IOTA/IOTA-ES occultation update for (1400) Tirela / TYC 5175-00878-1 event on 2012 Nov 15, 02:23 UT Visible from S USA, N Mexico Summary ------- On 2012 Nov 15 UT, the 15 km diameter asteroid (1400) Tirela will occult a 9.5 mag star in the constellation Aquila for observers along a path across S USA, N Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.8 mag to 16.3 mag (the magnitude of the asteroid) for at most 0.5 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: 18 * date and approx. time of event: 2012 Nov 15, 02:23 - 2012 Nov 15, 02:26 UT * geocentric midpoint of event [JD]: 2456246.59963333 * magnitude of target star: 9.5 * magnitude drop [mag]: 6.8 * estimated maximum duration [s]: 0.5 * Moon: 2 % sunlit, 58° distance * Sun: 75° distance * rough path description: S USA, N Mexico The occultation path -------------------- * approximate projected width [km]: 18 * 1 sigma uncertainty interval [path widths]: +/- 3.81 * 1 sigma uncertainty interval [seconds]: +/- 1.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .032 +/- .030) * 1 sigma uncertainty ellipse (major, minor, PA): ( .032", .030", 84° ) * approx speed of asteroid's shadow [km/s]: 29.4290 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5175-00878-1 by 1400 Tirela on 2012 Nov 15 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 -140 0 0 29 21 3 2 23 40 55 187 0 29 16 5 29 26 1 28 38 27 30 4 1 -139 0 0 29 20 45 2 23 43 55 189 -1 29 15 47 29 25 43 28 38 9 30 3 43 -138 0 0 29 20 33 2 23 47 55 191 -2 29 15 36 29 25 31 28 37 57 30 3 32 -137 0 0 29 20 29 2 23 50 54 192 -3 29 15 32 29 25 27 28 37 53 30 3 27 -136 0 0 29 20 32 2 23 53 54 194 -4 29 15 34 29 25 30 28 37 56 30 3 30 -135 0 0 29 20 41 2 23 57 54 196 -5 29 15 44 29 25 39 28 38 5 30 3 40 -134 0 0 29 20 58 2 24 0 54 197 -5 29 16 0 29 25 56 28 38 22 30 3 56 -133 0 0 29 21 22 2 24 3 53 199 -6 29 16 24 29 26 19 28 38 45 30 4 20 -132 0 0 29 21 52 2 24 7 53 201 -7 29 16 54 29 26 50 28 39 16 30 4 50 -131 0 0 29 22 29 2 24 10 53 202 -8 29 17 32 29 27 27 28 39 53 30 5 28 -130 0 0 29 23 14 2 24 13 52 204 -9 29 18 16 29 28 12 28 40 37 30 6 12 -129 0 0 29 24 5 2 24 16 52 205 -10 29 19 7 29 29 3 28 41 29 30 7 3 -128 0 0 29 25 3 2 24 19 52 207 -11 29 20 5 29 30 1 28 42 27 30 8 2 -127 0 0 29 26 8 2 24 23 51 208 -11 29 21 10 29 31 6 28 43 31 30 9 7 -126 0 0 29 27 20 2 24 26 51 210 -12 29 22 22 29 32 18 28 44 43 30 10 18 -125 0 0 29 28 38 2 24 29 50 211 -13 29 23 40 29 33 36 28 46 1 30 11 37 -124 0 0 29 30 3 2 24 32 50 212 -14 29 25 6 29 35 2 28 47 27 30 13 2 -123 0 0 29 31 36 2 24 35 49 214 -15 29 26 38 29 36 34 28 48 59 30 14 35 -122 0 0 29 33 14 2 24 38 49 215 -16 29 28 17 29 38 12 28 50 37 30 16 14 -121 0 0 29 35 0 2 24 41 48 216 -17 29 30 2 29 39 58 28 52 23 30 17 59 -120 0 0 29 36 52 2 24 44 48 218 -17 29 31 54 29 41 50 28 54 14 30 19 51 -119 0 0 29 38 50 2 24 47 47 219 -18 29 33 53 29 43 48 28 56 13 30 21 50 -118 0 0 29 40 56 2 24 50 47 220 -19 29 35 58 29 45 54 28 58 18 30 23 55 -117 0 0 29 43 7 2 24 53 46 221 -20 29 38 9 29 48 5 29 0 29 30 26 7 -116 0 0 29 45 25 2 24 56 45 222 -21 29 40 27 29 50 23 29 2 47 30 28 26 -115 0 0 29 47 50 2 24 59 45 224 -22 29 42 52 29 52 48 29 5 11 30 30 50 -114 0 0 29 50 21 2 25 2 44 225 -23 29 45 23 29 55 19 29 7 42 30 33 21 -113 0 0 29 52 58 2 25 5 43 226 -24 29 48 0 29 57 56 29 10 19 30 35 59 -112 0 0 29 55 41 2 25 7 43 227 -24 29 50 43 30 0 39 29 13 2 30 38 42 -111 0 0 29 58 30 2 25 10 42 228 -25 29 53 32 30 3 29 29 15 51 30 41 32 -110 0 0 30 1 26 2 25 13 41 229 -26 29 56 28 30 6 24 29 18 47 30 44 27 -109 0 0 30 4 27 2 25 16 41 230 -27 29 59 29 30 9 26 29 21 48 30 47 29 -108 0 0 30 7 35 2 25 18 40 231 -28 30 2 37 30 12 33 29 24 55 30 50 37 -107 0 0 30 10 48 2 25 21 39 232 -29 30 5 50 30 15 47 29 28 8 30 53 51 -106 0 0 30 14 8 2 25 23 39 232 -30 30 9 9 30 19 6 29 31 27 30 57 10 -105 0 0 30 17 33 2 25 26 38 233 -31 30 12 34 30 22 31 29 34 52 31 0 35 -104 0 0 30 21 3 2 25 28 37 234 -31 30 16 5 30 26 2 29 38 22 31 4 6 -103 0 0 30 24 39 2 25 31 36 235 -32 30 19 41 30 29 38 29 41 58 31 7 43 -102 0 0 30 28 21 2 25 33 36 236 -33 30 23 23 30 33 20 29 45 40 31 11 25 -101 0 0 30 32 8 2 25 35 35 237 -34 30 27 10 30 37 7 29 49 27 31 15 12 -100 0 0 30 36 1 2 25 38 34 238 -35 30 31 3 30 41 0 29 53 19 31 19 5 - 99 0 0 30 39 59 2 25 40 33 238 -36 30 35 0 30 44 57 29 57 17 31 23 3 - 98 0 0 30 44 2 2 25 42 33 239 -37 30 39 3 30 49 0 30 1 19 31 27 6 - 97 0 0 30 48 10 2 25 44 32 240 -38 30 43 11 30 53 8 30 5 27 31 31 15 - 96 0 0 30 52 23 2 25 46 31 241 -38 30 47 24 30 57 21 30 9 40 31 35 28 - 95 0 0 30 56 41 2 25 48 30 241 -39 30 51 42 31 1 39 30 13 57 31 39 46 - 94 0 0 31 1 3 2 25 50 29 242 -40 30 56 5 31 6 2 30 18 20 31 44 9 - 93 0 0 31 5 31 2 25 52 29 243 -41 31 0 32 31 10 30 30 22 47 31 48 37 - 92 0 0 31 10 3 2 25 54 28 243 -42 31 5 4 31 15 2 30 27 19 31 53 9 - 91 0 0 31 14 39 2 25 56 27 244 -43 31 9 41 31 19 38 30 31 55 31 57 46 - 90 0 0 31 19 20 2 25 58 26 245 -44 31 14 22 31 24 19 30 36 36 32 2 27 - 89 0 0 31 24 5 2 26 0 25 245 -44 31 19 7 31 29 4 30 41 21 32 7 13 - 88 0 0 31 28 55 2 26 1 24 246 -45 31 23 56 31 33 54 30 46 10 32 12 3 - 87 0 0 31 33 49 2 26 3 24 247 -46 31 28 50 31 38 48 30 51 3 32 16 56 - 86 0 0 31 38 46 2 26 4 23 247 -47 31 33 47 31 43 45 30 56 0 32 21 54 - 85 0 0 31 43 48 2 26 6 22 248 -48 31 38 49 31 48 47 31 1 2 32 26 56 - 84 0 0 31 48 53 2 26 7 21 249 -49 31 43 54 31 53 52 31 6 7 32 32 2 - 83 0 0 31 54 2 2 26 9 20 249 -49 31 49 3 31 59 1 31 11 15 32 37 11 - 82 0 0 31 59 14 2 26 10 20 250 -50 31 54 16 32 4 14 31 16 28 32 42 24 - 81 0 0 32 4 30 2 26 11 19 250 -51 31 59 31 32 9 30 31 21 43 32 47 40 - 80 0 0 32 9 50 2 26 13 18 251 -52 32 4 51 32 14 49 31 27 2 32 53 0 - 79 0 0 32 15 12 2 26 14 17 252 -53 32 10 13 32 20 12 31 32 25 32 58 22 - 78 0 0 32 20 38 2 26 15 16 252 -54 32 15 39 32 25 37 31 37 50 33 3 48 - 77 0 0 32 26 7 2 26 16 15 253 -54 32 21 8 32 31 6 31 43 19 33 9 17 - 76 0 0 32 31 38 2 26 17 15 253 -55 32 26 39 32 36 38 31 48 50 33 14 49 - 75 0 0 32 37 13 2 26 18 14 254 -56 32 32 14 32 42 12 31 54 24 33 20 24 - 74 0 0 32 42 50 2 26 19 13 255 -57 32 37 51 32 47 49 32 0 1 33 26 1 - 73 0 0 32 48 29 2 26 20 12 255 -58 32 43 30 32 53 29 32 5 41 33 31 41 - 72 0 0 32 54 12 2 26 21 11 256 -58 32 49 12 32 59 11 32 11 22 33 37 23 - 71 0 0 32 59 56 2 26 21 10 256 -59 32 54 57 33 4 55 32 17 7 33 43 8 - 70 0 0 33 5 43 2 26 22 9 257 -60 33 0 43 33 10 42 32 22 53 33 48 55 - 69 0 0 33 11 31 2 26 23 9 257 -61 33 6 32 33 16 31 32 28 41 33 54 43 - 68 0 0 33 17 22 2 26 23 8 258 -61 33 12 23 33 22 21 32 34 32 34 0 34 - 67 0 0 33 23 14 2 26 24 7 258 -62 33 18 15 33 28 14 32 40 24 34 6 27 - 66 0 0 33 29 8 2 26 24 6 259 -63 33 24 9 33 34 8 32 46 18 34 12 21 - 65 0 0 33 35 4 2 26 24 5 260 -63 33 30 5 33 40 4 32 52 14 34 18 17 - 64 0 0 33 41 2 2 26 25 4 260 -64 33 36 2 33 46 1 .. .. .. 34 24 15 - 63 0 0 33 47 0 2 26 25 4 261 -65 33 42 1 33 52 0 .. .. .. 34 30 14 - 62 0 0 33 53 0 2 26 25 3 261 -65 33 48 1 33 58 0 .. .. .. 34 36 14 - 61 0 0 33 59 1 2 26 25 2 262 -66 33 54 2 34 4 1 .. .. .. 34 42 15 - 60 0 0 34 5 3 2 26 26 1 262 -67 34 0 4 34 10 3 .. .. .. 34 48 17 - 59 0 0 34 11 6 2 26 26 0 263 -67 34 6 7 34 16 6 .. .. .. 34 54 20 Uncertainty in time = +/- 2 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: TYC 5175-00878-1 * constellation : Aquila * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 20 24 54.5115 DE: -05 46 25.012 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .027 ) * V mag [mag]: 9.5 * B mag [mag]: 11.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1400) Tirela approx. diameter [km]: 15 approx. diameter ["]: .008 distance from Earth [AU]: 2.45500 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1074 number of rejected observations: 18 time covered by the observations: 1930 Oct 15 - 2012 Oct 02 1 sigma uncertainty ellipse (major, minor, PA): 0.023, 0.014, 78° remarks: * orbital elements for (1400) Tirela : Mean anomaly = 6.03406428 deg Arg. of pericenter = 109.59517849 deg Long. of node = 210.74820156 deg Inclination = 15.54926355 deg Eccentricity = 0.23609087 Semimajor axis = 3.12150204 AU Perihelion dist = 2.38454390 AU Mag: H = 11.33, G = 0.15 Epoch of elements : MJD 56246.10000000 TDT (2012 Nov 15.100) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 15 1400 Tirela 2h 23.5m UT 9.5 20 24 54.512- 5 46 25.01TYC 5175-00878-1 11.0 16.3 15 0.5 2.455 3.986 -0.75 -144.2241 -5.773 140.29 -18.55 2.3912 0.00808 0.57237 16.60918 -0.21127 0.00529 0.00168 2000 4.943908201211 9.00000109.595178210.748202 15.5492640.23609087 3.1215020 2.384543911.3 5.00.15 RATE 1.7871410 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.032 0.030 84 4.81 0.032 0 0-5-2 056208.0020121115_0878-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 20:41 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org