IOTA/IOTA-ES occultation update for (2550) Houssay / HIP 89729 event on 2009 Aug 04, 01:06 UT Visible from Summary ------- On 2009 Aug 04 UT, the 19 km diameter asteroid (2550) Houssay will occult a 8.6 mag star in the constellation Serpens for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 7.9 mag to 16.5 mag (the magnitude of the asteroid) for at most 2.0 seconds. This update is based on historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: . The event at a glimpse ---------------------- * Rank: 9 * date and approx. time of event: 2009 Aug 04, 00:58 - 2009 Aug 04, 01:10 UT * magnitude of target star: 8.6 * magnitude drop [mag]: 7.9 * estimated maximum duration [s]: 2.0 * Moon: 96 % sunlit, 19° distance * Sun: 142° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 27 * 1 sigma uncertainty interval [path widths]: +/- 7.45 * 1 sigma uncertainty interval [seconds]: +/- 16.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .092 +/- .068) * 1 sigma uncertainty ellipse (major, minor, PA): ( .092", .068", 91° ) * approx speed of asteroid's shadow [km/s]: 9.6093 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 89729 by 2550 Houssay on 2009 Aug 4 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 -100 0 0 18 2 1 1 10 34 37 121 0 18 9 46 17 54 18 20 7 24 16 1 22 - 99 0 0 18 21 16 1 10 25 37 122 -1 18 29 2 18 13 31 20 27 9 16 20 9 - 98 0 0 18 41 12 1 10 15 38 123 -2 18 49 0 18 33 25 20 47 37 16 39 37 - 97 0 0 19 1 50 1 10 5 39 124 -3 19 9 40 18 54 1 21 8 48 16 59 45 - 96 0 0 19 23 9 1 9 55 39 125 -3 19 31 1 19 15 18 21 30 42 17 20 34 - 95 0 0 19 45 10 1 9 44 40 126 -4 19 53 4 19 37 17 21 53 18 17 42 3 - 94 0 0 20 7 51 1 9 34 40 127 -5 20 15 48 19 59 56 22 16 37 18 4 11 - 93 0 0 20 31 14 1 9 23 41 128 -5 20 39 13 20 23 17 22 40 39 18 27 0 - 92 0 0 20 55 17 1 9 13 41 129 -6 21 3 18 20 47 18 23 5 22 18 50 28 - 91 0 0 21 20 1 1 9 2 42 130 -7 21 28 5 21 11 59 23 30 47 19 14 36 - 90 0 0 21 45 25 1 8 51 42 131 -8 21 53 32 21 37 21 23 56 54 19 39 22 - 89 0 0 22 11 30 1 8 40 42 132 -8 22 19 38 22 3 22 24 23 43 20 4 48 - 88 0 0 22 38 14 1 8 29 43 134 -9 22 46 25 22 30 4 24 51 12 20 30 52 - 87 0 0 23 5 37 1 8 18 43 135 -9 23 13 51 22 57 24 25 19 22 20 57 34 - 86 0 0 23 33 39 1 8 7 43 136 -10 23 41 56 23 25 24 25 48 13 21 24 55 - 85 0 0 24 2 20 1 7 56 43 137 -11 24 10 40 23 54 2 26 17 44 21 52 52 - 84 0 0 24 31 40 1 7 44 44 139 -11 24 40 3 24 23 19 26 47 55 22 21 28 - 83 0 0 25 1 37 1 7 33 44 140 -12 25 10 3 24 53 13 27 18 45 22 50 39 - 82 0 0 25 32 13 1 7 21 44 141 -12 25 40 42 25 23 45 27 50 14 23 20 28 - 81 0 0 26 3 25 1 7 10 44 143 -13 26 11 57 25 54 54 28 22 21 23 50 52 - 80 0 0 26 35 13 1 6 58 44 144 -13 26 43 49 26 26 39 28 55 6 24 21 52 - 79 0 0 27 7 38 1 6 46 44 146 -14 27 16 17 26 59 0 29 28 29 24 53 26 - 78 0 0 27 40 38 1 6 35 44 147 -14 27 49 20 27 31 57 30 2 29 25 25 35 - 77 0 0 28 14 13 1 6 23 44 148 -15 28 22 59 28 5 29 30 37 4 25 58 18 - 76 0 0 28 48 22 1 6 11 44 150 -15 28 57 12 28 39 34 31 12 16 26 31 34 - 75 0 0 29 23 5 1 6 0 44 151 -16 29 31 58 29 14 13 31 48 2 27 5 23 - 74 0 0 29 58 21 1 5 48 44 153 -16 30 7 18 29 49 25 32 24 23 27 39 43 - 73 0 0 30 34 8 1 5 36 44 154 -17 30 43 9 30 25 9 33 1 16 28 14 34 - 72 0 0 31 10 27 1 5 25 44 156 -17 31 19 32 31 1 24 33 38 42 28 49 56 - 71 0 0 31 47 16 1 5 13 43 157 -17 31 56 25 31 38 9 34 16 40 29 25 47 - 70 0 0 32 24 34 1 5 1 43 159 -18 32 33 47 32 15 24 34 55 8 30 2 7 - 69 0 0 33 2 21 1 4 50 43 160 -18 33 11 38 32 53 6 35 34 6 30 38 54 - 68 0 0 33 40 36 1 4 39 42 161 -18 33 49 57 33 31 17 36 13 32 31 16 8 - 67 0 0 34 19 17 1 4 27 42 163 -18 34 28 42 34 9 53 36 53 26 31 53 48 - 66 0 0 34 58 22 1 4 16 42 164 -19 35 7 52 34 48 55 37 33 46 32 31 52 - 65 0 0 35 37 52 1 4 5 41 166 -19 35 47 26 35 28 21 38 14 30 33 10 20 - 64 0 0 36 17 45 1 3 54 41 167 -19 36 27 23 36 8 9 38 55 38 33 49 10 - 63 0 0 36 57 59 1 3 43 40 168 -19 37 7 42 36 48 19 39 37 9 34 28 21 - 62 0 0 37 38 33 1 3 32 40 170 -19 37 48 20 37 28 49 40 18 59 35 7 52 - 61 0 0 38 19 26 1 3 21 39 171 -19 38 29 17 38 9 37 41 1 9 35 47 41 - 60 0 0 39 0 36 1 3 11 39 172 -19 39 10 32 38 50 43 41 43 37 36 27 48 - 59 0 0 39 42 2 1 3 0 38 173 -20 39 52 2 39 32 4 42 26 20 37 8 10 - 58 0 0 40 23 42 1 2 50 37 175 -20 40 33 46 40 13 40 43 9 17 37 48 46 - 57 0 0 41 5 34 1 2 40 37 176 -20 41 15 42 40 55 27 43 52 27 38 29 35 - 56 0 0 41 47 36 1 2 30 36 177 -20 41 57 49 41 37 26 44 35 47 39 10 35 - 55 0 0 42 29 48 1 2 20 36 178 -19 42 40 5 42 19 33 45 19 15 39 51 44 - 54 0 0 43 12 6 1 2 11 35 179 -19 43 22 28 43 1 47 46 2 49 40 33 1 - 53 0 0 43 54 30 1 2 1 34 181 -19 44 4 56 43 44 7 46 46 28 41 14 24 - 52 0 0 44 36 57 1 1 52 33 182 -19 44 47 27 44 26 30 47 30 9 41 55 52 - 51 0 0 45 19 26 1 1 43 33 183 -19 45 30 0 45 8 54 48 13 50 42 37 22 - 50 0 0 46 1 53 1 1 35 32 184 -19 46 12 32 45 51 18 48 57 29 43 18 53 - 49 0 0 46 44 18 1 1 26 31 185 -19 46 55 0 46 33 39 49 41 3 44 0 22 - 48 0 0 47 26 38 1 1 18 30 186 -19 47 37 24 47 15 55 50 24 31 44 41 49 - 47 0 0 48 8 52 1 1 10 30 187 -18 48 19 42 47 58 5 51 7 49 45 23 10 - 46 0 0 48 50 56 1 1 3 29 188 -18 49 1 50 48 40 7 51 50 56 46 4 25 - 45 0 0 49 32 50 1 0 55 28 189 -18 49 43 47 49 21 57 52 33 50 46 45 31 - 44 0 0 50 14 31 1 0 48 27 190 -18 50 25 30 50 3 34 53 16 27 47 26 27 - 43 0 0 50 55 56 1 0 41 26 191 -17 51 6 59 50 44 57 53 58 46 48 7 10 - 42 0 0 51 37 5 1 0 34 26 192 -17 51 48 10 51 26 3 54 40 44 48 47 39 - 41 0 0 52 17 54 1 0 28 25 193 -17 52 29 2 52 6 50 55 22 19 49 27 52 - 40 0 0 52 58 22 1 0 22 24 194 -16 53 9 33 52 47 15 56 3 29 50 7 47 - 39 0 0 53 38 28 1 0 16 23 195 -16 53 49 40 53 27 19 56 44 12 50 47 22 - 38 0 0 54 18 8 1 0 10 23 196 -16 54 29 22 54 6 57 57 24 26 51 26 36 - 37 0 0 54 57 21 1 0 5 22 197 -15 55 8 37 54 46 9 58 4 8 52 5 26 - 36 0 0 55 36 7 1 0 0 21 198 -15 55 47 24 55 24 53 58 43 17 52 43 52 - 35 0 0 56 14 21 0 59 55 20 199 -14 56 25 40 56 3 7 59 21 51 53 21 51 - 34 0 0 56 52 5 0 59 50 19 200 -14 57 3 24 56 40 49 59 59 49 53 59 23 - 33 0 0 57 29 15 0 59 46 19 201 -14 57 40 35 57 17 59 60 37 8 54 36 25 - 32 0 0 58 5 50 0 59 41 18 201 -13 58 17 10 57 54 34 61 13 47 55 12 57 - 31 0 0 58 41 50 0 59 38 17 202 -13 58 53 10 58 30 34 61 49 45 55 48 57 - 30 0 0 59 17 13 0 59 34 16 203 -12 59 28 32 59 5 57 62 25 2 56 24 24 - 29 0 0 59 51 57 0 59 30 16 204 -12 60 3 16 59 40 42 62 59 35 56 59 16 - 28 0 0 60 26 3 0 59 27 15 205 -12 60 37 21 60 14 48 63 33 23 57 33 34 - 27 0 0 60 59 28 0 59 24 14 206 -11 61 10 45 60 48 15 64 6 27 58 7 16 - 26 0 0 61 32 13 0 59 21 14 207 -11 61 43 29 61 21 1 64 38 46 58 40 21 - 25 0 0 62 4 17 0 59 18 13 208 -10 62 15 31 61 53 7 65 10 18 59 12 48 - 24 0 0 62 35 39 0 59 16 12 209 -10 62 46 51 62 24 31 65 41 4 59 44 38 - 23 0 0 63 6 19 0 59 14 11 210 -9 63 17 29 62 55 13 66 11 4 60 15 49 - 22 0 0 63 36 17 0 59 12 11 211 -9 63 47 24 63 25 13 66 40 17 60 46 21 - 21 0 0 64 5 32 0 59 10 10 212 -9 64 16 37 63 54 31 67 8 44 61 16 13 - 20 0 0 64 34 5 0 59 8 10 212 -8 64 45 6 64 23 7 67 36 24 61 45 27 - 19 0 0 65 1 55 0 59 6 9 213 -8 65 12 54 64 51 0 68 3 18 62 14 1 - 18 0 0 65 29 3 0 59 5 8 214 -7 65 39 58 65 18 11 68 29 27 62 41 55 - 17 0 0 65 55 29 0 59 3 8 215 -7 66 6 20 65 44 40 68 54 50 63 9 9 - 16 0 0 66 21 12 0 59 2 7 216 -7 66 32 0 66 10 27 69 19 28 63 35 44 - 15 0 0 66 46 14 0 59 1 7 217 -6 66 56 59 66 35 33 69 43 23 .. .. .. - 14 0 0 67 10 36 0 59 0 6 218 -6 67 21 16 66 59 58 70 6 34 .. .. .. - 13 0 0 67 34 16 0 58 59 5 219 -5 67 44 52 67 23 43 70 29 2 .. .. .. - 12 0 0 67 57 17 0 58 58 5 220 -5 68 7 49 67 46 47 70 50 49 .. .. .. - 11 0 0 68 19 38 0 58 57 4 221 -5 68 30 5 68 9 12 71 11 54 .. .. .. - 10 0 0 68 41 20 0 58 57 4 222 -4 68 51 43 68 30 59 71 32 20 .. .. .. - 9 0 0 69 2 24 0 58 56 3 223 -4 69 12 43 68 52 7 71 52 6 .. .. .. - 8 0 0 69 22 50 0 58 56 3 224 -3 69 33 5 69 12 38 72 11 14 .. .. .. - 7 0 0 69 42 40 0 58 55 2 224 -3 69 52 50 69 32 32 72 29 44 .. .. .. - 6 0 0 70 1 54 0 58 55 2 225 -3 70 12 0 69 51 51 .. .. .. .. .. .. - 5 0 0 70 20 33 0 58 55 1 226 -2 70 30 34 70 10 34 .. .. .. .. .. .. - 4 0 0 70 38 37 0 58 55 1 227 -2 70 48 33 70 28 43 .. .. .. .. .. .. - 3 0 0 70 56 7 0 58 55 1 228 -2 71 5 59 70 46 18 .. .. .. .. .. .. - 2 0 0 71 13 5 0 58 55 0 229 -1 71 22 52 71 3 20 .. .. .. .. .. .. Uncertainty in time = +/- 17 secs [Prediction of 2008 Apr 25.0] Data for the target star ------------------------ * name: HIP 89729 * constellation : Serpens * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 18 40.8684 DE: -12 06 23.391 * position source: mpos:HIP pm:HIP plx:HIP * standard error: RA,DE ["]: ( .034, .022 ) * V mag [mag]: 8.6 * B mag [mag]: 9.1 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2550) Houssay approx. diameter [km]: 19 approx. diameter ["]: .010 distance from Earth [AU]: 2.50900 * orbital information: orbit source: Preston date of fit: 2008 Apr 25 source of used astrometry: MPC (via Astdys) number of used observations: 618 number of rejected observations: 15 time covered by the observations: 1970 Aug 29 - 2008 Mar 13 1 sigma uncertainty ellipse (major, minor, PA): 0.085, 0.064, 91° remarks: * orbital elements for (2550) Houssay : Mean anomaly = 261.33001192 deg Arg. of pericenter = 243.74989841 deg Long. of node = 158.57980505 deg Inclination = 10.39896933 deg Eccentricity = 0.17530019 Semimajor axis = 3.18888441 AU Perihelion dist = 2.62987238 AU Mag: H = 11.38, G = 0.15 Epoch of elements : MJD 55047.04600000 TDT (2009 Aug 04.046) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Aug 4 2550 Houssay 1h 6.6m UT 8.6 18 18 40.868-12 6 23.39HIP 89729 9.1 16.5 19 2.0 2.509 -1.125 -9.42 -54.7213 -12.103 164.89 17.24 1.1101 -0.35454 0.62070 -4.71162 -2.68664 0.00345 -0.00077 2000 260.1104932009 728.00000243.749898158.579805 10.3989690.17530019 3.1888844 2.629872411.2 5.00.15 RATE 1.7307960 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.092 0.068 91 8.45 0.078 0 54581.5020090804__89729 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 25, 07:48 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org