IOTA/IOTA-ES occultation update for (585) Bilkis / 2UCAC 37358307 event on 2008 May 19, 15:00 UT Visible from Madagascar Summary ------- On 2008 May 19 UT, the 58 km diameter asteroid (585) Bilkis will occult a 12.7 mag star in the constellation Cancer for observers along a path across Madagascar. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.4 mag to 15.0 mag (the magnitude of the asteroid) for at most 1.9 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: 44 * date and approx. time of event: 2008 May 19, 15:01 - 2008 May 19, 15:03 UT * midpoint of event [JD]: 2454606.1253125 * magnitude of target star: 12.7 * magnitude drop [mag]: 2.4 * estimated maximum duration [s]: 1.9 * Moon: 100 % sunlit, 108° distance * Sun: 67° distance * rough path description: Madagascar The occultation path -------------------- * approximate projected width [km]: 65 * 1 sigma uncertainty interval [path widths]: +/- 1.47 * 1 sigma uncertainty interval [seconds]: +/- 2.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .052 +/- .051) * 1 sigma uncertainty ellipse (major, minor, PA): ( .052", .051", 91° ) * approx speed of asteroid's shadow [km/s]: 30.7526 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 37358307 by 585 Bilkis on 2008 May 19 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 39 0 0 -13 21 51 15 1 29 58 334 0 -13 39 48 -13 3 57 -14 32 51 -12 11 34 40 0 0 -13 35 0 15 1 32 57 332 -1 -13 52 58 -13 17 4 -14 46 4 -12 24 38 41 0 0 -13 48 24 15 1 36 57 331 -2 -14 6 23 -13 30 28 -14 59 33 -12 37 59 42 0 0 -14 2 4 15 1 39 56 329 -3 -14 20 4 -13 44 6 -15 13 17 -12 51 35 43 0 0 -14 15 59 15 1 42 55 328 -4 -14 34 1 -13 58 1 -15 27 16 -13 5 26 44 0 0 -14 30 10 15 1 46 55 327 -5 -14 48 12 -14 12 10 -15 41 31 -13 19 32 45 0 0 -14 44 35 15 1 49 54 326 -6 -15 2 38 -14 26 34 -15 56 1 -13 33 53 46 0 0 -14 59 15 15 1 52 53 324 -7 -15 17 19 -14 41 13 -16 10 45 -13 48 29 47 0 0 -15 14 8 15 1 56 52 323 -8 -15 32 14 -14 56 6 -16 25 43 -14 3 18 48 0 0 -15 29 16 15 1 59 51 322 -9 -15 47 23 -15 11 12 -16 40 55 -14 18 22 49 0 0 -15 44 37 15 2 2 51 321 -10 -16 2 45 -15 26 32 -16 56 20 -14 33 39 50 0 0 -16 0 11 15 2 5 50 320 -11 -16 18 20 -15 42 5 -17 11 58 -14 49 9 51 0 0 -16 15 58 15 2 8 49 319 -12 -16 34 8 -15 57 51 -17 27 49 -15 4 52 52 0 0 -16 31 58 15 2 11 48 318 -13 -16 50 9 -16 13 50 -17 43 53 -15 20 47 53 0 0 -16 48 9 15 2 14 47 318 -14 -17 6 21 -16 30 0 -18 0 8 -15 36 55 54 0 0 -17 4 32 15 2 17 46 317 -15 -17 22 45 -16 46 22 -18 16 35 -15 53 14 55 0 0 -17 21 6 15 2 20 46 316 -16 -17 39 20 -17 2 55 -18 33 14 -16 9 44 56 0 0 -17 37 52 15 2 23 45 315 -17 -17 56 7 -17 19 40 -18 50 3 -16 26 26 57 0 0 -17 54 47 15 2 26 44 314 -18 -18 13 3 -17 36 34 -19 7 3 -16 43 17 58 0 0 -18 11 53 15 2 28 43 314 -19 -18 30 10 -17 53 39 -19 24 12 -17 0 20 59 0 0 -18 29 9 15 2 31 42 313 -20 -18 47 26 -18 10 54 -19 41 31 -17 17 31 60 0 0 -18 46 33 15 2 34 41 312 -21 -19 4 52 -18 28 18 -19 59 0 -17 34 53 61 0 0 -19 4 7 15 2 36 40 311 -22 -19 22 27 -18 45 50 -20 16 37 -17 52 23 62 0 0 -19 21 49 15 2 39 39 311 -23 -19 40 10 -19 3 32 -20 34 22 -18 10 2 63 0 0 -19 39 39 15 2 42 38 310 -24 -19 58 0 -19 21 21 -20 52 16 -18 27 48 64 0 0 -19 57 37 15 2 44 37 309 -25 -20 15 59 -19 39 18 -21 10 17 -18 45 43 65 0 0 -20 15 42 15 2 46 37 309 -26 -20 34 4 -19 57 22 -21 28 25 -19 3 45 66 0 0 -20 33 53 15 2 49 36 308 -27 -20 52 17 -20 15 32 -21 46 39 -19 21 53 67 0 0 -20 52 11 15 2 51 35 308 -28 -21 10 35 -20 33 49 -22 5 0 -19 40 8 68 0 0 -21 10 34 15 2 53 34 307 -29 -21 29 0 -20 52 12 -22 23 26 -19 58 29 69 0 0 -21 29 3 15 2 56 33 306 -30 -21 47 29 -21 10 41 -22 41 58 -20 16 55 70 0 0 -21 47 37 15 2 58 32 306 -31 -22 6 4 -21 29 14 -23 0 35 -20 35 27 71 0 0 -22 6 16 15 3 0 31 305 -32 -22 24 43 -21 47 52 -23 19 15 -20 54 3 72 0 0 -22 24 58 15 3 2 30 305 -33 -22 43 26 -22 6 34 -23 38 0 -21 12 43 73 0 0 -22 43 44 15 3 4 29 304 -34 -23 2 12 -22 25 19 -23 56 48 -21 31 27 74 0 0 -23 2 33 15 3 6 28 304 -35 -23 21 2 -22 44 8 -24 15 39 -21 50 14 75 0 0 -23 21 25 15 3 7 27 303 -36 -23 39 54 -23 2 59 -24 34 33 -22 9 4 76 0 0 -23 40 19 15 3 9 26 303 -37 -23 58 49 -23 21 52 -24 53 29 -22 27 56 77 0 0 -23 59 15 15 3 11 25 302 -38 -24 17 45 -23 40 48 -25 12 26 -22 46 50 78 0 0 -24 18 12 15 3 13 24 302 -39 -24 36 42 -23 59 44 -25 31 24 -23 5 46 79 0 0 -24 37 10 15 3 14 23 301 -40 -24 55 40 -24 18 42 -25 50 24 -23 24 43 80 0 0 -24 56 8 15 3 16 22 301 -41 -25 14 39 -24 37 40 -26 9 23 -23 43 40 81 0 0 -25 15 6 15 3 17 22 300 -42 -25 33 37 -24 56 38 -26 28 22 -24 2 37 82 0 0 -25 34 4 15 3 18 21 300 -43 -25 52 36 -25 15 36 -26 47 21 -24 21 35 83 0 0 -25 53 1 15 3 20 20 299 -44 -26 11 33 -25 34 33 -27 6 19 -24 40 31 84 0 0 -26 11 57 15 3 21 19 299 -44 -26 30 28 -25 53 28 -27 25 15 -24 59 26 85 0 0 -26 30 51 15 3 22 18 298 -45 -26 49 22 -26 12 22 -27 44 9 -25 18 20 86 0 0 -26 49 42 15 3 23 17 298 -46 -27 8 14 -26 31 14 -28 3 1 -25 37 11 87 0 0 -27 8 31 15 3 24 16 297 -47 -27 27 3 -26 50 3 -28 21 50 -25 56 0 88 0 0 -27 27 17 15 3 25 15 297 -48 -27 45 49 -27 8 49 -28 40 35 -26 14 46 89 0 0 -27 46 0 15 3 26 14 296 -49 -28 4 31 -27 27 31 -28 59 18 -26 33 29 90 0 0 -28 4 38 15 3 27 13 296 -50 -28 23 10 -27 46 10 -29 17 56 -26 52 8 91 0 0 -28 23 13 15 3 28 12 295 -51 -28 41 44 -28 4 45 -29 36 30 -27 10 43 92 0 0 -28 41 43 15 3 29 11 295 -52 -29 0 14 -28 23 14 -29 54 58 -27 29 14 93 0 0 -29 0 7 15 3 30 10 294 -52 -29 18 38 -28 41 39 -30 13 22 -27 47 39 94 0 0 -29 18 27 15 3 30 9 294 -53 -29 36 57 -28 59 59 -30 31 40 -28 6 0 95 0 0 -29 36 40 15 3 31 8 293 -54 -29 55 10 -29 18 13 -30 49 53 -28 24 15 96 0 0 -29 54 47 15 3 31 7 293 -55 -30 13 17 -29 36 21 -31 7 58 -28 42 23 97 0 0 -30 12 48 15 3 32 7 292 -56 -30 31 18 -29 54 22 -31 25 58 -29 0 26 98 0 0 -30 30 42 15 3 32 6 292 -57 -30 49 11 -30 12 16 -31 43 50 -29 18 22 99 0 0 -30 48 29 15 3 32 5 291 -57 -31 6 58 -30 30 3 -32 1 35 -29 36 10 100 0 0 -31 6 8 15 3 33 4 291 -58 -31 24 36 -30 47 43 -32 19 12 -29 53 51 101 0 0 -31 23 40 15 3 33 3 290 -59 -31 42 7 -31 5 15 -32 36 41 .. .. .. 102 0 0 -31 41 3 15 3 33 2 290 -60 -31 59 30 -31 22 39 -32 54 2 .. .. .. 103 0 0 -31 58 17 15 3 33 1 289 -60 -32 16 44 -31 39 54 -33 11 14 .. .. .. 104 0 0 -32 15 23 15 3 33 0 289 -61 -32 33 49 -31 57 1 .. .. .. .. .. .. Uncertainty in time = +/- 3 secs [Prediction of 2008 Apr 18.0] Data for the target star ------------------------ * name: 2UCAC 37358307 * constellation : Cancer * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 08 30 58.7076 DE: +15 32 01.527 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .050, .050 ) * V mag [mag]: 12.7 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 127.8628580232 DE(deg): 15.5063173711 * Equation of equinoxes (radians) : 0.000039638390919 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (585) Bilkis approx. diameter [km]: 58 approx. diameter ["]: .035 distance from Earth [AU]: 2.28800 * orbital information: orbit source: Preston date of fit: 2008 Apr 18 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1062 number of rejected observations: 80 time covered by the observations: 1906 Feb 16 - 2008 Feb 27 1 sigma uncertainty ellipse (major, minor, PA): 0.014, 0.010, 97° remarks: * orbital elements for (585) Bilkis : Mean anomaly = 3.03519880 deg Arg. of pericenter = 327.90004169 deg Long. of node = 180.36579122 deg Inclination = 7.55662318 deg Eccentricity = 0.12939342 Semimajor axis = 2.43058710 AU Perihelion dist = 2.11608513 AU Mag: H = 10.30, G = 0.15 Epoch of elements : MJD 54605.62500000 TDT (2008 May 19.625) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 19 585 Bilkis 15h 0.5m UT 12.7 8 30 58.708 15 32 1.532UCAC 37358307 0.0 15.0 58 1.9 2.288 4.575 -8.72 24.9785 15.536 -45.98 19.94 15.0075 -0.05739 -0.43460 17.20897 -2.26693 0.00464 -0.00128 2000 1.5721472008 514.00000327.900042180.365791 7.5566230.12939342 2.4305871 2.116085110.4 5.00.15 RATE 2.6009810 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.052 0.051 91 2.47 0.051 0 54574.5020080519_358307 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 18, 17:50 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org