IOTA/IOTA-ES occultation update for (83982) Crantor / UCAC2 24198278 event on 2012 Sep 08, 10:18 UT Visible from Possibly Australia, Asia Summary ------- On 2012 Sep 08 UT, the 67 km diameter asteroid (83982) Crantor will occult a 13.2 mag star in the constellation Sagittarius for observers along a path across Possibly Australia, Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 8.3 mag to 21.5 mag (the magnitude of the asteroid) for at most 14.2 seconds. This update is based on historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 0 * date and approx. time of event: 2012 Sep 08, 10:18 - 2012 Sep 08, 10:18 UT * geocentric midpoint of event [JD]: 2456178.9415125 * magnitude of target star: 13.2 * magnitude drop [mag]: 8.3 * estimated maximum duration [s]: 14.2 * Moon: 52 % sunlit, 155° distance * Sun: 113° distance * rough path description: Possibly Australia, Asia The occultation path -------------------- * approximate projected width [km]: 67 * 1 sigma uncertainty interval [path widths]: +/- 272.67 * 1 sigma uncertainty interval [seconds]: +/- 2597.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 1.892 +/- .515) * 1 sigma uncertainty ellipse (major, minor, PA): ( 1.928", .370", 101° ) * approx speed of asteroid's shadow [km/s]: 4.7241 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Path does not land on Earth. Data for the target star ------------------------ * name: UCAC2 24198278 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 36 13.5425 DE: -19 35 07.832 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .165, .168 ) * V mag [mag]: 13.2 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 279.2504379216 DE(deg): -19.5723966987 * Equation of equinoxes (radians) : 0.000068538431460 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (83982) Crantor approx. diameter [km]: 67 approx. diameter ["]: .006 distance from Earth [AU]: 16.03800 * orbital information: orbit source: Preston date of fit: 2011 May 05 source of used astrometry: MPC (via Astdys) number of used observations: 100 number of rejected observations: 0 time covered by the observations: 2001 Mar 20 - 2008 Jun 25 1 sigma uncertainty ellipse (major, minor, PA): 1.921, 0.330, 101° remarks: * orbital elements for (83982) Crantor : Mean anomaly = 43.70066001 deg Arg. of pericenter = 92.61461984 deg Long. of node = 117.41064057 deg Inclination = 12.78439879 deg Eccentricity = 0.27496551 Semimajor axis = 19.35696590 AU Perihelion dist = 14.03446789 AU Mag: H = 8.73, G = 0.15 Epoch of elements : MJD 56178.43000000 TDT (2012 Sep 08.430) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 8 83982 Crantor 10h 35.8m UT 13.2 18 36 13.543-19 35 7.83UCAC2 24198278 0.0 21.5 67 14.2 16.038 -0.069 -1.09 132.2148 -19.585 20.44 5.45 10.5963 0.95933 -0.85414 -1.77186 -1.99259 0.00547 0.00020 2000 43.6030992012 831.00000 92.614620117.410641 12.7843990.2749655119.356965914.0344679 9.1 5.00.15 RATE 0.1157310 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 1.928 0.370 101273.67 1.571 0 0-5-2 055687.0020120908_198278 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 20, 04:41 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org