International Occultation Timing Association
European Section
European Section
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European Section |
Occultations
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Occultation of UCAC4 374-103314 (14m7) by QuaoarNew update (10/6/16): According to prediction by Marc Buie, SWRI, the occultation track has shifted towards north. It will now cross Africa from central Angola to the northern tip of Madagascar. The prediction error (1-sigma is around 600km and the possible time error around 25 secondsThis is a bright occultation of (50000) Quaoar, which will pass probably through southern Africa and the eastern part of Brazil. From earlier occultation observation it is known that Quaoar has an approximative diameter of 1100 km (Brage-Ribas et. al. ApJ 773:26, 2013). . The occultation will take place on the 14th of June 2016 around 22h 37min UTCfor central southern Africa. The occultation can be seen also in many parts of the Indian Ocean, specially on the island of Reunion. Brage-Ribas et.al. found, that a possible atmosphere would have had an upper limit of 20 nbar to be detectable at that earlier observation. However, more detailed data from high resolution light curves are necessary, to definitely find or rule out an atmosphere around Quaoar. Also, teh degree of oblateness still has to be refined. 
Recently Julio Camargo got an updated position for the event, based on UCAC4 star positions. The combined errors on stellar posiition and Quaoar are about +/- 2000km. The errors are mostly from the ephemeris. Recent WFI-based Quaoar updates are not accurate enough to bring further improvements. The result is given below.
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Finding chartsCharts based on the UCAC4 catalogue and the XEPHEM (c) software are produced in different feld sizes. They can be downloaded from here.Field size5 min 10 min 1 degree 5 degree 10 degree 20 degree 40 degree The star magnitudesBased on VIZIER information.Magnitudes: f.mag (579-642nm) 13.937 Jmag 11.929 (2MASS) Hmag 11.405 (2MASS) Kmag 11.283 (2MASS) |
