IOTA/IOTA-ES occultation update for (19) Fortuna / HIP 88508 event on 2008 Mar 13, 13:48 UT Visible from Hawaii Summary ------- On 2008 Mar 13 UT, the 221 km diameter asteroid (19) Fortuna will occult a 10.0 mag star in the constellation Sagittarius for observers along a path across Hawaii. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.7 mag to 12.6 mag (the magnitude of the asteroid) for at most 10.6 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 Mar 13, 13:44 - 2008 Mar 13, 13:47 UT * magnitude of target star: 10.0 * magnitude drop [mag]: 2.7 * estimated maximum duration [s]: 10.6 * Moon: 40 % sunlit, 160° distance * Sun: 82° distance * rough path description: Hawaii The occultation path -------------------- * approximate projected width [km]: 272 * 1 sigma uncertainty interval [path widths]: +/- 0.24 * 1 sigma uncertainty interval [seconds]: +/- 2.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .028 +/- .028) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .028", 90° ) * approx speed of asteroid's shadow [km/s]: 20.8839 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 88508 by 19 Fortuna on 2008 Mar 13 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 178 0 0 30 12 35 13 44 10 0 116 -56 28 51 38 .. .. .. 28 13 18 .. .. .. 179 0 0 29 46 59 13 44 10 1 117 -55 28 26 10 31 9 20 27 47 53 31 49 26 180 0 0 29 21 30 13 44 11 2 117 -55 28 0 49 30 43 43 27 22 35 31 23 45 -179 0 0 28 56 8 13 44 11 3 118 -55 27 35 35 30 18 13 26 57 24 30 58 11 -178 0 0 28 30 54 13 44 11 4 118 -54 27 10 28 29 52 50 26 32 21 30 32 44 -177 0 0 28 5 48 13 44 12 5 119 -54 26 45 30 29 27 35 26 7 27 30 7 25 -176 0 0 27 40 51 13 44 12 6 119 -54 26 20 42 29 2 29 25 42 42 29 42 15 -175 0 0 27 16 4 13 44 13 7 120 -53 25 56 3 28 37 33 25 18 8 29 17 14 -174 0 0 26 51 28 13 44 14 8 120 -53 25 31 35 28 12 48 24 53 44 28 52 24 -173 0 0 26 27 2 13 44 15 9 121 -52 25 7 19 27 48 13 24 29 32 28 27 44 -172 0 0 26 2 49 13 44 16 10 121 -52 24 43 15 27 23 50 24 5 32 28 3 17 -171 0 0 25 38 48 13 44 17 11 122 -51 24 19 23 26 59 40 23 41 44 27 39 2 -170 0 0 25 15 1 13 44 19 12 122 -50 23 55 45 26 35 43 23 18 10 27 15 0 -169 0 0 24 51 28 13 44 20 13 123 -50 23 32 21 26 12 0 22 54 51 26 51 11 -168 0 0 24 28 9 13 44 22 14 123 -49 23 9 12 25 48 31 22 31 46 26 27 38 -167 0 0 24 5 5 13 44 23 15 124 -49 22 46 18 25 25 17 22 8 56 26 4 19 -166 0 0 23 42 18 13 44 25 16 124 -48 22 23 40 25 2 20 21 46 23 25 41 16 -165 0 0 23 19 47 13 44 27 17 124 -47 22 1 18 24 39 38 21 24 6 25 18 30 -164 0 0 22 57 33 13 44 29 18 125 -46 21 39 14 24 17 14 21 2 6 24 56 1 -163 0 0 22 35 36 13 44 31 19 125 -46 21 17 27 23 55 8 20 40 24 24 33 49 -162 0 0 22 13 58 13 44 33 20 126 -45 20 55 59 23 33 20 20 19 0 24 11 56 -161 0 0 21 52 39 13 44 35 21 126 -44 20 34 49 23 11 50 19 57 55 23 50 21 -160 0 0 21 31 39 13 44 38 22 127 -43 20 13 59 22 50 40 19 37 9 23 29 6 -159 0 0 21 11 0 13 44 40 23 127 -43 19 53 29 22 29 50 19 16 44 23 8 11 -158 0 0 20 50 40 13 44 43 24 128 -42 19 33 19 22 9 21 18 56 38 22 47 37 -157 0 0 20 30 42 13 44 45 25 128 -41 19 13 30 21 49 12 18 36 54 22 27 23 -156 0 0 20 11 5 13 44 48 26 129 -40 18 54 3 21 29 25 18 17 31 22 7 31 -155 0 0 19 51 50 13 44 51 27 129 -39 18 34 57 21 10 0 17 58 29 21 48 1 -154 0 0 19 32 57 13 44 54 28 130 -38 18 16 14 20 50 57 17 39 50 21 28 53 -153 0 0 19 14 27 13 44 57 28 130 -38 17 57 53 20 32 18 17 21 34 21 10 9 -152 0 0 18 56 20 13 45 0 29 131 -37 17 39 55 20 14 1 17 3 40 20 51 48 -151 0 0 18 38 37 13 45 4 30 131 -36 17 22 21 19 56 8 16 46 10 20 33 50 -150 0 0 18 21 17 13 45 7 31 132 -35 17 5 11 19 38 40 16 29 4 20 16 17 -149 0 0 18 4 23 13 45 10 32 133 -34 16 48 25 19 21 36 16 12 22 19 59 8 -148 0 0 17 47 53 13 45 14 33 133 -33 16 32 3 19 4 57 15 56 5 19 42 25 -147 0 0 17 31 48 13 45 18 34 134 -32 16 16 7 18 48 43 15 40 12 19 26 7 -146 0 0 17 16 8 13 45 21 35 134 -31 16 0 36 18 32 55 15 24 45 19 10 14 -145 0 0 17 0 55 13 45 25 36 135 -30 15 45 30 18 17 33 15 9 43 18 54 48 -144 0 0 16 46 7 13 45 29 36 136 -29 15 30 51 18 2 37 14 55 8 18 39 48 -143 0 0 16 31 46 13 45 33 37 137 -28 15 16 38 17 48 8 14 40 58 18 25 14 -142 0 0 16 17 52 13 45 37 38 137 -28 15 2 51 17 34 5 14 27 15 18 11 8 -141 0 0 16 4 24 13 45 41 39 138 -27 14 49 31 17 20 30 14 13 58 17 57 29 -140 0 0 15 51 24 13 45 45 40 139 -26 14 36 38 17 7 22 14 1 8 17 44 17 -139 0 0 15 38 51 13 45 49 41 140 -25 14 24 12 16 54 42 13 48 45 17 31 34 -138 0 0 15 26 46 13 45 54 41 140 -24 14 12 13 16 42 30 13 36 50 17 19 18 -137 0 0 15 15 9 13 45 58 42 141 -23 14 0 43 16 30 46 13 25 23 17 7 31 -136 0 0 15 4 0 13 46 3 43 142 -22 13 49 40 16 19 30 13 14 23 16 56 12 -135 0 0 14 53 19 13 46 7 44 143 -21 13 39 5 16 8 43 13 3 51 16 45 22 -134 0 0 14 43 7 13 46 12 44 144 -20 13 28 59 15 58 25 12 53 47 16 35 0 -133 0 0 14 33 23 13 46 16 45 145 -19 13 19 21 15 48 36 12 44 12 16 25 8 -132 0 0 14 24 9 13 46 21 46 146 -18 13 10 11 15 39 16 12 35 5 16 15 45 -131 0 0 14 15 23 13 46 26 46 147 -17 13 1 31 15 30 25 12 26 27 16 6 52 -130 0 0 14 7 7 13 46 30 47 148 -16 12 53 19 15 22 4 12 18 17 15 58 28 -129 0 0 13 59 20 13 46 35 48 149 -15 12 45 37 15 14 12 12 10 37 15 50 34 -128 0 0 13 52 2 13 46 40 48 150 -14 12 38 23 15 6 50 12 3 25 15 43 10 -127 0 0 13 45 14 13 46 45 49 151 -13 12 31 39 14 59 58 11 56 43 15 36 16 -126 0 0 13 38 56 13 46 50 49 152 -12 12 25 24 14 53 35 11 50 30 15 29 52 -125 0 0 13 33 7 13 46 55 50 154 -11 12 19 39 14 47 43 11 44 46 15 23 58 -124 0 0 13 27 48 13 47 0 51 155 -10 12 14 23 14 42 21 11 39 32 15 18 34 -123 0 0 13 23 0 13 47 5 51 156 -9 12 9 38 14 37 30 11 34 47 15 13 41 -122 0 0 13 18 41 13 47 10 51 158 -8 12 5 21 14 33 8 11 30 32 15 9 19 -121 0 0 13 14 52 13 47 15 52 159 -7 12 1 35 14 29 17 11 26 47 15 5 26 -120 0 0 13 11 34 13 47 20 52 160 -6 11 58 18 14 25 57 11 23 31 15 2 5 -119 0 0 13 8 46 13 47 25 53 162 -5 11 55 32 14 23 7 11 20 45 14 59 14 -118 0 0 13 6 28 13 47 31 53 163 -4 11 53 15 14 20 48 11 18 29 14 56 54 -117 0 0 13 4 40 13 47 36 53 165 -3 11 51 29 14 18 59 11 16 43 14 55 5 -116 0 0 13 3 23 13 47 41 54 166 -2 11 50 12 14 17 41 11 15 27 14 53 47 -115 0 0 13 2 36 13 47 46 54 168 -1 11 49 25 14 16 54 11 14 41 14 52 59 Uncertainty in time = +/- 3 secs [Prediction of 2008 Feb 27.0] Data for the target star ------------------------ * name: HIP 88508 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 04 24.3151 DE: -22 26 18.785 * position source: mpos:UCAC2 pm:UCAC2 plx:HIP * standard error: RA,DE ["]: ( .027, .027 ) * V mag [mag]: 10.0 * B mag [mag]: 10.1 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (19) Fortuna approx. diameter [km]: 221 approx. diameter ["]: .114 distance from Earth [AU]: 2.67900 * orbital information: orbit source: Preston date of fit: 2008 Feb 27 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1551 number of rejected observations: 256 time covered by the observations: 1900 Feb 12 - 2007 Jul 25 1 sigma uncertainty ellipse (major, minor, PA): 0.008, 0.006, 89° remarks: * orbital elements for (19) Fortuna : Mean anomaly = 228.61505712 deg Arg. of pericenter = 181.85808477 deg Long. of node = 211.36069619 deg Inclination = 1.57292244 deg Eccentricity = 0.15865855 Semimajor axis = 2.44263717 AU Perihelion dist = 2.05509189 AU Mag: H = 7.13, G = 0.10 Epoch of elements : MJD 54538.57500000 TDT (2008 Mar 13.575) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 13 19 Fortuna 13h 48.3m UT 10.0 18 4 24.315-22 26 18.79HIP 88508 10.1 12.6 221 10.6 2.679 2.788 1.72 -107.5425 -22.438 -24.73 -2.63 13.8052 -0.02499 0.58051 11.77579 0.52416 -0.00576 -0.00003 2000 226.4011992008 3 5.00000181.858085211.360696 1.5729220.15865855 2.4426372 2.0550919 7.1 5.00.10 RATE 2.5817590 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.028 90 1.24 0.028 0 54523.5020080313__88508 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 27, 20:28 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org