摘要
The first B-,V-,R_c-and I_c-band light curves of CSS J022914.4+044340 are presented and analyzed.It is found that CSS J022914.4+044340 is a low mass ratio(0.198 ± 0.005) deep(63.7 ± 7.9 %)contact binary,indicating that it is already at the end evolutionary stage of tidally-locked evolution via magnetized wind.Because of the totally eclipsing character,the photometric solutions are reliable.The temperature and metallicity are determined from the spectroscopic data as T=5855 ± 15 K and[Fe/H]=-0.842 ± 0.031,respectively.Based on the parallax of Gaia EDR3,the physical parameters of CSS J022914.4+044340 are estimated as M_(1)=1.44_(-0.22)^(+0.25) M_⊙,M_(2)=0.29_(-0.05)^(0.05) M_⊙,R_(1)=1.26_(-0.06)^(0.08) R_⊙,R2=0.65_(-0.04)^(0.03) R_⊙,L_(1)=1.718_(0.191)^(0.186) L_⊙ and L_(2)=0.416_(-0.050)^(0.039) L_⊙.Combining the fraction of light from the third body via the photometric solution(54%),the luminosity of the third body is estimated as 2.705 L_⊙.The third body may be inferred to be a subgiant.Thus,why the primary component of CSS J022914.4+044340 has higher mass compared to similar systems is explained,as well as why its metallicity is so poor.
基金
supports from the National Natural Science Foundation of China(Grant Nos.11773066 and 11933008)
the CAS Interdisciplinary Innovation Team
the Young Academic and Technology Leaders Project of Yunnan Province(No.2015HB098)
the Open Project Program of the Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences。
