Abstract
Photometric observations of four extreme low mass ratio W UMa binaries with wide total eclipses, and their absolute parameters are presented. The main results are as follows: (i) ASAS J015429+2042.8 is of A subtype while V755 Cep, VESPA V22 and GSC 02800-01387 are of W subtype; (ii) The mass ratios are close to the lower mass-ratio limit and can be classified as Extreme Low Mass Ratio Binaries (ELMRB). (iii) The fill-out factors of ASAS J015429+2042.8 and VESPA V22 are 0.16 and 0.21 respectively, the one of GSC 02800-01387 is 0.63 while the one of V755 Cep is 0.83; (iv) The smaller in size (and less massive) components of all targets are located above the MS band of the evolutional diagrams while the bigger (and more massive) components are located around ZAMS; (v) Our ELMRB systems fall into the stability zone with Jspin/Jorb lower than the Darwin’s instability ∼1/3.
Accepted Version (
Free)
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call