IOTA/IOTA-ES occultation update for (13) Egeria / TYC 2486-01416-1 event on 2012 Oct 13, 05:10 UT Visible from S Atlantic Ocean Summary ------- On 2012 Oct 13 UT, the 215 km diameter asteroid (13) Egeria will occult a 11.7 mag star in the constellation Cancer for observers along a path across S Atlantic Ocean. In the case of an occultation, the combined light of the asteroid and the star will drop by 0.7 mag to 11.6 mag (the magnitude of the asteroid) for at most 8.3 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: UCAC. The event at a glimpse ---------------------- * Rank: 99 * date and approx. time of event: 2012 Oct 13, 05:06 - 2012 Oct 13, 05:08 UT * geocentric midpoint of event [JD]: 2456213.71557917 * magnitude of target star: 11.7 * magnitude drop [mag]: 0.7 * estimated maximum duration [s]: 8.3 * Moon: 7 % sunlit, 51° distance * Sun: 78° distance * rough path description: S Atlantic Ocean The occultation path -------------------- * approximate projected width [km]: 255 * 1 sigma uncertainty interval [path widths]: +/- 0.19 * 1 sigma uncertainty interval [seconds]: +/- 1.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .023) * 1 sigma uncertainty ellipse (major, minor, PA): ( .026", .023", 93° ) * approx speed of asteroid's shadow [km/s]: 25.8810 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 2486-01416-1 by 13 Egeria on 2012 Oct 13 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 - 38 0 0 -29 25 42 5 6 58 1 51 -35 .. .. .. -27 58 58 .. .. .. -27 26 26 - 37 0 0 -28 44 6 5 6 58 2 51 -35 -30 12 21 -27 17 36 -30 46 23 -26 45 10 - 36 0 0 -28 2 32 5 6 59 3 50 -34 -29 30 31 -26 36 18 -30 4 27 -26 3 57 - 35 0 0 -27 21 3 5 6 59 4 50 -34 -28 48 45 -25 55 5 -29 22 34 -25 22 50 - 34 0 0 -26 39 41 5 6 59 5 49 -33 -28 7 5 -25 13 59 -28 40 47 -24 41 51 - 33 0 0 -25 58 26 5 7 0 6 49 -33 -27 25 32 -24 33 2 -27 59 7 -24 1 0 - 32 0 0 -25 17 21 5 7 1 7 48 -33 -26 44 8 -23 52 15 -27 17 35 -23 20 19 - 31 0 0 -24 36 28 5 7 1 9 48 -32 -26 2 55 -23 11 39 -26 36 14 -22 39 50 - 30 0 0 -23 55 47 5 7 2 10 48 -32 -25 21 54 -22 31 17 -25 55 5 -21 59 35 - 29 0 0 -23 15 20 5 7 3 11 47 -31 -24 41 7 -21 51 10 -25 14 10 -21 19 35 - 28 0 0 -22 35 9 5 7 4 12 47 -31 -24 0 35 -21 11 19 -24 33 30 -20 39 51 - 27 0 0 -21 55 16 5 7 6 13 46 -30 -23 20 20 -20 31 46 -23 53 7 -20 0 25 - 26 0 0 -21 15 41 5 7 7 14 46 -29 -22 40 24 -19 52 32 -23 13 2 -19 21 19 - 25 0 0 -20 36 27 5 7 9 15 46 -29 -22 0 48 -19 13 38 -22 33 17 -18 42 33 - 24 0 0 -19 57 35 5 7 10 16 45 -28 -21 21 33 -18 35 7 -21 53 54 -18 4 9 - 23 0 0 -19 19 5 5 7 12 18 45 -27 -20 42 41 -17 56 58 -21 14 53 -17 26 8 - 22 0 0 -18 40 59 5 7 14 19 44 -27 -20 4 13 -17 19 14 -20 36 16 -16 48 32 - 21 0 0 -18 3 20 5 7 16 20 44 -26 -19 26 11 -16 41 56 -19 58 4 -16 11 22 - 20 0 0 -17 26 6 5 7 18 21 44 -25 -18 48 34 -16 5 4 -19 20 19 -15 34 38 - 19 0 0 -16 49 21 5 7 20 22 43 -25 -18 11 26 -15 28 41 -18 43 2 -14 58 22 - 18 0 0 -16 13 4 5 7 22 23 43 -24 -17 34 46 -14 52 46 -18 6 13 -14 22 36 - 17 0 0 -15 37 18 5 7 24 24 42 -23 -16 58 37 -14 17 21 -17 29 54 -13 47 19 - 16 0 0 -15 2 2 5 7 27 25 42 -22 -16 22 58 -13 42 27 -16 54 6 -13 12 33 - 15 0 0 -14 27 18 5 7 29 26 41 -22 -15 47 51 -13 8 5 -16 18 51 -12 38 19 - 14 0 0 -13 53 7 5 7 32 27 41 -21 -15 13 17 -12 34 15 -15 44 8 -12 4 37 - 13 0 0 -13 19 29 5 7 35 29 41 -20 -14 39 17 -12 0 59 -15 9 58 -11 31 29 - 12 0 0 -12 46 25 5 7 37 30 40 -19 -14 5 51 -11 28 17 -14 36 24 -10 58 55 - 11 0 0 -12 13 57 5 7 40 31 40 -18 -13 33 1 -10 56 10 -14 3 25 -10 26 55 - 10 0 0 -11 42 5 5 7 43 32 39 -17 -13 0 46 -10 24 39 -13 31 1 - 9 55 32 - 9 0 0 -11 10 49 5 7 46 33 39 -16 -12 29 8 - 9 53 43 -12 59 15 - 9 24 44 - 8 0 0 -10 40 10 5 7 49 34 38 -16 -11 58 8 - 9 23 25 -12 28 6 - 8 54 33 - 7 0 0 -10 10 8 5 7 52 35 38 -15 -11 27 45 - 8 53 44 -11 57 35 - 8 25 0 - 6 0 0 - 9 40 45 5 7 56 36 37 -14 -10 58 0 - 8 24 40 -11 27 42 - 7 56 4 - 5 0 0 - 9 12 0 5 7 59 37 37 -13 -10 28 55 - 7 56 16 -10 58 28 - 7 27 46 - 4 0 0 - 8 43 54 5 8 2 38 36 -12 -10 0 29 - 7 28 29 -10 29 54 - 7 0 7 - 3 0 0 - 8 16 28 5 8 6 39 35 -11 - 9 32 43 - 7 1 22 -10 2 0 - 6 33 7 - 2 0 0 - 7 49 42 5 8 9 40 35 -10 - 9 5 37 - 6 34 55 - 9 34 47 - 6 6 46 - 1 0 0 - 7 23 36 5 8 13 41 34 -9 - 8 39 11 - 6 9 7 - 9 8 14 - 5 41 5 0 0 0 - 6 58 10 5 8 17 41 34 -8 - 8 13 27 - 5 43 59 - 8 42 22 - 5 16 4 1 0 0 - 6 33 25 5 8 20 42 33 -7 - 7 48 23 - 5 19 32 - 8 17 11 - 4 51 43 2 0 0 - 6 9 21 5 8 24 43 32 -6 - 7 24 2 - 4 55 45 - 7 52 42 - 4 28 3 3 0 0 - 5 45 58 5 8 28 44 32 -6 - 7 0 21 - 4 32 39 - 7 28 55 - 4 5 3 4 0 0 - 5 23 17 5 8 32 45 31 -5 - 6 37 23 - 4 10 14 - 7 5 50 - 3 42 45 5 0 0 - 5 1 17 5 8 36 46 30 -4 - 6 15 7 - 3 48 31 - 6 43 27 - 3 21 7 6 0 0 - 4 39 59 5 8 40 47 29 -3 - 5 53 33 - 3 27 28 - 6 21 47 - 3 0 10 7 0 0 - 4 19 24 5 8 44 47 28 -2 - 5 32 41 - 3 7 7 - 6 0 49 - 2 39 55 8 0 0 - 3 59 30 5 8 48 48 27 -1 - 5 12 32 - 2 47 28 - 5 40 34 - 2 20 21 Uncertainty in time = +/- 2 secs Prediction of 2012 Jul 10.0 Data for the target star ------------------------ * name: TYC 2486-01416-1 * constellation : Cancer * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 08 34 23.3508 DE: +32 44 39.208 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .021 ) * V mag [mag]: 11.7 * B mag [mag]: 12.5 * Apparent position with proper motion RA(deg): 128.7988025886 DE(deg): 32.6968744960 * Equation of equinoxes (radians) : 0.000060959212417 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (13) Egeria approx. diameter [km]: 215 approx. diameter ["]: .125 distance from Earth [AU]: 2.37900 * orbital information: orbit source: Preston date of fit: 2012 Jul 09 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1365 number of rejected observations: 136 time covered by the observations: 1904 Nov 15 - 2012 Jan 04 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.009, 100° remarks: * orbital elements for (13) Egeria : Mean anomaly = 339.55688609 deg Arg. of pericenter = 79.78983403 deg Long. of node = 43.26159155 deg Inclination = 16.54136008 deg Eccentricity = 0.08417737 Semimajor axis = 2.57689509 AU Perihelion dist = 2.35997882 AU Mag: H = 6.72, G = 0.15 Epoch of elements : MJD 56213.21500000 TDT (2012 Oct 13.215) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 13 13 Egeria 5h 10.4m UT 11.7 8 34 23.351 32 44 39.21TYC 2486-01416-1 12.5 11.6 215 8.3 2.379 4.272 3.47 28.8170 32.743 98.95 -7.92 5.1739 0.03411 -0.53421 14.57788 0.93690 -0.00524 0.00169 2000 338.79086620121010.00000 79.789834 43.261592 16.5413600.08417737 2.5768951 2.3599788 6.7 5.00.15 RATE 2.3826430 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.026 0.023 93 1.19 0.023 0 0-2-2 056118.0020121013_1416-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 26, 02:27 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org