We present multi-epoch optical and near-infrared ( NIR ) photometry and spectroscopy of the spectroscopic binary T Tauri star DQ Tau .
The photometric monitoring , obtained using SMARTS ANDICAM , recovers the previously-seen correlation between optical flux and the 15.8-day binary orbital period , with blue flux peaks occurring close to most observed periastron passages .
For the first time , we find an even more consistent correlation between orbital period and NIR brightness and color .
The onset of pulse events in the NIR on average precedes those in the optical by a few days , with the rise usually starting near apastron orbital phase .
We further obtained five epochs of spectroscopy using IRTF SpeX , with a wavelength range of 0.8 to 5 microns , and derived spectra of the infrared excess emission .
The shape and strength of the excess varies with time , with cooler and weaker characteristic dust emission ( T \sim 1100 - 1300 K ) over most of the binary orbit , and stronger/warmer dust emission ( T \sim 1600 K , indicative of dust sublimation ) just before periastron passage .
We suggest our results are broadly consistent with predictions of simulations of disk structure and accretion flows around close binaries , with the varying dust emission possibly tracing the evolution of accretion streams falling inwards through a circumbinary disk cavity and feeding the accretion pulses traced by the optical photometry and NIR emission lines .
However , our results also show more complicated behavior that is not fully explained by this simple picture , and will require further observations and modeling to fully interpret .