A new clock to determine the age of a coeval sample of binaries is proposed. The formalization relating the circularization cutoff period and the cluster age is developed, providing the mechanism for the new clock. The clock is applied to the cutoff observed by Mayor and Mermilliod (1984) among solar-mass binaries in the Hyades and Praesepe clusters, and the age of the Hyades is estimated at 1-2 billion years, comparable to the age of 0.8 billion yr derived from isochrone fitting. The presence of a Hyades binary composed of two 0.5 solar mass stars with a circular orbit of period 8.5 days, substantially longer than the cutoff period among the solar-mass binaries, is noted. A recently discovered cutoff among evolved main-seqeunce stars in the old open cluster M67 is compared with that predicted by the circularization theory, and the cutoff is found to be at a longer period than predicted by the clock mechanism.
No takes yet. Share an insight, caveat, or question.
Mathieu et al. (1988) studied this question.