IOTA/IOTA-ES occultation update for (249) Ilse / HIP 107556 event on 2010 Mar 08, 03:16 UT Visible from SE Australia in daylight Summary ------- On 2010 Mar 08 UT, the 37 km diameter asteroid (249) Ilse will occult a 2.9 mag star in the constellation Capricornus for observers along a path across SE Australia in daylight. In the case of an occultation, the combined light of the asteroid and the star will drop by 13.0 mag to 15.9 mag (the magnitude of the asteroid) for at most 0.7 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: 84 * date and approx. time of event: 2010 Mar 08, 03:14 - 2010 Mar 08, 03:14 UT * midpoint of event [JD]: 2455263.63634167 * magnitude of target star: 2.9 * magnitude drop [mag]: 13.0 * estimated maximum duration [s]: 0.7 * Moon: 46 % sunlit, 61° distance * Sun: 24° distance * rough path description: SE Australia in daylight Additional comments ------------------- wide double star The occultation path -------------------- * approximate projected width [km]: 42 * 1 sigma uncertainty interval [path widths]: +/- 0.61 * 1 sigma uncertainty interval [seconds]: +/- 0.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .015 +/- .012) * 1 sigma uncertainty ellipse (major, minor, PA): ( .016", .010", 64° ) * approx speed of asteroid's shadow [km/s]: 49.4160 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 107556 by 249 Ilse on 2010 Mar 8 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 4 0 0 -48 25 16 3 14 26 0 114 -21 -48 37 43 -48 12 50 -48 52 56 .. .. .. 5 0 0 -48 43 16 3 14 26 1 114 -21 -48 55 40 -48 30 52 -49 10 51 -48 15 47 6 0 0 -49 0 51 3 14 26 2 113 -20 -49 13 14 -48 48 30 -49 28 22 -48 33 27 7 0 0 -49 18 2 3 14 26 2 112 -19 -49 30 22 -49 5 43 -49 45 28 -48 50 43 8 0 0 -49 34 48 3 14 26 3 111 -18 -49 47 6 -49 22 31 -50 2 9 -49 7 34 9 0 0 -49 51 10 3 14 26 4 111 -18 -50 3 26 -49 38 55 -50 18 27 -49 24 1 10 0 0 -50 7 8 3 14 26 4 110 -17 -50 19 22 -49 54 56 -50 34 20 -49 40 4 11 0 0 -50 22 42 3 14 27 5 109 -16 -50 34 54 -50 10 32 -50 49 49 -49 55 43 12 0 0 -50 37 53 3 14 27 6 108 -16 -50 50 2 -50 25 44 -51 4 55 -50 10 57 13 0 0 -50 52 39 3 14 27 6 107 -15 -51 4 47 -50 40 33 -51 19 37 -50 25 49 14 0 0 -51 7 2 3 14 27 7 107 -14 -51 19 8 -50 54 58 -51 33 55 -50 40 16 15 0 0 -51 21 2 3 14 27 8 106 -14 -51 33 5 -51 9 0 -51 47 50 -50 54 20 16 0 0 -51 34 38 3 14 28 8 105 -13 -51 46 40 -51 22 38 -52 1 22 -51 8 1 17 0 0 -51 47 52 3 14 28 9 104 -12 -51 59 51 -51 35 53 -52 14 31 -51 21 19 18 0 0 -52 0 42 3 14 28 10 104 -12 -52 12 40 -51 48 46 -52 27 17 -51 34 14 19 0 0 -52 13 10 3 14 28 10 103 -11 -52 25 5 -52 1 15 -52 39 41 -51 46 46 20 0 0 -52 25 15 3 14 29 11 102 -10 -52 37 9 -52 13 22 -52 51 42 -51 58 55 21 0 0 -52 36 58 3 14 29 12 101 -10 -52 48 50 -52 25 7 -53 3 20 -52 10 42 22 0 0 -52 48 18 3 14 29 12 100 -9 -53 0 8 -52 36 29 -53 14 37 -52 22 6 23 0 0 -52 59 17 3 14 30 13 100 -8 -53 11 5 -52 47 29 -53 25 31 -52 33 9 24 0 0 -53 9 53 3 14 30 14 99 -8 -53 21 40 -52 58 8 -53 36 4 -52 43 49 25 0 0 -53 20 8 3 14 31 14 98 -7 -53 31 53 -53 8 24 -53 46 15 -52 54 7 26 0 0 -53 30 1 3 14 31 15 97 -7 -53 41 45 -53 18 19 -53 56 5 -53 4 4 27 0 0 -53 39 33 3 14 31 15 96 -6 -53 51 15 -53 27 53 -54 5 33 -53 13 40 28 0 0 -53 48 44 3 14 32 16 95 -5 -54 0 24 -53 37 5 -54 14 40 -53 22 54 29 0 0 -53 57 33 3 14 32 17 95 -5 -54 9 12 -53 45 56 -54 23 26 -53 31 47 30 0 0 -54 6 2 3 14 33 17 94 -4 -54 17 39 -53 54 26 -54 31 51 -53 40 18 31 0 0 -54 14 9 3 14 33 18 93 -4 -54 25 45 -54 2 35 -54 39 56 -53 48 29 32 0 0 -54 21 57 3 14 34 18 92 -3 -54 33 31 -54 10 23 -54 47 40 -53 56 19 33 0 0 -54 29 23 3 14 34 19 91 -2 -54 40 56 -54 17 51 -54 55 4 -54 3 49 34 0 0 -54 36 29 3 14 35 20 90 -2 -54 48 1 -54 24 59 -55 2 7 -54 10 58 35 0 0 -54 43 15 3 14 35 20 89 -1 -54 54 46 -54 31 46 -55 8 50 -54 17 46 36 0 0 -54 49 41 3 14 36 21 89 -1 -55 1 11 -54 38 13 -55 15 13 -54 24 15 37 0 0 -54 55 47 3 14 36 21 88 0 -55 7 15 -54 44 20 -55 21 17 -54 30 23 Uncertainty in time = +/- 1 secs Prediction of 2010 Jan 11.0 Data for the target star ------------------------ * name: HIP 107556 * constellation : Capricornus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 47 02.6312 DE: -16 07 41.240 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .004, .003 ) * V mag [mag]: 2.9 * B mag [mag]: 3.0 * Apparent position with proper motion RA(deg): 326.8999940049 DE(deg): -16.0812782402 * Equation of equinoxes (radians) : 0.000075560819812 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (249) Ilse approx. diameter [km]: 37 approx. diameter ["]: .017 distance from Earth [AU]: 2.94100 * orbital information: orbit source: Preston date of fit: 2010 Jan 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 868 number of rejected observations: 37 time covered by the observations: 1931 Feb 26 - 2009 Jul 10 1 sigma uncertainty ellipse (major, minor, PA): 0.016, 0.010, 62° remarks: * orbital elements for (249) Ilse : Mean anomaly = 316.19955101 deg Arg. of pericenter = 42.03032956 deg Long. of node = 334.77795772 deg Inclination = 9.62575078 deg Eccentricity = 0.21719417 Semimajor axis = 2.37763220 AU Perihelion dist = 1.86122434 AU Mag: H = 11.13, G = 0.15 Epoch of elements : MJD 55263.13600000 TDT (2010 Mar 08.136) ------ occelmnt file for Occult BEGIN ----------------------------------- 2010 Mar 8 249 Ilse 3h 16.3m UT 2.9 21 47 2.631-16 7 41.24HIP 107556 3.0 15.9 37 0.7 2.941 5.326 32.62 111.9493 -16.138 133.64 -4.96 3.2722 0.18199 -0.42872 25.66972 10.90939 -0.00197 -0.00093 2000 315.3564822010 3 5.00000 42.030330334.777958 9.6257510.21719417 2.3776322 1.861224311.3 5.00.15 RATE 2.6883580 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.016 0.010 64 1.61 0.010 0 055207.0020100308_107556 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2010 Jan 11, 17:45 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org