Is this project an undergraduate, graduate, or faculty project?
Undergraduate
Project Type
individual
Campus
Daytona Beach
Authors' Class Standing
Katelyn Sonnen, Senior
Lead Presenter's Name
Katelyn Sonnen
Lead Presenter's College
DB College of Arts and Sciences
Faculty Mentor Name
Jason Aufdenberg
Abstract
Sirius A (Alpha Canis Majoris), with its slow rotation and stable atmospheric conditions, serves as an ideal candidate for 1-D stellar atmosphere spectral synthesis. Its mass, radius, and surface gravity are known with great precision (within 1%), making it a key benchmark for stellar astrophysics. However, the elemental composition of Sirius’ atmosphere remains one of its most uncertain parameters. Kurucz and Furenlid (1979) produced the Sample Spectral Atlas for Sirius, covering wavelengths from 354 nm to 440 nm, the first high signal-to-noise, high spectral resolution atlas of the star. In an effort to improve the accuracy of the spectral synthesis, we have updated the model atoms to include the latest atomic data available in the literature. These updates include neutral species from Ni, Fe, and Mn, and singly ionized species from Si, Ca, Ti, V, Cr, and Fe. We present our spectral atlas with improved accuracy using updated atomic data provided by Wood et al. (2013, 2014), Lawler et al. (2013, 2017), Den Hartog et al. (2011) utilizing the Moog database. These updates correct systematic errors in line strength across the extended wavelength range, confirming previous abundance estimates for most species. Using the updated atomic data, we have improved the match between the synthetic spectrum and archival spectra taken for Sirius A. We will continue refining our Sirius atlas between 124 nm to 870 nm, incorporating data from the Hubble Space Telescope HST/STIS), the Very Large Telescope (VLT/UVES), and the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI).
Did this research project receive funding support (Spark, SURF, Research Abroad, Student Internal Grants, Collaborative, Climbing, or Ignite Grants) from the Office of Undergraduate Research?
Yes, Spark Grant
Sirius NLTE Updates and Improvements
Sirius A (Alpha Canis Majoris), with its slow rotation and stable atmospheric conditions, serves as an ideal candidate for 1-D stellar atmosphere spectral synthesis. Its mass, radius, and surface gravity are known with great precision (within 1%), making it a key benchmark for stellar astrophysics. However, the elemental composition of Sirius’ atmosphere remains one of its most uncertain parameters. Kurucz and Furenlid (1979) produced the Sample Spectral Atlas for Sirius, covering wavelengths from 354 nm to 440 nm, the first high signal-to-noise, high spectral resolution atlas of the star. In an effort to improve the accuracy of the spectral synthesis, we have updated the model atoms to include the latest atomic data available in the literature. These updates include neutral species from Ni, Fe, and Mn, and singly ionized species from Si, Ca, Ti, V, Cr, and Fe. We present our spectral atlas with improved accuracy using updated atomic data provided by Wood et al. (2013, 2014), Lawler et al. (2013, 2017), Den Hartog et al. (2011) utilizing the Moog database. These updates correct systematic errors in line strength across the extended wavelength range, confirming previous abundance estimates for most species. Using the updated atomic data, we have improved the match between the synthetic spectrum and archival spectra taken for Sirius A. We will continue refining our Sirius atlas between 124 nm to 870 nm, incorporating data from the Hubble Space Telescope HST/STIS), the Very Large Telescope (VLT/UVES), and the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI).