Delaware Asteroseismic Research Center (DARC)



Version 2.0 Released on August 19, 2009

Wqed v2.0 has the following changes
  • Fixed two small bugs in how barycentric corrections are calculated.
  • Introduction of a new program, wqverify to test and correct bjed calculations from previous versions of Wqed.
  • Added support for reducing 2 and 3 channel phototube data.
  • Output files includes information on how barycentric correction is calculated, to help find errors.
  • A new script, update-leapseconds keeps the leap seconds file up to date.
  • Fix bug in whiff where the first day of the year was handled incorrectly.
  • Improved support for gcc version 4.3.2.
  • Numerous bug fixes that reduced memory leaks and improved stability

Wqed (pronounced "Wicked") is a set of tools developed by DARC to simplify the process of reducing time-series CCD data on variable stars. It provides no tools to measure the brightness of stars in individual frames (instead DARC uses ccd_hsp developed by Antonio Kanaan in the IRAF envirnoment). Instead it is concerned with what comes next.

  • Selecting and removing data lost to cloud
  • Removing the effects of light cloud and seeing variations
  • Keeping track of what star a given data set refers to, and when that data was taken
  • Performing barycentric corrections to data.

Members of the Whole Earth Telescope familiar with the data reduction package QED will be familiar with many of the features of Wqed. A poster describing Wqed was presented at the 15th European White Dwarf Workshop in Barcelona in July 2008. You can download a copy of this poster in Power point format. A copy of the conference proceedings is available through the Journal of Physics

Wqed was used successfully by DARC in XCov26, where most of the bugs were found and fixed. Data to be published in Mullally et al. (2008, in prep) was reduced with this package. Wqed comes with a 15 page manual and detailed installation instructions. Using Wqed is not required to participate in Whole Earth Telescope campaigns, but we make it available in the hope that you find it useful.

Select a region and zoom in Mark a region of bad points and remove from lightcurve Divide lightcurve by a combination of reference stars

Barycentric Corrections

Wqed calculates barycentric corrections using the method of Stumpff (1980). The code used is copied from XQed created by Reed Riddle. The calculated times have been checked against QED for the period 2001--2006 and agree. Data reduced with QED has appeared in refereed journals since 1986.


Wqed can be downloaded from the link above as a compressed tar file. To unpack this file, type the following on your command line

tar -zxvf wqed.tgz

and read the installation instructions in the manual (in the subdirectory help/. The manual is also available as a separate file. If you get the tarball, you don't also need to download the manual.

If you have any comments, queries or suggestions please contact Susan Thompson or Fergal Mullally (fergal -dot- mullally -at- gmail -dot- com). To fix a bug, add a feature, or improve the documentation, request access to the Subversion repository where you can add your work to the next version of Wqed. Ask Susan for details.


Nov 2007 Run


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