Extended Data Fig. 2: Fits to archival PTF/iPTF data.
From: General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system
PTF least-squares fits of single harmonic sinusoids (smooth blue lines) to archival PTF/iPTF data used to determine the orbital decay rate. This archival data was extracted by using forced photometry on difference images. Because this is a least-squares fit of a sinusoid to the data, this timing technique uses the reflection effect in the system as its primary clock, rather than the mid-eclipse time. All error bars are 1σ. To determine the time of the epoch, we take the mean of all epochs used, and then calculate the phase of eclipse nearest to this mean time.
