IOTA/IOTA-ES occultation update for (2542) Calpurnia / HIP 61096 event on 2008 May 08, 20:32 UT Visible from Russia Summary ------- On 2008 May 08 UT, the 28 km diameter asteroid (2542) Calpurnia will occult a 8.6 mag star in the constellation Virgo for observers along a path across Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.5 mag to 16.1 mag (the magnitude of the asteroid) for at most 6.1 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: 27 * date and approx. time of event: 2008 May 08, 20:24 - 2008 May 08, 20:35 UT * magnitude of target star: 8.6 * magnitude drop [mag]: 7.5 * estimated maximum duration [s]: 6.1 * Moon: 16 % sunlit, 91° distance * Sun: 138° distance * rough path description: Russia The occultation path -------------------- * approximate projected width [km]: 81 * 1 sigma uncertainty interval [path widths]: +/- 2.52 * 1 sigma uncertainty interval [seconds]: +/- 24.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .073 +/- .051) * 1 sigma uncertainty ellipse (major, minor, PA): ( .074", .048", 107° ) * approx speed of asteroid's shadow [km/s]: 4.5501 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 61096 by 2542 Calpurnia on 2008 May 8 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude 101 51 42 54 6 42 20 24 6 4 269 -7 99 13 11 54 0 37 ... .. .. .. .. .. 91 32 32 53 17 20 ... .. .. .. .. .. 98 15 23 54 29 44 20 24 19 6 266 -9 96 22 43 54 21 45 100 36 59 54 36 38 89 47 22 53 35 28 ... .. .. .. .. .. 95 37 35 54 50 31 20 24 31 7 264 -9 94 4 34 54 41 40 97 25 6 54 58 51 88 10 16 53 53 20 ... .. .. .. .. .. 93 26 8 55 10 20 20 24 43 8 262 -10 92 4 41 55 0 56 94 56 58 55 19 25 86 39 26 54 11 2 ... .. .. .. .. .. 91 30 33 55 29 35 20 24 56 9 260 -10 90 16 53 55 19 47 92 51 2 55 39 10 85 13 35 54 28 35 104 53 1 56 15 51 89 45 47 55 48 28 20 25 8 10 259 -11 88 37 49 55 38 21 90 59 7 55 58 26 83 51 51 54 46 3 99 54 21 56 43 2 88 9 1 56 7 8 20 25 20 11 258 -11 87 5 26 55 56 45 89 17 1 56 17 24 82 33 32 55 3 26 96 56 1 57 5 32 86 38 26 56 25 37 20 25 33 12 256 -11 85 38 19 56 15 0 87 42 18 56 36 8 81 18 8 55 20 47 94 34 17 57 26 40 85 12 47 56 43 59 20 25 45 12 255 -11 84 15 31 56 33 10 86 13 19 56 54 45 80 5 15 55 38 7 92 32 22 57 47 6 83 51 11 57 2 17 20 25 57 13 254 -11 82 56 17 56 51 16 84 48 59 57 13 15 78 54 33 55 55 25 90 43 18 58 7 7 82 32 58 57 20 32 20 26 10 14 253 -11 81 40 6 57 9 21 83 28 30 57 31 41 77 45 45 56 12 44 89 3 24 58 26 52 81 17 39 57 38 46 20 26 22 14 252 -11 80 26 31 57 27 24 82 11 13 57 50 6 76 38 39 56 30 4 87 30 26 58 46 27 80 4 48 57 56 59 20 26 34 15 250 -11 79 15 10 57 45 28 80 56 42 58 8 29 75 33 1 56 47 24 86 2 57 59 5 56 78 54 7 58 15 13 20 26 47 15 249 -11 78 5 47 58 3 32 79 44 33 58 26 53 74 28 44 57 4 47 84 39 53 59 25 20 77 45 18 58 33 28 20 26 59 15 248 -11 76 58 8 58 21 38 78 34 28 58 45 18 73 25 38 57 22 12 83 20 30 59 44 43 76 38 9 58 51 45 20 27 11 16 247 -11 75 52 0 58 39 46 77 26 11 59 3 45 72 23 35 57 39 39 82 4 14 60 4 5 75 32 28 59 10 5 20 27 24 16 246 -11 74 47 14 58 57 58 76 19 30 59 22 14 71 22 29 57 57 10 80 50 36 60 23 28 74 28 5 59 28 29 20 27 36 17 245 -11 73 43 40 59 16 12 75 14 14 59 40 47 70 22 15 58 14 44 79 39 17 60 42 53 73 24 51 59 46 56 20 27 49 17 244 -11 72 41 10 59 34 31 74 10 13 59 59 23 69 22 47 58 32 22 78 29 57 61 2 21 72 22 40 60 5 27 20 28 1 17 243 -11 71 39 38 59 52 53 73 7 19 60 18 4 68 23 59 58 50 4 77 22 22 61 21 53 71 21 24 60 24 4 20 28 13 17 242 -11 70 38 58 60 11 21 72 5 25 60 36 49 67 25 49 59 7 51 76 16 20 61 41 30 70 20 58 60 42 45 20 28 26 18 241 -11 69 39 4 60 29 53 71 4 25 60 55 40 66 28 11 59 25 42 75 11 40 62 1 12 69 21 15 61 1 32 20 28 38 18 240 -11 68 39 50 60 48 32 70 4 12 61 14 36 65 31 2 59 43 39 74 8 14 62 21 0 68 22 12 61 20 26 20 28 50 18 239 -10 67 41 13 61 7 16 69 4 41 61 33 39 64 34 19 60 1 41 73 5 52 62 40 54 67 23 44 61 39 25 20 29 3 18 238 -10 66 43 8 61 26 6 68 5 48 61 52 48 63 37 58 60 19 48 72 4 29 63 0 55 66 25 46 61 58 32 20 29 15 19 237 -10 65 45 32 61 45 3 67 7 29 62 12 4 62 41 56 60 38 2 71 3 58 63 21 4 65 28 15 62 17 46 20 29 27 19 236 -10 64 48 20 62 4 8 66 9 38 62 31 27 61 46 10 60 56 22 70 4 12 63 41 21 64 31 8 62 37 7 20 29 40 19 235 -10 63 51 29 62 23 19 65 12 13 62 50 59 60 50 38 61 14 49 69 5 8 64 1 48 63 34 20 62 56 37 20 29 52 19 234 -9 62 54 56 62 42 39 64 15 10 63 10 38 59 55 17 61 33 23 68 6 40 64 22 23 62 37 48 63 16 15 20 30 4 19 233 -9 61 58 38 63 2 7 63 18 25 63 30 27 59 0 3 61 52 4 67 8 44 64 43 8 61 41 30 63 36 2 20 30 17 19 232 -9 61 2 31 63 21 44 62 21 55 63 50 24 58 4 56 62 10 52 66 11 15 65 4 4 60 45 23 63 55 58 20 30 29 19 231 -9 60 6 34 63 41 29 61 25 38 64 10 31 57 9 51 62 29 48 65 14 11 65 25 11 59 49 22 64 16 4 20 30 41 20 230 -8 59 10 42 64 1 25 60 29 29 64 30 49 56 14 47 62 48 53 64 17 27 65 46 30 58 53 27 64 36 20 20 30 54 20 230 -8 58 14 54 64 21 30 59 33 27 64 51 16 55 19 42 63 8 6 63 21 1 66 8 1 57 57 33 64 56 47 20 31 6 20 229 -8 57 19 6 64 41 45 58 37 27 65 11 55 54 24 32 63 27 29 62 24 48 66 29 45 57 1 37 65 17 25 20 31 19 20 228 -7 56 23 15 65 2 12 57 41 28 65 32 46 53 29 15 63 47 0 61 28 46 66 51 43 56 5 38 65 38 15 20 31 31 20 227 -7 55 27 19 65 22 49 56 45 26 65 53 48 52 33 49 64 6 41 60 32 51 67 13 55 55 9 32 65 59 18 20 31 43 20 226 -7 54 31 16 65 43 39 55 49 19 66 15 4 51 38 11 64 26 33 59 37 1 67 36 22 54 13 16 66 20 33 20 31 56 20 225 -6 53 35 1 66 4 41 54 53 2 66 36 32 50 42 18 64 46 35 58 41 12 67 59 6 53 16 47 66 42 2 20 32 8 20 224 -6 52 38 32 66 25 56 53 56 35 66 58 15 49 46 8 65 6 48 57 45 21 68 22 6 52 20 2 67 3 44 20 32 20 20 223 -6 51 41 46 66 47 25 52 59 52 67 20 12 48 49 38 65 27 12 56 49 26 68 45 24 51 22 57 67 25 42 20 32 33 20 222 -5 50 44 40 67 9 8 52 2 51 67 42 24 47 52 45 65 47 48 55 53 22 69 9 1 50 25 30 67 47 55 20 32 45 20 221 -5 49 47 11 67 31 6 51 5 28 68 4 53 46 55 26 66 8 37 54 57 7 69 32 57 49 27 36 68 10 24 20 32 57 20 220 -5 48 49 14 67 53 19 50 7 41 68 27 39 45 57 37 66 29 38 54 0 37 69 57 15 48 29 13 68 33 10 20 33 10 19 218 -4 47 50 46 68 15 49 49 9 24 68 50 42 44 59 16 66 50 53 53 3 49 70 21 54 47 30 15 68 56 15 20 33 22 19 217 -4 46 51 42 68 38 36 48 10 34 69 14 4 44 0 18 67 12 23 52 6 39 70 46 58 46 30 38 69 19 38 20 33 34 19 216 -3 45 52 0 69 1 42 47 11 6 69 37 46 43 0 39 67 34 7 51 9 3 71 12 26 45 30 18 69 43 21 20 33 47 19 215 -3 44 51 33 69 25 6 46 10 56 70 1 49 42 0 16 67 56 6 50 10 56 71 38 21 44 29 9 70 7 25 20 33 59 19 214 -3 43 50 17 69 48 50 45 9 58 70 26 14 40 59 3 68 18 22 49 12 14 72 4 44 43 27 6 70 31 52 20 34 11 19 213 -2 42 48 6 70 12 56 44 8 6 70 51 2 39 56 56 68 40 54 48 12 51 72 31 37 42 24 2 70 56 41 20 34 24 19 212 -2 41 44 54 70 37 24 43 5 15 71 16 14 38 53 49 69 3 45 47 12 42 72 59 3 41 19 50 71 21 56 20 34 36 18 211 -1 40 40 34 71 2 15 42 1 16 71 41 53 37 49 37 69 26 54 46 11 41 73 27 4 40 14 23 71 47 37 20 34 48 18 210 -1 39 34 58 71 27 32 40 56 2 72 8 0 36 44 12 69 50 22 45 9 40 73 55 42 39 7 31 72 13 47 20 35 1 18 209 0 38 27 58 71 53 15 39 49 24 72 34 37 35 37 27 70 14 11 44 6 32 74 25 1 Uncertainty in time = +/- 25 secs [Prediction of 2008 Apr 23.0] Data for the target star ------------------------ * name: HIP 61096 * constellation : Virgo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 12 31 17.3806 DE: +02 18 09.247 * position source: mpos:HIP pm:HIP plx:HIP * standard error: RA,DE ["]: ( .019, .014 ) * V mag [mag]: 8.6 * B mag [mag]: 9.8 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2542) Calpurnia approx. diameter [km]: 28 approx. diameter ["]: .019 distance from Earth [AU]: 2.08400 * orbital information: orbit source: Preston date of fit: 2008 Apr 22 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 772 number of rejected observations: 13 time covered by the observations: 1954 Jul 03 - 2008 Mar 28 1 sigma uncertainty ellipse (major, minor, PA): 0.072, 0.046, 108° remarks: * orbital elements for (2542) Calpurnia : Mean anomaly = 12.92548902 deg Arg. of pericenter = 38.84834938 deg Long. of node = 146.06499569 deg Inclination = 4.63209791 deg Eccentricity = 0.07244481 Semimajor axis = 3.13031070 AU Perihelion dist = 2.90353596 AU Mag: H = 11.49, G = 0.15 Epoch of elements : MJD 54594.85600000 TDT (2008 May 08.856) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 8 2542 Calpurnia 20h 31.9m UT 8.6 12 31 17.381 2 18 9.25HIP 61096 9.8 16.1 28 6.1 2.084 -0.692 3.07 12.8032 2.303 -128.86 17.36 20.5321 0.26561 0.89980 -2.46244 0.72946 0.00338 -0.00187 2000 12.0613142008 5 4.00000 38.848349146.064996 4.6320980.07244481 3.1303107 2.903535911.4 5.00.15 RATE 1.7796020 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.074 0.048 107 3.52 0.047 0 54579.5020080508__61096 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 23, 04:13 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org