(Proposal ID) S17B-122

(PI) Yerra, Bharat Kumar

(Proposal Title)
[EAO Time] Probing the role of Beryllium in Li-rich giants

(Abstract)
We propose to  make a first systematic study of Be abundance in Li-rich giants 
using Subaru/HDS spectra. Lithium (Li) and Beryllium (Be) play important roles 
in stellar mixing, and are regarded sensitive indicators of pollution from 
substellar companions and nearby explosions. A rare class of G/K-giants 
portrays Li abundance anomalies, for which generally acceptable theoretical 
explainations proven elusive. Dedicated surveys increased the number of Li-
rich giants, but the origins of their Li enrichment are not yet understood. 
The lead arguments include Li production through Cameron-Fowler mechanism 
(CFM) followed by convective extra mixing and/or Li enrichment caused by 
engulfed planet(s) and/or CFM products polluted by novae. The study anticipates
to clarify the arguments by understanding the role of Be, non-detection/
 detection/ enhancement of ^9 Be and/or ^7 Be and check the relations with 
the behaviour of light and refractory elements, and expect to resolve the 
issues with Li enhancement in K giants. The results shall put constraints 
on tracing chemical signatures of planet engulfment in parent stars and/or 
stellar mixing processes during evolution of low mass stars.