LAMOST spectroscopic binaries & variable stars

The first group has higher logg~4.621 and lower T~4870K which are mainly cool red dwarf binaries. The second group of SBVCs has logg around 4.171cm/s^2^ that includes binaries and pulsating stars such as {delta} Sct and {gamma} Dor variables. The gravitational accelerations of the third group of SBVCs are higher and some of them are below the zero-age main sequence.

They may be contact binaries in which the primary components are losing energy to the secondaries in the common envelopes and are at a special stellar evolutionary stage. The last group is composed of giants or supergiants with logg around 2.461cm/s^2^ that may be evolved pulsating stars. One target (C134624.29+333921.2) is confirmed as an eclipsing binary with a period of 0.65-days.

A preliminary analysis suggests that it is a detached binary with a mass ratio of 0.46. The primary fills its critical Roche lobe by about 89%, indicating that mass transfer will occur between the two components.