Skip to main content

Research Repository

Advanced Search

Spectroscopically resolving the Algol triple system

Kolbas, V.; Pavlovski, K.; Southworth, J.; Lee, C.-U.; Lee, D.-J. ; Lee, J.W.; Kim, S.-L.; Kim, H.-I.; Smalley, B.; Tkachenko, A.

Spectroscopically resolving the Algol triple system Thumbnail


V. Kolbas

K. Pavlovski

C.-U. Lee

D.-J. Lee

J.W. Lee

S.-L. Kim

H.-I. Kim

A. Tkachenko


Algol (ß Persei) is the prototypical semidetached eclipsing binary and a hierarchical triple system. From 2006 to 2010 we obtained 121 high-resolution and high signal-to-noise ratio echelle spectra of this object. Spectral disentangling yields the individual spectra of all three stars, and greatly improved elements both the inner and outer orbits. We find masses of
MA = 3.39 ± 0.06 M, MB = 0.770 ± 0.009 M and MC = 1.58 ± 0.09 M. The disentangled spectra also give the light ratios between the components in the B and V bands. Atmospheric parameters for the three stars are determined, including detailed elemental abundances for Algol A and Algol C. We find the following effective temperatures: TA = 12 550 ± 120 K, TB = 4900 ± 300 K and TC = 7550 ± 250 K. The projected rotational velocities are vAsin iA = 50.8 ± 0.8 km s-1, vBsin iB = 62 ± 2 km s-1 and vCsin iC = 12.4 ± 0.6 km s-1. This is the first measurement of the rotational velocity for Algol B, and confirms that it is synchronous with the orbital motion. The abundance patterns of components A and C are identical to within the measurement errors, and are basically solar. They can be summarized as mean metal abundances: [M/H]A = -0.03 ± 0.08 and [M/H]C = 0.04 ± 0.09. A carbon deficiency is confirmed for Algol A, with tentative indications for a slight overabundance of nitrogen. The ratio of their abundances is (C/N)A = 2.0 ± 0.4, half of the solar value of (C/N) = 4.0 ± 0.7. The new results derived in this study, including detailed abundances and metallicities, will enable tight constraints on theoretical evolutionary models for this complex system.

Journal Article Type Article
Acceptance Date Jun 3, 2015
Online Publication Date Jun 30, 2015
Publication Date Aug 21, 2015
Publicly Available Date May 26, 2023
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Publisher Oxford University Press
Peer Reviewed Peer Reviewed
Volume 451
Issue 4
Pages 4150 -4161
Keywords binaries, eclipsing, binaries, spectroscopic, stars, fundamental parameters, individual, Algol
Publisher URL


You might also like

Downloadable Citations