Open AccessThe Distribution of Oxygen, Calcium, and Strontium Over the Surface of 21 Com
Author(s) -
Richard Monier
Publication year - 2021
Publication title -
research notes of the aas
Language(s) - English
Resource type - Journals
ISSN - 2515-5172
DOI - 10.3847/2515-5172/ac3af8
Subject(s) - strontium , calcium , oxygen , spectral line , abundance (ecology) , chemistry , phase (matter) , analytical chemistry (journal) , line (geometry) , ultraviolet , mineralogy , physics , optics , geometry , environmental chemistry , biology , mathematics , organic chemistry , astronomy , fishery
Comparison of optical high resolution high signal-to-noise ELODIE spectra of 21 Com taken in 2004 April and separated by about half of the 2 days rotational period, reveals variations of the oxygen, calcium and strontium lines between rotational phases 0.94 and 0.48. Whereas the lines of oxygen and calcium are stronger at phase 0.94, those of strontium strengthen at phase 0.48. The synthesis of strong Sr ii lines yields disk-averaged estimates of the abundances of strontium: about 200 times solar at phase 0.94 and 450 solar at phase 0.48 for strontium. However the O i and Ca ii lines are too blended to derive unambiguous quantitative information on the abundance and distribution of oxygen and calcium over the surface of 21 Com. The likely underabundance of oxygen might be quantified using stronger far-ultraviolet transitions.