Although the evolution of binary systems
has been qualitatively interpreted with the
evolutionary scenario, the quantitative
interpretation of any observed system is still
unsatisfactory due to the difficulty of the
quantitative treatment of mass and angular
momentum transfer/loss. To reach a true
understanding of the evolution of binary systems,
we have to accumulate more observational evidence.
So far, we have observed several binaries that are
short-period and noncontact, and found the
existence of extremely small-mass systems. In the
present paper, we study another short-period
(P=0.659d), noncontact, eclipsing binary system,
V392 Ori. We have made photometric and
spectroscopic observations of V392 Ori. The light
curves are found to vary, suggesting the existence
of circumstellar matter around the system.
Combining the photometric and spectroscopic
results, we obtain parameters describing the
system; we find the mass of the primary component
is only 0.6Mʘ- undermassive
for its spectral and luminosity class A5V,
suggesting that a considerable amount of its
original mass has been lost from the system during
the course of evolution. The low-mass problem is
very important for investigation of the evolution
of close binary systems: largemass loss within
and/or after the main-sequence will have a
significant influence on the future evolution of
binary systems.
VERY-LOW-MASS STELLAR AND SUBSTELLAR COMPANIONS TO SOLAR-LIKE STARS FROM MARVELS. III. A SHORT-PERIOD BROWN DWARF CANDIDATE AROUND AN ACTIVE G0IV SUBGIANT
