IOTA/IOTA-ES occultation update for (202) Chryseis / TYC 0649-01108-1 event on 2010 Feb 20, 00:39 UT Visible from Brazil, Argentina, Chile Summary ------- On 2010 Feb 20 UT, the 86 km diameter asteroid (202) Chryseis will occult a 11.5 mag star in the constellation Cetus for observers along a path across Brazil, Argentina, Chile. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.8 mag to 13.1 mag (the magnitude of the asteroid) for at most 3.8 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: 79 * date and approx. time of event: 2010 Feb 20, 00:39 - 2010 Feb 20, 00:42 UT * magnitude of target star: 11.5 * magnitude drop [mag]: 1.8 * estimated maximum duration [s]: 3.8 * Moon: 29 % sunlit, 17° distance * Sun: 78° distance * rough path description: Brazil, Argentina, Chile The occultation path -------------------- * approximate projected width [km]: 137 * 1 sigma uncertainty interval [path widths]: +/- 0.68 * 1 sigma uncertainty interval [seconds]: +/- 2.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .030 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .030", .027", 87° ) * approx speed of asteroid's shadow [km/s]: 22.6704 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0649-01108-1 by 202 Chryseis on 2010 Feb 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 ' " Longitude Longitude Longitude Longitude Latitude Latitude Latitude Latitude - 87 0 0 -36 28 11 0 39 25 39 329 -1 -37 13 32 -35 43 42 -38 16 44 -34 44 31 - 86 0 0 -35 55 34 0 39 29 39 328 -2 -36 40 36 -35 11 24 -37 43 19 -34 12 37 - 85 0 0 -35 23 31 0 39 34 39 326 -3 -36 8 13 -34 39 40 -37 10 28 -33 41 15 - 84 0 0 -34 52 3 0 39 39 39 325 -4 -35 36 26 -34 8 29 -36 38 12 -33 10 28 - 83 0 0 -34 21 9 0 39 44 39 323 -5 -35 5 13 -33 37 53 -36 6 33 -32 40 14 - 82 0 0 -33 50 52 0 39 49 39 322 -6 -34 34 38 -33 7 53 -35 35 31 -32 10 36 - 81 0 0 -33 21 11 0 39 53 38 321 -7 -34 4 39 -32 38 29 -35 5 6 -31 41 34 - 80 0 0 -32 52 8 0 39 58 38 319 -8 -33 35 19 -32 9 43 -34 35 21 -31 13 9 - 79 0 0 -32 23 43 0 40 3 38 318 -9 -33 6 37 -31 41 34 -34 6 14 -30 45 21 - 78 0 0 -31 55 58 0 40 8 38 317 -10 -32 38 35 -31 14 4 -33 37 48 -30 18 11 - 77 0 0 -31 28 51 0 40 12 38 316 -10 -32 11 12 -30 47 13 -33 10 2 -29 51 40 - 76 0 0 -31 2 25 0 40 17 37 314 -11 -31 44 30 -30 21 2 -32 42 57 -29 25 48 - 75 0 0 -30 36 39 0 40 22 37 313 -12 -31 18 29 -29 55 30 -32 16 33 -29 0 35 - 74 0 0 -30 11 34 0 40 26 37 312 -13 -30 53 9 -29 30 39 -31 50 52 -28 36 2 - 73 0 0 -29 47 10 0 40 31 36 311 -14 -30 28 31 -29 6 29 -31 25 53 -28 12 10 - 72 0 0 -29 23 28 0 40 35 36 310 -15 -30 4 35 -28 43 1 -31 1 37 -27 48 59 - 71 0 0 -29 0 28 0 40 40 35 309 -16 -29 41 21 -28 20 14 -30 38 4 -27 26 28 - 70 0 0 -28 38 11 0 40 44 35 307 -17 -29 18 51 -27 58 9 -30 15 15 -27 4 39 - 69 0 0 -28 16 36 0 40 48 34 306 -18 -28 57 4 -27 36 46 -29 53 9 -26 43 32 - 68 0 0 -27 55 44 0 40 52 34 305 -19 -28 36 0 -27 16 6 -29 31 48 -26 23 7 - 67 0 0 -27 35 36 0 40 57 33 304 -20 -28 15 40 -26 56 9 -29 11 11 -26 3 25 - 66 0 0 -27 16 11 0 41 1 33 303 -21 -27 56 3 -26 36 55 -28 51 18 -25 44 24 - 65 0 0 -26 57 30 0 41 5 32 303 -22 -27 37 11 -26 18 24 -28 32 10 -25 26 7 - 64 0 0 -26 39 32 0 41 9 31 302 -23 -27 19 3 -26 0 36 -28 13 47 -25 8 32 - 63 0 0 -26 22 19 0 41 12 31 301 -24 -27 1 40 -25 43 32 -27 56 9 -24 51 41 - 62 0 0 -26 5 49 0 41 16 30 300 -25 -26 45 0 -25 27 12 -27 39 17 -24 35 32 - 61 0 0 -25 50 4 0 41 20 30 299 -26 -26 29 6 -25 11 35 -27 23 9 -24 20 7 - 60 0 0 -25 35 3 0 41 24 29 298 -27 -26 13 56 -24 56 43 -27 7 47 -24 5 25 - 59 0 0 -25 20 46 0 41 27 28 297 -28 -25 59 32 -24 42 34 -26 53 10 -23 51 27 - 58 0 0 -25 7 14 0 41 31 27 297 -29 -25 45 52 -24 29 9 -26 39 19 -23 38 12 - 57 0 0 -24 54 27 0 41 34 27 296 -29 -25 32 57 -24 16 29 -26 26 13 -23 25 40 - 56 0 0 -24 42 23 0 41 37 26 295 -30 -25 20 47 -24 4 33 -26 13 53 -23 13 53 - 55 0 0 -24 31 5 0 41 40 25 295 -31 -25 9 22 -23 53 20 -26 2 19 -23 2 49 - 54 0 0 -24 20 31 0 41 43 24 294 -32 -24 58 42 -23 42 53 -25 51 30 -22 52 29 - 53 0 0 -24 10 42 0 41 46 24 293 -33 -24 48 47 -23 33 9 -25 41 27 -22 42 52 - 52 0 0 -24 1 37 0 41 49 23 293 -34 -24 39 37 -23 24 9 -25 32 10 -22 33 59 - 51 0 0 -23 53 18 0 41 52 22 292 -35 -24 31 12 -23 15 54 -25 23 38 -22 25 50 - 50 0 0 -23 45 42 0 41 55 21 291 -36 -24 23 32 -23 8 23 -25 15 51 -22 18 25 - 49 0 0 -23 38 52 0 41 57 20 291 -36 -24 16 37 -23 1 37 -25 8 51 -22 11 43 - 48 0 0 -23 32 46 0 42 0 20 290 -37 -24 10 28 -22 55 34 -25 2 36 -22 5 45 - 47 0 0 -23 27 24 0 42 2 19 290 -38 -24 5 3 -22 50 16 -24 57 6 -22 0 31 - 46 0 0 -23 22 47 0 42 5 18 289 -39 -24 0 23 -22 45 41 -24 52 22 -21 56 1 - 45 0 0 -23 18 54 0 42 7 17 289 -40 -23 56 28 -22 41 51 -24 48 23 -21 52 14 - 44 0 0 -23 15 46 0 42 9 16 288 -40 -23 53 18 -22 38 45 -24 45 10 -21 49 10 - 43 0 0 -23 13 23 0 42 11 15 288 -41 -23 50 52 -22 36 23 -24 42 42 -21 46 50 - 42 0 0 -23 11 43 0 42 13 14 287 -42 -23 49 12 -22 34 45 -24 41 0 -21 45 14 - 41 0 0 -23 10 48 0 42 14 14 287 -42 -23 48 16 -22 33 51 -24 40 3 -21 44 21 - 40 0 0 -23 10 37 0 42 16 13 286 -43 -23 48 4 -22 33 41 -24 39 51 -21 44 11 - 39 0 0 -23 11 11 0 42 18 12 286 -44 -23 48 38 -22 34 14 -24 40 24 -21 44 45 - 38 0 0 -23 12 28 0 42 19 11 285 -44 -23 49 55 -22 35 31 -24 41 42 -21 46 1 - 37 0 0 -23 14 30 0 42 20 10 285 -45 -23 51 57 -22 37 32 -24 43 45 -21 48 2 - 36 0 0 -23 17 15 0 42 22 9 285 -46 -23 54 44 -22 40 17 -24 46 33 -21 50 45 - 35 0 0 -23 20 45 0 42 23 8 284 -46 -23 58 15 -22 43 45 -24 50 6 -21 54 11 - 34 0 0 -23 24 58 0 42 24 7 284 -47 -24 2 30 -22 47 56 -24 54 24 -21 58 20 - 33 0 0 -23 29 55 0 42 24 6 283 -47 -24 7 29 -22 52 51 -24 59 26 -22 3 12 - 32 0 0 -23 35 36 0 42 25 5 283 -48 -24 13 13 -22 58 29 -25 5 13 .. .. .. - 31 0 0 -23 42 0 0 42 26 5 283 -48 -24 19 40 -23 4 51 -25 11 45 .. .. .. - 30 0 0 -23 49 8 0 42 26 4 282 -49 -24 26 51 -23 11 55 -25 19 1 .. .. .. - 29 0 0 -23 56 59 0 42 27 3 282 -49 -24 34 46 -23 19 42 -25 27 1 .. .. .. - 28 0 0 -24 5 33 0 42 27 2 281 -49 -24 43 25 -23 28 13 -25 35 46 .. .. .. - 27 0 0 -24 14 51 0 42 27 1 281 -50 -24 52 47 -23 37 26 -25 45 15 .. .. .. Uncertainty in time = +/- 3 secs Prediction of 2010 Feb 4.0 Data for the target star ------------------------ * name: TYC 0649-01108-1 * constellation : Cetus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 14 17.5945 DE: +09 34 48.875 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .027, .026 ) * V mag [mag]: 11.5 * B mag [mag]: 13.2 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (202) Chryseis approx. diameter [km]: 86 approx. diameter ["]: .040 distance from Earth [AU]: 2.98400 * orbital information: orbit source: Preston date of fit: 2010 Feb 03 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 729 number of rejected observations: 168 time covered by the observations: 1901 Oct 17 - 2010 Feb 03 1 sigma uncertainty ellipse (major, minor, PA): 0.013, 0.008, 74° remarks: * orbital elements for (202) Chryseis : Mean anomaly = 300.45437655 deg Arg. of pericenter = 1.12213884 deg Long. of node = 136.87136099 deg Inclination = 8.85362384 deg Eccentricity = 0.10020567 Semimajor axis = 3.07003338 AU Perihelion dist = 2.76239863 AU Mag: H = 7.33, G = 0.15 Epoch of elements : MJD 55247.02700000 TDT (2010 Feb 20.027) ------ occelmnt file for Occult BEGIN ----------------------------------- 2010 Feb 20 202 Chryseis 0h 39.5m UT 11.5 3 14 17.595 9 34 48.87TYC 0649-01108-1 13.2 13.1 86 3.8 2.984 2.282 16.81 -111.1590 9.575 173.57 -11.02 0.6587 0.34898 -0.69494 11.45446 5.70339 0.00564 0.00136 2000 299.1668412010 213.00000 1.122139136.871361 8.8536240.10020567 3.0700334 2.7623986 7.4 5.00.15 RATE 1.8322700 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.030 0.027 87 1.68 0.027 0 055231.0020100220_1108-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2010 Feb 03, 18:26 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org