IOTA/IOTA-ES occultation update for (19) Fortuna / TYC 6307-01385-1 event on 2012 Oct 21, 14:52 UT Visible from Russia Summary ------- On 2012 Oct 21 UT, the 230 km diameter asteroid (19) Fortuna will occult a 10.0 mag star in the constellation Sagittarius for observers along a path across Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.0 mag to 11.8 mag (the magnitude of the asteroid) for at most 11.6 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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: 2012 Oct 21, 14:51 - 2012 Oct 21, 14:54 UT * geocentric midpoint of event [JD]: 2456222.11941667 * magnitude of target star: 10.0 * magnitude drop [mag]: 2.0 * estimated maximum duration [s]: 11.6 * Moon: 44 % sunlit, 3° distance * Sun: 85° distance * rough path description: Russia The occultation path -------------------- * approximate projected width [km]: 585 * 1 sigma uncertainty interval [path widths]: +/- 0.19 * 1 sigma uncertainty interval [seconds]: +/- 1.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .028) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .026", 360° ) * approx speed of asteroid's shadow [km/s]: 19.8324 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6307-01385-1 by 19 Fortuna on 2012 Oct 21 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 79 34 27 65 0 0 14 54 0 1 216 -25 ... .. .. 71 24 54 ... .. .. 68 4 6 77 49 14 64 0 0 14 54 0 2 214 -25 ... .. .. 69 47 29 ... .. .. 66 29 12 76 2 27 63 0 0 14 53 59 3 212 -25 83 17 13 68 6 43 ... .. .. 64 50 5 74 13 46 62 0 0 14 53 58 4 211 -24 81 22 23 66 22 15 ... .. .. 63 6 25 72 22 51 61 0 0 14 53 56 6 209 -24 79 26 45 64 33 42 ... .. .. 61 17 45 70 29 20 60 0 0 14 53 54 7 207 -23 77 29 58 62 40 36 80 1 8 59 23 29 68 32 47 59 0 0 14 53 52 8 206 -23 75 31 38 60 42 19 78 1 34 57 22 51 66 32 42 58 0 0 14 53 48 10 204 -22 73 31 21 58 38 5 76 0 31 55 14 50 Latitude Latitude Latitude Latitude 65 0 0 57 15 1 14 53 46 11 202 -21 53 59 42 61 14 19 52 52 47 63 5 53 64 0 0 56 46 32 14 53 44 11 202 -21 53 33 23 60 41 51 52 27 4 62 30 40 63 0 0 56 18 35 14 53 41 12 201 -20 53 7 31 60 10 6 52 1 46 61 56 23 62 0 0 55 51 9 14 53 39 13 200 -20 52 42 6 59 39 5 51 36 56 61 22 59 61 0 0 55 24 17 14 53 37 13 199 -19 52 17 10 59 8 47 51 12 32 60 50 29 60 0 0 54 57 57 14 53 34 14 198 -19 51 52 43 58 39 13 50 48 37 60 18 50 59 0 0 54 32 11 14 53 32 14 197 -18 51 28 46 58 10 21 50 25 11 59 48 3 58 0 0 54 7 0 14 53 29 15 196 -18 51 5 19 57 42 14 50 2 14 59 18 7 57 0 0 53 42 24 14 53 27 15 195 -17 50 42 23 57 14 49 49 39 47 58 49 1 56 0 0 53 18 22 14 53 24 16 194 -17 50 19 59 56 48 8 49 17 51 58 20 45 55 0 0 52 54 57 14 53 21 17 193 -16 49 58 7 56 22 11 48 56 26 57 53 17 54 0 0 52 32 8 14 53 18 17 192 -15 49 36 48 55 56 57 48 35 33 57 26 39 53 0 0 52 9 56 14 53 15 18 191 -15 49 16 2 55 32 27 48 15 13 57 0 50 52 0 0 51 48 21 14 53 11 18 190 -14 48 55 50 55 8 41 47 55 25 56 35 49 51 0 0 51 27 24 14 53 8 18 189 -14 48 36 12 54 45 39 47 36 11 56 11 36 50 0 0 51 7 5 14 53 5 19 188 -13 48 17 9 54 23 21 47 17 30 55 48 12 49 0 0 50 47 24 14 53 1 19 187 -12 47 58 41 54 1 47 46 59 24 55 25 35 48 0 0 50 28 21 14 52 58 20 186 -12 47 40 48 53 40 57 46 41 53 55 3 46 47 0 0 50 9 58 14 52 54 20 185 -11 47 23 32 53 20 52 46 24 56 54 42 45 46 0 0 49 52 13 14 52 51 20 184 -10 47 6 51 53 1 31 46 8 35 54 22 31 45 0 0 49 35 8 14 52 47 21 183 -10 46 50 47 52 42 54 45 52 49 54 3 5 44 0 0 49 18 43 14 52 44 21 182 -9 46 35 20 52 25 2 45 37 40 53 44 26 43 0 0 49 2 58 14 52 40 21 181 -8 46 20 30 52 7 54 45 23 7 53 26 35 42 0 0 48 47 53 14 52 36 22 180 -8 46 6 18 51 51 31 45 9 10 53 9 31 41 0 0 48 33 28 14 52 32 22 179 -7 45 52 43 51 35 53 44 55 51 52 53 14 40 0 0 48 19 44 14 52 28 22 178 -6 45 39 46 51 21 0 44 43 8 52 37 44 39 0 0 48 6 40 14 52 25 22 177 -5 45 27 27 51 6 51 44 31 3 52 23 1 38 0 0 47 54 18 14 52 21 22 176 -5 45 15 47 50 53 28 44 19 35 52 9 6 37 0 0 47 42 36 14 52 17 23 175 -4 45 4 45 50 40 49 44 8 46 51 55 58 36 0 0 47 31 36 14 52 13 23 174 -3 44 54 21 50 28 55 43 58 34 51 43 36 35 0 0 47 21 17 14 52 9 23 173 -3 44 44 37 50 17 47 43 49 0 51 32 2 34 0 0 47 11 39 14 52 5 23 172 -2 44 35 31 50 7 23 43 40 4 51 21 15 33 0 0 47 2 43 14 52 1 23 171 -1 44 27 5 49 57 44 43 31 47 51 11 14 32 0 0 46 54 28 14 51 57 23 170 0 44 19 18 49 48 51 43 24 8 51 2 1 Uncertainty in time = +/- 2 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: TYC 6307-01385-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 41 08.9150 DE: -19 47 13.549 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .027 ) * V mag [mag]: 10.0 * B mag [mag]: 10.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (19) Fortuna approx. diameter [km]: 230 approx. diameter ["]: .148 distance from Earth [AU]: 2.13700 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 1885 number of rejected observations: 263 time covered by the observations: 1900 Feb 12 - 2012 Oct 05 1 sigma uncertainty ellipse (major, minor, PA): 0.007, 0.005, 80° remarks: * orbital elements for (19) Fortuna : Mean anomaly = 302.65237678 deg Arg. of pericenter = 182.36953107 deg Long. of node = 211.23535122 deg Inclination = 1.57339556 deg Eccentricity = 0.15783782 Semimajor axis = 2.44196729 AU Perihelion dist = 2.05653250 AU Mag: H = 7.17, G = 0.10 Epoch of elements : MJD 56221.61900000 TDT (2012 Oct 21.619) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 21 19 Fortuna 14h 52.0m UT 10.0 19 41 8.915-19 47 13.55TYC 6307-01385-1 10.3 11.8 230 11.6 2.137 3.235 6.09 41.8430 -19.788 -46.85 -10.98 14.8660 -0.11711 0.91197 11.09585 1.47868 0.00548 0.00096 2000 302.23421820121020.00000182.369531211.235351 1.5733960.15783782 2.4419673 2.0565325 7.1 5.00.10 RATE 2.5828210 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.026 360 1.19 0.028 0 0 0 1 056208.0020121021_1385-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 19:11 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org