Target Pixel Files

The lightkurve documention has awesome resources for playing with Target Pixel Files (TPFs) from Kepler or TESS. Go look there! However, we added a few small wrappers to make it very slightly easier to download a simple Target Pixel File for either Kepler, K2, or TESS. Here’s the scoop:

import henrietta as hsl

Downloading TPFs

For Kepler, you’ll need to specify a Kepler quarter, a period of roughly 90 days. Remember that the pixels rotate on the sky 4 times a year, so you can’t seamlessly stitch together multiple TPFs.

tpf_kepler = hsl.download_kepler_tpf('Kepler-7', quarter=2)

For K2, you can include a star name or an EPIC ID number (which can often be found on the NASA Exoplanet Archive).

tpf_k2 = hsl.download_k2_tpf(206103150)

For TESS, only a tiny fraction of the data is available right now, all located at MAST. Still, here’s a wrapper to download a star, based on its TESS Input Catalog (TIC) identification number.

tpf_tess = hsl.download_tess_tpf(25155310)

Simple TPF Procedures

This is just a tiny sample of things you can do with a TPF. Again, you should go read the lightkurve documentation and tutorials for TPFs! You can make an imshow plot of a single frame, where you specify which image you want in the movie via the frame keyword.

tpf_k2.plot(frame=0)
tpf_k2.plot(frame=100);

You can make a light curve from the TPF.

lc =tpf_k2.to_lightcurve(aperture_mask='all')
lc.scatter();

You can access the times and the array of fluxes directly.

time = tpf_k2.time
movie = tpf_k2.flux
print('This TPF has {} times and an array of pixels with shape {}.'.format(len(time), movie.shape))