40 Years with DQ Tau: Leveraging Archival Data to Investigate the Pulsed Accretion Archetype

DQ Tau is a T Tauri binary in an eccentric, 15.8-day orbit surrounded by a circumbinary disk. This architecture gives rise to periodic, pulsed accretion events. Resonances from the binary orbit launch streams of material from the circumbinary disk that cross a dynamically cleared gap and fuel bursts of accretion near each periastron passage. Dramatic and predictable accretion events and its unique dynamical laboratory have made DQ Tau a frequent object of study for observers and theorists alike. This synergy allows for a degree of characterization which is rarely achieved for any system. In this presentation, we leverage 40+ years of radial velocity measurements and 30+ years of photometry to search for secular evolution not accessible in the seasonal-based observing programs typically presented in the literature. DQTau’s orbit is known to precess at ~1 degree per year. With our RV data set we precisely measure and interpret this precession as  evidence for a low-mass cirumbinary companion within 1.4 AU. DQ Tau’s accretion burst amplitude is known to vary, occasionally producing very small or ‘failed’ bursts. With uniformly analyzed time-series photometry, we characterize the burst profile, its variability, and quantify the frequency of failed bursts, which points to dynamical processes in the inner disk. Our work supports the ongoing analysis of time-series JWST/MIRI observations of DQ Tau to better understand accretion dynamics and disk chemistry in binary systems as well as single stars.