The ages of the components in very short period pre-main sequence ( PMS ) binaries are essential to an understanding of their formation .
We considered a sample of 7 PMS eclipsing binaries ( EBs ) with ages 1 to 6.3 MY and component masses 0.2 to 1.4 M _ { \odot } .
The very high precision with which their masses and radii have been measured , and the capability provided by the Modules for Experiments in Stellar Astrophysics ( MESA ) to calculate their evolutionary tracks at exactly the measured masses , allows the determination of age differences of the components independent of their luminosities and effective temperatures .
We found that the components of 5 EBs , ASAS J052821+0338.5 , Parenago 1802 , JW 380 , CoRoT 223992193 , & UScoCTIO 5 , formed within 0.3 MY of each other .
The parameters for the components of V1174 Ori , imply an implausible large age difference of 2.7 MY and should be reconsidered .
The 7th EB in our sample , RX J0529.4+0041 fell outside the applicability of our analysis .