IOTA/IOTA-ES occultation update for (923) Herluga / TYC 0627-00511-1 event on 2008 Jul 05, 09:35 UT Visible from SW USA, Mexico Summary ------- On 2008 Jul 05 UT, the 37 km diameter asteroid (923) Herluga will occult a 9.6 mag star in the constellation Pisces for observers along a path across SW USA, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.5 mag to 16.1 mag (the magnitude of the asteroid) for at most 1.3 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: 47 * date and approx. time of event: 2008 Jul 05, 09:31 - 2008 Jul 05, 09:33 UT * midpoint of event [JD]: 2454652.89934167 * magnitude of target star: 9.6 * magnitude drop [mag]: 6.5 * estimated maximum duration [s]: 1.3 * Moon: 7 % sunlit, 106° distance * Sun: 75° distance * rough path description: SW USA, Mexico The occultation path -------------------- * approximate projected width [km]: 44 * 1 sigma uncertainty interval [path widths]: +/- 1.39 * 1 sigma uncertainty interval [seconds]: +/- 2.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .050 +/- .031) * 1 sigma uncertainty ellipse (major, minor, PA): ( .050", .031", 87° ) * approx speed of asteroid's shadow [km/s]: 27.6138 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0627-00511-1 by 923 Herluga on 2008 Jul 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 -136 0 0 20 2 29 9 31 50 1 74 -47 19 49 58 20 15 1 .. .. .. 20 50 4 -135 0 0 20 18 50 9 31 50 2 75 -47 20 6 18 20 31 24 .. .. .. 21 6 30 -134 0 0 20 35 30 9 31 50 3 75 -46 20 22 57 20 48 5 .. .. .. 21 23 14 -133 0 0 20 52 27 9 31 50 4 76 -46 20 39 52 21 5 3 .. .. .. 21 40 16 -132 0 0 21 9 41 9 31 51 5 76 -45 20 57 5 21 22 18 20 22 14 21 57 34 -131 0 0 21 27 11 9 31 51 6 76 -45 21 14 35 21 39 50 20 39 41 22 15 9 -130 0 0 21 44 58 9 31 52 6 77 -44 21 32 20 21 57 38 20 57 23 22 33 1 -129 0 0 22 3 1 9 31 52 7 77 -44 21 50 22 22 15 42 21 15 21 22 51 8 -128 0 0 22 21 19 9 31 53 8 77 -43 22 8 39 22 34 2 21 33 35 23 9 31 -127 0 0 22 39 53 9 31 54 9 78 -42 22 27 11 22 52 36 21 52 4 23 28 9 -126 0 0 22 58 41 9 31 55 10 78 -42 22 45 58 23 11 26 22 10 48 23 47 2 -125 0 0 23 17 43 9 31 55 11 79 -41 23 4 59 23 30 29 22 29 46 24 6 9 -124 0 0 23 36 59 9 31 56 12 79 -41 23 24 14 23 49 46 22 48 58 24 25 29 -123 0 0 23 56 29 9 31 57 13 79 -40 23 43 42 24 9 17 23 8 23 24 45 3 -122 0 0 24 16 11 9 31 59 14 80 -39 24 3 23 24 29 0 23 28 0 25 4 49 -121 0 0 24 36 5 9 32 0 15 80 -39 24 23 17 24 48 56 23 47 51 25 24 48 -120 0 0 24 56 11 9 32 1 16 81 -38 24 43 22 25 9 3 24 7 53 25 44 59 -119 0 0 25 16 29 9 32 2 17 81 -37 25 3 38 25 29 22 24 28 6 26 5 20 -118 0 0 25 36 57 9 32 4 18 82 -37 25 24 6 25 49 51 24 48 31 26 25 53 -117 0 0 25 57 36 9 32 5 19 82 -36 25 44 43 26 10 31 25 9 6 26 46 36 -116 0 0 26 18 25 9 32 7 20 83 -35 26 5 31 26 31 20 25 29 50 27 7 28 -115 0 0 26 39 22 9 32 8 21 83 -34 26 26 28 26 52 19 25 50 44 27 28 30 -114 0 0 27 0 29 9 32 10 22 84 -34 26 47 33 27 13 27 26 11 47 27 49 40 -113 0 0 27 21 43 9 32 12 23 85 -33 27 8 47 27 34 42 26 32 58 28 10 58 -112 0 0 27 43 5 9 32 14 24 85 -32 27 30 8 27 56 5 26 54 17 28 32 24 -111 0 0 28 4 35 9 32 16 25 86 -31 27 51 36 28 17 35 27 15 43 28 53 56 -110 0 0 28 26 10 9 32 18 25 86 -30 28 13 11 28 39 12 27 37 15 29 15 35 -109 0 0 28 47 51 9 32 20 26 87 -30 28 34 51 29 0 54 27 58 53 29 37 20 -108 0 0 29 9 38 9 32 22 27 88 -29 28 56 37 29 22 41 28 20 37 29 59 9 -107 0 0 29 31 30 9 32 24 28 88 -28 29 18 28 29 44 33 28 42 25 30 21 4 -106 0 0 29 53 25 9 32 26 29 89 -27 29 40 23 30 6 30 29 4 18 30 43 2 -105 0 0 30 15 24 9 32 28 30 90 -26 30 2 21 30 28 29 29 26 15 31 5 4 -104 0 0 30 37 26 9 32 31 31 90 -26 30 24 22 30 50 32 29 48 14 31 27 8 -103 0 0 30 59 30 9 32 33 32 91 -25 30 46 26 31 12 37 30 10 16 31 49 14 -102 0 0 31 21 36 9 32 35 33 92 -24 31 8 31 31 34 43 30 32 20 32 11 23 -101 0 0 31 43 43 9 32 38 33 93 -23 31 30 38 31 56 51 30 54 26 32 33 32 -100 0 0 32 5 51 9 32 40 34 93 -22 31 52 45 32 18 59 31 16 32 32 55 41 - 99 0 0 32 27 59 9 32 43 35 94 -21 32 14 52 32 41 7 31 38 38 33 17 50 - 98 0 0 32 50 6 9 32 46 36 95 -20 32 36 59 33 3 15 32 0 43 33 39 59 - 97 0 0 33 12 12 9 32 48 37 96 -20 32 59 5 33 25 21 32 22 48 34 2 6 - 96 0 0 33 34 16 9 32 51 37 97 -19 33 21 9 33 47 25 32 44 51 34 24 11 - 95 0 0 33 56 18 9 32 54 38 98 -18 33 43 10 34 9 27 33 6 52 34 46 14 - 94 0 0 34 18 17 9 32 56 39 99 -17 34 5 9 34 31 26 33 28 50 35 8 14 - 93 0 0 34 40 12 9 32 59 40 100 -16 34 27 4 34 53 22 33 50 45 35 30 10 - 92 0 0 35 2 4 9 33 2 41 101 -15 34 48 56 35 15 14 34 12 37 35 52 1 - 91 0 0 35 23 51 9 33 5 41 102 -14 35 10 43 35 37 1 34 34 23 36 13 48 - 90 0 0 35 45 32 9 33 8 42 103 -14 35 32 25 35 58 42 34 56 5 36 35 30 - 89 0 0 36 7 9 9 33 11 43 104 -13 35 54 1 36 20 19 35 17 42 36 57 6 - 88 0 0 36 28 39 9 33 14 43 105 -12 36 15 31 36 41 49 35 39 12 37 18 36 - 87 0 0 36 50 2 9 33 17 44 106 -11 36 36 55 37 3 12 36 0 36 37 39 59 - 86 0 0 37 11 19 9 33 20 45 107 -10 36 58 11 37 24 28 36 21 54 38 1 14 - 85 0 0 37 32 27 9 33 23 45 109 -9 37 19 20 37 45 36 36 43 3 38 22 22 - 84 0 0 37 53 28 9 33 26 46 110 -9 37 40 21 38 6 37 37 4 5 38 43 21 - 83 0 0 38 14 20 9 33 29 47 111 -8 38 1 14 38 27 28 37 24 59 39 4 12 - 82 0 0 38 35 3 9 33 32 47 112 -7 38 21 57 38 48 11 37 45 43 39 24 53 - 81 0 0 38 55 37 9 33 35 48 114 -6 38 42 31 39 8 44 38 6 19 39 45 25 - 80 0 0 39 16 0 9 33 38 48 115 -5 39 2 55 39 29 8 38 26 44 40 5 47 - 79 0 0 39 36 14 9 33 41 49 116 -4 39 23 10 39 49 21 38 47 0 40 25 59 - 78 0 0 39 56 17 9 33 44 50 118 -3 39 43 13 40 9 23 39 7 5 40 45 59 - 77 0 0 40 16 9 9 33 47 50 119 -3 40 3 5 40 29 14 39 26 59 41 5 49 - 76 0 0 40 35 49 9 33 50 51 121 -2 40 22 47 40 48 54 39 46 42 41 25 26 - 75 0 0 40 55 18 9 33 53 51 122 -1 40 42 16 41 8 22 40 6 13 41 44 52 - 74 0 0 41 14 34 9 33 57 52 124 0 41 1 33 41 27 37 40 25 33 42 4 6 Uncertainty in time = +/- 3 secs [Prediction of 2008 May 26.0] Data for the target star ------------------------ * name: TYC 0627-00511-1 * constellation : Pisces * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 01 41 33.6946 DE: +14 44 36.749 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .019, .019 ) * V mag [mag]: 9.6 * B mag [mag]: 10.7 * Apparent position with proper motion RA(deg): 25.5061875696 DE(deg): 14.7873960763 * Equation of equinoxes (radians) : 0.000051964214749 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (923) Herluga approx. diameter [km]: 37 approx. diameter ["]: .023 distance from Earth [AU]: 2.21100 * orbital information: orbit source: Preston date of fit: 2008 Apr 28 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 599 number of rejected observations: 18 time covered by the observations: 1919 Sep 30 - 2007 Oct 12 1 sigma uncertainty ellipse (major, minor, PA): 0.046, 0.025, 87° remarks: * orbital elements for (923) Herluga : Mean anomaly = 334.72203905 deg Arg. of pericenter = 201.25516889 deg Long. of node = 197.69864049 deg Inclination = 14.47478534 deg Eccentricity = 0.19547900 Semimajor axis = 2.61468214 AU Perihelion dist = 2.10356670 AU Mag: H = 11.42, G = 0.15 Epoch of elements : MJD 54652.39900000 TDT (2008 Jul 05.399) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Jul 5 923 Herluga 9h 35.1m UT 9.6 1 41 33.695 14 44 36.75TYC 0627-00511-1 10.7 16.1 37 1.3 2.211 4.167 13.82 -42.1288 14.740 37.40 22.73 9.5842 -0.12129 0.53575 15.19374 3.47478 -0.00478 -0.00174 2000 334.1627892008 7 3.00000201.255169197.698640 14.4747850.19547900 2.6146821 2.103566711.5 5.00.15 RATE 2.3311800 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.050 0.031 87 2.39 0.032 0 54612.5020080705_0511-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 26, 16:20 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org