Classifying the secondary component of the binary star W Aquilae
Journal article, 2015

Aims. The object W Aql is an asymptotic giant branch (AGB) star with a faint companion. By determining more carefully the properties of the companion, we hope to better constrain the properties of the AGB star. Methods. We present new spectral observations of the binary star W Aql at minimum and maximum brightness and new photometric observations of W Aql at minimum brightness. Results. The composite spectrum near minimum light is predominantly from the companion at wavelengths lambda 6000 angstrom. This spectrum can be classified as F8 to G0, and the brightness of the companion is that of a dwarf star. Therefore, it can be concluded that the companion is a main sequence star. From this, we are able to constrain the mass of the AGB component to 1.04-3 M-circle dot and the mass of the W Aql system to 2.1-4.1 M-circle dot. Our photometric results are broadly consistent with this classification and suggest that the main sequence component suffers from approximately 2 mag of extinction in the V band primarily due to the dust surrounding the AGB component.

stars: individual: W Aquilae

binaries: visual

stars: atmospheres

binaries: spectroscopic

Author

Taissa Danilovich

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

G. Olofsson

Stockholm University

John H Black

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Kay Justtanont

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Hans Olofsson

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 574 Art- no. A23

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1051/0004-6361/201423672

More information

Latest update

3/1/2018 7