IOTA/IOTA-ES occultation update for (205) Martha / TYC 5666-01596-1 event on 2012 Sep 20, 03:42 UT Visible from S USA, NW Mexico Summary ------- On 2012 Sep 20 UT, the 68 km diameter asteroid (205) Martha will occult a 11.3 mag star in the constellation Serpens for observers along a path across S USA, NW Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.4 mag to 14.7 mag (the magnitude of the asteroid) for at most 3.4 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: 62 * date and approx. time of event: 2012 Sep 20, 03:42 - 2012 Sep 20, 03:45 UT * geocentric midpoint of event [JD]: 2456190.65446667 * magnitude of target star: 11.3 * magnitude drop [mag]: 3.4 * estimated maximum duration [s]: 3.4 * Moon: 21 % sunlit, 32° distance * Sun: 85° distance * rough path description: S USA, NW Mexico The occultation path -------------------- * approximate projected width [km]: 105 * 1 sigma uncertainty interval [path widths]: +/- 0.98 * 1 sigma uncertainty interval [seconds]: +/- 3.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .031 +/- .034) * 1 sigma uncertainty ellipse (major, minor, PA): ( .034", .031", 360° ) * approx speed of asteroid's shadow [km/s]: 19.7911 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5666-01596-1 by 205 Martha on 2012 Sep 20 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 -146 0 0 37 15 4 3 42 2 40 189 0 36 45 13 37 45 15 35 47 36 38 45 24 -145 0 0 37 0 17 3 42 7 40 190 -1 36 30 29 37 30 24 35 32 59 38 30 25 -144 0 0 36 45 49 3 42 12 40 191 -2 36 16 5 37 15 52 35 18 41 38 15 46 -143 0 0 36 31 41 3 42 17 40 193 -3 36 2 1 37 1 41 35 4 44 38 1 27 -142 0 0 36 17 54 3 42 21 40 194 -4 35 48 17 36 47 50 34 51 7 37 47 29 -141 0 0 36 4 28 3 42 26 40 195 -4 35 34 54 36 34 20 34 37 50 37 33 52 -140 0 0 35 51 23 3 42 31 40 197 -5 35 21 52 36 21 12 34 24 54 37 20 36 -139 0 0 35 38 39 3 42 36 40 198 -6 35 9 12 36 8 25 34 12 20 37 7 42 -138 0 0 35 26 17 3 42 41 40 199 -7 34 56 53 35 56 0 34 0 8 36 55 10 -137 0 0 35 14 17 3 42 45 40 201 -8 34 44 57 35 43 57 33 48 17 36 43 0 -136 0 0 35 2 40 3 42 50 40 202 -9 34 33 23 35 32 16 33 36 49 36 31 14 -135 0 0 34 51 26 3 42 55 40 203 -10 34 22 11 35 20 59 33 25 43 36 19 50 -134 0 0 34 40 35 3 43 0 39 204 -10 34 11 23 35 10 5 33 15 0 36 8 49 -133 0 0 34 30 6 3 43 5 39 206 -11 34 0 57 34 59 34 33 4 40 35 58 13 -132 0 0 34 20 2 3 43 9 39 207 -12 33 50 56 34 49 26 32 54 43 35 47 59 -131 0 0 34 10 21 3 43 14 39 208 -13 33 41 18 34 39 43 32 45 10 35 38 10 -130 0 0 34 1 4 3 43 19 38 209 -14 33 32 3 34 30 23 32 36 0 35 28 46 -129 0 0 33 52 12 3 43 23 38 211 -15 33 23 13 34 21 28 32 27 15 35 19 46 -128 0 0 33 43 44 3 43 28 38 212 -16 33 14 47 34 12 58 32 18 53 35 11 10 -127 0 0 33 35 40 3 43 33 37 213 -16 33 6 46 34 4 52 32 10 56 35 3 0 -126 0 0 33 28 1 3 43 37 37 214 -17 32 59 9 33 57 11 32 3 24 34 55 14 -125 0 0 33 20 48 3 43 42 37 215 -18 32 51 58 33 49 55 31 56 16 34 47 54 -124 0 0 33 13 59 3 43 46 36 216 -19 32 45 11 33 43 4 31 49 32 34 40 59 -123 0 0 33 7 35 3 43 50 36 217 -20 32 38 49 33 36 39 31 43 14 34 34 30 -122 0 0 33 1 37 3 43 55 35 219 -21 32 32 53 33 30 39 31 37 21 34 28 26 -121 0 0 32 56 5 3 43 59 35 220 -22 32 27 22 33 25 5 31 31 53 34 22 49 -120 0 0 32 50 58 3 44 3 34 221 -22 32 22 16 33 19 56 31 26 50 34 17 37 -119 0 0 32 46 16 3 44 8 34 222 -23 32 17 36 33 15 14 31 22 13 34 12 51 -118 0 0 32 42 1 3 44 12 33 223 -24 32 13 22 33 10 57 31 18 1 34 8 32 -117 0 0 32 38 11 3 44 16 33 224 -25 32 9 33 33 7 6 31 14 14 34 4 38 -116 0 0 32 34 47 3 44 20 32 225 -26 32 6 10 33 3 41 31 10 53 34 1 11 -115 0 0 32 31 49 3 44 24 32 226 -27 32 3 13 33 0 42 31 7 58 33 58 10 -114 0 0 32 29 17 3 44 28 31 227 -27 32 0 42 32 58 9 31 5 29 33 55 36 -113 0 0 32 27 11 3 44 32 31 227 -28 31 58 37 32 56 2 31 3 25 33 53 28 -112 0 0 32 25 31 3 44 36 30 228 -29 31 56 58 32 54 22 31 1 47 33 51 46 -111 0 0 32 24 18 3 44 39 29 229 -30 31 55 45 32 53 8 31 0 34 33 50 31 -110 0 0 32 23 30 3 44 43 29 230 -31 31 54 57 32 52 20 30 59 48 33 49 42 -109 0 0 32 23 8 3 44 47 28 231 -31 31 54 36 32 51 58 30 59 27 33 49 19 -108 0 0 32 23 13 3 44 50 27 232 -32 31 54 40 32 52 2 30 59 32 33 49 23 -107 0 0 32 23 43 3 44 53 27 233 -33 31 55 11 32 52 32 31 0 2 33 49 54 -106 0 0 32 24 39 3 44 57 26 233 -34 31 56 7 32 53 29 31 0 58 33 50 50 -105 0 0 32 26 2 3 45 0 25 234 -34 31 57 29 32 54 51 31 2 20 33 52 13 -104 0 0 32 27 50 3 45 3 25 235 -35 31 59 17 32 56 40 31 4 7 33 54 3 -103 0 0 32 30 4 3 45 6 24 236 -36 32 1 31 32 58 54 31 6 20 33 56 18 -102 0 0 32 32 44 3 45 9 23 236 -37 32 4 10 33 1 35 31 8 58 33 59 0 -101 0 0 32 35 49 3 45 12 22 237 -37 32 7 15 33 4 41 31 12 1 34 2 7 -100 0 0 32 39 20 3 45 15 22 238 -38 32 10 45 33 8 13 31 15 30 34 5 40 - 99 0 0 32 43 17 3 45 18 21 238 -39 32 14 40 33 12 10 31 19 24 34 9 40 - 98 0 0 32 47 38 3 45 20 20 239 -39 32 19 1 33 16 33 31 23 43 34 14 5 - 97 0 0 32 52 25 3 45 23 19 240 -40 32 23 47 33 21 21 31 28 27 34 18 55 - 96 0 0 32 57 37 3 45 25 19 240 -41 32 28 58 33 26 34 31 33 35 34 24 11 - 95 0 0 33 3 14 3 45 27 18 241 -41 32 34 34 33 32 13 31 39 8 34 29 52 - 94 0 0 33 9 16 3 45 30 17 242 -42 32 40 34 33 38 16 31 45 6 34 35 59 - 93 0 0 33 15 43 3 45 32 16 242 -43 32 46 59 33 44 44 31 51 28 34 42 30 - 92 0 0 33 22 34 3 45 34 15 243 -43 32 53 48 33 51 37 31 58 14 34 49 26 - 91 0 0 33 29 49 3 45 36 15 244 -44 33 1 2 33 58 54 32 5 25 34 56 47 - 90 0 0 33 37 28 3 45 38 14 244 -44 33 8 39 34 6 35 32 12 58 35 4 32 - 89 0 0 33 45 31 3 45 39 13 245 -45 33 16 40 34 14 40 32 20 56 35 12 41 - 88 0 0 33 53 58 3 45 41 12 246 -45 33 25 5 34 23 9 32 29 17 35 21 15 - 87 0 0 34 2 49 3 45 42 11 246 -46 33 33 53 34 32 2 32 38 1 35 30 12 - 86 0 0 34 12 2 3 45 44 10 247 -46 33 43 5 34 41 17 32 47 8 35 39 32 - 85 0 0 34 21 39 3 45 45 10 247 -47 33 52 39 34 50 57 32 56 38 35 49 16 - 84 0 0 34 31 38 3 45 46 9 248 -47 34 2 36 35 0 58 33 6 31 35 59 23 - 83 0 0 34 42 0 3 45 47 8 249 -47 34 12 55 35 11 23 33 16 45 36 9 53 - 82 0 0 34 52 44 3 45 48 7 249 -48 34 23 37 35 22 10 33 27 22 36 20 46 - 81 0 0 35 3 50 3 45 49 6 250 -48 34 34 40 35 33 18 33 38 20 36 32 0 - 80 0 0 35 15 18 3 45 50 5 250 -48 34 46 5 35 44 49 .. .. .. 36 43 37 - 79 0 0 35 27 7 3 45 50 5 251 -49 34 57 51 35 56 41 .. .. .. 36 55 35 - 78 0 0 35 39 17 3 45 51 4 251 -49 35 9 58 36 8 54 .. .. .. 37 7 54 - 77 0 0 35 51 48 3 45 51 3 252 -49 35 22 26 36 21 28 .. .. .. 37 20 34 - 76 0 0 36 4 39 3 45 52 2 253 -49 35 35 14 36 34 22 .. .. .. 37 33 35 - 75 0 0 36 17 50 3 45 52 1 253 -50 35 48 22 36 47 37 .. .. .. 37 46 57 - 74 0 0 36 31 21 3 45 52 0 254 -50 36 1 50 37 1 11 .. .. .. 38 0 38 Uncertainty in time = +/- 3 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 5666-01596-1 * constellation : Serpens * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 17 27 29.4295 DE: -12 44 15.986 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .029, .033 ) * V mag [mag]: 11.3 * B mag [mag]: 12.6 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (205) Martha approx. diameter [km]: 68 approx. diameter ["]: .035 distance from Earth [AU]: 2.70500 * orbital information: orbit source: Preston date of fit: 2012 Aug 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1060 number of rejected observations: 79 time covered by the observations: 1907 Nov 07 - 2012 Aug 12 1 sigma uncertainty ellipse (major, minor, PA): 0.012, 0.009, 85° remarks: * orbital elements for (205) Martha : Mean anomaly = 260.75689875 deg Arg. of pericenter = 174.67913386 deg Long. of node = 211.92942739 deg Inclination = 10.68356440 deg Eccentricity = 0.03408018 Semimajor axis = 2.77772509 AU Perihelion dist = 2.68305972 AU Mag: H = 9.37, G = 0.15 Epoch of elements : MJD 56190.15400000 TDT (2012 Sep 20.154) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 20 205 Martha 3h 42.4m UT 11.3 17 27 29.430-12 44 15.99TYC 5666-01596-1 12.6 14.7 68 3.4 2.705 2.425 -7.80 -153.1768 -12.735 122.74 0.96 3.7072 0.16724 0.74598 10.90974 -2.40013 0.00569 -0.00022 2000 260.7241132012 920.00000174.679134211.929427 10.6835640.03408018 2.7777251 2.6830597 9.2 5.00.15 RATE 2.1289730 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.034 0.031 360 1.98 0.034 0 0-5 4 056165.0020120920_1596-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 25, 23:00 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org