Abstract
In this paper I deal with the WD0137-349 binary system consisting of a white dwarf (WD) and a brown dwarf (BD) in a close circular orbit of about 116 min. I, first, constrain the admissible range of values for the inclination i by noting that, from looking for deviations from the third Kepler law, the quadrupole mass moment Q would assume unlikely large values, incompatible with zero at more than 1-sigma level for i≲35 deg and i≳43 deg. Then, by conservatively assuming that the most likely values for i are those that prevent such an anomalous behavior of Q, i.e. those for which the third Kepler law is an adequate modeling of the orbital period, I obtain i=39±2 deg. Such a result is incompatible with the value i=35 deg quoted in literature by more than 2 sigma. Conversely, it is shown that the white dwarf’s mass range obtained from spectroscopic measurements is compatible with my experimental range, but not for i=35 deg. As a consequence, my estimate of i yields an orbital separation of a=(0.59±0.05)R⊙ and an equilibrium temperature of BD of T eq=(2087±154) K which differ by 10% and 4%, respectively, from the corresponding values for i=35 deg.
Similar content being viewed by others
References
Baym, G., Pethick, C., Sutherland, P.: Astrophys. J. 170, 299 (1971)
Benvenuto, O.G., Althaus, L.G.: Mon. Not. R. Astron. Soc. 303, 30 (1999)
Burleigh, M.R., Hogan, E., Dobbie, P.D., Napiwotzki, R., Maxted, P.F.L.: Mon. Not. R. Astron. Soc. 373, L55 (2006)
Capderou, M.: Satellites Orbits and Missions. Springer, Berlin (2005)
Driebe, T., Schönberner, D., Blöcker, T., Herwig, F.: Astron. Astrophys. 339, 123 (1998)
Iorio, L.: Astrophys. Space Sci. 310, 73 (2007)
Köster, D., et al.: Astron. Astrophys. 378, 556 (2001)
Maxted, P.F.L., Napiwotzki, R., Dobbie, P.D., Burleigh, M.R.: Nature 422, 543 (2006)
Papoyan, V.V., Sedrakyan, D.M., Chubaryan, É.V.: Astrophysics 7, 55 (1971)
Politano, M.: Astrophys. J. 604, 817 (2004)
Roy, A.E.: Orbital Motion, 4th edn. Institute of Physics (2005)
Soffel, M.H.: Relativity in Astrometry, Celestial Mechanics and Geodesy. Springer, Berlin (1989)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Iorio, L. Dynamical constraints on some orbital and physical properties of the WD0137-349A/B binary system. Astrophys Space Sci 312, 337–341 (2007). https://doi.org/10.1007/s10509-007-9701-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10509-007-9701-7