IOTA/IOTA-ES occultation update for (3431) Nakano / HIP 12655 event on 2012 Dec 03, 16:24 UT Visible from W Australia Summary ------- On 2012 Dec 03 UT, the 41 km diameter asteroid (3431) Nakano will occult a 8.7 mag star in the constellation Triangulum for observers along a path across W Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.4 mag to 15.1 mag (the magnitude of the asteroid) for at most 3.7 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: . The event at a glimpse ---------------------- * Rank: 41 * date and approx. time of event: 2012 Dec 03, 16:23 - 2012 Dec 03, 16:26 UT * geocentric midpoint of event [JD]: 2456265.18377083 * magnitude of target star: 8.7 * magnitude drop [mag]: 6.4 * estimated maximum duration [s]: 3.7 * Moon: 78 % sunlit, 81° distance * Sun: 152° distance * rough path description: W Australia Additional comments ------------------- low altitude The occultation path -------------------- * approximate projected width [km]: 255 * 1 sigma uncertainty interval [path widths]: +/- 1.62 * 1 sigma uncertainty interval [seconds]: +/- 6.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .053 +/- .043) * 1 sigma uncertainty ellipse (major, minor, PA): ( .054", .042", 76° ) * approx speed of asteroid's shadow [km/s]: 11.0900 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 12655 by 3431 Nakano on 2012 Dec 3 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 127 2 21 -46 0 0 16 26 4 0 324 -20 125 3 26 ... .. .. ... .. .. ... .. .. 126 11 14 -45 0 0 16 26 3 2 324 -22 124 22 23 128 23 1 ... .. .. ... .. .. 125 35 55 -44 0 0 16 26 0 3 325 -23 123 53 46 127 36 33 ... .. .. ... .. .. 125 13 18 -43 0 0 16 25 57 4 325 -24 123 35 41 127 6 54 ... .. .. ... .. .. 125 1 34 -42 0 0 16 25 52 4 325 -25 123 26 56 126 50 48 ... .. .. ... .. .. 124 59 39 -41 0 0 16 25 47 5 325 -26 123 26 44 126 46 31 ... .. .. ... .. .. 125 6 59 -40 0 0 16 25 41 6 325 -27 123 34 39 126 53 12 119 29 27 ... .. .. 125 23 24 -39 0 0 16 25 33 7 325 -27 123 50 33 127 10 39 119 45 0 ... .. .. 125 49 6 -38 0 0 16 25 25 7 324 -28 124 14 32 127 39 21 120 6 33 ... .. .. 126 24 48 -37 0 0 16 25 15 8 324 -29 124 47 2 128 20 35 120 34 13 ... .. .. 127 11 52 -36 0 0 16 25 5 8 323 -30 125 28 53 129 17 7 121 8 17 ... .. .. 128 12 51 -35 0 0 16 24 52 9 322 -31 126 21 32 130 34 57 121 49 13 ... .. .. 129 32 52 -34 0 0 16 24 38 9 321 -31 127 27 32 132 31 0 122 37 47 ... .. .. 131 24 25 -33 0 0 16 24 20 9 320 -32 128 51 48 ... .. .. 123 35 4 ... .. .. 134 50 2 -32 0 0 16 23 52 8 318 -32 130 45 42 ... .. .. 124 42 50 ... .. .. Latitude Latitude Latitude Latitude 135 0 0 -31 58 29 16 23 51 8 318 -31 -30 49 15 -33 18 26 -27 46 7 .. .. .. 136 0 0 -31 51 55 16 23 44 7 317 -31 -30 43 14 -33 10 58 -27 41 8 .. .. .. 137 0 0 -31 49 36 16 23 38 7 317 -31 -30 41 3 -33 8 28 -27 39 9 .. .. .. 138 0 0 -31 51 32 16 23 32 6 316 -30 -30 42 40 -33 10 54 -27 40 10 .. .. .. 139 0 0 -31 57 48 16 23 26 5 316 -30 -30 48 8 -33 18 23 -27 44 13 .. .. .. 140 0 0 -32 8 32 16 23 22 5 315 -29 -30 57 34 -33 31 9 .. .. .. .. .. .. 141 0 0 -32 24 1 16 23 18 4 315 -29 -31 11 8 -33 49 42 .. .. .. .. .. .. 142 0 0 -32 44 39 16 23 14 3 314 -28 -31 29 8 -34 14 46 .. .. .. .. .. .. 143 0 0 -33 11 5 16 23 12 2 313 -27 -31 51 56 -34 47 36 .. .. .. .. .. .. 144 0 0 -33 44 17 16 23 10 1 313 -26 -32 20 7 .. .. .. .. .. .. .. .. .. 145 0 0 -34 25 48 16 23 9 0 312 -25 -32 54 30 .. .. .. .. .. .. .. .. .. Uncertainty in time = +/- 7 secs Prediction of 2012 Dec 3.0 Data for the target star ------------------------ * name: HIP 12655 * constellation : Triangulum * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 02 42 35.2780 DE: +33 46 02.460 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .028, .024 ) * V mag [mag]: 8.7 * B mag [mag]: 8.8 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (3431) Nakano approx. diameter [km]: 41 approx. diameter ["]: .027 distance from Earth [AU]: 2.11400 * orbital information: orbit source: Preston date of fit: 2012 Nov 29 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 917 number of rejected observations: 23 time covered by the observations: 1955 Mar 24 - 2012 Nov 26 1 sigma uncertainty ellipse (major, minor, PA): 0.046, 0.035, 71° remarks: * orbital elements for (3431) Nakano : Mean anomaly = 51.41701163 deg Arg. of pericenter = 47.96344599 deg Long. of node = 312.49076950 deg Inclination = 12.24827232 deg Eccentricity = 0.04355030 Semimajor axis = 3.09850915 AU Perihelion dist = 2.96356815 AU Mag: H = 10.57, G = 0.15 Epoch of elements : MJD 56264.68400000 TDT (2012 Dec 03.684) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 3 3431 Nakano 16h 24.6m UT 8.7 2 42 35.278 33 46 2.46HIP 12655 8.8 15.1 41 3.7 2.114 -1.633 -16.20 81.5894 33.771 -68.64 -22.22 16.4105 0.61419 -0.77263 -4.90018 -3.89485 0.00270 -0.00081 2000 50.57058120121129.00000 47.963446312.490769 12.2482720.04355030 3.0985092 2.963568110.5 5.00.15 RATE 1.8070690 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.054 0.042 76 2.62 0.043 0 0 0 0 056264.0020121203__12655 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Nov 29, 22:32 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org