A Search for A Planet Near A Black Hole

Gaia BH1 is the first black hole discovered using the data from Gaia, which is orbited by a sun-like companion star and has plenty of RV data. Motivated by the enthusiasm to find exoplanets and the high precision of the data about Gaia BH1 from the spectrograph ESPRESSO, after finding the best-fit model of the stars orbit, I searched the RV residuals for periodic signals, estimated the intensity of the signal, tested the statistical significance and calculated the parameters for the planet candidate. Finally, we can conclude that the signal,which has a 15.2-day period and 4m/s amplitude could not have been produced by random noise. However, the planet candidate is not stable, and it may encounter the black hole or escape in at least about 20 years based on different mean anomalies. It is possibly due to the assumptions we made to avoid overfitting because it is close to the edge of being stable. Now we only have 40 data covering a single period, and we hope to get 100 more data from further observation because it may lead to details to replace the assumptions. Therefore, it would be possible for us to verify whether it is an exoplanet.