Infrared photometry of RT Lacertae.

The first of a number of eclipsing binaries with asymmetric light curves has been examined in the near-infrared for evidence of a distribution of matter in and around the Roche lobes. The double-lined spectroscopic and peculiar eclipsing binary RT Lacertae has an apparent excess of radiation at JHKL over what is to be expected from the component stars, with due allowance for a reasonable degree of interstellar extinction. The peak value reached is about 0.7 mag at K. The excess has a phase-dependent component which reaches maximum, in the 1972-1974 light curve, near the secondary minimum and has an amplitude of about 0.3 mag at K. The remainder of the excess may be attributed to an anomalously high interstellar extinction, possibly produced as a result of mass loss from the system through the outer Lagrangian point L2. Subject headings: infrared: general - stars: eclipsing binaries - stars: individual