Archive for the ‘Uncategorized’ Category

Sonntag, Dezember 7th, 2008

First Reports from European Observers – “Clouded out”

 

Reports of observations in Europe were reported at “Occult Watcher” and Planoccult:

 

Gerhard Dangl (Austria), Jan Manek (Czech Republic), Wolfgang Rothe (Germany), Jean Lecacheux at Meudon Observatory (France) and Carles Schnabel (Spain) reporting “clouded out” for the event.

 

Waiting for more reports…

 

Oliver

Sonntag, Dezember 7th, 2008

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:

 

 EUMETSAT, Southern Africa, 2008 Dec 07, 00:00 UT

 

 EUMETSAT, Southern Africa, 2008 Dec 07, 03:00 UT

 

Brazil:

 

EUMETSAT, Northern Brazil, 2008 Dec 07, 00:00 UT

 

 EUMETSAT, Northern Brazil, 2008 Dec 07, 03:00 UT

 

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

Freitag, Dezember 5th, 2008

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

 

Finder Chart with “Red Photographic Magnitudes” (13.05′ x 12.35′)

Dienstag, Dezember 2nd, 2008

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

Dienstag, Dezember 2nd, 2008

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):

 

Potential Observing Sites

 

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

 

Potential Observing Sites (Update R. Behrend, Nov 27)

 

 

 

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

 

Finder Chart (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

Montag, Dezember 1st, 2008

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).

 

 Map of Prediction by Steve Preston, 2008 Nov 30, 23:46 UT

 

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