text:   transitioning to become an extremely low mass white dwarf",8,"['New paper. We found a new (sort of) type of interacting binary star! <LINK> <LINK>', ""It's a white dwarf and a tidally distorted, bloated, stripped helium core. It looks like a cataclysmic variable (white dwarf accreting from a normal star), but the donor star is much hotter than any known cataclysmic variable donor. https://t.co/fPC1gbUn9Z"", ""Conversely, it's cooler, more bloated, and more tidally distorted than known low-mass white dwarfs. https://t.co/e4Gr95qqBl"", 'There are a few other known stars with similar temperature and luminosity (“sdA” stars) but they are not close being mass transferring and are mostly in wider binaries.', ""We think this binary was a cataclysmic variable with a donor that started transferring mass to its white dwarf companion *just* at the end of the main sequence. Now it's becoming an extremely low-mass white dwarf. https://t.co/Qb6EDLUKOF"", 'In a few Gyr, the binary will shrink to extremely short periods, where it appear as an ultracompact white dwarf binary or maybe an ""AM CVn"" (ultra short period, mass-transferring) system. https://t.co/9N7zR1hZHW', ""There are more of these transitional systems to be characterized! We're looking forward to mapping the population. \n\nthanks to @kenjshen, @thomkupfer, @bigticketdw, and other coauthors not on twitter."", '@PNeunteufel @kenjshen In the best-fit models, there is still a ~0.005 Msun H-burning envelope (which is why the contraction is slow). There are no shell flashes for the best-fit mass of 0.15 Msun, but there would be for &gt;0.18 Msun or so. Thanks!']",21,04,1464