IOTA/IOTA-ES occultation update for (27) Euterpe / 2UCAC 39820521 event on 2008 Aug 21, 08:15 UT Visible from SE Canada, E USA Summary ------- On 2008 Aug 21 UT, the 125 km diameter asteroid (27) Euterpe will occult a 11.8 mag star in the constellation Gemini for observers along a path across SE Canada, E USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 0.6 mag to 11.5 mag (the magnitude of the asteroid) for at most 3.2 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: 99 * date and approx. time of event: 2008 Aug 21, 08:13 - 2008 Aug 21, 08:14 UT * magnitude of target star: 11.8 * magnitude drop [mag]: 0.6 * estimated maximum duration [s]: 3.2 * Moon: 78 % sunlit, 71° distance * Sun: 53° distance * rough path description: SE Canada, E USA The occultation path -------------------- * approximate projected width [km]: 151 * 1 sigma uncertainty interval [path widths]: +/- 0.31 * 1 sigma uncertainty interval [seconds]: +/- 1.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .025 +/- .022) * 1 sigma uncertainty ellipse (major, minor, PA): ( .025", .022", 90° ) * approx speed of asteroid's shadow [km/s]: 38.7285 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 39820521 by 27 Euterpe on 2008 Aug 21 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 -103 0 0 32 45 2 8 13 26 0 63 -42 .. .. .. 33 31 29 .. .. .. 34 0 32 -102 0 0 33 11 21 8 13 26 1 63 -41 32 25 20 33 57 51 31 57 2 34 26 55 -101 0 0 33 37 39 8 13 26 2 64 -40 32 51 36 34 24 11 32 23 16 34 53 17 -100 0 0 34 3 55 8 13 26 3 64 -39 33 17 49 34 50 29 32 49 29 35 19 36 - 99 0 0 34 30 8 8 13 27 4 65 -39 33 44 1 35 16 44 33 15 39 35 45 52 - 98 0 0 34 56 18 8 13 27 5 65 -38 34 10 9 35 42 55 33 41 46 36 12 5 - 97 0 0 35 22 23 8 13 27 6 66 -37 34 36 13 36 9 2 34 7 49 36 38 13 - 96 0 0 35 48 24 8 13 27 7 67 -36 35 2 13 36 35 4 34 33 48 37 4 15 - 95 0 0 36 14 19 8 13 28 7 67 -35 35 28 7 37 1 0 34 59 42 37 30 12 - 94 0 0 36 40 8 8 13 28 8 68 -35 35 53 55 37 26 50 35 25 30 37 56 2 - 93 0 0 37 5 50 8 13 29 9 68 -34 36 19 37 37 52 32 35 51 12 38 21 44 - 92 0 0 37 31 24 8 13 29 10 69 -33 36 45 11 38 18 6 36 16 46 38 47 19 - 91 0 0 37 56 51 8 13 30 11 70 -32 37 10 37 38 43 32 36 42 12 39 12 45 - 90 0 0 38 22 8 8 13 31 12 70 -31 37 35 55 39 8 49 37 7 30 39 38 1 - 89 0 0 38 47 15 8 13 31 13 71 -30 38 1 3 39 33 56 37 32 38 40 3 8 - 88 0 0 39 12 13 8 13 32 14 72 -30 38 26 2 39 58 53 37 57 37 40 28 4 - 87 0 0 39 37 0 8 13 33 15 72 -29 38 50 49 40 23 38 38 22 26 40 52 49 - 86 0 0 40 1 35 8 13 33 15 73 -28 39 15 26 40 48 12 38 47 3 41 17 22 - 85 0 0 40 25 58 8 13 34 16 74 -27 39 39 51 41 12 34 39 11 29 41 41 43 - 84 0 0 40 50 10 8 13 35 17 74 -26 40 4 4 41 36 43 39 35 43 42 5 51 - 83 0 0 41 14 8 8 13 36 18 75 -26 40 28 4 42 0 40 39 59 45 42 29 45 - 82 0 0 41 37 53 8 13 37 19 76 -25 40 51 52 42 24 22 40 23 33 42 53 26 - 81 0 0 42 1 23 8 13 38 20 77 -24 41 15 25 42 47 50 40 47 8 43 16 53 - 80 0 0 42 24 40 8 13 39 20 77 -23 41 38 44 43 11 4 41 10 29 43 40 5 - 79 0 0 42 47 41 8 13 40 21 78 -22 42 1 49 43 34 2 41 33 35 44 3 1 - 78 0 0 43 10 28 8 13 41 22 79 -22 42 24 38 43 56 46 41 56 27 44 25 42 - 77 0 0 43 32 59 8 13 42 23 80 -21 42 47 12 44 19 13 42 19 3 44 48 7 - 76 0 0 43 55 13 8 13 43 24 80 -20 43 9 31 44 41 24 42 41 24 45 10 16 - 75 0 0 44 17 12 8 13 44 24 81 -19 43 31 33 45 3 19 43 3 28 45 32 8 - 74 0 0 44 38 54 8 13 46 25 82 -18 43 53 19 45 24 56 43 25 16 45 53 44 - 73 0 0 45 0 19 8 13 47 26 83 -18 44 14 48 45 46 17 43 46 48 46 15 1 - 72 0 0 45 21 26 8 13 48 27 84 -17 44 35 59 46 7 20 44 8 2 46 36 2 - 71 0 0 45 42 16 8 13 49 27 85 -16 44 56 54 46 28 5 44 28 59 46 56 44 - 70 0 0 46 2 48 8 13 51 28 85 -15 45 17 31 46 48 33 44 49 39 47 17 9 - 69 0 0 46 23 2 8 13 52 29 86 -15 45 37 49 47 8 42 45 10 0 47 37 15 - 68 0 0 46 42 58 8 13 53 30 87 -14 45 57 50 47 28 33 45 30 4 47 57 2 - 67 0 0 47 2 36 8 13 54 30 88 -13 46 17 33 47 48 5 45 49 50 48 16 31 - 66 0 0 47 21 54 8 13 56 31 89 -12 46 36 56 48 7 19 46 9 17 48 35 41 - 65 0 0 47 40 54 8 13 57 32 90 -12 46 56 2 48 26 13 46 28 25 48 54 33 - 64 0 0 47 59 35 8 13 59 32 91 -11 47 14 48 48 44 49 46 47 15 49 13 5 - 63 0 0 48 17 57 8 14 0 33 92 -10 47 33 16 49 3 5 47 5 45 49 31 18 - 62 0 0 48 36 0 8 14 1 34 93 -9 47 51 24 49 21 2 47 23 57 49 49 11 - 61 0 0 48 53 44 8 14 3 34 94 -9 48 9 13 49 38 40 47 41 50 50 6 45 - 60 0 0 49 11 8 8 14 4 35 95 -8 48 26 43 49 55 59 47 59 23 50 24 0 - 59 0 0 49 28 13 8 14 6 36 96 -7 48 43 54 50 12 58 48 16 37 50 40 55 - 58 0 0 49 44 59 8 14 7 36 97 -6 49 0 45 50 29 37 48 33 32 50 57 31 - 57 0 0 50 1 25 8 14 8 37 98 -6 49 17 17 50 45 57 48 50 7 51 13 47 - 56 0 0 50 17 31 8 14 10 37 99 -5 49 33 29 51 1 58 49 6 23 51 29 44 - 55 0 0 50 33 18 8 14 11 38 100 -4 49 49 22 51 17 38 49 22 20 51 45 21 - 54 0 0 50 48 45 8 14 13 39 101 -4 50 4 55 51 33 0 49 37 57 52 0 38 - 53 0 0 51 3 53 8 14 14 39 102 -3 50 20 9 51 48 2 49 53 14 52 15 36 - 52 0 0 51 18 42 8 14 16 40 103 -2 50 35 3 52 2 44 50 8 12 52 30 15 - 51 0 0 51 33 10 8 14 17 40 104 -2 50 49 38 52 17 7 50 22 50 52 44 33 - 50 0 0 51 47 20 8 14 19 41 105 -1 51 3 54 52 31 10 50 37 9 52 58 33 - 49 0 0 52 1 10 8 14 20 41 107 0 51 17 49 52 44 54 50 51 9 53 12 13 Uncertainty in time = +/- 1 secs [Prediction of 2008 Aug 12.0] Data for the target star ------------------------ * name: 2UCAC 39820521 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 23 06.6606 DE: +22 48 20.807 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .022 ) * V mag [mag]: 11.8 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (27) Euterpe approx. diameter [km]: 125 approx. diameter ["]: .072 distance from Earth [AU]: 2.39100 * orbital information: orbit source: Preston date of fit: 2008 Aug 11 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1500 number of rejected observations: 250 time covered by the observations: 1903 Aug 31 - 2007 Dec 20 1 sigma uncertainty ellipse (major, minor, PA): 0.012, 0.005, 91° remarks: * orbital elements for (27) Euterpe : Mean anomaly = 345.51401636 deg Arg. of pericenter = 356.81935146 deg Long. of node = 94.80620587 deg Inclination = 1.58376248 deg Eccentricity = 0.17280368 Semimajor axis = 2.34655494 AU Perihelion dist = 1.94106160 AU Mag: H = 6.90, G = 0.15 Epoch of elements : MJD 54699.34400000 TDT (2008 Aug 21.344) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Aug 21 27 Euterpe 8h 15.7m UT 11.8 6 23 6.661 22 48 20.812UCAC 39820521 0.0 11.5 125 3.2 2.391 5.813 -2.29 1.8237 22.807 56.84 11.94 8.2618 0.01670 0.55968 21.85067 -0.62018 -0.00403 0.00013 2000 342.9519472008 812.00000356.819351 94.806206 1.5837620.17280368 2.3465549 1.9410616 7.0 5.00.15 RATE 2.7419400 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.025 0.022 90 1.31 0.022 0 54690.5020080821_820521 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Aug 12, 02:27 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org