IOTA/IOTA-ES occultation update for (2) Pallas / UCAC2 32172562 event on 2009 May 09, 00:26 UT Visible from Summary ------- On 2009 May 09 UT, the 554 km diameter asteroid (2) Pallas will occult a 12.0 mag star in the constellation Monoceros for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 0.1 mag to 8.9 mag (the magnitude of the asteroid) for at most 14.3 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: 99 * date and approx. time of event: 2009 May 09, 00:27 - 2009 May 09, 00:28 UT * magnitude of target star: 12.0 * magnitude drop [mag]: 0.1 * estimated maximum duration [s]: 14.3 * Moon: 100 % sunlit, 116° distance * Sun: 60° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 589 * 1 sigma uncertainty interval [path widths]: +/- 0.30 * 1 sigma uncertainty interval [seconds]: +/- 4.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .095 +/- .095) * 1 sigma uncertainty ellipse (major, minor, PA): ( .095", .095", 90° ) * approx speed of asteroid's shadow [km/s]: 38.6982 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 32172562 by 2 Pallas on 2009 May 9 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 - 86 0 0 33 14 21 0 27 56 39 241 0 30 32 27 35 59 4 28 56 28 37 39 28 - 85 0 0 33 25 19 0 27 57 38 241 -1 30 43 34 36 9 52 29 7 40 37 50 10 - 84 0 0 33 36 2 0 27 59 37 242 -2 30 54 27 36 20 26 29 18 38 38 0 38 - 83 0 0 33 46 31 0 28 0 37 243 -2 31 5 4 36 30 45 29 29 20 38 10 51 - 82 0 0 33 56 44 0 28 2 36 244 -3 31 15 26 36 40 49 29 39 47 38 20 50 - 81 0 0 34 6 42 0 28 3 35 244 -4 31 25 33 36 50 38 29 49 59 38 30 33 - 80 0 0 34 16 25 0 28 5 34 245 -4 31 35 24 37 0 12 29 59 55 38 40 1 - 79 0 0 34 25 53 0 28 6 33 246 -5 31 45 0 37 9 31 30 9 36 38 49 15 - 78 0 0 34 35 5 0 28 8 32 246 -6 31 54 21 37 18 35 30 19 2 38 58 13 - 77 0 0 34 44 2 0 28 9 32 247 -6 32 3 26 37 27 23 30 28 12 39 6 56 - 76 0 0 34 52 44 0 28 10 31 248 -7 32 12 16 37 35 57 30 37 6 39 15 24 - 75 0 0 35 1 10 0 28 12 30 248 -8 32 20 50 37 44 15 30 45 45 39 23 37 - 74 0 0 35 9 21 0 28 13 29 249 -8 32 29 9 37 52 17 30 54 8 39 31 35 - 73 0 0 35 17 17 0 28 14 28 250 -9 32 37 11 38 0 5 31 2 15 39 39 17 - 72 0 0 35 24 56 0 28 15 28 250 -10 32 44 59 38 7 37 31 10 6 39 46 45 - 71 0 0 35 32 20 0 28 17 27 251 -10 32 52 30 38 14 54 31 17 42 39 53 57 - 70 0 0 35 39 29 0 28 18 26 252 -11 32 59 45 38 21 55 31 25 1 40 0 53 - 69 0 0 35 46 22 0 28 19 25 252 -12 33 6 45 38 28 41 31 32 5 40 7 35 - 68 0 0 35 52 59 0 28 20 24 253 -12 33 13 28 38 35 11 31 38 52 40 14 1 - 67 0 0 35 59 20 0 28 21 24 254 -13 33 19 56 38 41 26 31 45 23 40 20 11 - 66 0 0 36 5 26 0 28 22 23 254 -14 33 26 8 38 47 25 31 51 39 40 26 7 - 65 0 0 36 11 16 0 28 23 22 255 -14 33 32 4 38 53 9 31 57 38 40 31 46 - 64 0 0 36 16 50 0 28 24 21 256 -15 33 37 43 38 58 37 32 3 21 40 37 11 - 63 0 0 36 22 8 0 28 25 20 256 -15 33 43 7 39 3 50 32 8 48 40 42 20 - 62 0 0 36 27 11 0 28 25 19 257 -16 33 48 15 39 8 47 32 13 58 40 47 14 - 61 0 0 36 31 58 0 28 26 19 258 -17 33 53 6 39 13 29 32 18 53 40 51 53 - 60 0 0 36 36 29 0 28 27 18 258 -17 33 57 42 39 17 55 32 23 31 40 56 16 - 59 0 0 36 40 44 0 28 28 17 259 -18 34 2 1 39 22 5 32 27 53 41 0 23 - 58 0 0 36 44 43 0 28 29 16 259 -18 34 6 5 39 26 0 32 31 59 41 4 16 - 57 0 0 36 48 26 0 28 29 15 260 -19 34 9 52 39 29 40 32 35 48 41 7 52 - 56 0 0 36 51 54 0 28 30 15 261 -20 34 13 23 39 33 3 32 39 21 41 11 14 - 55 0 0 36 55 6 0 28 30 14 261 -20 34 16 38 39 36 12 32 42 38 41 14 20 - 54 0 0 36 58 1 0 28 31 13 262 -21 34 19 37 39 39 4 32 45 39 41 17 11 - 53 0 0 37 0 41 0 28 32 12 262 -21 34 22 20 39 41 42 32 48 23 41 19 46 - 52 0 0 37 3 6 0 28 32 11 263 -22 34 24 46 39 44 3 32 50 51 41 22 6 - 51 0 0 37 5 14 0 28 33 11 264 -22 34 26 57 39 46 9 32 53 3 41 24 11 - 50 0 0 37 7 6 0 28 33 10 264 -23 34 28 51 39 48 0 32 54 58 41 26 0 - 49 0 0 37 8 43 0 28 33 9 265 -23 34 30 29 39 49 34 32 56 37 41 27 34 - 48 0 0 37 10 4 0 28 34 8 266 -24 34 31 51 39 50 54 32 58 0 41 28 52 - 47 0 0 37 11 8 0 28 34 7 266 -24 34 32 57 39 51 58 32 59 7 41 29 55 - 46 0 0 37 11 57 0 28 34 7 267 -25 34 33 47 39 52 46 32 59 57 41 30 43 - 45 0 0 37 12 31 0 28 35 6 267 -25 34 34 20 39 53 19 33 0 31 41 31 16 - 44 0 0 37 12 48 0 28 35 5 268 -26 34 34 38 39 53 36 33 0 48 41 31 33 - 43 0 0 37 12 49 0 28 35 4 269 -26 34 34 39 39 53 37 33 0 50 41 31 35 - 42 0 0 37 12 35 0 28 35 3 269 -27 34 34 24 39 53 24 33 0 35 41 31 21 - 41 0 0 37 12 5 0 28 35 3 270 -27 34 33 54 39 52 54 33 0 3 41 30 52 - 40 0 0 37 11 19 0 28 35 2 270 -28 34 33 7 39 52 9 32 59 16 41 30 8 - 39 0 0 37 10 17 0 28 36 1 271 -28 34 32 4 39 51 9 32 58 12 41 29 8 - 38 0 0 37 9 0 0 28 36 0 272 -29 34 30 45 39 49 53 32 56 52 41 27 54 Uncertainty in time = +/- 4 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: UCAC2 32172562 * constellation : Monoceros * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 01 06.2257 DE: +01 27 46.089 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .095, .095 ) * V mag [mag]: 12.0 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2) Pallas approx. diameter [km]: 554 approx. diameter ["]: .313 distance from Earth [AU]: 2.44300 * orbital information: orbit source: Preston date of fit: 2008 Mar 20 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 6743 number of rejected observations: 565 time covered by the observations: 1900 Jun 17 - 2008 Jan 01 1 sigma uncertainty ellipse (major, minor, PA): 0.009, 0.005, 80° remarks: * orbital elements for (2) Pallas : Mean anomaly = 2.14425001 deg Arg. of pericenter = 310.24444343 deg Long. of node = 173.12935982 deg Inclination = 34.83823838 deg Eccentricity = 0.23093791 Semimajor axis = 2.77290061 AU Perihelion dist = 2.13253275 AU Mag: H = 4.09, G = 0.11 Epoch of elements : MJD 54960.01800000 TDT (2009 May 09.018) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 May 9 2 Pallas 0h 26.0m UT 12.0 7 1 6.226 1 27 46.09UCAC2 32172562 0.0 8.9 554 14.3 2.443 5.010 23.13 -128.1875 1.457 172.61 17.34 0.4335 -0.10070 0.32386 20.87457 6.42956 0.00431 -0.00149 2000 0.0058762009 429.00000310.244443173.129360 34.8382380.23093791 2.7729006 2.1325327 4.1 5.00.11 RATE 2.1345320 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.095 0.095 90 1.30 0.095 0 54545.5020090509_172562 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 08:02 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org