IOTA/IOTA-ES occultation update for (930) Westphalia / TYC 7900-01940-1 event on 2008 Mar 05, 03:39 UT Visible from Africa Summary ------- On 2008 Mar 05 UT, the 37 km diameter asteroid (930) Westphalia will occult a 11.0 mag star in the constellation Corona Australis for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.1 mag to 16.1 mag (the magnitude of the asteroid) for at most 1.2 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: 51 * date and approx. time of event: 2008 Mar 05, 03:35 - 2008 Mar 05, 03:37 UT * midpoint of event [JD]: 2454530.65219583 * magnitude of target star: 11.0 * magnitude drop [mag]: 5.1 * estimated maximum duration [s]: 1.2 * Moon: 8 % sunlit, 40° distance * Sun: 72° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 39 * 1 sigma uncertainty interval [path widths]: +/- 1.25 * 1 sigma uncertainty interval [seconds]: +/- 2.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .047 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .047", .026", 85° ) * approx speed of asteroid's shadow [km/s]: 29.9760 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 7900-01940-1 by 930 Westphalia on 2008 Mar 5 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 - 15 0 0 21 37 27 3 35 49 0 131 -52 21 23 18 .. .. .. 20 48 2 .. .. .. - 14 0 0 20 47 44 3 35 49 1 132 -51 20 33 35 21 1 53 19 58 21 21 37 25 - 13 0 0 19 57 52 3 35 49 3 132 -50 19 43 45 20 12 1 19 8 34 20 47 30 - 12 0 0 19 7 54 3 35 50 4 133 -50 18 53 48 19 22 2 18 18 40 19 57 28 - 11 0 0 18 17 53 3 35 50 5 133 -49 18 3 48 18 31 59 17 28 43 19 7 21 - 10 0 0 17 27 49 3 35 50 6 133 -48 17 13 46 17 41 54 16 38 46 18 17 12 - 9 0 0 16 37 47 3 35 51 8 133 -47 16 23 46 16 51 49 15 48 49 17 27 3 - 8 0 0 15 47 47 3 35 52 9 134 -47 15 33 48 16 1 48 14 58 57 16 36 57 - 7 0 0 14 57 53 3 35 52 10 134 -46 14 43 56 15 11 51 14 9 10 15 46 55 - 6 0 0 14 8 6 3 35 53 11 134 -45 13 54 11 14 22 2 13 19 31 14 57 0 - 5 0 0 13 18 29 3 35 54 13 135 -44 13 4 37 13 32 23 12 30 3 14 7 14 - 4 0 0 12 29 4 3 35 56 14 135 -43 12 15 14 12 42 55 11 40 47 13 17 40 - 3 0 0 11 39 53 3 35 57 15 135 -42 11 26 6 11 53 42 10 51 45 12 28 19 - 2 0 0 10 50 59 3 35 58 16 135 -41 10 37 15 11 4 44 10 3 1 11 39 14 - 1 0 0 10 2 22 3 36 0 18 135 -40 9 48 41 10 16 5 9 14 35 10 50 28 0 0 0 9 14 6 3 36 1 19 136 -39 9 0 29 9 27 46 8 26 30 10 2 1 1 0 0 8 26 13 3 36 3 20 136 -38 8 12 38 8 39 49 7 38 47 9 13 55 2 0 0 7 38 43 3 36 5 22 136 -37 7 25 12 7 52 16 6 51 29 8 26 14 3 0 0 6 51 40 3 36 7 23 136 -36 6 38 12 7 5 9 6 4 38 7 38 58 4 0 0 6 5 4 3 36 9 24 137 -35 5 51 39 6 18 29 5 18 14 6 52 10 5 0 0 5 18 57 3 36 11 25 137 -34 5 5 36 5 32 19 4 32 20 6 5 51 6 0 0 4 33 21 3 36 13 27 137 -33 4 20 4 4 46 40 3 46 57 5 20 2 7 0 0 3 48 18 3 36 15 28 137 -32 3 35 5 4 1 33 3 2 7 4 34 45 8 0 0 3 3 49 3 36 17 29 137 -31 2 50 39 3 16 59 2 17 50 3 50 3 9 0 0 2 19 54 3 36 20 30 137 -30 2 6 48 2 33 1 1 34 9 3 5 55 10 0 0 1 36 36 3 36 22 31 138 -29 1 23 34 1 49 39 0 51 5 2 22 23 11 0 0 0 53 56 3 36 25 33 138 -28 0 40 58 1 6 55 0 8 38 1 39 29 12 0 0 0 11 54 3 36 28 34 138 -27 - 0 1 0 0 24 49 - 0 33 10 0 57 13 13 0 0 - 0 29 28 3 36 30 35 138 -26 - 0 42 19 - 0 16 37 - 1 14 19 0 15 37 14 0 0 - 1 10 10 3 36 33 36 138 -24 - 1 22 56 - 0 57 23 - 1 54 47 - 0 25 19 15 0 0 - 1 50 10 3 36 36 37 139 -23 - 2 2 53 - 1 37 27 - 2 34 33 - 1 5 33 16 0 0 - 2 29 28 3 36 39 38 139 -22 - 2 42 7 - 2 16 49 - 3 13 38 - 1 45 5 17 0 0 - 3 8 4 3 36 42 40 139 -21 - 3 20 38 - 2 55 28 - 3 51 59 - 2 23 54 18 0 0 - 3 45 56 3 36 45 41 139 -20 - 3 58 26 - 3 33 24 - 4 29 37 - 3 2 0 19 0 0 - 4 23 3 3 36 48 42 140 -19 - 4 35 30 - 4 10 36 - 5 6 32 - 3 39 22 20 0 0 - 4 59 27 3 36 51 43 140 -18 - 5 11 49 - 4 47 3 - 5 42 41 - 4 15 59 21 0 0 - 5 35 5 3 36 54 44 140 -17 - 5 47 24 - 5 22 45 - 6 18 6 - 4 51 50 22 0 0 - 6 9 58 3 36 57 45 140 -16 - 6 22 13 - 5 57 42 - 6 52 46 - 5 26 57 23 0 0 - 6 44 5 3 37 1 46 141 -15 - 6 56 16 - 6 31 53 - 7 26 40 - 6 1 17 24 0 0 - 7 17 26 3 37 4 47 141 -14 - 7 29 34 - 7 5 18 - 7 59 48 - 6 34 52 25 0 0 - 7 50 2 3 37 7 48 141 -13 - 8 2 6 - 7 37 57 - 8 32 11 - 7 7 40 26 0 0 - 8 21 51 3 37 11 49 142 -12 - 8 33 51 - 8 9 49 - 9 3 47 - 7 39 42 27 0 0 - 8 52 53 3 37 14 50 142 -10 - 9 4 50 - 8 40 56 - 9 34 37 - 8 10 57 28 0 0 - 9 23 9 3 37 17 51 143 -9 - 9 35 2 - 9 11 15 -10 4 41 - 8 41 26 29 0 0 - 9 52 39 3 37 21 52 143 -8 -10 4 28 - 9 40 48 -10 33 58 - 9 11 7 30 0 0 -10 21 22 3 37 24 53 144 -7 -10 33 8 -10 9 34 -11 2 29 - 9 40 2 31 0 0 -10 49 18 3 37 28 54 144 -6 -11 1 1 -10 37 34 -11 30 14 -10 8 10 32 0 0 -11 16 28 3 37 31 55 145 -5 -11 28 7 -11 4 47 -11 57 12 -10 35 32 33 0 0 -11 42 51 3 37 35 56 145 -4 -11 54 28 -11 31 14 -12 23 25 -11 2 6 34 0 0 -12 8 28 3 37 39 57 146 -3 -12 20 2 -11 56 54 -12 48 51 -11 27 55 35 0 0 -12 33 19 3 37 42 58 147 -2 -12 44 49 -12 21 48 -13 13 31 -11 52 56 36 0 0 -12 57 24 3 37 46 59 148 -1 -13 8 51 -12 45 56 -13 37 26 -12 17 12 37 0 0 -13 20 43 3 37 49 60 148 0 -13 32 7 -13 9 18 -14 0 35 -12 40 41 Uncertainty in time = +/- 3 secs [Prediction of 2008 Feb 2.0] Data for the target star ------------------------ * name: TYC 7900-01940-1 * constellation : Corona Australis * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 16 24.5435 DE: -38 02 12.700 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .022 ) * V mag [mag]: 11.0 * B mag [mag]: 11.2 * Apparent position with proper motion RA(deg): 274.2436441678 DE(deg): -38.0344222989 * Equation of equinoxes (radians) : 0.000045324795234 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (930) Westphalia approx. diameter [km]: 37 approx. diameter ["]: .022 distance from Earth [AU]: 2.33200 * orbital information: orbit source: Preston date of fit: 2008 Jan 31 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 644 number of rejected observations: 32 time covered by the observations: 1920 Mar 21 - 2007 May 22 1 sigma uncertainty ellipse (major, minor, PA): 0.040, 0.014, 83° remarks: * orbital elements for (930) Westphalia : Mean anomaly = 310.87772062 deg Arg. of pericenter = 329.54075639 deg Long. of node = 341.12898833 deg Inclination = 15.31521053 deg Eccentricity = 0.14343563 Semimajor axis = 2.43157228 AU Perihelion dist = 2.08279819 AU Mag: H = 11.06, G = 0.15 Epoch of elements : MJD 54530.15200000 TDT (2008 Mar 05.152) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 5 930 Westphalia 3h 39.2m UT 11.0 18 16 24.544-38 2 12.70TYC 7900-01940-1 11.2 16.1 37 1.2 2.332 5.345 -9.11 56.0482 -38.034 128.09 -5.93 3.6527 0.04885 0.33050 16.74569 -2.41737 -0.00531 -0.00061 2000 310.8382102008 3 5.00000329.540756341.128988 15.3152110.14343563 2.4315723 2.082798211.4 5.00.15 RATE 2.5994010 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.047 0.026 85 2.25 0.027 0 54498.5020080305_1940-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 03, 23:10 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org