IOTA/IOTA-ES occultation update for (246) Asporina / 2UCAC 36260911 event on 2008 May 01, 05:34 UT Visible from NW USA Summary ------- On 2008 May 01 UT, the 60 km diameter asteroid (246) Asporina will occult a 11.0 mag star in the constellation Gemini for observers along a path across NW USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.5 mag to 14.5 mag (the magnitude of the asteroid) for at most 1.9 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: 45 * date and approx. time of event: 2008 May 01, 05:36 - 2008 May 01, 05:37 UT * midpoint of event [JD]: 2454587.73249583 * magnitude of target star: 11.0 * magnitude drop [mag]: 3.5 * estimated maximum duration [s]: 1.9 * Moon: 23 % sunlit, 113° distance * Sun: 56° distance * rough path description: NW USA The occultation path -------------------- * approximate projected width [km]: 73 * 1 sigma uncertainty interval [path widths]: +/- 1.46 * 1 sigma uncertainty interval [seconds]: +/- 2.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .027 +/- .037) * 1 sigma uncertainty ellipse (major, minor, PA): ( .037", .027", 360° ) * approx speed of asteroid's shadow [km/s]: 32.4259 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 36260911 by 246 Asporina on 2008 May 1 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 -155 0 0 50 30 17 5 36 45 34 247 0 50 10 23 50 50 16 49 12 43 51 49 6 -154 0 0 50 26 29 5 36 46 33 248 -1 50 6 34 50 46 29 49 8 52 51 45 21 -153 0 0 50 22 27 5 36 48 33 249 -2 50 2 32 50 42 28 49 4 48 51 41 22 -152 0 0 50 18 13 5 36 49 32 250 -2 49 58 16 50 38 14 49 0 30 51 37 11 -151 0 0 50 13 44 5 36 51 32 251 -3 49 53 47 50 33 46 48 55 59 51 32 46 -150 0 0 50 9 3 5 36 52 31 252 -3 49 49 5 50 29 6 48 51 14 51 28 8 -149 0 0 50 4 8 5 36 54 30 253 -4 49 44 9 50 24 12 48 46 16 51 23 16 -148 0 0 49 59 0 5 36 55 30 254 -5 49 39 0 50 19 5 48 41 4 51 18 12 -147 0 0 49 53 39 5 36 56 29 255 -5 49 33 38 50 13 44 48 35 39 51 12 54 -146 0 0 49 48 4 5 36 58 29 256 -6 49 28 2 50 8 11 48 30 1 51 7 24 -145 0 0 49 42 16 5 36 59 28 256 -7 49 22 13 50 2 24 48 24 9 51 1 40 -144 0 0 49 36 15 5 37 0 27 257 -7 49 16 11 49 56 24 48 18 4 50 55 43 -143 0 0 49 30 1 5 37 2 27 258 -8 49 9 56 49 50 10 48 11 46 50 49 33 -142 0 0 49 23 33 5 37 3 26 259 -8 49 3 27 49 43 44 48 5 14 50 43 9 -141 0 0 49 16 52 5 37 4 26 260 -9 48 56 45 49 37 4 47 58 29 50 36 33 -140 0 0 49 9 58 5 37 5 25 261 -10 48 49 50 49 30 11 47 51 30 50 29 43 -139 0 0 49 2 51 5 37 6 24 262 -10 48 42 41 49 23 5 47 44 18 50 22 40 -138 0 0 48 55 30 5 37 8 24 263 -11 48 35 20 49 15 45 47 36 53 50 15 25 -137 0 0 48 47 56 5 37 9 23 263 -11 48 27 45 49 8 13 47 29 15 50 7 56 -136 0 0 48 40 10 5 37 10 22 264 -12 48 19 57 49 0 27 47 21 24 50 0 14 -135 0 0 48 32 10 5 37 11 22 265 -12 48 11 56 48 52 29 47 13 19 49 52 19 -134 0 0 48 23 57 5 37 12 21 266 -13 48 3 41 48 44 17 47 5 1 49 44 11 -133 0 0 48 15 31 5 37 13 20 267 -14 47 55 14 48 35 52 46 56 31 49 35 50 -132 0 0 48 6 51 5 37 14 20 268 -14 47 46 34 48 27 14 46 47 47 49 27 16 -131 0 0 47 57 59 5 37 15 19 268 -15 47 37 40 48 18 24 46 38 50 49 18 29 -130 0 0 47 48 54 5 37 16 18 269 -15 47 28 34 48 9 20 46 29 40 49 9 29 -129 0 0 47 39 37 5 37 17 18 270 -16 47 19 15 48 0 3 46 20 17 49 0 16 -128 0 0 47 30 6 5 37 18 17 271 -17 47 9 43 47 50 34 46 10 41 48 50 51 -127 0 0 47 20 22 5 37 18 16 271 -17 46 59 58 47 40 52 46 0 53 48 41 13 -126 0 0 47 10 26 5 37 19 16 272 -18 46 50 1 47 30 57 45 50 52 48 31 22 -125 0 0 47 0 17 5 37 20 15 273 -18 46 39 51 47 20 49 45 40 38 48 21 18 -124 0 0 46 49 56 5 37 21 14 274 -19 46 29 28 47 10 29 45 30 11 48 11 2 -123 0 0 46 39 22 5 37 22 14 275 -19 46 18 53 46 59 57 45 19 32 48 0 34 -122 0 0 46 28 36 5 37 22 13 275 -20 46 8 5 46 49 12 45 8 41 47 49 52 -121 0 0 46 17 37 5 37 23 12 276 -21 45 57 5 46 38 14 44 57 37 47 38 59 -120 0 0 46 6 26 5 37 24 12 277 -21 45 45 53 46 27 5 44 46 21 47 27 53 -119 0 0 45 55 3 5 37 24 11 278 -22 45 34 28 46 15 43 44 34 53 47 16 35 -118 0 0 45 43 27 5 37 25 10 278 -22 45 22 52 46 4 9 44 23 13 47 5 5 -117 0 0 45 31 40 5 37 25 9 279 -23 45 11 3 45 52 23 44 11 21 46 53 23 -116 0 0 45 19 41 5 37 26 9 280 -23 44 59 3 45 40 25 43 59 17 46 41 29 -115 0 0 45 7 30 5 37 26 8 280 -24 44 46 51 45 28 15 43 47 1 46 29 23 -114 0 0 44 55 8 5 37 27 7 281 -25 44 34 27 45 15 54 43 34 34 46 17 5 -113 0 0 44 42 34 5 37 27 6 282 -25 44 21 52 45 3 21 43 21 56 46 4 36 -112 0 0 44 29 49 5 37 27 6 283 -26 44 9 5 44 50 37 43 9 6 45 51 56 -111 0 0 44 16 52 5 37 28 5 283 -26 43 56 8 44 37 42 .. .. .. 45 39 4 -110 0 0 44 3 44 5 37 28 4 284 -27 43 42 59 44 24 35 .. .. .. 45 26 1 -109 0 0 43 50 26 5 37 28 3 285 -27 43 29 39 44 11 18 .. .. .. 45 12 47 -108 0 0 43 36 57 5 37 28 3 285 -28 43 16 9 43 57 50 .. .. .. 44 59 22 -107 0 0 43 23 17 5 37 28 2 286 -28 43 2 28 43 44 11 .. .. .. 44 45 47 -106 0 0 43 9 27 5 37 28 1 287 -29 42 48 37 43 30 22 .. .. .. 44 32 1 -105 0 0 42 55 27 5 37 28 0 287 -29 42 34 36 43 16 23 .. .. .. 44 18 5 Uncertainty in time = +/- 3 secs [Prediction of 2008 Mar 31.0] Data for the target star ------------------------ * name: 2UCAC 36260911 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 28 08.3389 DE: +12 57 44.604 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .036 ) * V mag [mag]: 11.0 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 97.1513787140 DE(deg): 12.9579494628 * Equation of equinoxes (radians) : 0.000039149926608 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (246) Asporina approx. diameter [km]: 60 approx. diameter ["]: .025 distance from Earth [AU]: 3.35300 * orbital information: orbit source: Preston date of fit: 2008 Mar 28 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 802 number of rejected observations: 105 time covered by the observations: 1907 Mar 11 - 2008 Mar 06 1 sigma uncertainty ellipse (major, minor, PA): 0.011, 0.006, 84° remarks: * orbital elements for (246) Asporina : Mean anomaly = 222.12885053 deg Arg. of pericenter = 95.64918293 deg Long. of node = 162.50188692 deg Inclination = 15.64189342 deg Eccentricity = 0.10622105 Semimajor axis = 2.69549363 AU Perihelion dist = 2.40917547 AU Mag: H = 8.33, G = 0.15 Epoch of elements : MJD 54587.23200000 TDT (2008 May 01.232) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 1 246 Asporina 5h 34.8m UT 11.0 6 28 8.339 12 57 44.602UCAC 36260911 0.0 14.5 60 1.9 3.353 3.245 7.38 153.8119 12.961 95.58 15.20 5.5799 -0.08958 0.56794 18.08400 2.81691 0.00471 -0.00080 2000 220.5181872008 424.00000 95.649183162.501887 15.6418930.10622105 2.6954936 2.4091755 8.6 5.00.15 RATE 2.2271350 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.037 0.027 360 2.46 0.037 0 54556.5020080501_260911 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 31, 03:24 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org