IOTA/IOTA-ES occultation update for (852) Wladilena / TYC 1821-00874-1 event on 2008 Jul 02, 23:02 UT Visible from India Summary ------- On 2008 Jul 02 UT, the 31 km diameter asteroid (852) Wladilena will occult a 9.1 mag star in the constellation Taurus for observers along a path across India. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.8 mag to 14.9 mag (the magnitude of the asteroid) for at most 0.8 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: 49 * date and approx. time of event: 2008 Jul 02, 23:01 - 2008 Jul 02, 23:01 UT * midpoint of event [JD]: 2454650.46041667 * magnitude of target star: 9.1 * magnitude drop [mag]: 5.8 * estimated maximum duration [s]: 0.8 * Moon: 0 % sunlit, 37° distance * Sun: 39° distance * rough path description: India The occultation path -------------------- * approximate projected width [km]: 43 * 1 sigma uncertainty interval [path widths]: +/- 1.30 * 1 sigma uncertainty interval [seconds]: +/- 0.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .018 +/- .018) * 1 sigma uncertainty ellipse (major, minor, PA): ( .018", .018", 70° ) * approx speed of asteroid's shadow [km/s]: 39.9725 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1821-00874-1 by 852 Wladilena on 2008 Jul 2 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 54 19 36 17 0 0 23 1 4 0 62 -35 54 45 1 ... .. .. ... .. .. ... .. .. 56 13 6 18 0 0 23 1 4 2 63 -33 56 37 35 55 48 24 ... .. .. 54 43 3 Latitude Latitude Latitude Latitude 57 0 0 18 25 42 23 1 4 3 63 -32 18 12 19 18 39 9 .. .. .. 19 14 22 58 0 0 18 59 21 23 1 4 4 63 -31 18 45 52 19 12 54 .. .. .. 19 48 24 59 0 0 19 33 52 23 1 5 5 63 -30 19 20 17 19 47 31 18 45 13 20 23 18 60 0 0 20 9 15 23 1 5 6 64 -29 19 55 33 20 23 0 19 20 13 20 59 4 61 0 0 20 45 29 23 1 6 7 64 -28 20 31 40 20 59 21 19 56 4 21 35 43 62 0 0 21 22 33 23 1 6 8 65 -27 21 8 38 21 36 33 20 32 44 22 13 13 63 0 0 22 0 29 23 1 7 10 65 -26 21 46 26 22 14 35 21 10 15 22 51 33 64 0 0 22 39 14 23 1 8 11 65 -25 22 25 4 22 53 27 21 48 35 23 30 45 65 0 0 23 18 48 23 1 9 12 66 -24 23 4 31 23 33 8 22 27 43 24 10 46 66 0 0 23 59 11 23 1 10 13 66 -22 23 44 47 24 13 39 23 7 40 24 51 37 67 0 0 24 40 21 23 1 11 14 67 -21 24 25 50 24 54 57 23 48 23 25 33 16 68 0 0 25 22 19 23 1 12 15 67 -20 25 7 40 25 37 3 24 29 54 26 15 43 69 0 0 26 5 3 23 1 13 16 68 -19 25 50 15 26 19 55 25 12 9 26 58 56 70 0 0 26 48 32 23 1 14 17 68 -18 26 33 36 27 3 32 25 55 10 27 42 56 71 0 0 27 32 45 23 1 15 18 69 -17 27 17 41 27 47 53 26 38 54 28 27 39 72 0 0 28 17 41 23 1 17 20 69 -15 28 2 28 28 32 58 27 23 20 29 13 7 73 0 0 29 3 18 23 1 18 21 70 -14 28 47 57 29 18 44 28 8 27 29 59 16 74 0 0 29 49 35 23 1 20 22 71 -13 29 34 6 30 5 10 28 54 14 30 46 6 75 0 0 30 36 31 23 1 22 23 71 -12 30 20 53 30 52 15 29 40 39 31 33 35 76 0 0 31 24 4 23 1 24 24 72 -11 31 8 17 31 39 57 30 27 40 32 21 41 77 0 0 32 12 12 23 1 25 25 73 -10 31 56 16 32 28 14 31 15 16 33 10 23 78 0 0 33 0 53 23 1 27 26 74 -9 32 44 48 33 17 4 32 3 25 33 59 38 79 0 0 33 50 6 23 1 29 27 74 -7 33 33 51 34 6 26 32 52 6 34 49 25 80 0 0 34 39 47 23 1 32 28 75 -6 34 23 24 34 56 17 33 41 15 35 39 41 81 0 0 35 29 56 23 1 34 29 76 -5 35 13 23 35 46 35 34 30 51 36 30 24 82 0 0 36 20 29 23 1 36 30 77 -4 36 3 47 36 37 17 35 20 51 37 21 32 83 0 0 37 11 24 23 1 38 31 78 -3 36 54 32 37 28 22 36 11 14 38 13 2 84 0 0 38 2 38 23 1 41 32 79 -2 37 45 37 38 19 45 37 1 56 39 4 51 85 0 0 38 54 9 23 1 43 33 80 -1 38 36 59 39 11 26 37 52 55 39 56 57 Uncertainty in time = +/- 1 secs [Prediction of 2008 May 22.0] Data for the target star ------------------------ * name: TYC 1821-00874-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 58 19.4680 DE: +26 44 28.855 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .012, .016 ) * V mag [mag]: 9.1 * B mag [mag]: 9.5 * Apparent position with proper motion RA(deg): 59.7088916024 DE(deg): 26.7662023071 * Equation of equinoxes (radians) : 0.000050507951150 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (852) Wladilena approx. diameter [km]: 31 approx. diameter ["]: .014 distance from Earth [AU]: 2.98100 * orbital information: orbit source: Preston date of fit: 2008 May 22 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 685 number of rejected observations: 44 time covered by the observations: 1913 Sep 28 - 2007 Jul 16 1 sigma uncertainty ellipse (major, minor, PA): 0.014, 0.010, 55° remarks: * orbital elements for (852) Wladilena : Mean anomaly = 66.95785627 deg Arg. of pericenter = 282.31332767 deg Long. of node = 27.38331716 deg Inclination = 23.02692518 deg Eccentricity = 0.27382865 Semimajor axis = 2.36275160 AU Perihelion dist = 1.71576253 AU Mag: H = 9.93, G = 0.15 Epoch of elements : MJD 54649.96000000 TDT (2008 Jul 02.960) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Jul 2 852 Wladilena 23h 3.0m UT 9.1 3 58 19.468 26 44 28.86TYC 1821-00874-1 9.5 14.9 31 0.8 2.981 4.529 27.39 152.4784 26.734 -164.69 22.95 23.0500 -0.28182 0.62462 20.56290 9.28402 -0.00334 -0.00024 2000 64.2549172008 623.00000282.313328 27.383317 23.0269250.27382865 2.3627516 1.7157625 9.9 5.00.15 RATE 2.7137940 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.018 0.018 70 2.30 0.019 0 54608.5020080702_0874-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 26, 14:38 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org