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Title: Fate of twin stars on the unstable branch: Implications for the formation of twin stars
Award ID(s):
1912619
NSF-PAR ID:
10363609
Author(s) / Creator(s):
;
Publisher / Repository:
American Physical Society
Date Published:
Journal Name:
Physical Review D
Volume:
105
Issue:
4
ISSN:
2470-0010; PRVDAQ
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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    We present the first isotopic abundances of both13CO and C18O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions. First, we compareM-band spectra from IRTF/iSHELL to synthetic spectra generated from custom solar atmosphere models using the PHOENIX atmosphere code. Next, we compare our calculated abundances to GCE models that consider isotopic yields from massive stars, asymptotic giant branch stars, and fast-rotating stars. The12C/13C ratios determined for this sample of solar twins are consistent with predictions from the selected GCE models; however, the16O/18O ratios tentatively contradict these predictions. This project constitutes the first in a stellar chemical abundance series seeking to (1) support the James Webb Space Telescope as it characterizes exoplanet atmospheres, interiors, and biosignatures by providing host star abundances; (2) identify how unexplored stellar abundances reveal the process of galactic chemical evolution and correlate with star formation, interior, age, metallicity, and activity; and (3) provide improved stellar ages using stellar abundance measurements. By measuring elemental and isotopic abundances in a variety of stars, we not only supply refined host star parameters, but also provide the necessary foundations for complementary exoplanet characterization studies—and ultimately contribute to the exploration of galactic, stellar, and planetary origins and evolution.

     
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