IOTA/IOTA-ES occultation update for (702) Alauda / TYC 1193-00257-1 event on 2008 May 16, 10:00 UT Visible from S USA, Mexico Summary ------- On 2008 May 16 UT, the 195 km diameter asteroid (702) Alauda will occult a 12.0 mag star in the constellation Andromeda for observers along a path across S USA, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.7 mag to 13.4 mag (the magnitude of the asteroid) for at most 4.9 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: 99 * date and approx. time of event: 2008 May 16, 10:00 - 2008 May 16, 10:00 UT * midpoint of event [JD]: 2454602.91789167 * magnitude of target star: 12.0 * magnitude drop [mag]: 1.7 * estimated maximum duration [s]: 4.9 * Moon: 88 % sunlit, 168° distance * Sun: 41° distance * rough path description: S USA, Mexico The occultation path -------------------- * approximate projected width [km]: 306 * 1 sigma uncertainty interval [path widths]: +/- 0.32 * 1 sigma uncertainty interval [seconds]: +/- 1.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .028 +/- .020) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .020", 87° ) * approx speed of asteroid's shadow [km/s]: 40.1249 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1193-00257-1 by 702 Alauda on 2008 May 16 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude -105 57 57 19 48 14 10 0 6 6 69 -31 ... .. .. .. .. .. -101 8 54 20 54 13 ... .. .. .. .. .. - 98 53 33 21 15 45 -102 5 34 21 57 56 10 0 9 10 70 -27 -107 27 10 20 38 48 - 98 31 26 22 32 16 ... .. .. .. .. .. - 96 36 43 22 44 51 - 99 25 54 23 37 24 10 0 11 13 71 -24 -103 14 45 22 57 21 - 96 23 14 23 58 2 -106 37 45 22 8 7 - 94 40 21 24 5 21 - 97 17 0 25 3 58 10 0 14 15 72 -22 -100 30 14 24 39 23 - 94 32 34 25 16 25 -102 59 39 24 12 49 - 92 57 28 25 20 6 - 95 26 15 26 22 54 10 0 16 17 74 -19 - 98 19 24 26 7 19 - 92 53 53 26 29 42 -100 26 24 25 50 31 - 91 24 20 26 30 43 - 93 47 48 27 36 38 10 0 19 19 75 -18 - 96 27 49 27 27 11 - 91 24 3 27 39 14 - 98 21 57 27 16 11 - 89 58 38 27 38 8 - 92 18 21 28 46 33 10 0 22 21 75 -16 - 94 49 5 28 41 37 - 90 1 3 28 45 50 - 96 34 45 28 34 35 - 88 38 49 28 43 2 - 90 55 51 29 53 31 10 0 24 22 76 -14 - 93 19 42 29 52 8 - 88 43 32 29 50 6 - 94 59 21 29 48 2 - 87 23 49 29 45 52 - 89 38 56 30 58 8 10 0 27 24 77 -13 - 91 57 29 30 59 37 - 87 30 31 30 52 27 - 93 32 41 30 57 50 - 86 12 49 30 46 59 - 88 26 35 32 0 49 10 0 30 25 78 -11 - 90 41 0 32 4 42 - 86 21 18 31 53 11 - 92 12 46 32 4 48 - 85 5 12 31 46 38 - 87 18 3 33 1 53 10 0 32 26 79 -10 - 89 29 12 33 7 50 - 85 15 17 32 52 32 - 90 58 17 33 9 30 - 84 0 30 32 45 2 - 86 12 48 34 1 35 10 0 35 27 80 -9 - 88 21 19 34 9 20 - 84 12 3 33 50 43 - 89 48 18 34 12 21 - 82 58 20 33 42 21 - 85 10 21 35 0 7 10 0 37 28 81 -7 - 87 16 46 35 9 27 - 83 11 14 34 47 52 - 88 42 5 35 13 40 - 81 58 22 34 38 43 - 84 10 22 35 57 38 10 0 40 29 83 -6 - 86 15 7 36 8 24 - 82 12 32 35 44 9 - 87 39 5 36 13 40 - 81 0 21 35 34 16 - 83 12 32 36 54 16 10 0 43 30 84 -5 - 85 15 58 37 6 21 - 81 15 43 36 39 38 - 86 38 54 37 12 32 - 80 4 4 36 29 5 - 82 16 36 37 50 8 10 0 45 31 85 -4 - 84 19 2 38 3 25 - 80 20 34 37 34 26 - 85 41 9 38 10 28 - 79 9 19 37 23 15 - 81 22 23 38 45 20 10 0 48 31 86 -3 - 83 24 5 38 59 43 - 79 26 54 38 28 37 - 84 45 35 39 7 33 - 78 15 56 38 16 51 - 80 29 41 39 39 56 10 0 51 32 87 -2 - 82 30 52 39 55 22 - 78 34 34 39 22 17 - 83 51 56 40 3 55 - 77 23 47 39 9 57 - 79 38 22 40 34 0 10 0 53 33 88 -1 - 81 39 14 40 50 25 - 77 43 26 40 15 28 - 83 0 1 40 59 39 - 76 32 44 40 2 36 Uncertainty in time = +/- 2 secs [Prediction of 2008 Apr 21.0] Data for the target star ------------------------ * name: TYC 1193-00257-1 * constellation : Andromeda * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 00 39 08.2574 DE: +22 00 38.607 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .019 ) * V mag [mag]: 12.0 * B mag [mag]: 12.6 * Apparent position with proper motion RA(deg): 9.8924612894 DE(deg): 22.0552656155 * Equation of equinoxes (radians) : 0.000039829501092 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (702) Alauda approx. diameter [km]: 195 approx. diameter ["]: .069 distance from Earth [AU]: 3.87900 * orbital information: orbit source: Preston date of fit: 2008 Apr 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 840 number of rejected observations: 68 time covered by the observations: 1910 Jul 17 - 2008 Jan 09 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.007, 64° remarks: * orbital elements for (702) Alauda : Mean anomaly = 81.71292402 deg Arg. of pericenter = 352.51803200 deg Long. of node = 289.96767610 deg Inclination = 20.61336297 deg Eccentricity = 0.02182854 Semimajor axis = 3.19142190 AU Perihelion dist = 3.12175780 AU Mag: H = 7.20, G = 0.15 Epoch of elements : MJD 54602.41700000 TDT (2008 May 16.417) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 16 702 Alauda 10h 1.8m UT 12.0 0 39 8.257 22 0 38.61TYC 1193-00257-1 12.6 13.4 195 4.9 3.879 3.132 27.20 -15.1479 22.004 28.66 19.24 10.0294 -0.40785 0.65325 19.20924 11.99660 -0.00372 -0.00029 2000 81.2950892008 514.00000352.518032289.967676 20.6133630.02182854 3.1914219 3.1217578 7.3 5.00.15 RATE 1.7287330 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.020 87 1.32 0.022 0 54577.5020080516_0257-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 21, 17:35 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org