Identification of Possible Stellar Companions via Speckle Interferometry in a Sample of Be Stars

• Published in: The Astronomical journal Vol. 159; no. 4; p. 132
• Main Authors: Souza, T. B., Guerrero, C. A., Borges Fernandes, M.
• Format: Journal Article
• Language: English
• Published: Madison IOP Publishing 01.04.2020
• Subjects: Astronomical catalogs; Astronomy; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DIFFRACTION; Double stars; Field of view; INTERFEROMETRY; RESOLUTION; SENSITIVITY; Separation; Speckle interferometry; STARS; TELESCOPES
• ISSN: 0004-6256; 1538-3881; 1538-3881
• DOI: 10.3847/1538-3881/ab6dcd

Abstract We present speckle interferometric measurements of Be stars made with the 1.60 m Perkin-Elmer telescope at the Pico dos Dias Observatory of the Laboratório Nacional de Astrofísica in Brazil. Using three different filters ( V , R , and I ), we obtained astrometric measurements for 23 stars, during three observing runs allocated in 2017 March, 2018 April, and 2019 July. We identified pairs with angular separation ranging from 0.″10 to 6.″69, including six systems with separations smaller than 1.″0. We estimated a mean error in separation of 15 mas, 1.°2 in position angle, and 0.29 mag for the magnitude difference. We discovered three new possible double systems that are not identified in the literature: HD 174886, HD 159032, and HD 168135 with an average angular separation of 0.″20, 3.″23, and 5.″41, respectively. In addition, we identified four new pairs in multiple systems previously known in the Washington Double Star Catalog. However, for 16 stars of our sample, we did not find evidence of binarity, based on the diffraction-limited resolution, the field of view, and/or the sensitivity of our observations. From the cross-match with data from Gaia Data Release 2, we verified the possibility of some of these systems be gravitationally bound or not.