IOTA/IOTA-ES occultation update for (1755) Lorbach / TYC 1312-02380-1 event on 2008 May 09, 00:51 UT Visible from Bahamas, Florida Summary ------- On 2008 May 09 UT, the 28 km diameter asteroid (1755) Lorbach will occult a 10.4 mag star in the constellation Taurus for observers along a path across Bahamas, Florida. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.3 mag to 16.7 mag (the magnitude of the asteroid) for at most 0.7 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: 24 * date and approx. time of event: 2008 May 09, 00:53 - 2008 May 09, 00:54 UT * midpoint of event [JD]: 2454595.53575 * magnitude of target star: 10.4 * magnitude drop [mag]: 6.3 * estimated maximum duration [s]: 0.7 * Moon: 18 % sunlit, 15° distance * Sun: 40° distance * rough path description: Bahamas, Florida The occultation path -------------------- * approximate projected width [km]: 29 * 1 sigma uncertainty interval [path widths]: +/- 2.83 * 1 sigma uncertainty interval [seconds]: +/- 2.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .032 +/- .031) * 1 sigma uncertainty ellipse (major, minor, PA): ( .032", .031", 87° ) * approx speed of asteroid's shadow [km/s]: 39.8401 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1312-02380-1 by 1755 Lorbach on 2008 May 9 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 - 94 0 0 27 27 52 0 53 34 35 271 -1 27 19 56 27 35 48 26 35 8 28 20 48 - 93 0 0 27 17 35 0 53 36 34 272 -2 27 9 39 27 25 32 26 24 48 28 10 33 - 92 0 0 27 7 3 0 53 37 33 272 -3 26 59 6 27 14 59 26 14 13 28 0 4 - 91 0 0 26 56 15 0 53 39 33 273 -3 26 48 18 27 4 12 26 3 23 27 49 19 - 90 0 0 26 45 12 0 53 40 32 273 -4 26 37 15 26 53 10 25 52 17 27 38 19 - 89 0 0 26 33 55 0 53 41 31 274 -5 26 25 57 26 41 53 25 40 57 27 27 4 - 88 0 0 26 22 22 0 53 43 30 274 -6 26 14 24 26 30 21 25 29 21 27 15 34 - 87 0 0 26 10 35 0 53 44 29 275 -7 26 2 36 26 18 34 25 17 31 27 3 50 - 86 0 0 25 58 33 0 53 45 28 275 -8 25 50 34 26 6 32 25 5 26 26 51 51 - 85 0 0 25 46 17 0 53 47 27 276 -9 25 38 17 25 54 17 24 53 7 26 39 38 - 84 0 0 25 33 46 0 53 48 26 276 -10 25 25 46 25 41 47 24 40 34 26 27 10 - 83 0 0 25 21 2 0 53 49 25 277 -11 25 13 1 25 29 3 24 27 47 26 14 29 - 82 0 0 25 8 3 0 53 50 24 277 -12 25 0 2 25 16 4 24 14 45 26 1 33 - 81 0 0 24 54 51 0 53 51 23 278 -13 24 46 50 25 2 53 24 1 30 25 48 24 - 80 0 0 24 41 25 0 53 52 22 278 -13 24 33 23 24 49 27 23 48 2 25 35 1 - 79 0 0 24 27 46 0 53 53 21 279 -14 24 19 44 24 35 48 23 34 19 25 21 24 - 78 0 0 24 13 53 0 53 54 21 279 -15 24 5 51 24 21 56 23 20 24 25 7 34 - 77 0 0 23 59 48 0 53 55 20 280 -16 23 51 45 24 7 51 23 6 16 24 53 32 - 76 0 0 23 45 29 0 53 56 19 280 -17 23 37 26 23 53 33 22 51 55 24 39 16 - 75 0 0 23 30 58 0 53 57 18 280 -18 23 22 55 23 39 3 22 37 21 24 24 48 - 74 0 0 23 16 15 0 53 58 17 281 -19 23 8 11 23 24 20 22 22 35 24 10 7 - 73 0 0 23 1 19 0 53 58 16 281 -20 22 53 15 23 9 24 22 7 37 23 55 14 - 72 0 0 22 46 12 0 53 59 15 282 -21 22 38 7 22 54 17 21 52 27 23 40 9 - 71 0 0 22 30 53 0 54 0 14 282 -22 22 22 47 22 38 58 21 37 5 23 24 53 - 70 0 0 22 15 22 0 54 1 13 282 -23 22 7 16 22 23 28 21 21 32 23 9 25 - 69 0 0 21 59 40 0 54 1 12 283 -24 21 51 34 22 7 47 21 5 48 22 53 45 - 68 0 0 21 43 48 0 54 2 11 283 -25 21 35 41 21 51 54 20 49 52 22 37 55 - 67 0 0 21 27 44 0 54 2 10 284 -26 21 19 37 21 35 51 20 33 47 22 21 54 - 66 0 0 21 11 30 0 54 3 9 284 -26 21 3 23 21 19 38 20 17 31 22 5 42 - 65 0 0 20 55 6 0 54 3 8 284 -27 20 46 59 21 3 14 20 1 4 21 49 20 - 64 0 0 20 38 33 0 54 3 7 285 -28 20 30 25 20 46 41 19 44 29 21 32 49 - 63 0 0 20 21 49 0 54 4 6 285 -29 20 13 41 20 29 58 19 27 43 21 16 8 - 62 0 0 20 4 57 0 54 4 5 285 -30 19 56 48 20 13 6 19 10 49 20 59 17 - 61 0 0 19 47 55 0 54 4 4 286 -31 19 39 47 19 56 4 18 53 45 20 42 18 - 60 0 0 19 30 45 0 54 4 3 286 -32 19 22 36 19 38 55 18 36 34 20 25 10 - 59 0 0 19 13 27 0 54 5 2 286 -33 19 5 18 19 21 37 .. .. .. 20 7 53 - 58 0 0 18 56 1 0 54 5 1 287 -34 18 47 51 19 4 11 .. .. .. 19 50 29 - 57 0 0 18 38 27 0 54 5 0 287 -35 18 30 17 18 46 37 .. .. .. 19 32 57 Uncertainty in time = +/- 2 secs [Prediction of 2008 Mar 31.0] Data for the target star ------------------------ * name: TYC 1312-02380-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 05 52 54.9855 DE: +16 13 21.382 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .027 ) * V mag [mag]: 10.4 * B mag [mag]: 10.3 * Apparent position with proper motion RA(deg): 88.3477440919 DE(deg): 16.2255102380 * Equation of equinoxes (radians) : 0.000040125559941 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1755) Lorbach approx. diameter [km]: 28 approx. diameter ["]: .011 distance from Earth [AU]: 3.64900 * orbital information: orbit source: Preston date of fit: 2008 Feb 16 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 762 number of rejected observations: 30 time covered by the observations: 1936 Nov 08 - 2008 Feb 09 1 sigma uncertainty ellipse (major, minor, PA): 0.023, 0.015, 84° remarks: * orbital elements for (1755) Lorbach : Mean anomaly = 338.03279937 deg Arg. of pericenter = 327.50026426 deg Long. of node = 157.31274056 deg Inclination = 10.69403796 deg Eccentricity = 0.04964259 Semimajor axis = 3.09144364 AU Perihelion dist = 2.93797637 AU Mag: H = 10.74, G = 0.15 Epoch of elements : MJD 54595.03600000 TDT (2008 May 09.036) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 9 1755 Lorbach 0h 51.5m UT 10.4 5 52 54.986 16 13 21.38TYC 1312-02380-1 10.3 16.7 28 0.7 3.649 3.741 5.76 -151.8560 16.221 166.25 17.41 0.8580 -0.02459 0.22628 22.35936 2.39116 0.00362 -0.00051 2000 337.1196372008 5 4.00000327.500264157.312741 10.6940380.04964259 3.0914436 2.937976410.8 5.00.15 RATE 1.8132680 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.032 0.031 87 3.83 0.031 0 54556.5020080509_2380-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 31, 04:20 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org