IOTA/IOTA-ES occultation update for (349) Dembowska / UCAC2 39614888 event on 2012 Aug 07, 06:59 UT Visible from N Brazil Summary ------- On 2012 Aug 07 UT, the 165 km diameter asteroid (349) Dembowska will occult a 11.8 mag star in the constellation Taurus for observers along a path across N Brazil. In the case of an occultation, the combined light of the asteroid and the star will drop by 0.5 mag to 11.1 mag (the magnitude of the asteroid) for at most 6.2 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: 96 * date and approx. time of event: 2012 Aug 07, 06:55 - 2012 Aug 07, 06:57 UT * geocentric midpoint of event [JD]: 2456146.79097083 * magnitude of target star: 11.8 * magnitude drop [mag]: 0.5 * estimated maximum duration [s]: 6.2 * Moon: 72 % sunlit, 45° distance * Sun: 71° distance * rough path description: N Brazil The occultation path -------------------- * approximate projected width [km]: 165 * 1 sigma uncertainty interval [path widths]: +/- 0.41 * 1 sigma uncertainty interval [seconds]: +/- 1.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .022 +/- .034) * 1 sigma uncertainty ellipse (major, minor, PA): ( .034", .022", 359° ) * approx speed of asteroid's shadow [km/s]: 26.6479 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of UCAC2 39614888 by 349 Dembowska on 2012 Aug 7 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 - 81 0 0 -16 56 13 6 55 1 0 67 -70 .. .. .. -16 7 29 .. .. .. -15 27 30 - 80 0 0 -16 31 1 6 55 1 1 66 -69 -17 19 52 -15 42 9 -17 59 56 -15 2 5 - 79 0 0 -16 5 24 6 55 1 2 66 -68 -16 54 22 -15 16 27 -17 34 31 -14 36 17 - 78 0 0 -15 39 24 6 55 1 3 66 -67 -16 28 28 -14 50 20 -17 8 43 -14 10 6 - 77 0 0 -15 13 2 6 55 1 4 65 -66 -16 2 12 -14 23 51 -16 42 31 -13 43 32 - 76 0 0 -14 46 16 6 55 2 6 65 -65 -15 35 33 -13 57 0 -16 15 57 -13 16 35 - 75 0 0 -14 19 9 6 55 2 7 65 -64 -15 8 31 -13 29 46 -15 49 1 -12 49 17 - 74 0 0 -13 51 40 6 55 3 8 65 -63 -14 41 8 -13 2 11 -15 21 42 -12 21 37 - 73 0 0 -13 23 49 6 55 3 9 64 -62 -14 13 24 -12 34 15 -14 54 3 -11 53 36 - 72 0 0 -12 55 38 6 55 4 10 64 -60 -13 45 18 -12 5 58 -14 26 2 -11 25 14 - 71 0 0 -12 27 7 6 55 5 11 64 -59 -13 16 53 -11 37 21 -13 57 41 -10 56 33 - 70 0 0 -11 58 16 6 55 6 12 64 -58 -12 48 7 -11 8 25 -13 29 0 -10 27 32 - 69 0 0 -11 29 6 6 55 7 13 64 -57 -12 19 3 -10 39 10 -13 0 0 - 9 58 12 - 68 0 0 -10 59 38 6 55 8 14 63 -56 -11 49 40 -10 9 36 -12 30 41 - 9 28 34 - 67 0 0 -10 29 52 6 55 9 15 63 -55 -11 19 58 - 9 39 45 -12 1 4 - 8 58 39 - 66 0 0 - 9 59 49 6 55 10 16 63 -54 -10 50 0 - 9 9 37 -11 31 10 - 8 28 27 - 65 0 0 - 9 29 29 6 55 12 18 63 -53 -10 19 45 - 8 39 13 -11 0 59 - 7 57 59 - 64 0 0 - 8 58 54 6 55 13 19 63 -52 - 9 49 14 - 8 8 33 -10 30 31 - 7 27 16 - 63 0 0 - 8 28 3 6 55 15 20 63 -51 - 9 18 28 - 7 37 39 - 9 59 49 - 6 56 18 - 62 0 0 - 7 56 59 6 55 16 21 62 -50 - 8 47 28 - 7 6 30 - 9 28 51 - 6 25 6 - 61 0 0 - 7 25 41 6 55 18 22 62 -49 - 8 16 13 - 6 35 8 - 8 57 40 - 5 53 41 - 60 0 0 - 6 54 10 6 55 20 23 62 -48 - 7 44 46 - 6 3 34 - 8 26 16 - 5 22 4 - 59 0 0 - 6 22 28 6 55 22 24 62 -46 - 7 13 7 - 5 31 48 - 7 54 40 - 4 50 16 - 58 0 0 - 5 50 34 6 55 24 25 62 -45 - 6 41 17 - 4 59 52 - 7 22 52 - 4 18 17 - 57 0 0 - 5 18 31 6 55 26 27 62 -44 - 6 9 16 - 4 27 46 - 6 50 54 - 3 46 8 - 56 0 0 - 4 46 18 6 55 28 28 62 -43 - 5 37 6 - 3 55 31 - 6 18 46 - 3 13 51 - 55 0 0 - 4 13 58 6 55 30 29 62 -42 - 5 4 48 - 3 23 7 - 5 46 29 - 2 41 26 - 54 0 0 - 3 41 29 6 55 33 30 62 -41 - 4 32 21 - 2 50 37 - 5 14 5 - 2 8 54 - 53 0 0 - 3 8 55 6 55 35 31 62 -40 - 3 59 48 - 2 18 1 - 4 41 33 - 1 36 16 - 52 0 0 - 2 36 14 6 55 37 32 61 -39 - 3 27 10 - 1 45 19 - 4 8 56 - 1 3 33 - 51 0 0 - 2 3 30 6 55 40 33 61 -37 - 2 54 26 - 1 12 33 - 3 36 13 - 0 30 47 - 50 0 0 - 1 30 42 6 55 43 35 61 -36 - 2 21 39 - 0 39 44 - 3 3 26 0 2 3 - 49 0 0 - 0 57 51 6 55 46 36 61 -35 - 1 48 49 - 0 6 53 - 2 30 37 0 34 55 - 48 0 0 - 0 24 58 6 55 48 37 61 -34 - 1 15 57 0 26 0 - 1 57 45 1 7 48 - 47 0 0 0 7 55 6 55 51 38 61 -33 - 0 43 4 0 58 53 - 1 24 52 1 40 41 - 46 0 0 0 40 47 6 55 54 39 61 -32 - 0 10 11 1 31 45 - 0 51 59 2 13 33 - 45 0 0 1 13 38 6 55 57 40 61 -31 0 22 41 2 4 36 - 0 19 7 2 46 23 - 44 0 0 1 46 27 6 56 0 41 61 -29 0 55 31 2 37 24 0 13 44 3 19 10 - 43 0 0 2 19 13 6 56 4 43 61 -28 1 28 17 3 10 8 0 46 31 3 51 54 - 42 0 0 2 51 54 6 56 7 44 61 -27 2 1 0 3 42 48 1 19 15 4 24 32 - 41 0 0 3 24 30 6 56 10 45 62 -26 2 33 37 4 15 22 1 51 54 4 57 5 - 40 0 0 3 56 59 6 56 14 46 62 -25 3 6 9 4 47 49 2 24 27 5 29 31 - 39 0 0 4 29 21 6 56 17 47 62 -24 3 38 33 5 20 9 2 56 53 6 1 49 - 38 0 0 5 1 35 6 56 21 48 62 -23 4 10 50 5 52 21 3 29 12 6 33 58 - 37 0 0 5 33 40 6 56 24 49 62 -22 4 42 58 6 24 23 4 1 22 7 5 58 - 36 0 0 6 5 35 6 56 28 51 62 -20 5 14 56 6 56 15 4 33 22 7 37 47 - 35 0 0 6 37 19 6 56 32 52 62 -19 5 46 43 7 27 55 5 5 12 8 9 25 - 34 0 0 7 8 51 6 56 35 53 62 -18 6 18 19 7 59 24 5 36 51 8 40 51 - 33 0 0 7 40 11 6 56 39 54 62 -17 6 49 42 8 30 39 6 8 17 9 12 3 - 32 0 0 8 11 17 6 56 43 55 62 -16 7 20 52 9 1 41 6 39 31 9 43 2 - 31 0 0 8 42 8 6 56 47 56 62 -15 7 51 48 9 32 28 7 10 30 10 13 45 - 30 0 0 9 12 44 6 56 51 57 63 -14 8 22 28 10 3 0 7 41 14 10 44 13 - 29 0 0 9 43 5 6 56 55 59 63 -13 8 52 53 10 33 16 8 11 43 11 14 25 - 28 0 0 10 13 8 6 56 59 60 63 -11 9 23 2 11 3 14 8 41 56 11 44 20 - 27 0 0 10 42 55 6 57 3 61 63 -10 9 52 53 11 32 56 9 11 51 12 13 56 - 26 0 0 11 12 23 6 57 7 62 63 -9 10 22 27 12 2 18 9 41 29 12 43 15 - 25 0 0 11 41 32 6 57 11 63 63 -8 10 51 41 12 31 22 10 10 48 13 12 14 - 24 0 0 12 10 22 6 57 15 64 64 -7 11 20 37 13 0 6 10 39 48 13 40 53 - 23 0 0 12 38 51 6 57 19 65 64 -6 11 49 12 13 28 30 11 8 28 14 9 12 - 22 0 0 13 7 0 6 57 24 66 64 -5 12 17 27 13 56 33 11 36 48 14 37 10 - 21 0 0 13 34 48 6 57 28 67 64 -4 12 45 21 14 24 14 12 4 47 15 4 47 - 20 0 0 14 2 13 6 57 32 68 64 -3 13 12 52 14 51 34 12 32 24 15 32 1 - 19 0 0 14 29 17 6 57 36 69 64 -2 13 40 2 15 18 31 12 59 39 15 58 53 - 18 0 0 14 55 57 6 57 40 71 65 -1 14 6 49 15 45 5 13 26 31 16 25 22 Uncertainty in time = +/- 3 secs Prediction of 2012 Jun 21.0 Data for the target star ------------------------ * name: UCAC2 39614888 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 04 05 24.3287 DE: +22 14 38.558 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .020, .034 ) * V mag [mag]: 11.8 * B mag [mag]: 0.0 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (349) Dembowska approx. diameter [km]: 165 approx. diameter ["]: .081 distance from Earth [AU]: 2.82500 * orbital information: orbit source: Preston date of fit: 2012 Jun 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1677 number of rejected observations: 175 time covered by the observations: 1904 Mar 18 - 2011 Nov 24 1 sigma uncertainty ellipse (major, minor, PA): 0.011, 0.006, 71° remarks: * orbital elements for (349) Dembowska : Mean anomaly = 18.85907958 deg Arg. of pericenter = 347.65055437 deg Long. of node = 32.48100997 deg Inclination = 8.25543422 deg Eccentricity = 0.09028693 Semimajor axis = 2.92611752 AU Perihelion dist = 2.66192735 AU Mag: H = 5.93, G = 0.37 Epoch of elements : MJD 56146.29100000 TDT (2012 Aug 07.291) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Aug 7 349 Dembowska 6h 59.0m UT 11.8 4 5 24.329 22 14 38.56UCAC2 39614888 0.0 11.1 165 6.2 2.825 3.209 14.37 0.3940 22.240 76.69 16.28 6.9833 0.00252 -0.00781 14.31467 4.61700 -0.00514 -0.00096 2000 17.6203232012 8 1.00000347.650554 32.481010 8.2554340.09028693 2.9261175 2.6619274 5.9 5.00.37 RATE 1.9690940 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.034 0.022 359 1.41 0.033 0 0-3-2 056099.0020120807_614888 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jun 21, 00:40 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org