Recent studies from both observations and theories show that planetary systems can be present and active around white dwarfs. In the first part, I will review results on the compositions of extrasolar planets from polluted white dwarf studies. Then I will discuss our on-going efforts to characterize circumstellar dust and gas disks around white dwarfs. In the last part, I will talk about the discovery of the first transiting planet around a white dwarf WD 1856+534 b and present an optical transmission spectrum with Gemini/GMOS. Finally, I will highlight new opportunities to characterize planetary systems around white dwarfs from current and future facilities.
Siyi did her undergraduate degree in Nanjing University and obtained her PhD from University of California, Los Angeles (UCLA) in 2014. After that, she was a postdoc fellow at the European Southern Observatory (ESO) based in Germany and also worked at the Paranal Observatory in Chile. Since 2017, Siyi has been an astronomer at the Gemini Observatory/NSF's NOIRLab in Hawaii.