text: 442,63,1083410795407372293,70874545,Josh Lothringer,"Check out a new paper (<LINK>) led by Ian Crossfield, where we detect 3(!) isotopologues of CO in both stars of an M-dwarf binary. This gives us C12/C13 and O16/O18 ratios, telling us this binary was enriched by a massive core-collapse SN. You can hear Ian talk about this in Session 420 this morning at 11:20 at #aas233, 10 minutes after I'm done giving my dissertation talk in Session 404! @StellarTayar That's a good question- I don't have a good intuition when it comes to stellar abundances so I would probably chalk it up to uncertainty. Maybe that is good reason to get add'l observations though.",https://arxiv.org/abs/1901.02607,"Low-mass M dwarfs represent the most common outcome of star formation, but their complex emergent spectra hinder detailed studies of their composition and initial formation. The measurement of isotopic ratios is a key tool that has been used to unlock the formation of our Solar System, the Sun, and the nuclear processes within more massive stars. We observed GJ 745AB, two M dwarfs orbiting in a wide binary, with the IRTF/iSHELL spectrograph. Our spectroscopy of CO in these stars at the 4.7 micron fundamental and 2.3 micron first-overtone rovibrational bandheads reveals 12C16O, 13C16O, and 12C18O in their photospheres. Since the stars are fully convective, the atomic constituents of these isotopologues should be uniformly mixed throughout the stars' interiors. We find that in these M dwarfs, both 12C/13C and 16O/18O greatly exceed the Solar values. These measurements cannot be explained solely by models of Galactic chemical evolution, but require that the stars formed from an ISM significantly enriched by material ejected from an exploding core-collape supernova. These isotopic measurements complement the elemental abundances provided by large-scale spectroscopic surveys, and open a new window onto studies of Galactic evolution, stellar populations, and individual systems. ",Unusual Isotopic Abundances in a Fully-Convective Stellar Binary,3,"['Check out a new paper (<LINK>) led by Ian Crossfield, where we detect 3(!) isotopologues of CO in both stars of an M-dwarf binary. This gives us C12/C13 and O16/O18 ratios, telling us this binary was enriched by a massive core-collapse SN.', ""You can hear Ian talk about this in Session 420 this morning at 11:20 at #aas233, 10 minutes after I'm done giving my dissertation talk in Session 404!"", ""@StellarTayar That's a good question- I don't have a good intuition when it comes to stellar abundances so I would probably chalk it up to uncertainty. Maybe that is good reason to get add'l observations though.""]",19,01,603