IOTA/IOTA-ES occultation update for (705) Erminia / TYC 7789-00042-1 event on 2008 May 10, 06:52 UT Visible from near North America Summary ------- On 2008 May 10 UT, the 134 km diameter asteroid (705) Erminia will occult a 10.8 mag star in the constellation Centaurus for observers along a path across near North America. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 12.9 mag (the magnitude of the asteroid) for at most 9.8 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: 95 * date and approx. time of event: 2008 May 10, 06:52 - 2008 May 10, 06:52 UT * magnitude of target star: 10.8 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 9.8 * Moon: 30 % sunlit, 102° distance * Sun: 153° distance * rough path description: near North America The occultation path -------------------- * approximate projected width [km]: 134 * 1 sigma uncertainty interval [path widths]: +/- 0.43 * 1 sigma uncertainty interval [seconds]: +/- 3.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .033 +/- .039) * 1 sigma uncertainty ellipse (major, minor, PA): ( .042", .029", 150° ) * approx speed of asteroid's shadow [km/s]: 13.6521 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Path does not land on Earth. Data for the target star ------------------------ * name: TYC 7789-00042-1 * constellation : Centaurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 13 49 14.9045 DE: -37 45 28.559 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .026 ) * V mag [mag]: 10.8 * B mag [mag]: 11.2 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (705) Erminia approx. diameter [km]: 134 approx. diameter ["]: .089 distance from Earth [AU]: 2.06800 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 684 number of rejected observations: 48 time covered by the observations: 1910 Oct 06 - 2008 Apr 23 1 sigma uncertainty ellipse (major, minor, PA): 0.035, 0.016, 135° remarks: * orbital elements for (705) Erminia : Mean anomaly = 120.66962211 deg Arg. of pericenter = 97.22480720 deg Long. of node = 3.02195153 deg Inclination = 25.01237349 deg Eccentricity = 0.05164904 Semimajor axis = 2.92278649 AU Perihelion dist = 2.77182738 AU Mag: H = 8.43, G = 0.15 Epoch of elements : MJD 54596.28600000 TDT (2008 May 10.286) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 10 705 Erminia 6h 52.3m UT 10.8 13 49 14.905-37 45 28.56TYC 7789-00042-1 11.2 12.9 134 9.8 2.068 -2.739 4.18 -124.2162 -37.758 76.02 17.74 6.8720 0.13190 1.03041 -7.64290 0.98109 0.00190 0.00173 2000 119.4297332008 5 4.00000 97.224807 3.021952 25.0123730.05164904 2.9227865 2.7718274 8.4 5.00.15 RATE 1.9724610 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.042 0.029 150 1.43 0.038 0 54594.5020080510_0042-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 08, 02:54 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org