More Like this

1. Visual Orbits of Spectroscopic Binaries with the CHARA Array. IV. HD 61859, HD 89822, HD 109510, and HD 191692

   https://doi.org/10.3847/1538-3881/ac9385  

   Lester, Kathryn V. ; Schaefer, Gail H. ; Fekel, Francis C. ; Gies, Douglas R. ; Henry, Todd J. ; Jao, Wei-Chun ; Paredes, Leonardo A. ; Hubbard-James, Hodari-Sadiki ; Farrington, Christopher D. ; Gordon, Kathryn D. ; et al ( November 2022 , The Astronomical Journal)

   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
2. Studies of FCAPT UVBY photometry for the mCP stars HD  32966, HD 35298, HD 68292, HD 93226, HD 171247, HD  217833, HD 220147, and HD 223358

   https://doi.org/10.1002/asna.20220040  

   Wittman, Todd ; Dukes, Jr, Robert J. ; Adelman, Saul J. ( November 2022 , Astronomische Nachrichten)

   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
3. Accurate effective temperatures of the metal-poor benchmark stars HD 140283, HD 122563, and HD 103095 from CHARA interferometry

   https://doi.org/10.1093/mnrasl/sly010  

   Karovicova, I ; White, T R ; Nordlander, T ; Lind, K ; Casagrande, L ; Ireland, M J ; Huber, D ; Creevey, O ; Mourard, D ; Schaefer, G H ; et al ( January 2018 , Monthly Notices of the Royal Astronomical Society: Letters)
4. Geometric phase effects in the ultracold D + HD $ \rightarrow $ D + HD and D + HD $\leftrightarrow $ H + D 2 reactions

   https://doi.org/10.1088/1367-2630/aa4fd2  

   Kendrick, B K ; Hazra, Jisha ; Balakrishnan, N ( December 2016 , New Journal of Physics)
5. High-contrast imaging of HD 29992 and HD 196385 with the Gemini Planet Imager

   https://doi.org/10.1093/mnras/stac1929  

   García, Luciano H. ; Petrucci, R. ; Jofré, E. ; Gómez, M. ( August 2022 , Monthly Notices of the Royal Astronomical Society)

   Based on high-contrast images obtained with the Gemini Planet Imager (GPI), we report the discovery of two point-like sources at angular separations ρ ∼ 0.18 and 0.80 arcsec from the stars HD 29992 and HD 196385. A combined analysis of the new GPI observations and images from the literature indicates that the source close to HD 29992 could be a companion to the star. Concerning HD 196385, the small number of contaminants (∼0.5) suggests that the detected source may be gravitationally bound to the star. For both systems, we discarded the presence of other potential companions with m > 75 MJup at ρ ∼ 0.3–1.3 arcsec. From stellar model atmospheres and low-resolution GPI spectra, we derive masses of ∼0.2–0.3 M⊙ for these sources. Using a Markov-chain Monte Carlo approach, we performed a joint fit of the new astrometry measurements and published radial velocity data to characterize the possible orbits. For HD 196385B, the median dynamic mass is in agreement with that derived from model atmospheres, whilst for HD 29992B the orbital fit favours masses close to the brown dwarf regime (∼0.08 M⊙). HD 29992 and HD 196385 might be two new binary systems with M-type stellar companions. However, new high angular resolution images would help to confirm definitively whether the detected sources are gravitationally bound to their respective stars, and permit tighter constraints on the orbital parameters of both systems.

    

   more » « less