Does Near-Contact Binary Star System ZZ Eridani Have a Brown Dwarf Orbiting?

ANALYSIS OF THE SOUTHERN PRE-CONTACT W UMA BINARY ZZ ERIDANI: A 34 YEAR PERIOD STUDY YIELDS A POSSIBLE LOW-MASS COMPANION

Authors:

Samec et al

Abstract:

Complete Bessel BVRI light curves of ZZ Eridani [2MASS J04130109-1044545, HV 6280, NSVS 14888164 α(2000) = 04h13m1centerdots10, δ(2000) = −10°44'54centerdot''5 (ICRS), V = 13.9-14.4-15.0] are observed and analyzed. The system is a southern pre-contact W UMa binary. Its light curve has the appearance of an Algol (EA) light curve, however, it is made up of dwarf solar-type components with a period of only 0.4521 days. Our 34 year period study yields a sinusoidal fit or an increasing quadratic fit. The sinusoid may indicate that a third body is orbiting the close binary. The lower-limit mass of the third body is near that of the brown dwarf limit (0.095 M $\alpha $). Also included is an improved ephemeris, a mass ratio search, and a simultaneous BVRI Wilson–Devinney solution.

Where Are The Circumbinary Planets of Contact Binaries?

Where Are The Circumbinary Planets of Contact Binaries?

Authors:

Demircan et al

Abstract:

Up to present date, no circumbinary planet around contact binaries were discovered neither by transit method nor by the minima times variation, although they are known having third component stars around. We thus ask: where are the circumbinary planets of contact binaries?

By considering the physical and geometrical parameters we simulated the light curves of contact binaries with possible transiting circumbinary jovian planets.

It seems either the circumbinary jovian planets are not formed around contact binaries, probably due to dynamical effects of the binary and third component stars, or they are present but the discovery of such planets were not possible so far due to larger distortions then expected in the photometric data and in the minima times.