IOTA/IOTA-ES occultation update for (2) Pallas / TYC 4790-00575-1 event on 2009 Apr 10, 04:10 UT Visible from Summary ------- On 2009 Apr 10 UT, the 554 km diameter asteroid (2) Pallas will occult a 11.5 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 8.7 mag (the magnitude of the asteroid) for at most 16.7 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: 100 * date and approx. time of event: 2009 Apr 10, 04:11 - 2009 Apr 10, 04:12 UT * magnitude of target star: 11.5 * magnitude drop [mag]: 0.1 * estimated maximum duration [s]: 16.7 * Moon: 99 % sunlit, 110° distance * Sun: 74° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 583 * 1 sigma uncertainty interval [path widths]: +/- 0.10 * 1 sigma uncertainty interval [seconds]: +/- 1.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .027 +/- .038) * 1 sigma uncertainty ellipse (major, minor, PA): ( .038", .027", 360° ) * approx speed of asteroid's shadow [km/s]: 33.0874 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 4790-00575-1 by 2 Pallas on 2009 Apr 10 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 -148 0 0 28 26 3 4 11 39 51 216 0 25 25 56 31 29 41 24 50 17 32 6 55 -147 0 0 28 56 9 4 11 42 50 217 -1 25 56 20 31 59 30 25 20 44 32 36 39 -146 0 0 29 25 55 4 11 44 49 218 -2 26 26 23 32 28 57 25 50 51 33 6 2 -145 0 0 29 55 20 4 11 47 49 219 -3 26 56 7 32 58 2 26 20 38 33 35 3 -144 0 0 30 24 23 4 11 50 48 220 -3 27 25 30 33 26 45 26 50 5 34 3 42 -143 0 0 30 53 5 4 11 52 47 221 -4 27 54 32 33 55 5 27 19 11 34 31 58 -142 0 0 31 21 24 4 11 55 46 222 -5 28 23 13 34 23 2 27 47 55 34 59 50 -141 0 0 31 49 20 4 11 57 45 223 -6 28 51 31 34 50 35 28 16 18 35 27 18 -140 0 0 32 16 53 4 12 0 44 224 -6 29 19 26 35 17 44 28 44 17 35 54 23 -139 0 0 32 44 3 4 12 2 43 224 -7 29 46 58 35 44 29 29 11 54 36 21 2 -138 0 0 33 10 48 4 12 4 42 225 -8 30 14 7 36 10 49 29 39 7 36 47 17 -137 0 0 33 37 8 4 12 7 41 226 -8 30 40 51 36 36 44 30 5 57 37 13 7 -136 0 0 34 3 4 4 12 9 40 227 -9 31 7 12 37 2 14 30 32 22 37 38 32 -135 0 0 34 28 35 4 12 11 39 228 -10 31 33 8 37 27 19 30 58 23 38 3 31 -134 0 0 34 53 41 4 12 13 38 228 -10 31 58 39 37 51 57 31 23 59 38 28 4 -133 0 0 35 18 21 4 12 15 38 229 -11 32 23 45 38 16 10 31 49 9 38 52 11 -132 0 0 35 42 35 4 12 17 37 230 -12 32 48 25 38 39 57 32 13 55 39 15 52 -131 0 0 36 6 24 4 12 19 36 231 -12 33 12 40 39 3 18 32 38 15 39 39 7 -130 0 0 36 29 46 4 12 21 35 231 -13 33 36 29 39 26 13 33 2 9 40 1 56 -129 0 0 36 52 43 4 12 22 34 232 -14 33 59 53 39 48 41 33 25 38 40 24 18 -128 0 0 37 15 13 4 12 24 33 233 -14 34 22 50 40 10 43 33 48 40 40 46 14 -127 0 0 37 37 17 4 12 26 32 234 -15 34 45 21 40 32 18 34 11 17 41 7 44 -126 0 0 37 58 54 4 12 28 31 234 -15 35 7 26 40 53 27 34 33 27 41 28 47 -125 0 0 38 20 6 4 12 29 31 235 -16 35 29 4 41 14 9 34 55 11 41 49 23 -124 0 0 38 40 50 4 12 31 30 236 -17 35 50 16 41 34 26 35 16 28 42 9 34 -123 0 0 39 1 9 4 12 32 29 236 -17 36 11 2 41 54 15 35 37 19 42 29 17 -122 0 0 39 21 1 4 12 34 28 237 -18 36 31 21 42 13 39 35 57 43 42 48 35 -121 0 0 39 40 26 4 12 35 27 238 -18 36 51 13 42 32 36 36 17 41 43 7 26 -120 0 0 39 59 26 4 12 36 26 239 -19 37 10 40 42 51 7 36 37 13 43 25 51 -119 0 0 40 17 59 4 12 38 26 239 -19 37 29 39 43 9 12 36 56 17 43 43 50 -118 0 0 40 36 5 4 12 39 25 240 -20 37 48 13 43 26 51 37 14 56 44 1 23 -117 0 0 40 53 46 4 12 40 24 241 -20 38 6 20 43 44 3 37 33 8 44 18 31 -116 0 0 41 11 0 4 12 41 23 241 -21 38 24 0 44 0 51 37 50 54 44 35 12 -115 0 0 41 27 49 4 12 42 22 242 -21 38 41 14 44 17 12 38 8 13 44 51 28 -114 0 0 41 44 11 4 12 43 22 243 -22 38 58 3 44 33 8 38 25 6 45 7 18 -113 0 0 42 0 8 4 12 44 21 244 -22 39 14 25 44 48 38 38 41 33 45 22 43 -112 0 0 42 15 40 4 12 45 20 244 -23 39 30 21 45 3 43 38 57 34 45 37 43 -111 0 0 42 30 45 4 12 46 19 245 -23 39 45 51 45 18 23 39 13 9 45 52 18 -110 0 0 42 45 25 4 12 47 18 246 -24 40 0 55 45 32 38 39 28 18 46 6 27 -109 0 0 42 59 40 4 12 48 18 246 -24 40 15 34 45 46 29 39 43 1 46 20 12 -108 0 0 43 13 30 4 12 49 17 247 -25 40 29 47 45 59 54 39 57 19 46 33 33 -107 0 0 43 26 55 4 12 50 16 248 -25 40 43 35 46 12 55 40 11 11 46 46 29 -106 0 0 43 39 55 4 12 50 15 249 -25 40 56 57 46 25 32 40 24 38 46 59 1 -105 0 0 43 52 30 4 12 51 15 249 -26 41 9 54 46 37 44 40 37 39 47 11 8 -104 0 0 44 4 41 4 12 52 14 250 -26 41 22 26 46 49 32 40 50 15 47 22 52 -103 0 0 44 16 27 4 12 52 13 251 -27 41 34 33 47 0 57 41 2 26 47 34 12 -102 0 0 44 27 49 4 12 53 12 251 -27 41 46 15 47 11 57 41 14 12 47 45 8 -101 0 0 44 38 46 4 12 53 12 252 -27 41 57 32 47 22 34 41 25 33 47 55 41 -100 0 0 44 49 20 4 12 54 11 253 -28 42 8 25 47 32 48 41 36 29 48 5 51 - 99 0 0 44 59 30 4 12 54 10 253 -28 42 18 53 47 42 38 41 47 1 48 15 37 - 98 0 0 45 9 16 4 12 55 10 254 -28 42 28 57 47 52 6 41 57 8 48 25 0 - 97 0 0 45 18 38 4 12 55 9 255 -29 42 38 36 48 1 10 42 6 51 48 34 1 - 96 0 0 45 27 37 4 12 56 8 256 -29 42 47 52 48 9 51 42 16 10 48 42 39 - 95 0 0 45 36 12 4 12 56 7 256 -29 42 56 43 48 18 10 42 25 5 48 50 54 - 94 0 0 45 44 24 4 12 56 7 257 -30 43 5 11 48 26 6 42 33 35 48 58 47 - 93 0 0 45 52 13 4 12 56 6 258 -30 43 13 14 48 33 40 42 41 42 49 6 17 - 92 0 0 45 59 40 4 12 57 5 258 -30 43 20 55 48 40 51 42 49 25 49 13 25 - 91 0 0 46 6 43 4 12 57 5 259 -30 43 28 11 48 47 40 42 56 44 49 20 12 - 90 0 0 46 13 23 4 12 57 4 260 -31 43 35 4 48 54 7 43 3 40 49 26 36 - 89 0 0 46 19 41 4 12 57 3 261 -31 43 41 34 49 0 12 43 10 12 49 32 39 - 88 0 0 46 25 36 4 12 57 2 261 -31 43 47 41 49 5 56 43 16 21 49 38 19 - 87 0 0 46 31 9 4 12 57 2 262 -32 43 53 24 49 11 17 43 22 6 49 43 39 - 86 0 0 46 36 19 4 12 58 1 263 -32 43 58 44 49 16 17 43 27 28 49 48 37 - 85 0 0 46 41 7 4 12 58 0 264 -32 44 3 42 49 20 56 43 32 28 .. .. .. Uncertainty in time = +/- 2 secs [Prediction of 2008 Mar 20.0] Data for the target star ------------------------ * name: TYC 4790-00575-1 * constellation : Monoceros * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 06 20.4590 DE: -04 13 01.226 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .037 ) * V mag [mag]: 11.5 * B mag [mag]: 12.3 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2) Pallas approx. diameter [km]: 554 approx. diameter ["]: .349 distance from Earth [AU]: 2.18800 * orbital information: orbit source: Preston date of fit: 2008 Mar 19 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): 0.010, 0.005, 84° remarks: * orbital elements for (2) Pallas : Mean anomaly = 355.98571386 deg Arg. of pericenter = 310.24672927 deg Long. of node = 173.12995541 deg Inclination = 34.83796345 deg Eccentricity = 0.23093731 Semimajor axis = 2.77289795 AU Perihelion dist = 2.13253236 AU Mag: H = 4.09, G = 0.11 Epoch of elements : MJD 54931.17400000 TDT (2009 Apr 10.174) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Apr 10 2 Pallas 4h 9.9m UT 11.5 6 6 20.459- 4 13 1.23TYC 4790-00575-1 12.3 8.7 554 16.7 2.188 4.412 35.72 -169.4232 -4.227 117.87 7.98 4.1652 -0.14942 0.27476 16.42251 8.89231 0.00506 -0.00085 2000 355.7351202009 4 9.00000310.246729173.129955 34.8379630.23093731 2.7728980 2.1325324 4.1 5.00.11 RATE 2.1345340 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.038 0.027 360 1.10 0.035 0 54545.5020090410_0575-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Mar 20, 06:57 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org