The abstract of the paper[0] clearly says<p>&gt; We combined optical light curves provided by the Kepler Space Telescope–K2 extended mission and thermal infrared data provided by the Herschel Space Observatory.<p>Kepler hasn&#x27;t been staring at the same patch of stars for a while now[1]<p>[0] <a href="http:&#x2F;&#x2F;iopscience.iop.org&#x2F;article&#x2F;10.3847&#x2F;0004-6256&#x2F;151&#x2F;5&#x2F;117&#x2F;" rel="nofollow">http:&#x2F;&#x2F;iopscience.iop.org&#x2F;article&#x2F;10.3847&#x2F;0004-6256&#x2F;151&#x2F;5&#x2F;11...</a>
[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Kepler_(spacecraft)#Second_Light_.28K2.29" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Kepler_(spacecraft)#Second_Lig...</a>