IOTA/IOTA-ES occultation update for (154) Bertha / TYC 6777-00920-1 event on 2009 Apr 09, 03:37 UT Visible from Summary ------- On 2009 Apr 09 UT, the 185 km diameter asteroid (154) Bertha will occult a 10.2 mag star in the constellation Libra for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 12.3 mag (the magnitude of the asteroid) for at most 18.3 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, 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: 2009 Apr 09, 03:32 - 2009 Apr 09, 03:41 UT * magnitude of target star: 10.2 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 18.3 * Moon: 99 % sunlit, 45° distance * Sun: 141° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 400 * 1 sigma uncertainty interval [path widths]: +/- 0.30 * 1 sigma uncertainty interval [seconds]: +/- 4.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .037 +/- .033) * 1 sigma uncertainty ellipse (major, minor, PA): ( .037", .032", 113° ) * approx speed of asteroid's shadow [km/s]: 10.0907 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6777-00920-1 by 154 Bertha on 2009 Apr 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 - 34 38 36 64 0 0 3 32 15 1 163 -17 ... .. .. - 30 27 3 ... .. .. ... .. .. - 34 3 2 63 0 0 3 32 15 2 163 -18 - 38 24 3 - 30 2 13 - 41 13 32 ... .. .. - 33 34 42 62 0 0 3 32 16 3 164 -19 - 37 44 17 - 29 43 21 - 40 25 28 ... .. .. - 33 12 45 61 0 0 3 32 17 4 164 -20 - 37 12 21 - 29 29 47 - 39 46 25 ... .. .. - 32 56 29 60 0 0 3 32 19 5 164 -21 - 36 47 18 - 29 20 59 - 39 15 11 - 27 17 36 - 32 45 19 59 0 0 3 32 21 6 165 -22 - 36 28 23 - 29 16 29 - 38 50 51 - 27 16 44 - 32 38 46 58 0 0 3 32 24 7 165 -23 - 36 14 56 - 29 15 56 - 38 32 40 - 27 19 27 - 32 36 26 57 0 0 3 32 27 8 165 -23 - 36 6 29 - 29 18 59 - 38 20 1 - 27 25 28 - 32 37 59 56 0 0 3 32 30 9 165 -24 - 36 2 33 - 29 25 23 - 38 12 23 - 27 34 32 - 32 43 8 55 0 0 3 32 34 10 165 -25 - 36 2 48 - 29 34 53 - 38 9 21 - 27 46 28 - 32 51 38 54 0 0 3 32 38 10 164 -26 - 36 6 56 - 29 47 19 - 38 10 34 - 28 1 6 - 33 3 16 53 0 0 3 32 42 11 164 -27 - 36 14 40 - 30 2 29 - 38 15 44 - 28 18 16 - 33 17 54 52 0 0 3 32 47 12 164 -28 - 36 25 49 - 30 20 17 - 38 24 36 - 28 37 51 - 33 35 21 51 0 0 3 32 53 13 164 -29 - 36 40 12 - 30 40 34 - 38 36 59 - 28 59 45 - 33 55 31 50 0 0 3 32 58 14 163 -30 - 36 57 40 - 31 3 15 - 38 52 43 - 29 23 52 - 34 18 19 49 0 0 3 33 4 15 163 -31 - 37 18 6 - 31 28 16 - 39 11 38 - 29 50 9 - 34 43 38 48 0 0 3 33 11 16 162 -32 - 37 41 24 - 31 55 31 - 39 33 39 - 30 18 32 - 35 11 26 47 0 0 3 33 18 17 162 -33 - 38 7 30 - 32 24 59 - 39 58 42 - 30 48 59 - 35 41 41 46 0 0 3 33 25 18 161 -34 - 38 36 20 - 32 56 38 - 40 26 42 - 31 21 28 - 36 14 21 45 0 0 3 33 33 18 161 -35 - 39 7 53 - 33 30 26 - 40 57 37 - 31 55 58 - 36 49 24 44 0 0 3 33 41 19 160 -36 - 39 42 9 - 34 6 23 - 41 31 27 - 32 32 29 - 37 26 52 43 0 0 3 33 50 20 159 -38 - 40 19 7 - 34 44 29 - 42 8 13 - 33 11 0 - 38 6 46 42 0 0 3 33 59 21 159 -39 - 40 58 50 - 35 24 45 - 42 47 56 - 33 51 33 - 38 49 8 41 0 0 3 34 9 22 158 -40 - 41 41 20 - 36 7 13 - 43 30 41 - 34 34 11 - 39 34 2 40 0 0 3 34 19 22 157 -41 - 42 26 42 - 36 51 56 - 44 16 32 - 35 18 54 - 40 21 32 39 0 0 3 34 30 23 156 -42 - 43 15 2 - 37 38 58 - 45 5 37 - 36 5 47 - 41 11 43 38 0 0 3 34 41 24 155 -43 - 44 6 27 - 38 28 24 - 45 58 6 - 36 54 54 - 42 4 45 37 0 0 3 34 52 24 154 -44 - 45 1 8 - 39 20 18 - 46 54 9 - 37 46 20 - 43 0 44 36 0 0 3 35 5 25 153 -45 - 45 59 16 - 40 14 49 - 47 54 2 - 38 40 11 - 43 59 53 35 0 0 3 35 17 25 152 -47 - 47 1 7 - 41 12 5 - 48 58 4 - 39 36 36 - 45 2 26 34 0 0 3 35 31 26 151 -48 - 48 6 59 - 42 12 16 - 50 6 38 - 40 35 42 - 46 8 38 33 0 0 3 35 45 26 150 -49 - 49 17 17 - 43 15 35 - 51 20 16 - 41 37 40 - 47 18 50 32 0 0 3 35 59 27 149 -50 - 50 32 29 - 44 22 17 - 52 39 36 - 42 42 44 - 48 33 29 31 0 0 3 36 14 27 147 -51 - 51 53 15 - 45 32 41 - 54 5 32 - 43 51 10 - 49 53 5 30 0 0 3 36 31 27 146 -52 - 53 20 26 - 46 47 7 - 55 39 13 - 45 3 14 - 51 18 21 29 0 0 3 36 47 27 145 -53 - 54 55 9 - 48 6 6 - 57 22 23 - 46 19 22 - 52 50 11 28 0 0 3 37 5 27 143 -54 - 56 39 2 - 49 30 11 - 59 17 31 - 47 40 0 - 54 29 48 27 0 0 3 37 24 27 142 -55 - 58 34 26 - 51 0 9 - 61 28 42 - 49 5 45 - 56 18 55 26 0 0 3 37 45 27 140 -56 - 60 45 7 - 52 36 59 - 64 3 22 - 50 37 23 - 58 20 8 25 0 0 3 38 6 27 138 -57 - 63 17 45 - 54 22 2 - 67 18 10 - 52 15 53 Latitude Latitude Latitude Latitude - 60 0 0 24 15 34 3 38 24 26 137 -58 26 19 47 22 20 13 27 39 37 21 14 29 - 61 0 0 23 50 59 3 38 34 26 136 -58 25 53 41 21 56 50 27 12 24 20 51 44 - 62 0 0 23 27 56 3 38 44 26 135 -58 25 29 15 21 34 54 26 46 57 20 30 22 - 63 0 0 23 6 23 3 38 54 25 134 -58 25 6 26 21 14 22 26 23 13 20 10 21 - 64 0 0 22 46 19 3 39 3 25 133 -58 24 45 14 20 55 14 26 1 11 19 51 42 - 65 0 0 22 27 43 3 39 13 24 133 -58 24 25 36 20 37 28 25 40 48 19 34 23 - 66 0 0 22 10 34 3 39 22 24 132 -58 24 7 31 20 21 4 25 22 3 19 18 22 - 67 0 0 21 54 50 3 39 31 24 131 -58 23 50 57 20 6 1 25 4 53 19 3 41 - 68 0 0 21 40 30 3 39 40 23 130 -58 23 35 53 19 52 18 24 49 18 18 50 17 - 69 0 0 21 27 35 3 39 48 22 130 -58 23 22 19 19 39 55 24 35 15 18 38 10 - 70 0 0 21 16 3 3 39 56 22 129 -57 23 10 13 19 28 51 24 22 45 18 27 21 - 71 0 0 21 5 53 3 40 4 21 129 -57 22 59 34 19 19 5 24 11 45 18 17 48 - 72 0 0 20 57 5 3 40 12 21 128 -57 22 50 22 19 10 38 24 2 16 18 9 31 - 73 0 0 20 49 40 3 40 20 20 127 -56 22 42 37 19 3 28 23 54 17 18 2 29 - 74 0 0 20 43 35 3 40 27 19 127 -56 22 36 18 18 57 36 23 47 47 17 56 44 - 75 0 0 20 38 52 3 40 34 19 126 -56 22 31 24 18 53 2 23 42 47 17 52 14 - 76 0 0 20 35 31 3 40 41 18 126 -55 22 27 57 18 49 45 23 39 15 17 49 0 - 77 0 0 20 33 31 3 40 48 17 125 -54 22 25 55 18 47 46 23 37 12 17 47 1 - 78 0 0 20 32 52 3 40 54 16 125 -54 22 25 20 18 47 5 23 36 39 17 46 19 - 79 0 0 20 33 35 3 41 0 16 124 -53 22 26 10 18 47 41 23 37 35 17 46 52 - 80 0 0 20 35 40 3 41 6 15 124 -53 22 28 27 18 49 36 23 40 1 17 48 42 - 81 0 0 20 39 8 3 41 11 14 123 -52 22 32 12 18 52 50 23 43 57 17 51 48 - 82 0 0 20 43 58 3 41 17 13 123 -51 22 37 24 18 57 22 23 49 24 17 56 11 - 83 0 0 20 50 12 3 41 21 13 122 -50 22 44 4 19 3 15 23 56 23 18 1 52 - 84 0 0 20 57 51 3 41 26 12 122 -50 22 52 14 19 10 28 24 4 55 18 8 51 - 85 0 0 21 6 55 3 41 30 11 121 -49 23 1 55 19 19 1 24 15 1 18 17 10 - 86 0 0 21 17 25 3 41 34 10 121 -48 23 13 6 19 28 57 24 26 43 18 26 47 - 87 0 0 21 29 23 3 41 38 9 121 -47 23 25 51 19 40 16 24 40 2 18 37 45 - 88 0 0 21 42 49 3 41 41 8 120 -46 23 40 11 19 52 58 24 55 0 18 50 5 - 89 0 0 21 57 45 3 41 44 7 120 -46 23 56 7 20 7 6 25 11 38 19 3 47 - 90 0 0 22 14 13 3 41 47 6 119 -45 24 13 40 20 22 39 25 30 0 19 18 53 - 91 0 0 22 32 14 3 41 49 5 119 -44 24 32 55 20 39 41 25 50 7 19 35 24 - 92 0 0 22 51 50 3 41 51 4 119 -43 24 53 51 20 58 12 26 12 3 .. .. .. - 93 0 0 23 13 3 3 41 53 3 118 -42 25 16 34 21 18 14 26 35 50 .. .. .. - 94 0 0 23 35 56 3 41 54 2 118 -41 25 41 4 21 39 48 27 1 32 .. .. .. - 95 0 0 24 0 31 3 41 55 1 117 -40 26 7 26 22 2 58 .. .. .. .. .. .. - 96 0 0 24 26 51 3 41 55 0 117 -39 .. .. .. 22 27 44 .. .. .. .. .. .. Uncertainty in time = +/- 6 secs [Prediction of 2008 Apr 25.0] Data for the target star ------------------------ * name: TYC 6777-00920-1 * constellation : Libra * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 15 38 08.4839 DE: -24 17 49.752 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .029 ) * V mag [mag]: 10.2 * B mag [mag]: 10.8 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (154) Bertha approx. diameter [km]: 185 approx. diameter ["]: .120 distance from Earth [AU]: 2.11700 * orbital information: orbit source: Preston date of fit: 2008 Apr 24 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 648 number of rejected observations: 88 time covered by the observations: 1903 Sep 28 - 2008 Apr 17 1 sigma uncertainty ellipse (major, minor, PA): 0.031, 0.015, 124° remarks: * orbital elements for (154) Bertha : Mean anomaly = 29.59917908 deg Arg. of pericenter = 154.63319973 deg Long. of node = 36.94516354 deg Inclination = 21.03266618 deg Eccentricity = 0.08345814 Semimajor axis = 3.18847919 AU Perihelion dist = 2.92237465 AU Mag: H = 7.64, G = 0.15 Epoch of elements : MJD 54930.15100000 TDT (2009 Apr 09.151) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Apr 9 154 Bertha 3h 37.1m UT 10.2 15 38 8.484-24 17 49.75TYC 6777-00920-1 10.8 12.3 185 18.3 2.117 -1.412 -13.71 -17.2499 -24.293 126.15 7.60 3.6176 -0.51335 0.72259 -4.64171 -3.30044 -0.00340 0.00119 2000 29.5730392009 4 9.00000154.633200 36.945164 21.0326660.08345814 3.1884792 2.9223746 7.6 5.00.15 RATE 1.7311260 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.037 0.032 113 1.30 0.036 0 54581.5020090409_0920-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 25, 06:19 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org