IOTA/IOTA-ES occultation update for (6156) Dall / HIP 107596 event on 2009 Nov 26, 22:24 UT Visible from W Africa, N Brazil Summary ------- On 2009 Nov 26 UT, the 12 km diameter asteroid (6156) Dall will occult a 6.2 mag star in the constellation Aquarius for observers along a path across W Africa, N Brazil. In the case of an occultation, the combined light of the asteroid and the star will drop by 11.7 mag to 17.9 mag (the magnitude of the asteroid) for at most 0.6 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: . The event at a glimpse ---------------------- * Rank: 9 * date and approx. time of event: 2009 Nov 26, 22:25 - 2009 Nov 26, 22:30 UT * magnitude of target star: 6.2 * magnitude drop [mag]: 11.7 * estimated maximum duration [s]: 0.6 * Moon: 70 % sunlit, 31° distance * Sun: 82° distance * rough path description: W Africa, N Brazil Additional comments ------------------- possible double star The occultation path -------------------- * approximate projected width [km]: 12 * 1 sigma uncertainty interval [path widths]: +/- 7.48 * 1 sigma uncertainty interval [seconds]: +/- 6.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .053 +/- .041) * 1 sigma uncertainty ellipse (major, minor, PA): ( .055", .037", 66° ) * approx speed of asteroid's shadow [km/s]: 19.7360 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 107596 by 6156 Dall on 2009 Nov 26 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 - 66 0 0 - 6 33 33 22 25 29 81 273 -1 - 6 36 58 - 6 30 8 - 7 28 11 - 5 38 59 - 65 0 0 - 6 14 30 22 25 35 80 271 -2 - 6 17 55 - 6 11 5 - 7 9 9 - 5 19 55 - 64 0 0 - 5 55 23 22 25 40 79 269 -3 - 5 58 48 - 5 51 57 - 6 50 2 - 5 0 46 - 63 0 0 - 5 36 12 22 25 46 78 268 -4 - 5 39 37 - 5 32 46 - 6 30 52 - 4 41 35 - 62 0 0 - 5 16 58 22 25 52 77 267 -5 - 5 20 23 - 5 13 32 - 6 11 39 - 4 22 20 - 61 0 0 - 4 57 41 22 25 58 76 266 -6 - 5 1 6 - 4 54 15 - 5 52 22 - 4 3 2 - 60 0 0 - 4 38 22 22 26 4 75 265 -7 - 4 41 47 - 4 34 56 - 5 33 4 - 3 43 43 - 59 0 0 - 4 19 0 22 26 10 74 264 -8 - 4 22 26 - 4 15 35 - 5 13 43 - 3 24 21 - 58 0 0 - 3 59 38 22 26 16 72 263 -9 - 4 3 4 - 3 56 12 - 4 54 21 - 3 4 59 - 57 0 0 - 3 40 14 22 26 21 71 262 -10 - 3 43 40 - 3 36 49 - 4 34 57 - 2 45 35 - 56 0 0 - 3 20 51 22 26 27 70 262 -12 - 3 24 16 - 3 17 25 - 4 15 33 - 2 26 11 - 55 0 0 - 3 1 26 22 26 33 69 261 -13 - 3 4 52 - 2 58 1 - 3 56 9 - 2 6 47 - 54 0 0 - 2 42 3 22 26 38 68 261 -14 - 2 45 28 - 2 38 37 - 3 36 45 - 1 47 24 - 53 0 0 - 2 22 40 22 26 44 67 260 -15 - 2 26 6 - 2 19 15 - 3 17 22 - 1 28 1 - 52 0 0 - 2 3 19 22 26 50 66 260 -16 - 2 6 44 - 1 59 53 - 2 58 0 - 1 8 40 - 51 0 0 - 1 43 59 22 26 55 65 260 -17 - 1 47 25 - 1 40 34 - 2 38 40 - 0 49 21 - 50 0 0 - 1 24 42 22 27 1 64 259 -18 - 1 28 7 - 1 21 16 - 2 19 22 - 0 30 5 - 49 0 0 - 1 5 27 22 27 6 63 259 -19 - 1 8 52 - 1 2 2 - 2 0 7 - 0 10 51 - 48 0 0 - 0 46 15 22 27 11 62 259 -20 - 0 49 41 - 0 42 50 - 1 40 54 0 8 20 - 47 0 0 - 0 27 7 22 27 17 61 259 -21 - 0 30 33 - 0 23 42 - 1 21 45 0 27 27 - 46 0 0 - 0 8 3 22 27 22 60 259 -22 - 0 11 29 - 0 4 38 - 1 2 40 0 46 30 - 45 0 0 0 10 56 22 27 27 59 258 -23 0 7 31 0 14 21 - 0 43 39 1 5 28 - 44 0 0 0 29 51 22 27 32 58 258 -24 0 26 26 0 33 16 - 0 24 43 1 24 22 - 43 0 0 0 48 40 22 27 37 57 258 -25 0 45 15 0 52 5 - 0 5 53 1 43 10 - 42 0 0 1 7 24 22 27 42 55 258 -26 1 3 59 1 10 49 0 12 52 2 1 52 - 41 0 0 1 26 1 22 27 47 54 258 -28 1 22 36 1 29 26 0 31 31 2 20 28 - 40 0 0 1 44 32 22 27 52 53 258 -29 1 41 7 1 47 57 0 50 4 2 38 57 - 39 0 0 2 2 56 22 27 57 52 258 -30 1 59 31 2 6 20 1 8 30 2 57 19 - 38 0 0 2 21 12 22 28 1 51 258 -31 2 17 48 2 24 37 1 26 48 3 15 33 - 37 0 0 2 39 21 22 28 6 50 258 -32 2 35 57 2 42 45 1 44 58 3 33 40 - 36 0 0 2 57 21 22 28 11 49 258 -33 2 53 57 3 0 46 2 3 1 3 51 39 - 35 0 0 3 15 13 22 28 15 48 258 -34 3 11 49 3 18 38 2 20 55 4 9 29 - 34 0 0 3 32 57 22 28 20 47 258 -35 3 29 33 3 36 20 2 38 40 4 27 9 - 33 0 0 3 50 30 22 28 24 46 258 -36 3 47 6 3 53 54 2 56 16 4 44 41 - 32 0 0 4 7 54 22 28 28 45 258 -37 4 4 31 4 11 18 3 13 43 5 2 3 - 31 0 0 4 25 8 22 28 32 44 258 -38 4 21 45 4 28 32 3 30 59 5 19 15 - 30 0 0 4 42 12 22 28 36 43 258 -39 4 38 49 4 45 36 3 48 5 5 36 16 - 29 0 0 4 59 5 22 28 40 42 258 -40 4 55 42 5 2 28 4 5 1 5 53 6 - 28 0 0 5 15 47 22 28 44 41 258 -41 5 12 24 5 19 10 4 21 45 6 9 46 - 27 0 0 5 32 18 22 28 48 40 258 -42 5 28 55 5 35 41 4 38 19 6 26 14 - 26 0 0 5 48 37 22 28 52 39 258 -43 5 45 14 5 52 0 4 54 40 6 42 31 - 25 0 0 6 4 44 22 28 55 38 258 -44 6 1 22 6 8 7 5 10 50 6 58 35 - 24 0 0 6 20 39 22 28 59 37 258 -45 6 17 17 6 24 2 5 26 48 7 14 27 - 23 0 0 6 36 22 22 29 2 35 258 -46 6 32 59 6 39 44 5 42 33 7 30 7 - 22 0 0 6 51 51 22 29 6 34 258 -47 6 48 29 6 55 13 5 58 5 7 45 34 - 21 0 0 7 7 8 22 29 9 33 258 -48 7 3 46 7 10 30 6 13 24 8 0 48 - 20 0 0 7 22 11 22 29 12 32 258 -49 7 18 49 7 25 33 6 28 30 8 15 48 - 19 0 0 7 37 1 22 29 15 31 258 -50 7 33 39 7 40 22 6 43 23 8 30 35 - 18 0 0 7 51 36 22 29 18 30 258 -51 7 48 15 7 54 58 6 58 1 8 45 8 - 17 0 0 8 5 58 22 29 21 29 259 -52 8 2 37 8 9 19 7 12 26 8 59 27 - 16 0 0 8 20 6 22 29 24 28 259 -53 8 16 45 8 23 27 7 26 36 9 13 32 - 15 0 0 8 33 59 22 29 27 27 259 -54 8 30 38 8 37 19 7 40 32 9 27 22 - 14 0 0 8 47 37 22 29 29 26 259 -55 8 44 16 8 50 57 7 54 13 9 40 57 - 13 0 0 9 1 0 22 29 32 25 259 -56 8 57 40 9 4 21 8 7 39 9 54 18 - 12 0 0 9 14 8 22 29 34 24 259 -57 9 10 48 9 17 29 8 20 50 10 7 23 - 11 0 0 9 27 1 22 29 37 23 259 -58 9 23 41 9 30 21 8 33 46 10 20 13 - 10 0 0 9 39 39 22 29 39 22 260 -59 9 36 19 9 42 58 8 46 26 10 32 48 - 9 0 0 9 52 0 22 29 41 21 260 -60 9 48 41 9 55 20 8 58 51 10 45 7 - 8 0 0 10 4 6 22 29 43 20 260 -61 10 0 47 10 7 26 9 10 59 10 57 10 - 7 0 0 10 15 56 22 29 45 19 260 -62 10 12 37 10 19 16 9 22 52 11 8 57 - 6 0 0 10 27 30 22 29 47 18 260 -63 10 24 11 10 30 49 9 34 29 11 20 28 - 5 0 0 10 38 47 22 29 48 17 260 -64 10 35 28 10 42 6 9 45 49 11 31 43 - 4 0 0 10 49 49 22 29 50 16 261 -65 10 46 30 10 53 7 9 56 52 11 42 41 - 3 0 0 11 0 33 22 29 51 15 261 -66 10 57 14 11 3 52 10 7 40 11 53 23 - 2 0 0 11 11 1 22 29 53 14 261 -67 11 7 42 11 14 20 10 18 10 12 3 49 - 1 0 0 11 21 12 22 29 54 13 261 -68 11 17 54 11 24 30 10 28 24 12 13 57 0 0 0 11 31 6 22 29 55 12 261 -69 11 27 48 11 34 24 10 38 20 12 23 49 1 0 0 11 40 43 22 29 57 11 262 -70 11 37 25 11 44 2 10 48 0 12 33 24 2 0 0 11 50 3 22 29 58 10 262 -71 11 46 46 11 53 21 10 57 22 12 42 42 3 0 0 11 59 6 22 29 59 9 262 -72 11 55 49 12 2 24 11 6 28 12 51 42 4 0 0 12 7 52 22 29 59 8 262 -73 12 4 34 12 11 10 11 15 15 13 0 25 5 0 0 12 16 20 22 30 0 7 262 -74 12 13 3 12 19 38 11 23 46 13 8 51 6 0 0 12 24 31 22 30 1 6 263 -74 12 21 13 12 27 48 11 31 59 13 17 0 7 0 0 12 32 24 22 30 1 5 263 -75 12 29 7 12 35 41 11 39 54 13 24 51 8 0 0 12 40 0 22 30 2 4 263 -76 12 36 42 12 43 17 11 47 32 13 32 25 9 0 0 12 47 18 22 30 2 3 263 -77 12 44 1 12 50 35 11 54 51 13 39 41 10 0 0 12 54 18 22 30 2 2 263 -78 12 51 1 12 57 35 12 1 54 13 46 39 11 0 0 13 1 0 22 30 2 1 264 -79 12 57 43 13 4 17 12 8 38 13 53 20 12 0 0 13 7 25 22 30 3 0 264 -79 13 4 8 13 10 42 12 15 4 13 59 42 Uncertainty in time = +/- 6 secs Prediction of 2009 Nov 15.0 Data for the target star ------------------------ * name: HIP 107596 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 47 38.2799 DE: -05 55 00.343 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .022, .009 ) * V mag [mag]: 6.2 * B mag [mag]: 6.4 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (6156) Dall approx. diameter [km]: 12 approx. diameter ["]: .005 distance from Earth [AU]: 3.02500 * orbital information: orbit source: Preston date of fit: 2009 Oct 16 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 598 number of rejected observations: 9 time covered by the observations: 1934 Feb 14 - 2009 May 27 1 sigma uncertainty ellipse (major, minor, PA): 0.051, 0.036, 61° remarks: * orbital elements for (6156) Dall : Mean anomaly = 256.53021833 deg Arg. of pericenter = 158.07420598 deg Long. of node = 298.98776116 deg Inclination = 9.41228176 deg Eccentricity = 0.06704444 Semimajor axis = 2.99829309 AU Perihelion dist = 2.79727420 AU Mag: H = 12.13, G = 0.15 Epoch of elements : MJD 55161.93400000 TDT (2009 Nov 26.934) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Nov 26 6156 Dall 22h 24.7m UT 6.2 21 47 38.280- 5 55 0.34HIP 107596 6.4 17.9 12 0.6 3.025 2.082 9.16 -75.2370 -5.919 -159.29 -21.10 22.4112 0.01730 -0.05488 10.68488 3.15005 0.00554 0.00208 2000 256.16306320091125.00000158.074206298.987761 9.4122820.06704444 2.9982931 2.797274212.1 5.00.15 RATE 1.8984230 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.055 0.037 66 8.48 0.041 0 055150.0020091126_107596 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2009 Oct 16, 11:48 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org