Observe TNOs !

Waiting for Observation Reports, 2008 Dec 07, 09:55 UT

(20000) Varuna has now passed the target star and we are awaiting the observation reports.

These images by EUMETSAT show the cloud cover at 00:00 UT and 03:00 UT respectively at the most promising observing places.

Southern Africa:

Brazil:

Andrew Elliot from U.K. has sent a report to Planoccult. He tried the observation:

“Tonight I attempted the (20000) Varuna occultation ‘just in case…’, and because the sky was totally clear.

The target star (Mr 14.2) was easily visible using a Watec 120N with 16-frame integrations (0.64 sec/frame), + 406mm S-C at f/10.  Unfortunately, the recording had to be abandoned around the time of the expected occultation due to ice forming on *both* sides of the Schmidt corrector plate (despite a dew zapper)!  At least this was ‘proof of concept’ for future faint star occultations.”

Stay tuned…

Oliver

A Finder Chart with “Red Photographic Magnitudes”

Bruno Sicardy has set another finder chart at his web page The possible Varuna stellar occultation of 6/7 December 2008  .

This map is the same as in message “Maps of Potential Observing Stations and Finder Charts “ (Dec 02 at the blog), but with “Red photographic magnitudes” added for several stars.

Oliver

Independed Prediction from MIT

The MIT (Massachusetts Institute of Technology) has published an independed prediction for the Varuna occultation:

Check the link for details.

Varuna.20081207 Occultation Dec 07, 2008

The prediction (2008 Nov 26) following the results taken from the analysis of 101 frames obtained at the Lowell 42-inch Telescope, du Pont Telescope, SMARTS 0.9m Telescope, and Swope Telescope.

There is no major path shift compared to the predictions by the Rio Group or Raoul Behrend.

Oliver

Maps of Potential Observing Stations and Finder Charts

Bruno Sicardy has updated his web page The possible Varuna stellar occultation of 6/7 December 2008  with a map of potential observing sites near and inside the predicted path (path update Nov 29, Rio Group):

and according to the update by Raoul Brehrend (Nov 27):

A finder chart of the target star from Bruno’s webpage (DSS2.365 at 645nm, 13.05′ x 12.35′):

Additional to these maps you can find more finder charts for this occultation with different fields of view on the same web page:

20 deg

5 deg

1.5 deg

30 min

10 min

Less than 5 days to go…

Oliver

New Update by Steve Preston, Based on Astrometry from the Rio Group

Steve Preston has posted a new update for the Varuna event at:

http://asteroidoccultation.com/2008_12/1207_20000_20018.htm

This update uses most recent astrometry from Marcelo Assafin (Rio Group).

Steve has set the uncertainty larger than the formal uncertainty.

With the relatively small number of observations and the strong weighting for this recent astrometry he was reluctant to trust the formal uncertainties of the orbit fit.

Oliver