text:   exoplanet population?",6,"['1/4 New paper based on @almaobs <LINK> @ESO VLT/X-Shooter #GaiaDR2 data: \n""Why do protoplanetary disks appear not massive enough to form the known exoplanet population?""\n<LINK>\nwith A LOT of help from Alessandro Morbidelli and Tristan Guillot <LINK>', '2/4 Take home: we do not have enough mass in disks at 1-3 Myr to explain exoplanetary systems, even when considering the mass in solids in disks vs the mass of solids in planets. \nThis is now true for a large range of stellar masses covered both in disks and exoplanet surveys https://t.co/ebtdU5l6eN', '3/4 Possible solutions:\n0) protoplanetary disk masses are underestimated (but I have reasons to believe this is not the case)\n1) cores of planets have formed very rapidly (&lt;0.1-1 Myr) \n2) disks are continuously replenished of fresh planet-forming material from the environment', '4/4 I want to also point to (some of the) relevant references for the various points:\n0) https://t.co/i1hlQnitOx https://t.co/bvRTlRGZzn\n1) https://t.co/mISVRLILyh https://t.co/nphETM5oYV https://t.co/mb87Cek9xN \n2) https://t.co/Zy6lHNfjhX https://t.co/3pZFSDZoJS', 'P.S. the right link is https://t.co/yElqOqW9EI.....', '@exohugh Assuming at least 100% efficiency, which is not expected by models?']",18,09,1066