IOTA/IOTA-ES occultation update for (270) Anahita / TYC 1247-01102-1 event on 2008 Jul 04, 17:59 UT Visible from Japan Summary ------- On 2008 Jul 04 UT, the 51 km diameter asteroid (270) Anahita will occult a 11.0 mag star in the constellation Taurus for observers along a path across Japan. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.5 mag to 13.4 mag (the magnitude of the asteroid) for at most 1.3 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: 54 * date and approx. time of event: 2008 Jul 04, 17:58 - 2008 Jul 04, 17:58 UT * midpoint of event [JD]: 2454652.24998333 * magnitude of target star: 11.0 * magnitude drop [mag]: 2.5 * estimated maximum duration [s]: 1.3 * Moon: 4 % sunlit, 67° distance * Sun: 45° distance * rough path description: Japan Additional comments ------------------- 11" double star The occultation path -------------------- * approximate projected width [km]: 75 * 1 sigma uncertainty interval [path widths]: +/- 1.18 * 1 sigma uncertainty interval [seconds]: +/- 0.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .020 +/- .032) * 1 sigma uncertainty ellipse (major, minor, PA): ( .032", .020", 360° ) * approx speed of asteroid's shadow [km/s]: 40.0753 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1247-01102-1 by 270 Anahita on 2008 Jul 4 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 119 0 0 32 40 45 17 58 11 0 65 -29 .. .. .. 33 3 30 .. .. .. 33 57 56 120 0 0 33 4 40 17 58 11 1 66 -28 32 42 0 33 27 30 .. .. .. 34 22 10 121 0 0 33 28 59 17 58 11 2 66 -27 33 6 14 33 51 55 .. .. .. 34 46 48 122 0 0 33 53 42 17 58 11 3 67 -26 33 30 51 34 16 44 .. .. .. 35 11 51 123 0 0 34 18 48 17 58 12 4 67 -26 33 55 52 34 41 55 .. .. .. 35 37 17 124 0 0 34 44 17 17 58 12 5 68 -25 34 21 15 35 7 30 .. .. .. 36 3 5 125 0 0 35 10 7 17 58 12 6 68 -24 34 47 0 35 33 26 .. .. .. 36 29 15 126 0 0 35 36 18 17 58 13 6 69 -23 35 13 5 35 59 43 34 19 3 36 55 46 127 0 0 36 2 50 17 58 13 7 70 -22 35 39 31 36 26 20 34 45 16 37 22 38 128 0 0 36 29 40 17 58 14 8 70 -22 36 6 16 36 53 17 35 11 48 37 49 49 129 0 0 36 56 50 17 58 14 9 71 -21 36 33 20 37 20 32 35 38 39 38 17 18 130 0 0 37 24 17 17 58 15 10 71 -20 37 0 41 37 48 5 36 5 47 38 45 6 131 0 0 37 52 1 17 58 16 11 72 -19 37 28 20 38 15 55 36 33 13 39 13 10 132 0 0 38 20 1 17 58 16 12 73 -18 37 56 14 38 44 1 37 0 55 39 41 30 133 0 0 38 48 16 17 58 17 13 73 -17 38 24 24 39 12 21 37 28 51 40 10 5 134 0 0 39 16 45 17 58 18 14 74 -16 38 52 47 39 40 56 37 57 2 40 38 54 135 0 0 39 45 28 17 58 19 15 75 -16 39 21 24 40 9 44 38 25 27 41 7 56 136 0 0 40 14 22 17 58 20 15 76 -15 39 50 13 40 38 44 38 54 3 41 37 10 137 0 0 40 43 28 17 58 21 16 76 -14 40 19 13 41 7 56 39 22 51 42 6 35 138 0 0 41 12 43 17 58 22 17 77 -13 40 48 24 41 37 17 39 51 50 42 36 10 139 0 0 41 42 8 17 58 23 18 78 -12 41 17 43 42 6 47 40 20 57 43 5 54 140 0 0 42 11 41 17 58 24 19 79 -11 41 47 11 42 36 25 40 50 13 43 35 45 141 0 0 42 41 21 17 58 25 20 79 -10 42 16 45 43 6 10 41 19 36 44 5 43 142 0 0 43 11 6 17 58 27 20 80 -9 42 46 26 43 36 0 41 49 6 44 35 46 143 0 0 43 40 57 17 58 28 21 81 -9 43 16 12 44 5 56 42 18 41 45 5 53 144 0 0 44 10 50 17 58 29 22 82 -8 43 46 1 44 35 54 42 48 19 45 36 4 145 0 0 44 40 47 17 58 31 23 83 -7 44 15 53 45 5 56 43 18 1 46 6 17 146 0 0 45 10 45 17 58 32 24 84 -6 44 45 46 45 35 58 43 47 45 46 36 30 147 0 0 45 40 43 17 58 34 24 84 -5 45 15 40 46 6 1 44 17 30 47 6 43 148 0 0 46 10 40 17 58 35 25 85 -4 45 45 34 46 36 2 44 47 14 47 36 55 149 0 0 46 40 36 17 58 37 26 86 -3 46 15 25 47 6 1 45 16 57 48 7 4 150 0 0 47 10 28 17 58 38 27 87 -3 46 45 14 47 35 57 45 46 38 48 37 10 151 0 0 47 40 16 17 58 40 27 88 -2 47 14 59 48 5 49 46 16 15 49 7 10 152 0 0 48 9 59 17 58 41 28 89 -1 47 44 39 48 35 36 46 45 47 49 37 5 153 0 0 48 39 36 17 58 43 29 90 0 48 14 12 49 5 15 47 15 14 50 6 52 Uncertainty in time = +/- 2 secs [Prediction of 2008 May 26.0] Data for the target star ------------------------ * name: TYC 1247-01102-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 42 19.2466 DE: +20 49 10.350 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .018, .032 ) * V mag [mag]: 11.0 * B mag [mag]: 11.5 * Apparent position with proper motion RA(deg): 55.7029335660 DE(deg): 20.8475340570 * Equation of equinoxes (radians) : 0.000051755992264 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (270) Anahita approx. diameter [km]: 51 approx. diameter ["]: .027 distance from Earth [AU]: 2.59600 * orbital information: orbit source: Preston date of fit: 2008 May 22 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 940 number of rejected observations: 127 time covered by the observations: 1900 Sep 20 - 2007 Sep 07 1 sigma uncertainty ellipse (major, minor, PA): 0.009, 0.005, 80° remarks: * orbital elements for (270) Anahita : Mean anomaly = 47.89466141 deg Arg. of pericenter = 80.24931634 deg Long. of node = 254.55415072 deg Inclination = 2.36581857 deg Eccentricity = 0.15021171 Semimajor axis = 2.19823928 AU Perihelion dist = 1.86803799 AU Mag: H = 8.71, G = 0.15 Epoch of elements : MJD 54651.75000000 TDT (2008 Jul 04.750) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Jul 4 270 Anahita 17h 60.0m UT 11.0 3 42 19.247 20 49 10.35TYC 1247-01102-1 11.5 13.4 51 1.3 2.596 5.338 16.40 -137.5300 20.816 -88.86 22.79 17.9996 -0.15751 0.71905 22.09527 4.84213 -0.00354 -0.00075 2000 47.3654492008 7 3.00000 80.249316254.554151 2.3658190.15021171 2.1982393 1.8680380 8.8 5.00.15 RATE 3.0240690 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.032 0.020 360 2.18 0.032 0 54612.5020080704_1102-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 26, 16:16 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org