IOTA/IOTA-ES occultation update for (5508) 1988 EB / HIP 80815 event on 2008 Apr 17, 05:52 UT Visible from E USA Summary ------- On 2008 Apr 17 UT, the 13 km diameter asteroid (5508) 1988 EB will occult a 4.8 mag star in the constellation Scorpius for observers along a path across E USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 12.3 mag to 17.1 mag (the magnitude of the asteroid) for at most 1.7 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: . The event at a glimpse ---------------------- * Rank: 8 * date and approx. time of event: 2008 Apr 17, 05:47 - 2008 Apr 17, 05:57 UT * midpoint of event [JD]: 2454573.74482917 * magnitude of target star: 4.8 * magnitude drop [mag]: 12.3 * estimated maximum duration [s]: 1.7 * Moon: 90 % sunlit, 79° distance * Sun: 138° distance * rough path description: E USA The occultation path -------------------- * approximate projected width [km]: 34 * 1 sigma uncertainty interval [path widths]: +/- 8.03 * 1 sigma uncertainty interval [seconds]: +/- 16.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .085 +/- .061) * 1 sigma uncertainty ellipse (major, minor, PA): ( .086", .059", 104° ) * approx speed of asteroid's shadow [km/s]: 7.7430 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 80815 by 5508 1988 EB on 2008 Apr 17 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 - 20 36 43 62 0 0 5 47 22 1 202 -1 - 20 58 48 - 20 14 45 - 27 12 53 ... .. .. - 21 34 13 61 0 0 5 47 23 2 201 -2 - 21 55 57 - 21 12 37 - 28 4 16 ... .. .. - 22 34 59 60 0 0 5 47 25 3 200 -3 - 22 56 25 - 22 13 41 - 29 0 8 ... .. .. - 23 39 2 59 0 0 5 47 28 4 199 -4 - 24 0 14 - 23 17 58 - 30 0 29 ... .. .. - 24 46 26 58 0 0 5 47 31 5 198 -5 - 25 7 27 - 24 25 32 - 31 5 21 ... .. .. - 25 57 15 57 0 0 5 47 36 6 197 -6 - 26 18 10 - 25 36 28 - 32 14 52 ... .. .. - 27 11 39 56 0 0 5 47 41 8 196 -7 - 27 32 31 - 26 50 56 - 33 29 14 ... .. .. - 28 29 49 55 0 0 5 47 48 9 195 -8 - 28 50 41 - 28 9 5 - 34 48 44 ... .. .. - 29 51 58 54 0 0 5 47 55 10 194 -9 - 30 12 56 - 29 31 9 - 36 13 45 ... .. .. - 31 18 26 53 0 0 5 48 4 11 193 -11 - 31 39 33 - 30 57 28 - 37 44 48 - 25 39 27 - 32 49 35 52 0 0 5 48 15 12 191 -12 - 33 10 58 - 32 28 23 - 39 22 34 - 27 7 50 - 34 25 56 51 0 0 5 48 26 13 190 -13 - 34 47 40 - 34 4 23 - 41 8 0 - 28 40 0 - 36 8 4 50 0 0 5 48 39 15 189 -15 - 36 30 17 - 35 46 4 - 43 2 20 - 30 16 23 - 37 56 50 49 0 0 5 48 54 16 187 -16 - 38 19 41 - 37 34 13 - 45 7 22 - 31 57 26 - 39 53 16 48 0 0 5 49 11 17 185 -18 - 40 16 57 - 39 29 50 - 47 25 45 - 33 43 46 - 41 58 49 47 0 0 5 49 30 18 183 -20 - 42 23 37 - 41 34 20 - 50 1 36 - 35 36 8 Latitude Latitude Latitude Latitude - 43 0 0 46 32 28 5 49 40 18 182 -20 46 43 39 46 21 23 50 1 11 43 35 44 - 44 0 0 46 6 32 5 49 49 19 181 -21 46 17 34 45 55 36 49 31 37 43 12 0 - 45 0 0 45 41 38 5 49 59 19 181 -22 45 52 31 45 30 51 49 3 23 42 49 10 - 46 0 0 45 17 45 5 50 9 20 180 -23 45 28 30 45 7 7 48 36 25 42 27 13 - 47 0 0 44 54 53 5 50 19 20 179 -24 45 5 29 44 44 22 48 10 40 42 6 10 - 48 0 0 44 33 0 5 50 29 20 178 -24 44 43 30 44 22 37 47 46 8 41 45 59 - 49 0 0 44 12 7 5 50 39 21 177 -25 44 22 29 44 1 50 47 22 47 41 26 41 - 50 0 0 43 52 12 5 50 50 21 176 -26 44 2 27 43 42 1 47 0 35 41 8 16 - 51 0 0 43 33 14 5 51 0 21 175 -26 43 43 24 43 23 9 46 39 30 40 50 42 - 52 0 0 43 15 14 5 51 10 22 174 -27 43 25 18 43 5 14 46 19 32 40 34 0 - 53 0 0 42 58 10 5 51 21 22 173 -28 43 8 9 42 48 16 46 0 40 40 18 9 - 54 0 0 42 42 3 5 51 31 22 172 -28 42 51 57 42 32 13 45 42 52 40 3 9 - 55 0 0 42 26 52 5 51 42 22 171 -29 42 36 42 42 17 6 45 26 7 39 49 1 - 56 0 0 42 12 36 5 51 53 22 170 -30 42 22 22 42 2 54 45 10 26 39 35 43 - 57 0 0 41 59 15 5 52 3 22 169 -30 42 8 57 41 49 37 44 55 47 39 23 16 - 58 0 0 41 46 49 5 52 14 22 168 -31 41 56 28 41 37 15 44 42 10 39 11 40 - 59 0 0 41 35 18 5 52 25 22 167 -31 41 44 54 41 25 47 44 29 33 39 0 54 - 60 0 0 41 24 41 5 52 35 22 166 -32 41 34 14 41 15 13 44 17 57 38 50 58 - 61 0 0 41 14 59 5 52 46 22 166 -32 41 24 29 41 5 32 44 7 21 38 41 52 - 62 0 0 41 6 10 5 52 56 22 165 -33 41 15 38 40 56 46 43 57 45 38 33 37 - 63 0 0 40 58 15 5 53 7 22 164 -33 41 7 41 40 48 53 43 49 8 38 26 11 - 64 0 0 40 51 14 5 53 17 22 163 -34 41 0 38 40 41 54 43 41 31 38 19 35 - 65 0 0 40 45 6 5 53 28 22 162 -34 40 54 29 40 35 47 43 34 52 38 13 49 - 66 0 0 40 39 52 5 53 38 22 161 -35 40 49 13 40 30 34 43 29 12 38 8 53 - 67 0 0 40 35 31 5 53 48 22 160 -35 40 44 52 40 26 15 43 24 30 38 4 47 - 68 0 0 40 32 4 5 53 58 22 159 -36 40 41 23 40 22 48 43 20 47 38 1 31 - 69 0 0 40 29 30 5 54 8 21 158 -36 40 38 49 40 20 15 43 18 2 37 59 5 - 70 0 0 40 27 50 5 54 18 21 157 -36 40 37 8 40 18 35 43 16 16 37 57 28 - 71 0 0 40 27 3 5 54 28 21 156 -36 40 36 21 40 17 48 43 15 28 37 56 42 - 72 0 0 40 27 9 5 54 38 20 156 -37 40 36 28 40 17 54 43 15 39 37 56 45 - 73 0 0 40 28 9 5 54 48 20 155 -37 40 37 29 40 18 54 43 16 48 37 57 39 - 74 0 0 40 30 3 5 54 57 20 154 -37 40 39 23 40 20 47 43 18 56 37 59 23 - 75 0 0 40 32 51 5 55 6 19 153 -37 40 42 12 40 23 34 43 22 3 38 1 57 - 76 0 0 40 36 33 5 55 15 19 152 -38 40 45 55 40 27 15 43 26 9 38 5 21 - 77 0 0 40 41 9 5 55 24 19 151 -38 40 50 33 40 31 49 43 31 15 38 9 37 - 78 0 0 40 46 40 5 55 33 18 151 -38 40 56 5 40 37 18 43 37 20 38 14 43 - 79 0 0 40 53 5 5 55 42 18 150 -38 41 2 32 40 43 42 43 44 25 38 20 40 - 80 0 0 41 0 25 5 55 50 17 149 -38 41 9 55 40 51 0 43 52 31 38 27 28 - 81 0 0 41 8 41 5 55 58 17 148 -38 41 18 13 40 59 13 44 1 38 38 35 7 - 82 0 0 41 17 52 5 56 6 16 147 -38 41 27 27 41 8 21 44 11 47 38 43 38 - 83 0 0 41 27 59 5 56 14 16 147 -38 41 37 37 41 18 25 44 22 58 38 53 1 - 84 0 0 41 39 3 5 56 21 15 146 -38 41 48 44 41 29 26 44 35 11 39 3 15 - 85 0 0 41 51 3 5 56 29 15 145 -38 42 0 48 41 41 22 44 48 28 39 14 23 - 86 0 0 42 4 0 5 56 36 14 144 -37 42 13 49 41 54 16 45 2 49 39 26 22 - 87 0 0 42 17 55 5 56 42 13 143 -37 42 27 48 42 8 6 45 18 15 39 39 15 - 88 0 0 42 32 48 5 56 49 13 143 -37 42 42 46 42 22 55 45 34 48 39 53 1 - 89 0 0 42 48 40 5 56 55 12 142 -37 42 58 43 42 38 42 45 52 27 40 7 41 - 90 0 0 43 5 32 5 57 1 11 141 -36 43 15 40 42 55 28 46 11 14 40 23 14 - 91 0 0 43 23 23 5 57 7 11 140 -36 43 33 37 43 13 13 46 31 11 40 39 42 - 92 0 0 43 42 15 5 57 12 10 140 -36 43 52 36 43 31 59 46 52 18 40 57 5 - 93 0 0 44 2 8 5 57 17 9 139 -35 44 12 36 43 51 46 47 14 37 41 15 22 - 94 0 0 44 23 4 5 57 21 9 138 -35 44 33 39 44 12 34 47 38 11 41 34 36 - 95 0 0 44 45 2 5 57 26 8 138 -35 44 55 45 44 34 25 48 2 59 41 54 45 - 96 0 0 45 8 5 5 57 29 7 137 -34 45 18 56 44 57 19 48 29 5 .. .. .. - 97 0 0 45 32 12 5 57 33 6 136 -34 45 43 12 45 21 18 48 56 31 .. .. .. - 98 0 0 45 57 25 5 57 36 6 135 -33 46 8 35 45 46 22 49 25 20 .. .. .. - 99 0 0 46 23 46 5 57 39 5 135 -32 46 35 6 46 12 32 49 55 33 .. .. .. -100 0 0 46 51 14 5 57 41 4 134 -32 47 2 46 46 39 50 50 27 14 .. .. .. -101 0 0 47 19 52 5 57 43 3 133 -31 47 31 36 47 8 16 51 0 28 .. .. .. -102 0 0 47 49 42 5 57 44 2 132 -31 48 1 38 47 37 53 .. .. .. .. .. .. -103 0 0 48 20 44 5 57 45 1 132 -30 48 32 54 48 8 42 .. .. .. .. .. .. -104 0 0 48 53 0 5 57 46 1 131 -29 49 5 25 48 40 44 .. .. .. .. .. .. Uncertainty in time = +/- 19 secs [Prediction of 2008 Apr 15.0] Data for the target star ------------------------ * name: HIP 80815 * constellation : Scorpius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 16 30 12.4740 DE: -25 06 55.027 * position source: mpos:HIP pm:HIP plx:HIP * standard error: RA,DE ["]: ( .014, .012 ) * V mag [mag]: 4.8 * B mag [mag]: 4.7 * Apparent position with proper motion RA(deg): 247.6851119751 DE(deg): -25.1356853231 * Equation of equinoxes (radians) : 0.000039873628435 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (5508) 1988 EB approx. diameter [km]: 13 approx. diameter ["]: .008 distance from Earth [AU]: 2.35400 * orbital information: orbit source: Preston date of fit: 2008 Apr 14 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 627 number of rejected observations: 16 time covered by the observations: 1969 Mar 12 - 2008 Apr 13 1 sigma uncertainty ellipse (major, minor, PA): 0.085, 0.058, 104° remarks: * orbital elements for (5508) 1988 EB : Mean anomaly = 109.46664095 deg Arg. of pericenter = 69.61054471 deg Long. of node = 36.68587559 deg Inclination = 6.76618669 deg Eccentricity = 0.22622533 Semimajor axis = 2.84163346 AU Perihelion dist = 2.19878398 AU Mag: H = 12.24, G = 0.15 Epoch of elements : MJD 54573.24500000 TDT (2008 Apr 17.245) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Apr 17 5508 1988 EB 5h 52.6m UT 4.8 16 30 12.474-25 6 55.03HIP 80815 4.7 17.1 13 1.7 2.354 -1.181 -3.13 -46.3245 -25.113 91.75 10.62 5.8759 -0.17686 0.90596 -4.28930 -0.83773 -0.00378 0.00083 2000 108.7989642008 414.00000 69.610545 36.685876 6.7661870.22622533 2.8416335 2.198784012.0 5.00.15 RATE 2.0575570 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.086 0.059 104 9.03 0.064 0 54571.5020080417__80815 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 15, 14:42 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org