IOTA/IOTA-ES occultation update for (287) Nephthys / TYC 5775-01052-1 event on 2008 May 11, 03:17 UT Visible from Europe Summary ------- On 2008 May 11 UT, the 68 km diameter asteroid (287) Nephthys will occult a 9.7 mag star in the constellation Aquarius for observers along a path across Europe. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.1 mag to 12.7 mag (the magnitude of the asteroid) for at most 4.3 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: 97 * date and approx. time of event: 2008 May 11, 03:14 - 2008 May 11, 03:17 UT * midpoint of event [JD]: 2454597.6371125 * magnitude of target star: 9.7 * magnitude drop [mag]: 3.1 * estimated maximum duration [s]: 4.3 * Moon: 39 % sunlit, 169° distance * Sun: 94° distance * rough path description: Europe The occultation path -------------------- * approximate projected width [km]: 155 * 1 sigma uncertainty interval [path widths]: +/- 0.39 * 1 sigma uncertainty interval [seconds]: +/- 1.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .020 +/- .018) * 1 sigma uncertainty ellipse (major, minor, PA): ( .020", .018", 89° ) * approx speed of asteroid's shadow [km/s]: 15.8947 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5775-01052-1 by 287 Nephthys on 2008 May 11 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 ' " Longitude Longitude Longitude Longitude Latitude Latitude Latitude Latitude 16 0 0 51 18 8 3 17 17 26 155 0 50 32 48 52 4 51 49 58 18 52 42 21 15 0 0 51 2 30 3 17 13 26 153 -1 50 17 22 51 49 1 49 43 2 52 26 19 14 0 0 50 47 18 3 17 8 26 152 -1 50 2 21 51 33 36 49 28 9 52 10 44 13 0 0 50 32 31 3 17 3 26 151 -2 49 47 46 51 18 36 49 13 42 51 55 34 12 0 0 50 18 10 3 16 58 25 150 -3 49 33 36 51 4 4 48 59 40 51 40 51 11 0 0 50 4 16 3 16 53 25 149 -3 49 19 52 50 49 58 48 46 4 51 26 35 10 0 0 49 50 48 3 16 49 25 148 -4 49 6 35 50 36 19 48 32 54 51 12 47 9 0 0 49 37 48 3 16 44 25 147 -5 48 53 44 50 23 8 48 20 11 50 59 27 8 0 0 49 25 15 3 16 39 25 146 -5 48 41 21 50 10 24 48 7 54 50 46 35 7 0 0 49 13 10 3 16 35 25 145 -6 48 29 25 49 58 9 47 56 5 50 34 11 6 0 0 49 1 33 3 16 30 24 144 -7 48 17 56 49 46 22 47 44 43 50 22 16 5 0 0 48 50 24 3 16 25 24 142 -7 48 6 56 49 35 4 47 33 49 50 10 50 4 0 0 48 39 44 3 16 21 24 141 -8 47 56 24 49 24 15 47 23 23 49 59 54 3 0 0 48 29 32 3 16 16 23 140 -9 47 46 21 49 13 56 47 13 25 49 49 27 2 0 0 48 19 50 3 16 12 23 139 -9 47 36 46 49 4 5 47 3 55 49 39 30 1 0 0 48 10 37 3 16 7 23 138 -10 47 27 40 48 54 45 46 54 55 49 30 3 0 0 0 48 1 54 3 16 3 22 137 -11 47 19 3 48 45 54 46 46 23 49 21 6 - 1 0 0 47 53 40 3 15 59 22 136 -11 47 10 56 48 37 34 46 38 20 49 12 40 - 2 0 0 47 45 56 3 15 55 22 135 -12 47 3 18 48 29 43 46 30 46 49 4 44 - 3 0 0 47 38 42 3 15 50 21 134 -12 46 56 9 48 22 23 46 23 42 48 57 19 - 4 0 0 47 31 59 3 15 46 21 133 -13 46 49 31 48 15 34 46 17 7 48 50 25 - 5 0 0 47 25 45 3 15 42 20 132 -13 46 43 22 48 9 15 46 11 2 48 44 2 - 6 0 0 47 20 2 3 15 39 20 132 -14 46 37 44 48 3 27 46 5 27 48 38 10 - 7 0 0 47 14 49 3 15 35 20 131 -14 46 32 35 47 58 10 46 0 21 48 32 49 - 8 0 0 47 10 7 3 15 31 19 130 -15 46 27 57 47 53 24 45 55 46 48 27 59 - 9 0 0 47 5 55 3 15 27 19 129 -15 46 23 49 47 49 9 45 51 40 48 23 41 - 10 0 0 47 2 15 3 15 24 18 128 -16 46 20 11 47 45 24 45 48 4 48 19 54 - 11 0 0 46 59 4 3 15 21 18 127 -16 46 17 3 47 42 11 45 44 59 48 16 39 - 12 0 0 46 56 25 3 15 17 17 126 -17 46 14 26 47 39 29 45 42 23 48 13 54 - 13 0 0 46 54 16 3 15 14 17 125 -17 46 12 19 47 37 19 45 40 18 48 11 42 - 14 0 0 46 52 38 3 15 11 16 124 -18 46 10 43 47 35 39 45 38 43 48 10 1 - 15 0 0 46 51 31 3 15 8 15 124 -18 46 9 37 47 34 30 45 37 38 48 8 51 - 16 0 0 46 50 55 3 15 5 15 123 -19 46 9 1 47 33 53 45 37 3 48 8 13 - 17 0 0 46 50 49 3 15 2 14 122 -19 46 8 56 47 33 47 45 36 58 48 8 6 - 18 0 0 46 51 14 3 14 59 14 121 -19 46 9 21 47 34 11 45 37 23 48 8 31 - 19 0 0 46 52 9 3 14 57 13 120 -20 46 10 16 47 35 7 45 38 19 48 9 27 - 20 0 0 46 53 35 3 14 54 12 119 -20 46 11 42 47 36 34 45 39 44 48 10 54 - 21 0 0 46 55 32 3 14 52 12 119 -20 46 13 38 47 38 31 45 41 39 48 12 52 - 22 0 0 46 57 59 3 14 50 11 118 -21 46 16 3 47 40 59 45 44 3 48 15 22 - 23 0 0 47 0 56 3 14 48 11 117 -21 46 18 59 47 43 58 45 46 58 48 18 22 - 24 0 0 47 4 23 3 14 46 10 116 -21 46 22 24 47 47 28 45 50 22 48 21 54 - 25 0 0 47 8 21 3 14 44 9 115 -21 46 26 19 47 51 28 45 54 15 48 25 56 - 26 0 0 47 12 48 3 14 42 9 115 -22 46 30 44 47 55 58 45 58 38 48 30 28 - 27 0 0 47 17 45 3 14 41 8 114 -22 46 35 38 48 0 59 46 3 30 48 35 32 - 28 0 0 47 23 12 3 14 39 7 113 -22 46 41 2 48 6 29 46 8 51 48 41 5 - 29 0 0 47 29 8 3 14 38 7 112 -22 46 46 54 48 12 30 46 14 40 48 47 9 - 30 0 0 47 35 34 3 14 37 6 112 -22 46 53 16 48 19 0 46 20 59 48 53 43 - 31 0 0 47 42 29 3 14 36 5 111 -22 47 0 6 48 26 0 46 27 46 49 0 47 - 32 0 0 47 49 53 3 14 35 5 110 -22 47 7 25 48 33 29 46 35 1 49 8 20 - 33 0 0 47 57 45 3 14 34 4 109 -23 47 15 12 48 41 27 46 42 45 49 16 23 - 34 0 0 48 6 6 3 14 33 3 109 -23 47 23 27 48 49 54 46 50 56 49 24 55 - 35 0 0 48 14 55 3 14 33 3 108 -23 47 32 11 48 58 49 .. .. .. 49 33 56 - 36 0 0 48 24 13 3 14 32 2 107 -23 47 41 22 49 8 13 .. .. .. 49 43 26 - 37 0 0 48 33 58 3 14 32 1 106 -23 47 51 0 49 18 6 .. .. .. 49 53 25 - 38 0 0 48 44 10 3 14 32 1 106 -23 48 1 6 49 28 26 .. .. .. 50 3 51 Uncertainty in time = +/- 2 secs [Prediction of 2008 Mar 31.0] Data for the target star ------------------------ * name: TYC 5775-01052-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 10 20.6521 DE: -09 57 10.939 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .018, .017 ) * V mag [mag]: 9.7 * B mag [mag]: 10.1 * Apparent position with proper motion RA(deg): 317.7018260711 DE(deg): -9.9197319709 * Equation of equinoxes (radians) : 0.000041171965951 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (287) Nephthys approx. diameter [km]: 68 approx. diameter ["]: .047 distance from Earth [AU]: 2.00600 * orbital information: orbit source: Preston date of fit: 2008 Feb 16 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1462 number of rejected observations: 149 time covered by the observations: 1900 Sep 21 - 2007 Jun 14 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.007, 87° remarks: * orbital elements for (287) Nephthys : Mean anomaly = 27.12297675 deg Arg. of pericenter = 119.65127593 deg Long. of node = 142.45246938 deg Inclination = 10.02552078 deg Eccentricity = 0.02426564 Semimajor axis = 2.35370311 AU Perihelion dist = 2.29658901 AU Mag: H = 8.25, G = 0.22 Epoch of elements : MJD 54597.13700000 TDT (2008 May 11.137) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 11 287 Nephthys 3h 17.4m UT 9.7 21 10 20.652- 9 57 10.94TYC 5775-01052-1 10.1 12.7 68 4.3 2.006 2.576 9.85 38.9383 -9.955 129.74 17.96 3.2907 -0.22391 0.87012 8.68544 2.24704 -0.00515 -0.00163 2000 25.1749622008 5 4.00000119.651276142.452469 10.0255210.02426564 2.3537031 2.2965890 8.3 5.00.22 RATE 2.7294590 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.020 0.018 89 1.39 0.018 0 54556.5020080511_1052-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 31, 04:33 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org