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Orbital Period Variation in the Chromospherically Active Binary FF UMa (2RE J0933+624)

Published online by Cambridge University Press:  09 August 2007

M.C. Gálvez ,
D. Montes ,
M.J. Fernández-Figueroa ,
E. De Castro  and
M. Cornide
M.C. Gálvez
Affiliation:
Departmento de Astronomía, Facultad de Físicas, Universidad Complutense de Madrid, Madrid, Spain email: [email protected] Department of Astronomy, University of Florida, Bryant Space Science Center, Gainesville, Florida, USA email: [email protected]
D. Montes
Affiliation:
Departmento de Astronomía, Facultad de Físicas, Universidad Complutense de Madrid, Madrid, Spain email: [email protected]
M.J. Fernández-Figueroa
Affiliation:
Departmento de Astronomía, Facultad de Físicas, Universidad Complutense de Madrid, Madrid, Spain email: [email protected]
E. De Castro
Affiliation:
Departmento de Astronomía, Facultad de Físicas, Universidad Complutense de Madrid, Madrid, Spain email: [email protected]
M. Cornide
Affiliation:
Departmento de Astronomía, Facultad de Físicas, Universidad Complutense de Madrid, Madrid, Spain email: [email protected]
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Abstract

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We present here a detailed study of FF UMa (2RE J0933+624), a recently discovered, X-ray/EUV selected, active binary system with strong Hα emission. By using high-resolution echelle spectroscopic observations taken during five observing runs from 1998 to 2004, we derived precise radial velocities that allowed us to determine the orbital solution of the system at different epochs. Analyzing these orbital solutions, together with a previous one determined in 1993 by other authors, we have found a change in the heliocentric Julian date on conjunction (Tconj) that can be explained by a change with time in the orbital period of the system. The relative amplitude of the orbital period variation derived from these data was dP/P ≈ 5 x 10−4, which is larger than the variations found in other similar chromospherically active binaries like AR Lac and HR 1099. This orbital period variation can be related (Applegate 1992; Lanza 1998, 2006) with the modulation of the gravitational quadrupole-moment of its magnetically active secondary star produced by angular momentum exchanges within its convective envelope. In addition, using these observations, we have determined the stellar parameters of the components and we have carried out a study of the chromospheric activity using all the optical indicators from Ca ii H&K to Ca ii IRT lines.

Keywords

stars: binaries: spectroscopicstars: activitystars: atmospheresstars: chromospheresstars: late-typestars: fundamental parameters
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 2 , Symposium S240: Binary Stars as Critical Tools & Tests in Contemporary Astrophysics , August 2006 , pp. 706 - 713
Copyright
Copyright © International Astronomical Union 2007

References

Applegate, J.H. 1992, ApJ 365, 621 CrossRefGoogle Scholar
Barden, S.C. 1985, ApJ 295, 162 Google Scholar
Cumming, A. 2004, MNRAS 354, 1165 Google Scholar
Frasca, A. & Lanza, A.F. 2005, ApJ 429, 309 Google Scholar
Jeffries, R.D., Bertram, D. & Spurgeon, R.D. 1995, MNRAS 276, 397 CrossRefGoogle Scholar
Lanza, A.F., Rodono, M. & Rosner, R. 1998, MNRAS 296, 893 Google Scholar
Lanza, A.F. 2006, MNRAS 369, 1773 Google Scholar
Matese, J.J. & Whirtmere, D.P. 1983, A&A 117, L7 Google Scholar
Montes, D., Fernández-Figueroa, M.J., De Castro, E. & Cornide, M. 1995, A&A 294, 165 Google Scholar
Montes, D., Fernández-Figueroa, M.J., De Castro, E. & Sanz-Forcada, J. 1997, A&A 125, 263 Google Scholar
Montes, D., Sanz-Forcada, J., Fernández-Figueroa, M.J., De Castro, E. & Poncet, A. 1998, A&A 330, 155 Google Scholar