7 16 46 9 - 39 0 0 16 6 34 7 58 49 69 74 -9 15 53 43 16 19 24 15 20 34 16 52 31 - 38 0 0 16 12 36 7 58 54 69 74 -8 15 59 46 16 25 26 15 26 38 16 58 32 - 37 0 0 16 18 17 7 58 59 70 73 -7 16 5 27 16 31 6 15 32 20 17 4 10 - 36 0 0 16 23 35 7 59 4 71 73 -6 16 10 45 16 36 24 15 37 39 17 9 27 - 35 0 0 16 28 30 7 59 10 72 73 -5 16 15 41 16 41 19 15 42 37 17 14 21 - 34 0 0 16 33 4 7 59 15 73 72 -4 16 20 15 16 45 52 15 47 12 17 18 53 - 33 0 0 16 37 15 7 59 20 74 72 -3 16 24 27 16 50 3 15 51 24 17 23 3 - 32 0 0 16 41 4 7 59 25 75 71 -2 16 28 16 16 53 51 15 55 14 17 26 51 - 31 0 0 16 44 30 7 59 31 76 70 -1 16 31 43 16 57 18 15 58 42 17 30 16 - 30 0 0 16 47 34 7 59 36 77 70 0 16 34 47 17 0 21 16 1 47 17 33 19 Uncertainty in time = +/- 5 secs Prediction of 2012 Jul 10.0 Data for the target star ------------------------ * name: HIP 45671 * constellation : Cancer * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 09 18 36.2456 DE: +20 48 48.734 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .028, .013 ) * V mag [mag]: 8.6 * B mag [mag]: 9.1 * Apparent position with proper motion RA(deg): 139.8350271874 DE(deg): 20.7569334074 * Equation of equinoxes (radians) : 0.000058332799528 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2621) Goto approx. diameter [km]: 47 approx. diameter ["]: .020 distance from Earth [AU]: 3.19600 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1047 number of rejected observations: 26 time covered by the observations: 1971 Apr 27 - 2012 Mar 21 1 sigma uncertainty ellipse (major, minor, PA): 0.027, 0.022, 96° remarks: * orbital elements for (2621) Goto : Mean anomaly = 89.48719717 deg Arg. of pericenter = 273.09448358 deg Long. of node = 95.75419590 deg Inclination = 13.04471235 deg Eccentricity = 0.17605300 Semimajor axis = 3.08017322 AU Perihelion dist = 2.53789947 AU Mag: H = 10.88, G = 0.15 Epoch of elements : MJD 56228.33400000 TDT (2012 Oct 28.334) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 28 2621 Goto 8h 0.7m UT 8.6 9 18 36.246 20 48 48.73HIP 45671 9.1 16.8 47 2.3 3.196 2.224 -0.97 -17.6000 20.814 55.77 -13.29 8.0119 -0.00216 -0.06900 11.33327 -0.35215 -0.00549 0.00185 2000 87.96771720121020.00000273.094484 95.754196 13.0447120.17605300 3.0801732 2.537899510.8 5.00.15 RATE 1.8232300 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.039 0.026 93 2.29 0.026 0 0-4 4 056118.0020121028__45671 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Sep 03, 20:27 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org