2016/02/05 by N. O. Baella, C. B. Pereira, L. F. Miranda +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Balmer series #Binary number #Emission spectrum #Stars #Stellar classification #Stellar, planetary, and galactic studies #Symbiotic star #astro-ph.SR
paper · pdf · doi:10.3847/0004-6256/151/4/100
24 pages, 3 tables, 5 figures, accepted by Astronomical Journal
arxiv created 2016/02/05 · openalex publication_date 2016/03/28 · arxiv updated 2016/04/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
ABSTRACT Yellow symbiotic stars are useful targets for probing whether mass transfer has happened in their binary systems. However, the number of known yellow symbiotic stars is very scarce. We report spectroscopic observations of five candidate yellow symbiotic stars that were selected by their positions in the 2MASS ( J − H ) versus ( H − K s ) diagram and which were included in some emission-line catalogs. Among the five candidates, only StH α 63 is identified as a new yellow symbiotic star because of its spectrum and its position in the [TiO] 1 –[TiO] 2 diagram, which indicates a K4–K6 spectral type. In addition, the derived electron density (∼10 8.4 cm −3 ) and several emission-line intensity ratios provide further support for that classification. The other four candidates are rejected as symbiotic stars because three of them actually do not show emission lines and the fourth one only Balmer emission lines. We also found that the WISE W3–W4 index clearly separates normal K-giants from yellow symbiotic stars and therefore can be used as an additional tool for selecting candidate yellow symbiotic stars.