How to cut out Target Pixel Files from Kepler Super Stamps or TESS FFIs

You can use lightkurve to cut Target Pixel Files (TPFs) out of a series of standard astronomical images, such as K2 Superstamp Mosaics or TESS Full-Frame-Images (FFIs). This brief tutorial will demonstrate how!

In [23]:
%matplotlib inline
from lightkurve import KeplerTargetPixelFile
from glob import glob
import numpy as np

Let’s assume you have downloaded a set simulated TESS FFI images to a local directory called data. lightkurve will assume that the files are given in time order. So we’ll sort the filenames first:

In [28]:
fnames = np.sort(glob('data/*.fits'))

Now we use the KeplerTargetPixelFile class and its function from_fits_images() to create the new TPF. This will cut out around the position keyword. You can pass a pixel position in units of the original image or RA and Dec coordinates.

In [29]:
tpf = KeplerTargetPixelFile.from_fits_images(images=fnames,
                                             position=(197,210),
                                             size=(5,5))
100%|██████████| 45/45 [00:01<00:00, 39.26it/s]
In [30]:
tpf.plot()
Out[30]:
<matplotlib.axes._subplots.AxesSubplot at 0x1c17d4dac8>
../_images/tutorials_cutting-out-tpfs-from-tess-ffis_6_1.png
In [31]:
tpf.to_lightcurve().plot()
Out[31]:
<matplotlib.axes._subplots.AxesSubplot at 0x1c1b9f2d68>
../_images/tutorials_cutting-out-tpfs-from-tess-ffis_7_1.png