Proposal #597

Good morning. I'm Sauro Gaudenzi, my observer code is GSAD, in support of AAVSO alert nr 883, I ask for the use of a telescope to observe the subject DQ Tau, I ask for a weekly observation x 6 months, 60 shots of 60 seconds with filter V. Dr. Agnes Kospal (Konkoly Observatory) writes: "DQ Tau is being observed with the VLBA in the radio, JWST in the infrared, and Chandra in the X-ray. Four sets of observations are planned between now and March 4, 2025. We request optical photometric observations to monitor the brightness of DQ Tau in order to know its exact state of accretion during the VLBA, JWST, and Chandra observations." "DQ Tau is a young binary system consisting of two equal-mass T Tauri stars surrounded by a circumbinary protoplanetary disk. The two stars orbit each other on an eccentric orbit with a period of 15.8 days. During periastron, the mass accretion from the disk onto the stars have a peak, causing the brightening of the system. Although the brightenings are periodic with P=15.8 days, not all events have the same light curve shape: the strength and duration of the brightenings change from orbit to orbit, thus the need for contemporaneous monitoring. DQ Tau with its periodically changing accretion rate offers a unique opportunity to study how the disks react to variable irradiation, such as changes in its physical (temperature, emitting area) and chemical (molecular abundances) properties. The results of this research project will have important implications on disk evolution and planet formation, as the disk provides the material necessary to form the solid cores of planets and their atmospheres as well." We request CCD observations with standard Johnson-Cousins BVRcIc or Sloan gri filters (filters should be alternated). Priority is for the V filter. Unfiltered observations are not needed. Re cadence, during the campaign, at least nightly observations are requested, but during/around the actual JWST observations, a more frequent cadance (e.g. 5 minutes) would be welcome. The first JWST observation is scheduled for January 29, 04:50 - 06:40 UT. The remaining three JWST observations are yet to be scheduled; when scheduled, the dates/times will be posted in the forum for this observing campaign.