By the end of last summers' antenna maintenance period the reflector of antenna 4 was equipped with new aluminum panels, replacing the previous carbon fiber panels. The antenna was moved out of the maintenance hall on October 17 and the surface was subsequently adjusted to an accuracy of better than 50 rms in a series of holographic measurements and panel adjustments.
The current winter semester was affected by quite variable weather conditions so far with periods of excellent atmospheric stability and transparency in particular at the end of November and the beginning of January but with very poor weather during most of December and the second half of January. Bure entered into the winter observing period with the array in its C-configuration and we switched to the B configuration already on December 28. The most extended A configuration was available from January 30 and it is now planned to move back to the C configuration by beginning of March. Compared with the original planning, scheduling of the B and A configuration has been interchanged due to the already acceptable though not exceptional atmospheric conditions in late December. The switch back to the compact D configuration is foreseen before the end of April. Global VLBI observations, which include the array in the 3mm phased-array mode, are planned from May 7 to 12, 2009. According to these plans, it will not be possible to complete projects requesting deep integrations using the compact configurations before the end of the current observing period.
As far as A-rated projects are concerned, we expect to bring most of these to completion before the end of the current winter semester. B-rated projects are likely to be observed only if they fall in a favorable LST range. We remind users of the Plateau de Bure interferometer that B-rated proposals which are not started before the end of the winter period have to be resubmitted.
Investigators who wish to check the status of their project may consult the interferometer schedule on the Web at http://www.iram.fr/IRAM/PDBI/ongoing.html. This page is updated daily.