IOTA/IOTA-ES occultation update for (19) Fortuna / TYC 6277-01014-1 event on 2008 Mar 25, 00:39 UT Visible from Arabia, Africa Summary ------- On 2008 Mar 25 UT, the 221 km diameter asteroid (19) Fortuna will occult a 11.8 mag star in the constellation Sagittarius for observers along a path across Arabia, Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.1 mag to 12.4 mag (the magnitude of the asteroid) for at most 13.4 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 25, 00:34 - 2008 Mar 25, 00:39 UT * midpoint of event [JD]: 2454550.5272 * magnitude of target star: 11.8 * magnitude drop [mag]: 1.1 * estimated maximum duration [s]: 13.4 * Moon: 90 % sunlit, 53° distance * Sun: 91° distance * rough path description: Arabia, Africa The occultation path -------------------- * approximate projected width [km]: 280 * 1 sigma uncertainty interval [path widths]: +/- 0.21 * 1 sigma uncertainty interval [seconds]: +/- 2.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .025 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .025", .025", 360° ) * approx speed of asteroid's shadow [km/s]: 16.5046 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6277-01014-1 by 19 Fortuna on 2008 Mar 25 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 7 0 0 30 43 18 0 34 5 0 116 -55 29 20 11 .. .. .. 28 45 46 .. .. .. 8 0 0 30 17 55 0 34 5 1 117 -55 28 54 58 31 42 37 28 20 36 32 18 45 9 0 0 29 52 41 0 34 5 2 117 -55 28 29 53 31 17 13 27 55 35 31 53 17 10 0 0 29 27 37 0 34 5 3 118 -55 28 4 59 30 51 59 27 30 45 31 27 58 11 0 0 29 2 44 0 34 6 4 118 -55 27 40 15 30 26 55 27 6 5 31 2 50 12 0 0 28 38 2 0 34 6 5 119 -55 27 15 43 30 2 2 26 41 36 30 37 52 13 0 0 28 13 31 0 34 7 6 119 -54 26 51 22 29 37 22 26 17 20 30 13 7 14 0 0 27 49 14 0 34 8 7 120 -54 26 27 15 29 12 53 25 53 17 29 48 34 15 0 0 27 25 10 0 34 9 8 120 -54 26 3 21 28 48 38 25 29 27 29 24 14 16 0 0 27 1 20 0 34 10 9 121 -54 25 39 42 28 24 37 25 5 52 29 0 8 17 0 0 26 37 45 0 34 12 10 121 -53 25 16 17 28 0 51 24 42 31 28 36 17 18 0 0 26 14 25 0 34 13 11 122 -53 24 53 8 27 37 20 24 19 27 28 12 41 19 0 0 25 51 21 0 34 15 12 122 -53 24 30 15 27 14 5 23 56 38 27 49 21 20 0 0 25 28 35 0 34 17 13 122 -52 24 7 39 26 51 7 23 34 6 27 26 18 21 0 0 25 6 5 0 34 19 14 123 -52 23 45 20 26 28 27 23 11 51 27 3 33 22 0 0 24 43 54 0 34 21 15 123 -51 23 23 19 26 6 4 22 49 55 26 41 5 23 0 0 24 22 1 0 34 23 16 124 -51 23 1 37 25 44 0 22 28 17 26 18 56 24 0 0 24 0 27 0 34 25 17 124 -50 22 40 14 25 22 15 22 6 58 25 57 6 25 0 0 23 39 13 0 34 28 18 125 -50 22 19 11 25 0 50 21 45 59 25 35 36 26 0 0 23 18 20 0 34 30 19 125 -49 21 58 28 24 39 45 21 25 21 25 14 26 27 0 0 22 57 47 0 34 33 19 126 -49 21 38 5 24 19 1 21 5 3 24 53 38 28 0 0 22 37 36 0 34 36 20 126 -48 21 18 5 23 58 39 20 45 6 24 33 11 29 0 0 22 17 47 0 34 39 21 127 -47 20 58 26 23 38 39 20 25 31 24 13 5 30 0 0 21 58 20 0 34 42 22 127 -47 20 39 9 23 19 1 20 6 19 23 53 23 31 0 0 21 39 15 0 34 45 23 128 -46 20 20 15 22 59 46 19 47 29 23 34 3 32 0 0 21 20 35 0 34 49 24 128 -45 20 1 44 22 40 54 19 29 2 23 15 7 33 0 0 21 2 18 0 34 52 25 129 -45 19 43 37 22 22 27 19 10 59 22 56 35 34 0 0 20 44 25 0 34 56 26 129 -44 19 25 54 22 4 24 18 53 20 22 38 28 35 0 0 20 26 57 0 35 0 27 130 -43 19 8 36 21 46 46 18 36 5 22 20 45 36 0 0 20 9 54 0 35 4 28 131 -42 18 51 42 21 29 33 18 19 16 22 3 28 37 0 0 19 53 16 0 35 8 29 131 -41 18 35 14 21 12 45 18 2 51 21 46 36 38 0 0 19 37 5 0 35 12 30 132 -41 18 19 11 20 56 24 17 46 52 21 30 10 39 0 0 19 21 19 0 35 16 31 132 -40 18 3 35 20 40 29 17 31 19 21 14 11 40 0 0 19 6 0 0 35 20 31 133 -39 17 48 24 20 25 1 17 16 13 20 58 39 41 0 0 18 51 8 0 35 25 32 133 -38 17 33 41 20 9 59 17 1 32 20 43 34 42 0 0 18 36 43 0 35 30 33 134 -37 17 19 24 19 55 26 16 47 19 20 28 56 43 0 0 18 22 45 0 35 34 34 135 -36 17 5 34 19 41 20 16 33 33 20 14 46 44 0 0 18 9 15 0 35 39 35 135 -36 16 52 13 19 27 42 16 20 14 20 1 5 45 0 0 17 56 14 0 35 44 36 136 -35 16 39 18 19 14 32 16 7 23 19 47 51 46 0 0 17 43 40 0 35 49 37 137 -34 16 26 52 19 1 51 15 55 0 19 35 7 47 0 0 17 31 36 0 35 54 37 138 -33 16 14 55 18 49 38 15 43 5 19 22 51 48 0 0 17 20 0 0 35 59 38 138 -32 16 3 26 18 37 55 15 31 39 19 11 5 49 0 0 17 8 53 0 36 4 39 139 -31 15 52 25 18 26 41 15 20 41 18 59 48 50 0 0 16 58 15 0 36 10 40 140 -30 15 41 54 18 15 57 15 10 13 18 49 1 51 0 0 16 48 7 0 36 15 40 141 -29 15 31 52 18 5 42 15 0 13 18 38 43 52 0 0 16 38 28 0 36 21 41 142 -28 15 22 19 17 55 58 14 50 42 18 28 56 53 0 0 16 29 19 0 36 26 42 143 -27 15 13 16 17 46 43 14 41 41 18 19 39 54 0 0 16 20 41 0 36 32 43 144 -27 15 4 42 17 37 59 14 33 10 18 10 52 55 0 0 16 12 32 0 36 38 43 145 -26 14 56 39 17 29 45 14 25 8 18 2 36 56 0 0 16 4 54 0 36 44 44 145 -25 14 49 5 17 22 2 14 17 37 17 54 51 57 0 0 15 57 46 0 36 50 45 147 -24 14 42 1 17 14 50 14 10 35 17 47 37 58 0 0 15 51 9 0 36 56 45 148 -23 14 35 28 17 8 8 14 4 3 17 40 53 59 0 0 15 45 2 0 37 2 46 149 -22 14 29 25 17 1 58 13 58 2 17 34 41 60 0 0 15 39 27 0 37 8 46 150 -21 14 23 53 16 56 19 13 52 31 17 29 1 61 0 0 15 34 22 0 37 14 47 151 -20 14 18 51 16 51 11 13 47 31 17 23 51 62 0 0 15 29 48 0 37 20 48 152 -19 14 14 20 16 46 34 13 43 1 17 19 13 63 0 0 15 25 45 0 37 26 48 153 -18 14 10 20 16 42 29 13 39 2 17 15 7 64 0 0 15 22 14 0 37 33 49 154 -17 14 6 51 16 38 55 13 35 33 17 11 33 65 0 0 15 19 14 0 37 39 49 156 -16 14 3 52 16 35 53 13 32 35 17 8 30 66 0 0 15 16 45 0 37 46 49 157 -15 14 1 25 16 33 23 13 30 8 17 5 59 67 0 0 15 14 47 0 37 52 50 158 -14 13 59 29 16 31 24 13 28 13 17 3 59 68 0 0 15 13 21 0 37 58 50 160 -13 13 58 3 16 29 57 13 26 47 17 2 32 69 0 0 15 12 27 0 38 5 51 161 -12 13 57 9 16 29 2 13 25 53 17 1 37 70 0 0 15 12 3 0 38 12 51 163 -11 13 56 46 16 28 39 13 25 30 17 1 13 71 0 0 15 12 12 0 38 18 51 164 -10 13 56 54 16 28 47 13 25 38 17 1 22 72 0 0 15 12 51 0 38 25 51 165 -9 13 57 33 16 29 27 13 26 17 17 2 2 73 0 0 15 14 2 0 38 31 52 167 -8 13 58 43 16 30 39 13 27 27 17 3 15 74 0 0 15 15 45 0 38 38 52 168 -7 14 0 25 16 32 23 13 29 8 17 4 59 75 0 0 15 17 59 0 38 45 52 170 -6 14 2 37 16 34 39 13 31 20 17 7 16 76 0 0 15 20 45 0 38 51 52 172 -5 14 5 21 16 37 27 13 34 3 17 10 4 77 0 0 15 24 2 0 38 58 52 173 -4 14 8 36 16 40 46 13 37 17 17 13 25 78 0 0 15 27 50 0 39 5 52 175 -3 14 12 22 16 44 37 13 41 2 17 17 17 79 0 0 15 32 10 0 39 11 52 176 -2 14 16 39 16 48 59 13 45 17 17 21 41 80 0 0 15 37 1 0 39 18 52 178 -1 14 21 26 16 53 54 13 50 4 17 26 36 81 0 0 15 42 23 0 39 25 52 179 0 14 26 45 16 59 19 13 55 21 17 32 4 Uncertainty in time = +/- 3 secs [Prediction of 2008 Feb 14.0] Data for the target star ------------------------ * name: TYC 6277-01014-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 16 11.3693 DE: -22 16 28.429 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .023, .024 ) * V mag [mag]: 11.8 * B mag [mag]: 12.2 * Apparent position with proper motion RA(deg): 274.1743309143 DE(deg): -22.2735780583 * Equation of equinoxes (radians) : 0.000040762304527 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (19) Fortuna approx. diameter [km]: 221 approx. diameter ["]: .121 distance from Earth [AU]: 2.51200 * orbital information: orbit source: Preston date of fit: 2008 Feb 13 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): 0.009, 0.007, 88° remarks: * orbital elements for (19) Fortuna : Mean anomaly = 231.57709881 deg Arg. of pericenter = 181.85284099 deg Long. of node = 211.35928801 deg Inclination = 1.57287586 deg Eccentricity = 0.15862463 Semimajor axis = 2.44271657 AU Perihelion dist = 2.05524156 AU Mag: H = 7.13, G = 0.10 Epoch of elements : MJD 54550.02700000 TDT (2008 Mar 25.027) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 25 19 Fortuna 0h 39.2m UT 11.8 18 16 11.369-22 16 28.43TYC 6277-01014-1 12.2 12.4 221 13.4 2.512 2.343 2.52 81.4021 -22.275 171.72 1.89 0.6528 -0.04596 0.61090 9.28793 0.71807 -0.00573 -0.00016 2000 228.9884962008 315.00000181.852841211.359288 1.5728760.15862463 2.4427166 2.0552416 7.1 5.00.10 RATE 2.5816330 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.025 0.025 360 1.21 0.025 0 54510.5020080325_1014-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 14, 19:32 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org