IOTA/IOTA-ES occultation update for (974) Lioba / TYC 1248-00091-1 event on 2009 Aug 09, 02:10 UT Visible from Summary ------- On 2009 Aug 09 UT, the 18 km diameter asteroid (974) Lioba will occult a 10.4 mag star in the constellation Taurus for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 4.6 mag to 15.0 mag (the magnitude of the asteroid) for at most 0.7 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: 31 * date and approx. time of event: 2009 Aug 09, 02:08 - 2009 Aug 09, 02:09 UT * magnitude of target star: 10.4 * magnitude drop [mag]: 4.6 * estimated maximum duration [s]: 0.7 * Moon: 92 % sunlit, 69° distance * Sun: 77° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 34 * 1 sigma uncertainty interval [path widths]: +/- 2.15 * 1 sigma uncertainty interval [seconds]: +/- 1.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .030 +/- .024) * 1 sigma uncertainty ellipse (major, minor, PA): ( .030", .024", 81° ) * approx speed of asteroid's shadow [km/s]: 24.7653 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1248-00091-1 by 974 Lioba on 2009 Aug 9 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 - 35 49 52 45 0 0 2 8 3 1 69 -29 - 35 17 1 - 36 23 7 ... .. .. ... .. .. - 32 38 56 46 0 0 2 8 4 4 71 -28 - 32 7 36 - 33 10 36 - 29 56 15 - 35 30 42 Latitude Latitude Latitude Latitude - 32 0 0 46 12 41 2 8 4 4 72 -28 46 2 29 46 22 56 .. .. .. 47 7 39 - 31 0 0 46 32 30 2 8 5 5 73 -28 46 22 16 46 42 48 45 38 49 47 27 43 - 30 0 0 46 52 39 2 8 6 6 73 -27 46 42 22 47 3 0 45 58 45 47 48 7 - 29 0 0 47 13 8 2 8 6 7 74 -27 47 2 48 47 23 31 46 19 0 48 8 51 - 28 0 0 47 33 56 2 8 7 7 75 -27 47 23 33 47 44 22 46 39 33 48 29 54 - 27 0 0 47 55 2 2 8 8 8 76 -26 47 44 36 48 5 30 47 0 25 48 51 15 - 26 0 0 48 16 25 2 8 9 9 76 -26 48 5 57 48 26 57 47 21 34 49 12 54 - 25 0 0 48 38 5 2 8 10 10 77 -25 48 27 34 48 48 40 47 43 0 49 34 50 - 24 0 0 49 0 2 2 8 11 10 78 -25 48 49 28 49 10 39 48 4 42 49 57 2 - 23 0 0 49 22 13 2 8 12 11 79 -25 49 11 37 49 32 54 48 26 39 50 19 30 - 22 0 0 49 44 40 2 8 13 12 80 -24 49 34 0 49 55 23 48 48 51 50 42 12 - 21 0 0 50 7 20 2 8 15 12 80 -24 49 56 38 50 18 6 49 11 17 51 5 9 - 20 0 0 50 30 14 2 8 16 13 81 -23 50 19 29 50 41 3 49 33 56 51 28 19 - 19 0 0 50 53 20 2 8 18 14 82 -23 50 42 32 51 4 12 49 56 47 51 51 41 - 18 0 0 51 16 37 2 8 19 14 83 -22 51 5 46 51 27 32 50 19 50 52 15 14 - 17 0 0 51 40 5 2 8 21 15 84 -22 51 29 12 51 51 3 50 43 3 52 38 58 - 16 0 0 52 3 43 2 8 23 16 85 -21 51 52 47 52 14 44 51 6 27 53 2 52 - 15 0 0 52 27 31 2 8 24 16 86 -20 52 16 31 52 38 34 51 30 0 53 26 55 - 14 0 0 52 51 26 2 8 26 17 86 -20 52 40 23 53 2 32 51 53 41 53 51 6 - 13 0 0 53 15 28 2 8 28 18 87 -19 53 4 23 53 26 37 52 17 29 54 15 24 - 12 0 0 53 39 37 2 8 30 18 88 -19 53 28 29 53 50 49 52 41 24 54 39 48 - 11 0 0 54 3 51 2 8 32 19 89 -18 53 52 41 54 15 6 53 5 24 55 4 18 - 10 0 0 54 28 10 2 8 34 19 90 -18 54 16 57 54 39 27 53 29 29 55 28 51 - 9 0 0 54 52 32 2 8 36 20 91 -17 54 41 16 55 3 52 53 53 38 55 53 28 - 8 0 0 55 16 57 2 8 38 21 92 -16 55 5 39 55 28 20 54 17 50 56 18 7 - 7 0 0 55 41 24 2 8 40 21 93 -16 55 30 3 55 52 49 54 42 4 56 42 48 - 6 0 0 56 5 51 2 8 42 22 94 -15 55 54 28 56 17 19 55 6 19 57 7 29 - 5 0 0 56 30 18 2 8 45 22 95 -15 56 18 53 56 41 48 55 30 35 57 32 9 - 4 0 0 56 54 44 2 8 47 23 96 -14 56 43 16 57 6 16 55 54 49 57 56 48 - 3 0 0 57 19 8 2 8 49 23 97 -13 57 7 38 57 30 43 56 19 2 58 21 25 - 2 0 0 57 43 29 2 8 51 24 98 -13 57 31 57 57 55 6 56 43 13 58 45 57 - 1 0 0 58 7 46 2 8 54 24 99 -12 57 56 12 58 19 25 57 7 20 59 10 26 0 0 0 58 31 59 2 8 56 25 100 -12 58 20 23 58 43 39 57 31 22 59 34 49 1 0 0 58 56 5 2 8 58 25 102 -11 58 44 28 59 7 48 57 55 20 59 59 6 2 0 0 59 20 5 2 9 1 26 103 -10 59 8 26 59 31 49 58 19 11 60 23 15 3 0 0 59 43 58 2 9 3 26 104 -10 59 32 17 59 55 44 58 42 56 60 47 17 4 0 0 60 7 42 2 9 6 26 105 -9 59 56 0 60 19 29 59 6 33 61 11 9 5 0 0 60 31 17 2 9 8 27 106 -8 60 19 33 60 43 6 59 30 1 61 34 52 6 0 0 60 54 42 2 9 11 27 107 -8 60 42 57 61 6 32 59 53 20 61 58 23 7 0 0 61 17 57 2 9 13 27 108 -7 61 6 11 61 29 47 60 16 29 62 21 44 8 0 0 61 40 59 2 9 15 28 109 -7 61 29 12 61 52 51 60 39 27 62 44 52 9 0 0 62 3 50 2 9 18 28 111 -6 61 52 2 62 15 43 61 2 14 63 7 47 10 0 0 62 26 27 2 9 20 28 112 -6 62 14 39 62 38 21 61 24 48 63 30 28 11 0 0 62 48 51 2 9 23 29 113 -5 62 37 3 63 0 45 61 47 9 63 52 55 12 0 0 63 11 1 2 9 25 29 114 -4 62 59 12 63 22 55 62 9 17 64 15 7 13 0 0 63 32 56 2 9 28 29 115 -4 63 21 6 63 44 50 62 31 11 64 37 3 14 0 0 63 54 35 2 9 30 29 117 -3 63 42 46 64 6 30 62 52 49 64 58 43 15 0 0 64 15 58 2 9 32 30 118 -3 64 4 9 64 27 53 63 14 13 65 20 6 16 0 0 64 37 5 2 9 35 30 119 -2 64 25 16 64 49 0 63 35 21 65 41 12 17 0 0 64 57 55 2 9 37 30 120 -2 64 46 6 65 9 49 63 56 12 66 1 59 18 0 0 65 18 27 2 9 39 30 121 -1 65 6 39 65 30 21 64 16 47 66 22 29 19 0 0 65 38 42 2 9 42 30 123 0 65 26 54 65 50 34 64 37 5 66 42 40 Uncertainty in time = +/- 2 secs [Prediction of 2008 Apr 25.0] Data for the target star ------------------------ * name: TYC 1248-00091-1 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 03 51 30.2339 DE: +15 38 01.357 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .021 ) * V mag [mag]: 10.4 * B mag [mag]: 11.8 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (974) Lioba approx. diameter [km]: 18 approx. diameter ["]: .011 distance from Earth [AU]: 2.24700 * orbital information: orbit source: Preston date of fit: 2008 Apr 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 745 number of rejected observations: 72 time covered by the observations: 1906 Mar 27 - 2007 Jul 25 1 sigma uncertainty ellipse (major, minor, PA): 0.022, 0.012, 72° remarks: * orbital elements for (974) Lioba : Mean anomaly = 3.32857324 deg Arg. of pericenter = 301.95368971 deg Long. of node = 86.74269196 deg Inclination = 5.45989360 deg Eccentricity = 0.10988921 Semimajor axis = 2.53318625 AU Perihelion dist = 2.25481641 AU Mag: H = 10.35, G = 0.15 Epoch of elements : MJD 55052.09100000 TDT (2009 Aug 09.091) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Aug 9 974 Lioba 2h 10.3m UT 10.4 3 51 30.234 15 38 1.36TYC 1248-00091-1 11.8 15.0 18 0.7 2.247 3.711 10.88 67.5818 15.632 148.81 15.85 2.1721 -0.16762 0.82952 13.69867 2.78155 -0.00503 -0.00119 2000 2.8174122009 8 7.00000301.953690 86.742692 5.4598940.10988921 2.5331863 2.254816410.3 5.00.15 RATE 2.4445750 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.030 0.024 81 3.15 0.024 0 54581.5020090809_0091-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 25, 07:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org