Zé Vinícius bio photo

Zé Vinícius

Intern at NASA Ames Research Center Kepler/K2 Mission

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Hi everyone!

PyKE v3.0beta has been announced!

Quite a few things have changed since PyKE v2.6.3, more precisely PyKE v3.0:

  • does not depend on PyRAF anymore
  • is installable using pip install pyketools
  • is being developed actively in a fully collaborative and open manner on GitHub
  • can be used as both command line tools or function calls
  • is up to date with its dependencies (numpy, scipy, astropy, etc)

PyKE has been a very versatile package. For example, one can execute quick-look tasks like plot a lightcurve with kepdraw:

In [1]: from pyke import kepdraw
In [2]: kepdraw("kplr005110407-2009350155506_llc.fits")

Or analogously,

$ kepdraw kplr005110407-2009350155506_llc.fits

To look and create an aperture mask (left-click on the pixels and hit “dump”), one can use kepmask:

In [3]: from pyke import kepmask
In [4]: kepmask("ktwo201572338-c01_lpd-targ.fits.gz")

      KepID:  201572338
 RA (J2000):  171.92976
Dec (J2000):  1.620142
     KepMag:  15.827
   SkyGroup:  0
     Season:  0
    Channel:  62
     Module:  18
     Output:  2

To extract a light curve using that specific mask, one can use kepextract:

In [5]: from pyke import kepextract, kepdraw
In [6]: kepextract("ktwo201572338-c01_lpd-targ.fits.gz", maskfile="mask.txt")
Writing output file ktwo201572338-c01_lpd-targ-kepextract.fits...
In [7]: kepdraw("ktwo201572338-c01_lpd-targ-kepextract.fits")

To remove low-frequency components from the above lightcurve, we can use kepflatten:

In [8]: from pyke import kepflatten
In [9]: kepflatten("ktwo201572338-c01_lpd-targ-kepextract.fits")
Writing output file ktwo201572338-c01_lpd-targ-kepextract-kepflatten.fits...
In [10]: kepdraw("ktwo201572338-c01_lpd-targ-kepextract-kepflatten.fits", datacol='DETSAP_FLUX')

K2 data has correlated noise due to the motion of the spacecraft; this correlated noise can be compensated with kepsff:

In [11]: from pyke import kepsff
In [12]: kepsff("ktwo201572338-c01_lpd-targ-kepextract-kepflatten.fits", stepsize=0.5)
Writing output file ktwo201572338-c01_lpd-targ-kepextract-kepflatten-kepsff.fits...
In [13]: kepdraw("ktwo201572338-c01_lpd-targ-kepextract-kepflatten-kepsff.fits", datacol='DETSAP_FLUX')

Need to tweak the bits a little more to get a cleaner lightcurve =)

The full documentation of PyKE lives in https://pyke.keplerscience.org.

Feel free to contribute via GitHub issues or pull requests ;-)