Context : Recent observations of the low-mass pre-main sequence ( PMS ) , eccentric spectroscopic binaries DQ Tau and V773 Tau A reveal that their millimeter spectrum is occasionally dominated by flares from non-thermal emission processes .
The transient activity is believed to be synchrotron in nature , resulting from powerful magnetic reconnection events when the separate magnetic structures of the binary components are briefly capable of interacting and forced to reorganize , typically near periastron .

Aims : We conducted the first systematic study of the millimeter variability toward a sample of 12 PMS spectroscopic binaries with the aim to characterize the proliferation of flares amongst sources likely to experience similar interbinary reconnection events .
The source sample consists entirely of short-period , close-separation binaries that possess either a high orbital eccentricity ( e { > } 0.1 ) or a circular orbit ( e { \approx } 0 ) .

Methods : Using the MAMBO2 array on the IRAM 30m telescope , we carried out continuous monitoring at 1.25 mm ( 240 GHz ) over a 4-night period during which all of the high-eccentricity binaries approached periastron .
We also obtained simultaneous optical VRI measurements , since a strong link is often observed between stellar reconnection events ( traced via X-rays ) and optical brightenings .

Results : UZ Tau E is the only source to be detected at millimeter wavelengths , and it exhibited significant variation ( F _ { 1.25 mm } = 87–179 mJy ) ; it is also the only source to undergo strong simultaneous optical variability ( \Delta { } R { \approx } 0.9 mag ) .
The binary possesses the largest orbital eccentricity in the current sample , a predicted factor in star-star magnetic interaction events .
With orbital parameters and variable accretion activity similar to DQ Tau , the millimeter behavior of UZ Tau E draws many parallels to the DQ Tau model for colliding magnetospheres .
However , on the basis of our observations alone , we can not determine whether the variability is repetitive , or if it could also be due to variable free-free emission in an ionized wind .

Conclusions : UZ Tau E brings the number of known millimeter-varying PMS sources to 3 out of a total of 14 monitored binaries now in the literature .
Important factors in the non-detection of the rest of our targets are the coarse time-sampling and limited millimeter sensitivity of our survey .
We recommend that future studies concentrate on close-by targets , and obtain millimeter and optical data points with better temporal resolution .