Discovery and Classification of New Circumstellar Disks in the AllWISE Catalog from Disk Detective

In its four years since launch, DiskDetective.org has led to many new discoveries in the field of circumstellar disks. This presentation gives a brief overview of the project, and highlights our new results. We show that at most 7.9% of all WISE-detected infrared excesses are circumstellar disks, and find that some published excess searches have false positive rates greater than 70%. We also highlight new data on WISEA J080822.18-644357.3, a 45-Myr primordial disk around an M5 star in the Carina association first identified by Disk Detective in 2016. We find accretion rates of 10^(-12)-10^(-10) solar masses per year, variable on 24-hour timescales, based on near-IR spectroscopy. We also note flare activity and potential accretion bursts in nine nights of ground-based high-cadence optical photometry. We use J0808 as the prototypical example of "Peter Pan" disks, long-lived primordial disks around mid-M or later stars. Using these characteristics, we explore possible origin scenarios for Peter Pan disks, including longer lives for primordial disks around mid-M stars than previously thought, and discuss methods of testing their validity. If Peter Pan disks are shown to be a typical phenomenon around mid-M stars, the timescale for planet formation around these stars would also be greatly increased, affecting our expectations for planet yields and UV input onto the newly formed planets. Such disks would also potentially explain the near-circular resonant orbits of the TRAPPIST-1 system. This work was supported by grant 14-ADAP14-0161 from the NASA Astrophysics Data Analysis Program and grant 16-XRP16_2-0127 from the NASA Exoplanets Research Program.