UTILIZING SYNTHETIC VISIBLE SPECTRA TO EXPLORE THE PHYSICAL BASIS FOR THE CLASSIFICATION OF LAMBDA BOÖTIS STARS

Journal Article · Sun Jan 01 04:00:00 EST 2017 · Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/153/1/39· OSTI ID:22664057

Cheng, Kwang-Ping; Johnson, Dustin M.; Tarbell, Erik S.; Romo, Christopher A. ^[1]; Neff, James E. ^[2]; Gray, Richard O. ^[3]; Corbally, Christopher J. ^[4]

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1. California State University, Fullerton CA (United States)
2. College of Charleston, Charleston, SC (United States)
3. Appalachian State University, Boone, NC (United States)
4. Vatican Observatory, Tucson, AZ (United States)

Since the peculiar nature of Lambda Boötis was first noticed in 1943, the Lambda Boo stars have been recognized as a group of peculiar A-type stars. They are Population I dwarfs that show deficiencies of iron-peak elements (up to 2 dex), but have near-solar C, N, O, and S abundances. In a previous paper, we used both observed and synthetic ultraviolet spectra to demonstrate that the C i 1657 Å/Al ii 1671 Å equivalent width ratio can help distinguish between Lambda Boo stars and other metal-weak stars hotter than 8000 K. In this paper, using observed and synthetic visible (4000–6800 Å) spectra, we demonstrate that the C i 5052.17 Å/Mg ii 4481 Å equivalent width ratio can be used as a quantitative diagnostic for cooler Lambda Boo stars.

• OSTI ID: 22664057
• Journal Information: Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 1 Vol. 153; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
CARBON
CLASSIFICATION
DWARF STARS
ELEMENT ABUNDANCE
IRON
NITROGEN
OXYGEN
SULFUR
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA