Planetary debris transiting a second white dwarf
In July 2020, collaborators led by PhD student Zachary Vanderbosch at the University of Texas at Austin have published in The Astrophysical Journal only the second white dwarf known to show transits from an asteroid or planetesimal that got too close to its retired host star. The transits recur roughly every 100 days as the cloud of debris passes in front of the white dwarf. A thread first announcing the submitted paper is here, https://twitter.com/jotajotahermes/status/1166521382336913408, and the system continues to provide interesting surprises, including a deep new transit in November 2020: https://twitter.com/jotajotahermes/status/1326235133297520642