Preparing the Varuna Event – Status Report, 2008 Nov 21, 21:30 U.T.

Raoul Behrend (Observatoire de Genève, Switzerland) reports at Nov 20:
„Bernard Trégon is actually using the 60cm telescope at Pic-du-Midi, France. He had taken a few hours ago some images from the Varuna & target area. Unfortunately, the sky got foggy and moon illuminated just before and during the first shoots.
Nevertheless, I could use one frame for the measurement the star’s position on 2008 11 20.196121 : 07 29 48.161 +25 40 07.68 using UCAC2 stars including proper motions and no other corrections. This position is to be taken with the „only indicative“ flag. Varuna is totally lost in the fog. More observations will be available in the coming nights.”

Later this day Dave Herald made a prediction according to the position measured by Bernard Trégon:
Map of Prediction

He comments:
“The main effect – 3 minutes later, with the path being slightly further north (over France). I think this astrometry confirms that the star position is ‚about right‘. The real uncertainty is the position of Varuna – and hopefully someone will succeed in getting a current position…”

Marcelo Assafin (Valongo Observatory, UFRJ, Brazil) want to perform an independent reduction with his astrometric software PRAIA.

Francois Colas (IMCCE, France) has taken some images at Pic du Midi:
“I just have done some images of Varuna this night at Pic du Midi. Unfortunately we still have the old CCD, so it noise, big pixels and small field… I hope it will be useful. I observe 6 hours to get a light curve.
The observational conditions are: 105 cm telescope F (with reducer) = 5.65 m Pixel size 23 x 23 microns so 0.84 “ on the sky Field : 5 x 4 arcmin.“

There is a discussion now how to incorporate any new astrometry. Whether that be by way of a simple offset, or by way of a new orbit computation.

More in the next days…

Oliver

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