skip to main content


Title: Visual Orbits of Spectroscopic Binaries with the CHARA Array. III. HD 8374 and HD 24546
Award ID(s):
1715788 1908026 1636624
NSF-PAR ID:
10193721
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
The Astronomical Journal
Volume:
160
Issue:
2
ISSN:
1538-3881
Page Range / eLocation ID:
58
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    We present differential Strömgrenuvbyobservations from the Four College Automated Photometric Telescope (FCAPT) in Washington Camp, AZ of eight magnetic Chemically Peculiar (mCP) stars: HD 32966, HD 35298, HD 68292, HD 93226, HD 171247, HD 217833, HD 220147, and HD 223358. We use multiple period‐finding algorithms and incorporate data from the ESA Hipparcos catalogue to study the amplitudes, periods, and asymmetries in the light curves. No previous FCAPT data have been published for HD 68292. For the seven other stars, these studies substantially extend the analyses of published FCAPT datasets.

     
    more » « less
  2. Abstract We present the visual orbits of four spectroscopic binary stars, HD 61859, HD 89822, HD 109510, and HD 191692, using long baseline interferometry with the CHARA Array. We also obtained new radial velocities from echelle spectra using the APO 3.5 m, CTIO 1.5 m, and Fairborn Observatory 2.0 m telescopes. By combining the astrometric and spectroscopic observations, we solve for the full, three-dimensional orbits and determine the stellar masses to 1%–12% uncertainty and distances to 0.4%–6% uncertainty. We then estimate the effective temperature and radius of each component star through Doppler tomography and spectral energy distribution analyses. We found masses of 1.4–3.5 M ⊙ , radii of 1.5–4.7 R ⊙ , and temperatures of 6400–10,300 K. We then compare the observed stellar parameters to the predictions of the stellar evolution models, but found that only one of our systems fits well with the evolutionary models. 
    more » « less
  3. null (Ed.)
  4. ABSTRACT The determination of fundamental parameters of stars is one of the main tasks of astrophysics. For magnetic chemically peculiar stars, this problem is complicated by the anomalous chemical composition of their atmospheres, which requires special analysis methods. We present the results of the effective temperature, surface gravity, abundance, and radius determinations for three CP stars HD 188041, HD 111133, and HD 204411. Our analysis is based on a self-consistent model fitting of high-resolution spectra and spectrophotometric observations over a wide wavelength range, taking into account the anomalous chemical composition of atmospheres and the inhomogeneous vertical distribution for three chemical elements: Ca, Cr, and Fe. For two stars, HD 188041 and HD 204411, we also performed interferometric observations that provided us with the direct estimates of stellar radii. Comparison of the radii determined from the analysis of spectroscopic/spectrophotometric observations with direct measurements of the radii by interferometry methods for seven CP stars shows that the radii agree within the limits of measurement errors, which proves indirect spectroscopic analysis capable of proving reliable determinations of the fundamental parameters of fainter Ap stars that are not possible to study with modern interferometric facilities. 
    more » « less