Free Access

Fig. 2

image

Example of how the detrending procedure alone can produce an exomoon-like transit signal around a planetary transit. We use “transit 5” of Kepler-1625 b as an example. Top panel: gray dots indicate the Kepler PDCSAP flux. The lines show a fourth-order polynomial fit for which we exclude 7.5 d (blue) or 4 d (orange) of data around the mid-point (dashed parts), respectively. Middle panel: dots show the detrended light curve derived from the blue polynomial fit in the top panel. The blue line illustrates a planet-only transit model. Bottom panel: dots visualize the detrended light curve using the orange polynomial fit from the top panel. We note the additional moon-like transit feature caused by the overshooting of the orange polynomial in the top panel. The orange line shows a planet–moon transit model with moon parameters as in Table 1 (see Fig. 4 for transit dynamics). As an alternative interpretation, the blue detrending function filters out an actually existing moon signature while the orange detrending fit preserves the moon signal.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.