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                                    NUSTAR
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NuSTARDAS V1.9.0:

- This is primarily a quality-of-life upgrade for the NuSTARDAS.
  The two main additions are: (1) Add the ability to save the
  barycenter-corrected event files in the output directory when
  barycorr=yes. Previously the user had to use cleanup=no to retail the
  barycenter-corrected event file, which also stored a number of other
  intermediate files. This allows for a more streamlined analysis
  approach for timing observations; (2) The "PRIOR" column is now
  preserved by default when producing the cleaned event files. This
  column is useful for recovering the time-dependent livetime on
  sub-second timescales and for high-rate observations. Please see
  the NuSTAR Software User's Guide for more details.

  There are also several minor bug fixes and other improvements:

- nupipeline: 1) when barycorr=yes and existage=3: updated the
  'nuproducts' run setting the orbit file to the "attorb" file;
  2) updated the 'nuproducts' run with `write_baryevtfile=no'.

- nuproducts: 1) added new input parameter `write_baryevtfile' to
  optionally save the barycenter-corrected event file when barycorr=yes;
  2) added an internal check to make sure that pilow, pihigh, pilowarf,
  pihigharf, grppibadhigh, grppibadlow are integer numbers; 3) added an
  internal gunzip of input mastaspectfile (to speed-up processing).

- nuscreen: added the "PRIOR" column to the list of columns that are
  preserved by default when the cleaned event files are created.