IOTA/IOTA-ES occultation update for (1746) Brouwer / TYC 6749-01100-1 event on 2008 Mar 31, 06:23 UT Visible from USA Summary ------- On 2008 Mar 31 UT, the 64 km diameter asteroid (1746) Brouwer will occult a 10.9 mag star in the constellation Hydra for observers along a path across USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.8 mag to 16.7 mag (the magnitude of the asteroid) for at most 5.3 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: 42 * date and approx. time of event: 2008 Mar 31, 06:18 - 2008 Mar 31, 06:28 UT * midpoint of event [JD]: 2454556.7663875 * magnitude of target star: 10.9 * magnitude drop [mag]: 5.8 * estimated maximum duration [s]: 5.3 * Moon: 37 % sunlit, 70° distance * Sun: 144° distance * rough path description: USA The occultation path -------------------- * approximate projected width [km]: 119 * 1 sigma uncertainty interval [path widths]: +/- 1.57 * 1 sigma uncertainty interval [seconds]: +/- 8.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .043 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .043", .036", 104° ) * approx speed of asteroid's shadow [km/s]: 12.1210 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6749-01100-1 by 1746 Brouwer on 2008 Mar 31 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 -117 55 40 51 0 0 6 28 18 1 135 -32 -116 40 40 -119 9 38 -112 37 33 ... .. .. -116 17 9 50 0 0 6 28 17 2 136 -33 -115 2 15 -117 30 58 -110 58 58 ... .. .. -114 36 55 49 0 0 6 28 16 4 138 -34 -113 21 56 -115 50 45 -109 17 53 ... .. .. -112 54 43 48 0 0 6 28 14 5 139 -36 -111 39 28 -114 8 43 -107 33 59 ... .. .. -111 10 13 47 0 0 6 28 11 7 140 -37 -109 54 31 -112 24 36 -105 46 52 ... .. .. -109 23 6 46 0 0 6 28 8 8 142 -38 -108 6 43 -110 38 3 -103 56 5 ... .. .. -107 32 57 45 0 0 6 28 4 10 143 -40 -106 15 38 -108 48 43 -102 1 4 ... .. .. -105 39 21 44 0 0 6 27 59 11 144 -41 -104 20 49 -106 56 10 -100 1 10 -110 47 43 -103 41 44 43 0 0 6 27 52 13 146 -42 -102 21 39 -104 59 56 - 97 55 34 -108 54 49 -101 39 29 42 0 0 6 27 45 15 147 -43 -100 17 26 -102 59 24 - 95 43 14 -106 58 32 Latitude Latitude Latitude Latitude -101 0 0 41 41 9 6 27 43 15 148 -44 42 20 16 41 2 52 44 29 7 39 7 23 -100 0 0 41 13 1 6 27 39 16 149 -44 41 51 48 40 35 2 43 59 26 38 40 26 - 99 0 0 40 45 29 6 27 34 17 149 -45 41 23 57 40 7 49 43 30 25 38 14 3 - 98 0 0 40 18 35 6 27 30 17 150 -45 40 56 44 39 41 13 43 2 4 37 48 17 - 97 0 0 39 52 19 6 27 26 18 151 -46 40 30 9 39 15 13 42 34 24 37 23 5 - 96 0 0 39 26 41 6 27 21 19 152 -46 40 4 13 38 49 52 42 7 25 36 58 30 - 95 0 0 39 1 41 6 27 16 20 152 -47 39 38 57 38 25 8 41 41 7 36 34 32 - 94 0 0 38 37 20 6 27 11 20 153 -47 39 14 19 38 1 2 41 15 31 36 11 10 - 93 0 0 38 13 38 6 27 6 21 154 -47 38 50 21 37 37 35 40 50 37 35 48 25 - 92 0 0 37 50 35 6 27 0 22 155 -48 38 27 3 37 14 47 40 26 25 35 26 17 - 91 0 0 37 28 12 6 26 55 22 156 -48 38 4 26 36 52 38 40 2 55 35 4 48 - 90 0 0 37 6 29 6 26 49 23 156 -48 37 42 28 36 31 8 39 40 7 34 43 56 - 89 0 0 36 45 26 6 26 43 24 157 -49 37 21 11 36 10 18 39 18 2 34 23 42 - 88 0 0 36 25 3 6 26 37 24 158 -49 37 0 35 35 50 7 38 56 39 34 4 6 - 87 0 0 36 5 20 6 26 31 25 159 -49 36 40 40 35 30 36 38 36 0 33 45 9 - 86 0 0 35 46 17 6 26 25 25 160 -49 36 21 25 35 11 45 38 16 3 33 26 51 - 85 0 0 35 27 56 6 26 19 26 161 -49 36 2 52 34 53 34 37 56 49 33 9 11 - 84 0 0 35 10 15 6 26 12 27 162 -49 35 45 0 34 36 4 37 38 18 32 52 10 - 83 0 0 34 53 14 6 26 6 27 162 -49 35 27 49 34 19 14 37 20 30 32 35 48 - 82 0 0 34 36 55 6 25 59 28 163 -49 35 11 20 34 3 4 37 3 26 32 20 6 - 81 0 0 34 21 17 6 25 53 28 164 -49 34 55 32 33 47 34 36 47 4 32 5 2 - 80 0 0 34 6 19 6 25 46 29 165 -49 34 40 26 33 32 46 36 31 26 31 50 38 - 79 0 0 33 52 3 6 25 39 29 166 -49 34 26 1 33 18 38 36 16 31 31 36 54 - 78 0 0 33 38 28 6 25 32 29 167 -49 34 12 17 33 5 10 36 2 19 31 23 49 - 77 0 0 33 25 34 6 25 25 30 168 -49 33 59 16 32 52 24 35 48 51 31 11 23 - 76 0 0 33 13 21 6 25 18 30 169 -48 33 46 56 32 40 18 35 36 6 30 59 37 - 75 0 0 33 1 50 6 25 10 30 170 -48 33 35 18 32 28 53 35 24 4 30 48 31 - 74 0 0 32 51 0 6 25 3 31 171 -48 33 24 21 32 18 9 35 12 45 30 38 5 - 73 0 0 32 40 51 6 24 56 31 172 -48 33 14 7 32 8 6 35 2 10 30 28 18 - 72 0 0 32 31 24 6 24 49 31 173 -47 33 4 34 31 58 44 34 52 18 30 19 11 - 71 0 0 32 22 38 6 24 41 32 174 -47 32 55 43 31 50 3 34 43 9 30 10 44 - 70 0 0 32 14 33 6 24 34 32 175 -46 32 47 34 31 42 3 34 34 44 30 2 56 - 69 0 0 32 7 10 6 24 26 32 176 -46 32 40 6 31 34 44 34 27 2 29 55 49 - 68 0 0 32 0 29 6 24 19 32 177 -46 32 33 21 31 28 6 34 20 3 29 49 21 - 67 0 0 31 54 28 6 24 11 32 178 -45 32 27 17 31 22 9 34 13 47 29 43 34 - 66 0 0 31 49 10 6 24 4 32 179 -45 32 21 55 31 16 53 34 8 15 29 38 26 - 65 0 0 31 44 32 6 23 56 32 180 -44 32 17 15 31 12 18 34 3 26 29 33 58 - 64 0 0 31 40 36 6 23 48 32 181 -44 32 13 17 31 8 24 33 59 20 29 30 11 - 63 0 0 31 37 22 6 23 41 32 182 -43 32 10 1 31 5 12 33 55 58 29 27 3 - 62 0 0 31 34 49 6 23 33 32 183 -42 32 7 27 31 2 40 33 53 18 29 24 35 - 61 0 0 31 32 58 6 23 26 32 184 -42 32 5 34 31 0 50 33 51 22 29 22 48 - 60 0 0 31 31 48 6 23 18 32 185 -41 32 4 24 30 59 40 33 50 10 29 21 40 - 59 0 0 31 31 19 6 23 11 32 186 -41 32 3 55 30 59 12 33 49 41 29 21 12 - 58 0 0 31 31 32 6 23 3 32 187 -40 32 4 8 30 59 25 33 49 55 29 21 25 - 57 0 0 31 32 27 6 22 55 32 188 -39 32 5 4 31 0 19 33 50 52 29 22 17 - 56 0 0 31 34 3 6 22 48 32 189 -39 32 6 41 31 1 54 33 52 33 29 23 50 - 55 0 0 31 36 21 6 22 41 32 190 -38 32 9 0 31 4 11 33 54 57 29 26 2 - 54 0 0 31 39 20 6 22 33 32 191 -37 32 12 1 31 7 8 33 58 4 29 28 55 - 53 0 0 31 43 1 6 22 26 31 192 -37 32 15 44 31 10 47 34 1 55 29 32 28 - 52 0 0 31 47 24 6 22 18 31 193 -36 32 20 9 31 15 7 34 6 29 29 36 40 - 51 0 0 31 52 28 6 22 11 31 194 -35 32 25 17 31 20 8 34 11 46 29 41 33 - 50 0 0 31 58 14 6 22 4 31 195 -34 32 31 6 31 25 51 34 17 47 29 47 6 - 49 0 0 32 4 41 6 21 57 30 196 -34 32 37 37 31 32 15 34 24 32 29 53 20 - 48 0 0 32 11 50 6 21 50 30 197 -33 32 44 50 31 39 20 34 32 0 30 0 13 - 47 0 0 32 19 41 6 21 43 29 198 -32 32 52 45 31 47 6 34 40 11 30 7 46 - 46 0 0 32 28 13 6 21 36 29 199 -31 33 1 23 31 55 33 34 49 7 30 16 0 - 45 0 0 32 37 27 6 21 29 29 200 -30 33 10 42 32 4 42 34 58 45 30 24 53 - 44 0 0 32 47 22 6 21 22 28 201 -30 33 20 44 32 14 32 35 9 7 30 34 27 - 43 0 0 32 57 59 6 21 15 28 202 -29 33 31 27 32 25 3 35 20 13 30 44 40 - 42 0 0 33 9 18 6 21 9 27 203 -28 33 42 53 32 36 15 35 32 3 30 55 34 - 41 0 0 33 21 19 6 21 2 27 204 -27 33 55 1 32 48 9 35 44 36 31 7 8 - 40 0 0 33 34 1 6 20 56 26 204 -26 34 7 50 33 0 43 35 57 52 31 19 21 - 39 0 0 33 47 24 6 20 49 26 205 -26 34 21 22 33 13 59 36 11 53 31 32 15 - 38 0 0 34 1 30 6 20 43 25 206 -25 34 35 36 33 27 56 36 26 37 31 45 48 - 37 0 0 34 16 16 6 20 37 25 207 -24 34 50 32 33 42 34 36 42 5 32 0 1 - 36 0 0 34 31 45 6 20 31 24 208 -23 35 6 10 33 57 53 36 58 16 32 14 54 - 35 0 0 34 47 54 6 20 25 23 209 -22 35 22 29 34 13 53 37 15 11 32 30 27 - 34 0 0 35 4 45 6 20 20 23 209 -21 35 39 31 34 30 34 37 32 50 32 46 39 - 33 0 0 35 22 18 6 20 14 22 210 -21 35 57 14 34 47 56 37 51 12 33 3 31 - 32 0 0 35 40 31 6 20 9 21 211 -20 36 15 39 35 5 59 38 10 18 33 21 3 - 31 0 0 35 59 26 6 20 4 21 212 -19 36 34 46 35 24 42 38 30 7 33 39 13 - 30 0 0 36 19 1 6 19 59 20 213 -18 36 54 34 35 44 5 38 50 40 33 58 3 - 29 0 0 36 39 18 6 19 54 19 213 -17 37 15 4 36 4 9 39 11 56 34 17 32 - 28 0 0 37 0 15 6 19 49 19 214 -16 37 36 15 36 24 54 39 33 55 34 37 39 - 27 0 0 37 21 53 6 19 44 18 215 -15 37 58 7 36 46 18 39 56 38 34 58 25 - 26 0 0 37 44 11 6 19 40 17 215 -15 38 20 40 37 8 22 40 20 4 35 19 50 - 25 0 0 38 7 10 6 19 36 16 216 -14 38 43 54 37 31 6 40 44 12 35 41 53 - 24 0 0 38 30 48 6 19 32 16 217 -13 39 7 48 37 54 30 41 9 3 36 4 34 - 23 0 0 38 55 6 6 19 28 15 218 -12 39 32 23 38 18 32 41 34 37 36 27 52 - 22 0 0 39 20 4 6 19 24 14 218 -11 39 57 37 38 43 13 42 0 52 36 51 48 - 21 0 0 39 45 40 6 19 21 13 219 -10 40 23 32 39 8 33 42 27 50 37 16 22 - 20 0 0 40 11 56 6 19 17 12 220 -9 40 50 5 39 34 32 42 55 30 37 41 31 - 19 0 0 40 38 50 6 19 14 11 220 -9 41 17 18 40 1 8 43 23 51 38 7 18 - 18 0 0 41 6 21 6 19 11 11 221 -8 41 45 10 40 28 21 43 52 53 38 33 40 - 17 0 0 41 34 31 6 19 9 10 222 -7 42 13 39 40 56 12 44 22 36 39 0 37 - 16 0 0 42 3 17 6 19 6 9 223 -6 42 42 47 41 24 39 44 52 59 39 28 10 - 15 0 0 42 32 41 6 19 4 8 223 -5 43 12 31 41 53 42 45 24 2 39 56 17 - 14 0 0 43 2 40 6 19 2 7 224 -5 43 42 53 42 23 20 45 55 44 40 24 58 - 13 0 0 43 33 14 6 19 0 6 225 -4 44 13 50 42 53 33 46 28 4 .. .. .. - 12 0 0 44 4 23 6 18 59 6 225 -3 44 45 23 43 24 20 47 1 3 .. .. .. - 11 0 0 44 36 7 6 18 58 5 226 -2 45 17 30 43 55 41 47 34 39 .. .. .. - 10 0 0 45 8 23 6 18 56 4 227 -1 45 50 11 44 27 35 48 8 52 .. .. .. - 9 0 0 45 41 12 6 18 56 3 227 -1 46 23 25 45 0 0 48 43 41 .. .. .. Uncertainty in time = +/- 10 secs [Prediction of 2008 Feb 15.0] Data for the target star ------------------------ * name: TYC 6749-01100-1 * constellation : Hydra * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 14 38 52.7366 DE: -25 57 07.671 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .026 ) * V mag [mag]: 10.9 * B mag [mag]: 12.0 * Apparent position with proper motion RA(deg): 219.8466599179 DE(deg): -25.9905268801 * Equation of equinoxes (radians) : 0.000041549359839 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1746) Brouwer approx. diameter [km]: 64 approx. diameter ["]: .023 distance from Earth [AU]: 3.79500 * orbital information: orbit source: Preston date of fit: 2008 Feb 13 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 776 number of rejected observations: 37 time covered by the observations: 1940 Nov 29 - 2007 Aug 07 1 sigma uncertainty ellipse (major, minor, PA): 0.038, 0.025, 108° remarks: * orbital elements for (1746) Brouwer : Mean anomaly = 217.85842514 deg Arg. of pericenter = 49.96829077 deg Long. of node = 322.46987710 deg Inclination = 8.37878874 deg Eccentricity = 0.20391215 Semimajor axis = 3.95535798 AU Perihelion dist = 3.14881244 AU Mag: H = 9.82, G = 0.15 Epoch of elements : MJD 54556.26600000 TDT (2008 Mar 31.266) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 31 1746 Brouwer 6h 23.6m UT 10.9 14 38 52.737-25 57 7.67TYC 6749-01100-1 12.0 16.7 64 5.3 3.795 -1.175 0.75 -65.1818 -25.952 85.14 4.32 6.3933 0.04037 0.84138 -6.83387 0.32151 -0.00299 0.00187 2000 217.0733422008 325.00000 49.968291322.469877 8.3787890.20391215 3.9553580 3.148812410.0 5.00.15 RATE 1.2529260 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.043 0.036 104 2.57 0.036 0 54511.5020080331_1100-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 15, 00:29 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org