This poster summarizes Silverberg et al. (2020) and subsequent new results in the literature regarding “Peter Pan” disks, a class of substantial M star disks with spectroscopic evidence of accretion in young stellar associations (YSAs) at ages ≥20 Myr—i.e. they seem to "never grow up." We outline the ensemble characteristics of the eight known Peter Pan disks from optical and near-IR spectroscopy, ALMA observations of WISEA J080822.18-644357.3 (J0808; the prototypical Peter Pan disk), and optical light curves, including TESS Cycle 3 observations of J0808. We find that these objects most plausibly represent long-lived CO-poor primordial disks, or "hybrid" disks, exhibiting both debris and primordial-disk features. We finally outline Disk Detective v2.0, a citizen science project for identifying circumstellar disks in WISE data that is explicitly designed to leverage Gaia to search for new Peter Pan disks.

{"references": ["Carpenter, John et al. (2009). ApJS, 181, 197", "Cody, Ann Marie et al. (2014). AJ, 147, 82", "Coleman, Gavin & Haworth, Thomas. (2020). MNRAS, 496, L111", "Esplin, Taran et al. (2018). AJ, 156, 75", "Flaherty, Kevin et al. (2019). ApJ, 872, 92", "Gagne, Jonathan et al. (2018). ApJ, 856, 23", "Gillon, Michael et al. (2016). Nature, 533, 221", "Gillon, Michael et al. (2017). Nature, 542, 456", "Kuchner, Marc et al. (2016). ApJ, 830, 84", "Lee, Jinhee et al. (2020). MNRAS, 494, 62", "Matsumura, Soko & Pudritz, Ralph E. (2006). MNRAS, 365, 572", "Murphy, Simon et al. (2018). MNRAS, 476, 3290", "Quarles, Billy et al. (2017). ApJL, 842, L5", "Silverberg, Steven et al. (2016). ApJ, 830, L28", "Silverberg, Steven et al. (2020). ApJ, 890, 106", "White, Russel & Basri, Gibor. (2003) ApJ, 582, 1109"]}