IOTA/IOTA-ES occultation update for (416) Vaticana / 2UCAC 17576663 event on 2008 Oct 18, 01:12 UT Visible from USA, Mexico Summary ------- On 2008 Oct 18 UT, the 86 km diameter asteroid (416) Vaticana will occult a 12.1 mag star in the constellation Sagittarius for observers along a path across USA, Mexico. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.1 mag to 12.7 mag (the magnitude of the asteroid) for at most 2.7 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: 86 * date and approx. time of event: 2008 Oct 18, 01:13 - 2008 Oct 18, 01:14 UT * magnitude of target star: 12.1 * magnitude drop [mag]: 1.1 * estimated maximum duration [s]: 2.7 * Moon: 86 % sunlit, 156° distance * Sun: 68° distance * rough path description: USA, Mexico The occultation path -------------------- * approximate projected width [km]: 136 * 1 sigma uncertainty interval [path widths]: +/- 0.58 * 1 sigma uncertainty interval [seconds]: +/- 1.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .040 +/- .028) * 1 sigma uncertainty ellipse (major, minor, PA): ( .040", .028", 91° ) * approx speed of asteroid's shadow [km/s]: 32.0178 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 17576663 by 416 Vaticana on 2008 Oct 18 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 - 79 26 15 42 0 0 1 14 7 0 222 -31 ... .. .. - 80 32 43 ... .. .. - 81 50 54 - 80 38 42 41 0 0 1 14 6 2 221 -30 - 79 33 11 - 81 45 4 ... .. .. - 83 3 10 - 81 52 15 40 0 0 1 14 6 3 220 -29 - 80 46 47 - 82 58 36 ... .. .. - 84 16 44 - 83 7 1 39 0 0 1 14 6 4 219 -29 - 82 1 30 - 84 13 26 ... .. .. - 85 31 44 - 84 23 8 38 0 0 1 14 5 6 218 -28 - 83 17 29 - 85 29 45 - 82 2 28 - 86 48 19 - 85 40 45 37 0 0 1 14 4 7 218 -27 - 84 34 51 - 86 47 39 - 83 19 37 - 88 6 40 - 87 0 1 36 0 0 1 14 3 9 217 -26 - 85 53 46 - 88 7 21 - 84 38 12 - 89 26 56 - 88 21 8 35 0 0 1 14 2 10 216 -25 - 87 14 24 - 89 29 1 - 85 58 21 - 90 49 20 - 89 44 17 34 0 0 1 14 0 12 215 -24 - 88 36 57 - 90 52 52 - 87 20 16 - 92 14 7 - 91 9 42 33 0 0 1 13 58 13 214 -23 - 90 1 36 - 92 19 9 - 88 44 8 - 93 41 32 - 92 37 39 32 0 0 1 13 56 15 213 -22 - 91 28 37 - 93 48 9 - 90 10 12 - 95 11 54 - 94 8 26 31 0 0 1 13 54 16 212 -20 - 92 58 16 - 95 20 12 - 91 38 41 - 96 45 37 - 95 42 25 30 0 0 1 13 51 18 211 -19 - 94 30 53 - 96 55 42 - 93 9 54 - 98 23 6 - 97 20 1 29 0 0 1 13 48 19 210 -18 - 96 6 52 - 98 35 7 - 94 44 12 -100 4 55 - 99 1 44 28 0 0 1 13 45 21 209 -16 - 97 46 38 -100 19 1 - 96 21 59 -101 51 44 -100 48 14 27 0 0 1 13 41 23 208 -14 - 99 30 47 -102 8 10 - 98 3 43 -103 44 24 -102 40 17 26 0 0 1 13 37 24 207 -13 -101 19 59 -104 3 27 - 99 50 2 -105 44 3 -104 38 55 25 0 0 1 13 32 26 205 -11 -103 15 8 -106 6 6 -101 41 40 -107 52 10 -106 45 30 24 0 0 1 13 27 28 204 -9 -105 17 22 -108 17 45 -103 39 34 -110 10 53 Latitude Latitude Latitude Latitude -108 0 0 23 26 38 1 13 23 29 203 -7 22 46 6 24 7 49 21 59 51 24 56 29 -109 0 0 23 0 49 1 13 20 29 202 -7 22 20 33 23 41 43 21 34 37 24 30 1 -110 0 0 22 35 55 1 13 18 30 201 -6 21 55 55 23 16 33 21 10 16 24 4 31 -111 0 0 22 11 58 1 13 15 31 200 -5 21 32 13 22 52 20 20 46 51 23 40 0 -112 0 0 21 48 58 1 13 12 31 200 -4 21 9 27 22 29 5 20 24 20 23 16 25 -113 0 0 21 26 53 1 13 9 32 199 -3 20 47 36 22 6 46 20 2 45 22 53 49 -114 0 0 21 5 45 1 13 6 33 198 -2 20 26 41 21 45 24 19 42 4 22 32 11 -115 0 0 20 45 32 1 13 3 33 197 -1 20 6 41 21 24 59 19 22 17 22 11 30 Uncertainty in time = +/- 2 secs [Prediction of 2008 Oct 16.0] Data for the target star ------------------------ * name: 2UCAC 17576663 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 11 35.8384 DE: -33 37 32.562 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .039, .026 ) * V mag [mag]: 12.1 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (416) Vaticana approx. diameter [km]: 86 approx. diameter ["]: .048 distance from Earth [AU]: 2.45600 * orbital information: orbit source: Preston date of fit: 2008 Oct 15 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 839 number of rejected observations: 101 time covered by the observations: 1900 Jan 26 - 2008 Aug 21 1 sigma uncertainty ellipse (major, minor, PA): 0.012, 0.009, 101° remarks: * orbital elements for (416) Vaticana : Mean anomaly = 25.96014612 deg Arg. of pericenter = 198.90122880 deg Long. of node = 58.19131781 deg Inclination = 12.85813010 deg Eccentricity = 0.21918644 Semimajor axis = 2.79215957 AU Perihelion dist = 2.18015606 AU Mag: H = 7.68, G = 0.20 Epoch of elements : MJD 54757.05000000 TDT (2008 Oct 18.050) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 18 416 Vaticana 1h 12.0m UT 12.1 18 11 35.838-33 37 32.562UCAC 17576663 0.0 12.7 86 2.7 2.456 5.175 2.89 -132.0104 -33.626 158.29 -9.69 1.2003 -0.03547 0.77446 18.05372 0.80661 0.00513 -0.00027 2000 24.47084420081011.00000198.901229 58.191318 12.8581300.21918644 2.7921596 2.1801561 7.9 5.00.20 RATE 2.1124850 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.040 0.028 91 1.58 0.028 0 54755.5020081018_576663 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Oct 16, 00:39 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org