IOTA/IOTA-ES occultation update for (89) Julia / UCAC2 18924764 event on 2008 Sep 05, 00:12 UT Visible from Brazil, Peru Summary ------- On 2008 Sep 05 UT, the 175 km diameter asteroid (89) Julia will occult a 11.4 mag star in the constellation Lupus for observers along a path across Brazil, Peru. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.1 mag to 11.9 mag (the magnitude of the asteroid) for at most 6.4 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 Sep 05, 00:14 - 2008 Sep 05, 00:16 UT * midpoint of event [JD]: 2454714.50862917 * magnitude of target star: 11.4 * magnitude drop [mag]: 1.1 * estimated maximum duration [s]: 6.4 * Moon: 26 % sunlit, 10° distance * Sun: 70° distance * rough path description: Brazil, Peru The occultation path -------------------- * approximate projected width [km]: 179 * 1 sigma uncertainty interval [path widths]: +/- 0.27 * 1 sigma uncertainty interval [seconds]: +/- 2.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .033 +/- .024) * 1 sigma uncertainty ellipse (major, minor, PA): ( .033", .024", 93° ) * approx speed of asteroid's shadow [km/s]: 27.4144 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 18924764 by 89 Julia on 2008 Sep 5 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 - 95 0 0 -15 14 12 0 14 7 61 233 -1 -16 4 3 -14 24 11 -16 30 55 -13 57 5 - 94 0 0 -15 0 15 0 14 10 60 233 -2 -15 50 12 -14 10 7 -16 17 7 -13 42 59 - 93 0 0 -14 45 45 0 14 14 59 234 -3 -15 35 48 -13 55 30 -16 2 46 -13 28 18 - 92 0 0 -14 30 41 0 14 17 58 234 -3 -15 20 52 -13 40 21 -15 47 53 -13 13 5 - 91 0 0 -14 15 5 0 14 21 57 235 -4 -15 5 22 -13 24 37 -15 32 28 -12 57 18 - 90 0 0 -13 58 56 0 14 25 56 235 -5 -14 49 20 -13 8 21 -15 16 29 -12 40 58 - 89 0 0 -13 42 14 0 14 28 55 235 -6 -14 32 45 -12 51 32 -14 59 58 -12 24 5 - 88 0 0 -13 24 59 0 14 32 54 235 -7 -14 15 38 -12 34 10 -14 42 54 -12 6 38 - 87 0 0 -13 7 11 0 14 35 53 235 -8 -13 57 57 -12 16 14 -14 25 18 -11 48 39 - 86 0 0 -12 48 51 0 14 39 52 236 -9 -13 39 44 -11 57 46 -14 7 9 -11 30 6 - 85 0 0 -12 29 57 0 14 42 51 236 -10 -13 20 59 -11 38 45 -13 48 28 -11 11 1 - 84 0 0 -12 10 32 0 14 45 50 236 -11 -13 1 41 -11 19 11 -13 29 15 -10 51 23 - 83 0 0 -11 50 33 0 14 49 49 236 -12 -12 41 51 -10 59 4 -13 9 29 -10 31 12 - 82 0 0 -11 30 3 0 14 52 48 236 -13 -12 21 29 -10 38 25 -12 49 11 -10 10 28 - 81 0 0 -11 9 0 0 14 55 47 236 -14 -12 0 34 -10 17 14 -12 28 21 - 9 49 12 - 80 0 0 -10 47 25 0 14 58 46 236 -15 -11 39 7 - 9 55 31 -12 6 59 - 9 27 24 - 79 0 0 -10 25 18 0 15 2 45 236 -16 -11 17 9 - 9 33 15 -11 45 5 - 9 5 4 - 78 0 0 -10 2 39 0 15 5 44 236 -17 -10 54 39 - 9 10 27 -11 22 40 - 8 42 11 - 77 0 0 - 9 39 29 0 15 8 43 237 -18 -10 31 38 - 8 47 8 -10 59 43 - 8 18 48 - 76 0 0 - 9 15 47 0 15 11 42 237 -19 -10 8 5 - 8 23 18 -10 36 15 - 7 54 52 - 75 0 0 - 8 51 35 0 15 14 41 237 -20 - 9 44 2 - 7 58 57 -10 12 16 - 7 30 26 - 74 0 0 - 8 26 52 0 15 17 40 237 -21 - 9 19 27 - 7 34 4 - 9 47 47 - 7 5 29 - 73 0 0 - 8 1 38 0 15 19 39 237 -22 - 8 54 23 - 7 8 41 - 9 22 47 - 6 40 1 - 72 0 0 - 7 35 54 0 15 22 38 237 -23 - 8 28 48 - 6 42 49 - 8 57 17 - 6 14 3 - 71 0 0 - 7 9 40 0 15 25 37 237 -24 - 8 2 43 - 6 16 26 - 8 31 17 - 5 47 35 - 70 0 0 - 6 42 57 0 15 28 36 237 -25 - 7 36 9 - 5 49 34 - 8 4 48 - 5 20 38 - 69 0 0 - 6 15 45 0 15 30 35 237 -26 - 7 9 6 - 5 22 12 - 7 37 50 - 4 53 12 - 68 0 0 - 5 48 5 0 15 33 33 237 -27 - 6 41 35 - 4 54 23 - 7 10 23 - 4 25 17 - 67 0 0 - 5 19 56 0 15 35 32 237 -28 - 6 13 35 - 4 26 5 - 6 42 29 - 3 56 55 - 66 0 0 - 4 51 20 0 15 38 31 237 -29 - 5 45 8 - 3 57 20 - 6 14 6 - 3 28 4 - 65 0 0 - 4 22 17 0 15 40 30 237 -30 - 5 16 13 - 3 28 7 - 5 45 16 - 2 58 47 - 64 0 0 - 3 52 47 0 15 43 29 237 -30 - 4 46 52 - 2 58 29 - 5 16 0 - 2 29 3 - 63 0 0 - 3 22 51 0 15 45 28 237 -31 - 4 17 5 - 2 28 24 - 4 46 18 - 1 58 54 - 62 0 0 - 2 52 30 0 15 47 27 237 -32 - 3 46 53 - 1 57 54 - 4 16 10 - 1 28 19 - 61 0 0 - 2 21 44 0 15 49 26 237 -33 - 3 16 16 - 1 27 0 - 3 45 37 - 0 57 20 - 60 0 0 - 1 50 34 0 15 51 25 237 -34 - 2 45 14 - 0 55 41 - 3 14 40 - 0 25 57 - 59 0 0 - 1 19 1 0 15 53 23 237 -35 - 2 13 49 - 0 24 0 - 2 43 20 0 5 49 - 58 0 0 - 0 47 6 0 15 55 22 237 -36 - 1 42 2 0 8 4 - 2 11 37 0 37 57 - 57 0 0 - 0 14 48 0 15 57 21 237 -37 - 1 9 53 0 40 29 - 1 39 32 1 10 27 - 56 0 0 0 17 50 0 15 58 20 237 -38 - 0 37 22 1 13 15 - 1 7 6 1 43 17 - 55 0 0 0 50 48 0 16 0 19 237 -39 - 0 4 31 1 46 21 - 0 34 19 2 16 27 - 54 0 0 1 24 6 0 16 1 18 237 -40 0 28 39 2 19 47 - 0 1 12 2 49 56 - 53 0 0 1 57 42 0 16 3 17 237 -41 1 2 8 2 53 30 0 32 13 3 23 44 - 52 0 0 2 31 35 0 16 4 15 237 -42 1 35 54 3 27 30 1 5 55 3 57 48 - 51 0 0 3 5 45 0 16 5 14 237 -42 2 9 58 4 1 47 1 39 55 4 32 8 - 50 0 0 3 40 11 0 16 6 13 237 -43 2 44 17 4 36 19 2 14 11 5 6 43 - 49 0 0 4 14 51 0 16 7 12 237 -44 3 18 50 5 11 5 2 48 41 5 41 33 - 48 0 0 4 49 44 0 16 8 11 237 -45 3 53 38 5 46 4 3 23 25 6 16 35 - 47 0 0 5 24 50 0 16 9 10 238 -46 4 28 38 6 21 15 3 58 23 6 51 50 - 46 0 0 6 0 7 0 16 10 9 238 -47 5 3 50 6 56 38 4 33 32 7 27 15 - 45 0 0 6 35 34 0 16 11 7 238 -47 5 39 12 7 32 10 5 8 52 8 2 50 - 44 0 0 7 11 11 0 16 11 6 238 -48 6 14 44 8 7 51 5 44 21 8 38 34 - 43 0 0 7 46 55 0 16 12 5 238 -49 6 50 24 8 43 40 6 19 59 9 14 25 - 42 0 0 8 22 47 0 16 12 4 238 -50 7 26 12 9 19 35 6 55 44 9 50 22 - 41 0 0 8 58 44 0 16 12 3 238 -50 8 2 6 9 55 36 7 31 36 10 26 25 - 40 0 0 9 34 46 0 16 13 2 238 -51 8 38 4 10 31 41 8 7 33 11 2 32 - 39 0 0 10 10 51 0 16 13 0 239 -52 9 14 7 .. .. .. 8 43 34 .. .. .. Uncertainty in time = +/- 2 secs [Prediction of 2008 Jul 23.0] Data for the target star ------------------------ * name: UCAC2 18924764 * constellation : Lupus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 15 04 00.0179 DE: -30 41 53.909 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .030, .022 ) * V mag [mag]: 11.4 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 226.1320163758 DE(deg): -30.7347209470 * Equation of equinoxes (radians) : 0.000052825509516 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (89) Julia approx. diameter [km]: 175 approx. diameter ["]: .088 distance from Earth [AU]: 2.73300 * orbital information: orbit source: Preston date of fit: 2008 Jul 23 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1004 number of rejected observations: 129 time covered by the observations: 1907 Sep 09 - 2008 Jun 14 1 sigma uncertainty ellipse (major, minor, PA): 0.014, 0.008, 104° remarks: * orbital elements for (89) Julia : Mean anomaly = 277.99722631 deg Arg. of pericenter = 44.83333323 deg Long. of node = 311.64423526 deg Inclination = 16.14286273 deg Eccentricity = 0.18396469 Semimajor axis = 2.55027023 AU Perihelion dist = 2.08111055 AU Mag: H = 6.70, G = 0.15 Epoch of elements : MJD 54714.00900000 TDT (2008 Sep 05.009) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Sep 5 89 Julia 0h 12.4m UT 11.4 15 4 0.018-30 41 53.91UCAC2 18924764 0.0 11.9 175 6.4 2.733 3.859 -0.63 -121.5880 -30.698 176.58 6.75 0.2071 0.00193 0.22094 15.47226 -0.19383 0.00488 -0.00190 2000 277.0270272008 9 1.00000 44.833333311.644235 16.1428630.18396469 2.5502702 2.0811106 6.6 5.00.15 RATE 2.4200520 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.033 0.024 93 1.27 0.024 0 54670.5020080905_924764 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Jul 26, 15:25 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org