IOTA/IOTA-ES occultation update for (19) Fortuna / 2UCAC 22978994 event on 2008 Apr 04, 03:43 UT Visible from Africa Summary ------- On 2008 Apr 04 UT, the 221 km diameter asteroid (19) Fortuna will occult a 11.9 mag star in the constellation Sagittarius for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.0 mag to 12.3 mag (the magnitude of the asteroid) for at most 17.7 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: 99 * date and approx. time of event: 2008 Apr 04, 03:35 - 2008 Apr 04, 03:44 UT * midpoint of event [JD]: 2454560.65499583 * magnitude of target star: 11.9 * magnitude drop [mag]: 1.0 * estimated maximum duration [s]: 17.7 * Moon: 6 % sunlit, 72° distance * Sun: 99° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 241 * 1 sigma uncertainty interval [path widths]: +/- 0.19 * 1 sigma uncertainty interval [seconds]: +/- 5.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .043 +/- .025) * 1 sigma uncertainty ellipse (major, minor, PA): ( .043", .025", 90° ) * approx speed of asteroid's shadow [km/s]: 12.4700 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 22978994 by 19 Fortuna on 2008 Apr 4 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 - 53 0 0 15 46 25 3 35 23 1 113 -68 14 36 6 16 57 24 14 9 33 17 24 34 - 52 0 0 15 21 56 3 35 23 2 113 -69 14 11 42 16 32 50 13 45 10 16 59 57 - 51 0 0 14 57 36 3 35 23 3 114 -69 13 47 28 16 8 25 13 20 58 16 35 30 - 50 0 0 14 33 27 3 35 24 4 114 -69 13 23 24 15 44 10 12 56 57 16 11 13 - 49 0 0 14 9 30 3 35 25 5 114 -70 12 59 32 15 20 6 12 33 7 15 47 7 - 48 0 0 13 45 43 3 35 26 6 114 -70 12 35 52 14 56 14 12 9 28 15 23 13 - 47 0 0 13 22 10 3 35 27 7 115 -70 12 12 24 14 32 35 11 46 3 14 59 31 - 46 0 0 12 58 49 3 35 28 8 115 -70 11 49 9 14 9 8 11 22 50 14 36 2 - 45 0 0 12 35 42 3 35 30 9 115 -70 11 26 8 13 45 55 10 59 52 14 12 46 - 44 0 0 12 12 49 3 35 31 10 115 -70 11 3 22 13 22 55 10 37 7 13 49 45 - 43 0 0 11 50 11 3 35 33 11 116 -70 10 40 50 13 0 11 10 14 38 13 26 57 - 42 0 0 11 27 48 3 35 35 12 116 -70 10 18 33 12 37 42 9 52 24 13 4 26 - 41 0 0 11 5 41 3 35 38 13 116 -69 9 56 33 12 15 28 9 30 26 12 42 10 - 40 0 0 10 43 51 3 35 40 14 116 -69 9 34 49 11 53 31 9 8 44 12 20 10 - 39 0 0 10 22 17 3 35 43 15 117 -69 9 13 22 11 31 51 8 47 20 11 58 27 - 38 0 0 10 1 1 3 35 45 16 117 -68 8 52 12 11 10 28 8 26 13 11 37 1 - 37 0 0 9 40 3 3 35 48 18 117 -68 8 31 21 10 49 23 8 5 24 11 15 54 - 36 0 0 9 19 24 3 35 52 19 117 -67 8 10 48 10 28 36 7 44 53 10 55 5 - 35 0 0 8 59 3 3 35 55 20 117 -67 7 50 34 10 8 9 7 24 42 10 34 34 - 34 0 0 8 39 1 3 35 59 21 118 -66 7 30 39 9 48 1 7 4 50 10 14 24 - 33 0 0 8 19 20 3 36 2 22 118 -65 7 11 5 9 28 12 6 45 17 9 54 33 - 32 0 0 7 59 59 3 36 6 23 118 -65 6 51 50 9 8 44 6 26 5 9 35 2 - 31 0 0 7 40 59 3 36 10 24 118 -64 6 32 56 8 49 37 6 7 14 9 15 52 - 30 0 0 7 22 19 3 36 14 25 118 -63 6 14 24 8 30 51 5 48 44 8 57 3 - 29 0 0 7 4 2 3 36 19 26 119 -63 5 56 13 8 12 26 5 30 36 8 38 36 - 28 0 0 6 46 6 3 36 23 27 119 -62 5 38 24 7 54 24 5 12 49 8 20 31 - 27 0 0 6 28 32 3 36 28 28 119 -61 5 20 57 7 36 44 4 55 24 8 2 48 - 26 0 0 6 11 22 3 36 33 29 119 -60 5 3 52 7 19 26 4 38 23 7 45 28 - 25 0 0 5 54 34 3 36 38 30 120 -59 4 47 11 7 2 32 4 21 44 7 28 32 - 24 0 0 5 38 10 3 36 43 31 120 -58 4 30 53 6 46 1 4 5 28 7 11 58 - 23 0 0 5 22 9 3 36 49 32 120 -58 4 14 59 6 29 54 3 49 36 6 55 49 - 22 0 0 5 6 32 3 36 54 33 121 -57 3 59 28 6 14 11 3 34 8 6 40 3 - 21 0 0 4 51 20 3 37 0 34 121 -56 3 44 22 5 58 53 3 19 4 6 24 42 - 20 0 0 4 36 32 3 37 5 35 121 -55 3 29 40 5 43 59 3 4 24 6 9 46 - 19 0 0 4 22 9 3 37 11 36 121 -54 3 15 23 5 29 30 2 50 10 5 55 15 - 18 0 0 4 8 12 3 37 17 37 122 -53 3 1 31 5 15 26 2 36 20 5 41 9 - 17 0 0 3 54 39 3 37 24 38 122 -52 2 48 5 5 1 48 2 22 55 5 27 29 - 16 0 0 3 41 33 3 37 30 39 122 -51 2 35 3 4 48 36 2 9 56 5 14 14 - 15 0 0 3 28 52 3 37 36 40 123 -50 2 22 28 4 35 50 1 57 22 5 1 26 - 14 0 0 3 16 37 3 37 43 41 123 -49 2 10 18 4 23 30 1 45 15 4 49 4 - 13 0 0 3 4 49 3 37 50 42 124 -48 1 58 35 4 11 36 1 33 33 4 37 8 - 12 0 0 2 53 27 3 37 57 43 124 -47 1 47 18 4 0 9 1 22 18 4 25 40 - 11 0 0 2 42 32 3 38 4 44 124 -46 1 36 28 3 49 9 1 11 30 4 14 38 - 10 0 0 2 32 3 3 38 11 45 125 -45 1 26 4 3 38 36 1 1 7 4 4 3 - 9 0 0 2 22 2 3 38 18 46 125 -44 1 16 7 3 28 30 0 51 12 3 53 55 - 8 0 0 2 12 28 3 38 25 47 126 -44 1 6 37 3 18 52 0 41 44 3 44 15 - 7 0 0 2 3 21 3 38 33 47 127 -43 0 57 34 3 9 41 0 32 43 3 35 3 - 6 0 0 1 54 42 3 38 40 48 127 -42 0 48 59 3 0 58 0 24 9 3 26 18 - 5 0 0 1 46 30 3 38 48 49 128 -41 0 40 51 2 52 43 0 16 2 3 18 2 - 4 0 0 1 38 47 3 38 55 50 128 -40 0 33 11 2 44 56 0 8 23 3 10 13 - 3 0 0 1 31 31 3 39 3 51 129 -39 0 25 58 2 37 37 0 1 12 3 2 53 - 2 0 0 1 24 43 3 39 11 52 130 -38 0 19 13 2 30 46 - 0 5 32 2 56 0 - 1 0 0 1 18 23 3 39 19 53 131 -37 0 12 57 2 24 23 - 0 11 47 2 49 37 0 0 0 1 12 32 3 39 27 54 132 -36 0 7 8 2 18 29 - 0 17 35 2 43 42 1 0 0 1 7 9 3 39 36 54 132 -35 0 1 47 2 13 3 - 0 22 55 2 38 15 2 0 0 1 2 14 3 39 44 55 133 -33 - 0 3 6 2 8 6 - 0 27 47 2 33 17 3 0 0 0 57 48 3 39 52 56 134 -32 - 0 7 30 2 3 38 - 0 32 10 2 28 48 4 0 0 0 53 50 3 40 1 57 135 -31 - 0 11 26 1 59 39 - 0 36 6 2 24 48 5 0 0 0 50 21 3 40 9 58 136 -30 - 0 14 53 1 56 8 - 0 39 33 2 21 17 6 0 0 0 47 21 3 40 18 58 138 -29 - 0 17 52 1 53 6 - 0 42 31 2 18 15 7 0 0 0 44 49 3 40 26 59 139 -28 - 0 20 23 1 50 33 - 0 45 1 2 15 41 8 0 0 0 42 46 3 40 35 60 140 -27 - 0 22 25 1 48 30 - 0 47 3 2 13 37 9 0 0 0 41 12 3 40 44 60 142 -26 - 0 23 58 1 46 55 - 0 48 36 2 12 2 10 0 0 0 40 7 3 40 53 61 143 -25 - 0 25 3 1 45 50 - 0 49 41 2 10 57 11 0 0 0 39 31 3 41 1 62 145 -24 - 0 25 39 1 45 13 - 0 50 17 2 10 20 12 0 0 0 39 23 3 41 10 62 146 -23 - 0 25 46 1 45 6 - 0 50 24 2 10 13 13 0 0 0 39 45 3 41 19 63 148 -22 - 0 25 25 1 45 28 - 0 50 3 2 10 35 14 0 0 0 40 36 3 41 28 63 150 -21 - 0 24 35 1 46 19 - 0 49 13 2 11 26 15 0 0 0 41 55 3 41 37 64 152 -20 - 0 23 16 1 47 39 - 0 47 54 2 12 47 16 0 0 0 43 44 3 41 46 64 153 -19 - 0 21 29 1 49 29 - 0 46 7 2 14 37 17 0 0 0 46 1 3 41 56 65 156 -18 - 0 19 12 1 51 48 - 0 43 51 2 16 56 18 0 0 0 48 48 3 42 5 65 158 -17 - 0 16 27 1 54 36 - 0 41 7 2 19 45 19 0 0 0 52 3 3 42 14 65 160 -16 - 0 13 14 1 57 53 - 0 37 54 2 23 3 20 0 0 0 55 47 3 42 23 66 162 -15 - 0 9 31 2 1 39 - 0 34 12 2 26 49 21 0 0 1 0 1 3 42 32 66 164 -14 - 0 5 20 2 5 54 - 0 30 2 2 31 6 22 0 0 1 4 43 3 42 42 66 167 -13 - 0 0 41 2 10 39 - 0 25 23 2 35 51 23 0 0 1 9 53 3 42 51 66 169 -12 0 4 28 2 15 52 - 0 20 16 2 41 5 24 0 0 1 15 33 3 43 0 66 171 -11 0 10 4 2 21 34 - 0 14 40 2 46 49 25 0 0 1 21 41 3 43 10 66 174 -10 0 16 10 2 27 46 - 0 8 36 2 53 2 26 0 0 1 28 18 3 43 19 66 176 -9 0 22 43 2 34 26 - 0 2 4 2 59 43 27 0 0 1 35 23 3 43 28 66 179 -8 0 29 45 2 41 35 0 4 57 3 6 53 28 0 0 1 42 57 3 43 38 66 181 -7 0 37 16 2 49 13 0 12 26 3 14 32 29 0 0 1 51 0 3 43 47 66 183 -6 0 45 14 2 57 19 0 20 23 3 22 40 30 0 0 1 59 30 3 43 56 66 186 -5 0 53 41 3 5 53 0 28 48 3 31 16 31 0 0 2 8 29 3 44 6 66 188 -3 1 2 35 3 14 57 0 37 41 3 40 21 32 0 0 2 17 56 3 44 15 65 190 -2 1 11 57 3 24 28 0 47 2 3 49 54 33 0 0 2 27 51 3 44 24 65 192 -1 1 21 48 3 34 27 0 56 50 3 59 56 34 0 0 2 38 13 3 44 33 64 194 0 1 32 5 3 44 55 1 7 6 4 10 25 Uncertainty in time = +/- 6 secs [Prediction of 2008 Feb 4.0] Data for the target star ------------------------ * name: 2UCAC 22978994 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 24 45.4696 DE: -22 05 24.060 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .042, .024 ) * V mag [mag]: 11.9 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 276.3174674234 DE(deg): -22.0872394944 * Equation of equinoxes (radians) : 0.000040516610020 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (19) Fortuna approx. diameter [km]: 221 approx. diameter ["]: .129 distance from Earth [AU]: 2.36300 * orbital information: orbit source: Preston date of fit: 2008 Feb 03 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, 87° remarks: * orbital elements for (19) Fortuna : Mean anomaly = 234.19631472 deg Arg. of pericenter = 181.84839803 deg Long. of node = 211.35791688 deg Inclination = 1.57283394 deg Eccentricity = 0.15859465 Semimajor axis = 2.44278531 AU Perihelion dist = 2.05537262 AU Mag: H = 7.13, G = 0.10 Epoch of elements : MJD 54560.15500000 TDT (2008 Apr 04.155) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Apr 4 19 Fortuna 3h 43.2m UT 11.9 18 24 45.470-22 5 24.062UCAC 22978994 0.0 12.3 221 17.7 2.363 1.872 2.89 27.5561 -22.090 124.95 5.82 3.7199 -0.04305 0.39780 6.99543 0.77658 -0.00568 -0.00026 2000 234.1563012008 4 4.00000181.848398211.357917 1.5728340.15859465 2.4427853 2.0553726 7.1 5.00.10 RATE 2.5815240 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.043 0.025 90 1.19 0.025 0 54500.5020080404_978994 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 07, 13:45 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org