IOTA/IOTA-ES occultation update for (348) May / HIP 67741 event on 2012 Sep 12, 09:29 UT Visible from NE Australia Summary ------- On 2012 Sep 12 UT, the 81 km diameter asteroid (348) May will occult a 9.0 mag star in the constellation Virgo for observers along a path across NE Australia. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.4 mag to 15.4 mag (the magnitude of the asteroid) for at most 2.0 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: 90 * date and approx. time of event: 2012 Sep 12, 09:31 - 2012 Sep 12, 09:31 UT * geocentric midpoint of event [JD]: 2456182.89537917 * magnitude of target star: 9.0 * magnitude drop [mag]: 6.4 * estimated maximum duration [s]: 2.0 * Moon: 16 % sunlit, 85° distance * Sun: 39° distance * rough path description: NE Australia Additional comments ------------------- possible double star The occultation path -------------------- * approximate projected width [km]: 82 * 1 sigma uncertainty interval [path widths]: +/- 0.53 * 1 sigma uncertainty interval [seconds]: +/- 1.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .017 +/- .016) * 1 sigma uncertainty ellipse (major, minor, PA): ( .017", .016", 95° ) * approx speed of asteroid's shadow [km/s]: 40.3047 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 67741 by 348 May on 2012 Sep 12 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 126 0 0 -15 31 27 9 31 24 38 275 -1 -15 54 4 -15 8 49 -16 18 1 -14 44 48 127 0 0 -15 43 11 9 31 26 37 275 -2 -16 5 46 -15 20 34 -16 29 41 -14 56 35 128 0 0 -15 54 27 9 31 27 36 275 -3 -16 17 0 -15 31 53 -16 40 53 -15 7 56 129 0 0 -16 5 17 9 31 29 35 275 -4 -16 27 48 -15 42 45 -16 51 39 -15 18 50 130 0 0 -16 15 41 9 31 30 34 275 -5 -16 38 10 -15 53 10 -17 1 59 -15 29 17 131 0 0 -16 25 37 9 31 32 33 274 -6 -16 48 5 -16 3 8 -17 11 52 -15 39 17 132 0 0 -16 35 7 9 31 33 32 274 -7 -16 57 33 -16 12 40 -17 21 18 -15 48 50 133 0 0 -16 44 10 9 31 35 31 274 -8 -17 6 35 -16 21 44 -17 30 18 -15 57 57 134 0 0 -16 52 47 9 31 36 30 274 -9 -17 15 9 -16 30 22 -17 38 52 -16 6 36 135 0 0 -17 0 56 9 31 38 29 273 -10 -17 23 18 -16 38 34 -17 46 58 -16 14 49 136 0 0 -17 8 39 9 31 39 28 273 -11 -17 30 59 -16 46 18 -17 54 39 -16 22 35 137 0 0 -17 15 55 9 31 40 27 273 -12 -17 38 14 -16 53 35 -18 1 52 -16 29 54 138 0 0 -17 22 45 9 31 41 26 273 -13 -17 45 2 -17 0 26 -18 8 39 -16 36 46 139 0 0 -17 29 8 9 31 42 25 272 -13 -17 51 24 -17 6 50 -18 14 59 -16 43 11 140 0 0 -17 35 4 9 31 44 24 272 -14 -17 57 19 -17 12 47 -18 20 53 -16 49 9 141 0 0 -17 40 33 9 31 45 23 272 -15 -18 2 47 -17 18 17 -18 26 21 -16 54 40 142 0 0 -17 45 36 9 31 46 22 272 -16 -18 7 49 -17 23 21 -18 31 21 -16 59 45 143 0 0 -17 50 12 9 31 47 21 271 -17 -18 12 24 -17 27 58 -18 35 55 -17 4 22 144 0 0 -17 54 21 9 31 48 20 271 -18 -18 16 33 -17 32 8 -18 40 3 -17 8 33 145 0 0 -17 58 3 9 31 48 19 271 -19 -18 20 14 -17 35 51 -18 43 44 -17 12 17 146 0 0 -18 1 19 9 31 49 18 270 -20 -18 23 30 -17 39 7 -18 46 59 -17 15 34 147 0 0 -18 4 9 9 31 50 17 270 -21 -18 26 19 -17 41 57 -18 49 47 -17 18 25 148 0 0 -18 6 31 9 31 51 16 270 -22 -18 28 41 -17 44 20 -18 52 9 -17 20 48 149 0 0 -18 8 27 9 31 52 15 270 -23 -18 30 36 -17 46 17 -18 54 4 -17 22 45 150 0 0 -18 9 57 9 31 52 14 269 -24 -18 32 5 -17 47 46 -18 55 33 -17 24 15 151 0 0 -18 10 59 9 31 53 13 269 -25 -18 33 8 -17 48 49 -18 56 35 -17 25 18 152 0 0 -18 11 36 9 31 54 13 269 -26 -18 33 44 -17 49 26 -18 57 11 -17 25 55 153 0 0 -18 11 45 9 31 54 12 268 -27 -18 33 54 -17 49 36 -18 57 21 -17 26 5 154 0 0 -18 11 28 9 31 55 11 268 -28 -18 33 37 -17 49 19 -18 57 4 -17 25 48 155 0 0 -18 10 45 9 31 55 10 268 -29 -18 32 54 -17 48 35 -18 56 21 -17 25 4 156 0 0 -18 9 35 9 31 56 9 267 -30 -18 31 44 -17 47 25 -18 55 11 -17 23 54 157 0 0 -18 7 59 9 31 56 8 267 -31 -18 30 8 -17 45 48 -18 53 36 -17 22 17 158 0 0 -18 5 56 9 31 56 7 267 -32 -18 28 5 -17 43 45 -18 51 33 -17 20 13 159 0 0 -18 3 26 9 31 57 6 266 -32 -18 25 36 -17 41 15 -18 49 5 -17 17 43 160 0 0 -18 0 31 9 31 57 5 266 -33 -18 22 41 -17 38 19 -18 46 10 -17 14 46 161 0 0 -17 57 8 9 31 57 4 266 -34 -18 19 19 -17 34 56 -18 42 49 -17 11 22 162 0 0 -17 53 20 9 31 57 3 266 -35 -18 15 31 -17 31 7 -18 39 2 -17 7 32 163 0 0 -17 49 4 9 31 57 2 265 -36 -18 11 17 -17 26 51 -18 34 48 -17 3 16 164 0 0 -17 44 23 9 31 57 1 265 -37 -18 6 36 -17 22 8 -18 30 8 -16 58 32 165 0 0 -17 39 15 9 31 57 0 265 -38 -18 1 29 -17 17 0 -18 25 2 -16 53 23 Uncertainty in time = +/- 1 secs Prediction of 2012 Jul 21.0 Data for the target star ------------------------ * name: HIP 67741 * constellation : Virgo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 13 52 35.2381 DE: -05 04 13.646 * position source: Pos: UCAC2, pm: UCAC2, pi:HIP2 * standard error: RA,DE ["]: ( .015, .015 ) * V mag [mag]: 9.0 * B mag [mag]: 9.5 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (348) May approx. diameter [km]: 81 approx. diameter ["]: .030 distance from Earth [AU]: 3.77200 * orbital information: orbit source: Preston date of fit: 2012 Jul 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1372 number of rejected observations: 82 time covered by the observations: 1905 May 10 - 2012 May 29 1 sigma uncertainty ellipse (major, minor, PA): 0.007, 0.005, 116° remarks: * orbital elements for (348) May : Mean anomaly = 109.79519942 deg Arg. of pericenter = 12.52594397 deg Long. of node = 90.05775543 deg Inclination = 9.74491443 deg Eccentricity = 0.06727118 Semimajor axis = 2.97069945 AU Perihelion dist = 2.77085699 AU Mag: H = 9.33, G = 0.15 Epoch of elements : MJD 56182.39500000 TDT (2012 Sep 12.395) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 12 348 May 9h 29.3m UT 9.0 13 52 35.238- 5 4 13.65HIP 67741 9.5 15.4 81 2.0 3.772 3.207 -22.73 74.0166 -5.064 36.70 3.95 9.4891 0.05879 0.12185 20.55343 -9.75076 0.00351 -0.00081 2000 109.3341772012 910.00000 12.525944 90.057755 9.7449140.06727118 2.9706995 2.7708570 9.4 5.00.15 RATE 1.9249350 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.017 0.016 95 1.53 0.016 0 0 1 4 056129.0020120912__67741 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 21, 15:40 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org