A Submillimeter‐Wave “Flare” from GG Tauri?

We have monitored the millimeter and submillimeter emission from the youngstellar object GG Tau, a T Tauri binary system surrounded by a massivecircumbinary disk. We find that between 1992 and 1994, the flux has increasedsignificantly at 800, 1100, and 1300 microns, resulting in a steepening of theobserved spectral energy distribution at those wavelengths. Such an increaseappears consistent with a modest increase in disk luminosity (a factor of two).The increase in the effective disk temperature might arise from a slight changein the disk heating processes. Alternatively, the flux increase may reflect asudden change in the underlying dust optical properties.Comment: 15 pages, AASTex v.4.0 format, four postscript figures, four tables, to appear in The Astrophysical Journa