The series of blank-sky observations carried out last November and December is now publicly available in the RXTE Archive. These observations form part of the PCA Team's continuing efforts to understand and characterize the background of their instrument. In fact, they are just the first to appear in the Archive: one day a month is planned for this effort, and further observations will become available as soon as processing allows.

• The observations are collected under the proposal number 20801 and comprise the non-slew ObsIds:

         ObsId       RA (deg)   Dec (deg)   dd/mm/yy
  
     20801-01-01-00      5.00     -67.00    01/11/96
     20801-01-02-00      5.00     -67.00    02/12/96
     20801-02-01-00     60.00       2.00    01/11/96
     20801-02-01-00     60.00       2.00    01/12/96
     20801-03-01-00    138.00      15.00    01/11/96
     20801-03-02-00    138.00      15.00    01/12/96
     20801-04-01-00    235.00      10.00    01/12/96
     20801-05-01-00    345.00     -18.00    01/11/96
     20801-05-02-00    345.00     -18.00    01/12/96
  

• To obtain the data, either FTP anonymously to heasarc.gsfc.nasa.gov and get the files in the directory /xte/data/archive/AO2/P20801 or use Browse on the XTEPUBLIC catalogue to find the proposal 20801.

• The observations were made during the third gain epoch that began April 15, 1996 and still applies.

• The latest version of the background estimator, pcabackest, is now part of the the March 4th release of version-3.6.1 of the RXTE Ftools package. Also included in the new release is the latest version of xtefilt which you need to run to make the enhanced filter files required by pcabackest.