Fluorine in the carbon-enhanced metal-poor star HE 1305+0132

Simon C. Schuler, Katia Cunha, Verne V. Smith, Thirupathi Sivarani, Timothy C. Beers, Young Sun Lee

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The fluorine abundance of the Carbon-Enhanced Metal-Poor (CEMP) star HE 1305+0132 has been derived by analysis of the molecular HF (1-0) R9 line at 2.3357 μm in a high-resolution (R=50,000) spectrum obtained with the Phoenix spectrometer and Gemini-South telescope. Our abundance analysis makes use of a CNO-enhanced ATLAS12 model atmosphere characterized by a metallicity and CNO enhancements determined utilizing medium-resolution (R=3,000) optical and near-IR spectra. The effective iron abundance is found to be [Fe/H]=-2.5, making HE 1305+0132 the most Fe-deficient star, by more than an order of magnitude, for which the abundance of fluorine has been measured. Using spectral synthesis, we derive a super-solar fluorine abundance of A(19F)=4.96±0. 21, corresponding to a relative abundance of [F/Fe]=+2.90. A single line of the Phillips C2 system is identified in our Phoenix spectrum, and along with multiple lines of the first-overtone vibration-rotation CO (3-1) band head, C and O abundances of A(12C)=8.57±0.11 and A( 16O)=7.04±0.14 are derived. We consider the striking fluorine overabundance in the framework of the nucleosynthetic processes thought to be responsible for the C-enhancement of CEMP stars and conclude that the atmosphere of HE 1305+0132 was polluted via mass transfer by a primary companion during its asymptotic giant branch phase. This is the first study of fluorine in a CEMP star, and it demonstrates that this rare nuclide can be a key diagnostic of nucleosynthetic processes in the early Galaxy.

Original languageEnglish (US)
Title of host publicationFirst Stars III
Number of pages5
StatePublished - 2008
Externally publishedYes
EventFirst Stars III - Santa Fe, NM, United States
Duration: Jul 15 2007Jul 20 2007

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherFirst Stars III
Country/TerritoryUnited States
CitySanta Fe, NM


  • Abundances
  • Pop II Stars

ASJC Scopus subject areas

  • General Physics and Astronomy


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