Preparing the Varuna Event – Status Report, 2008 Nov 16, 20:00 U.T.

At the moment position data and data of proper motion of the target star 2UCAC 40846256 are compared from various catalogues.
Dave Herald from Canberrra, Australia, has made a table of Vizier catalogue information. See the text file at the end of this report.

His comments about this table:

„In particular, the nominal catalogue precision is not indicated, and there are data items present in some of these catalogues that are not displayed in this listing. Main thing to conclude, however, is that UCAC2, CMC14 and SDSS give consistent positions with the UCAC2 proper motions. The one area of concern: the position from USNO-A2 would suggest a proper motion in Dec that is about half the UCAC2 value, and the APM-North position (epoch ~1950, internal precision ~0.1″, fit to Tycho2 ~0.5″) would suggest a proper motion of the other sign – I would discount the APM position, as it is inconsistent with all the others.“ (Dave Herald)

Robert McNaught (Australian National University) was asked by Dave Herald whether he might be able to get some astrometry of Varuna in the next couple of weeks – particularly if the asteroid and star could be on the same image. Because of the faintness, Mr. McNaught will have trouble with a precision for a single measurement of better than 0.2″. He will try over several nights, to improve. He will also see if there is an opportunity with the 2.3 meter scope.

Eric Frappa (euraster.net) asked Martine Castets & Bernard Tregon, the amateur astronomers using the T60cm from Pic du Midi Observatory between November 17 and 23, to make an attempt also with Varuna and target star in the same field. They agree to try in case of clear sky…

Stay tuned…

Oliver
Varuna Target star

Leave a Reply

You must be logged in to post a comment.