CCD PHOTOMETRY OF VARIABLE-STARS IN THE MAGELLANIC-CLOUDS - VI - THE ECLIPSING BINARY HV982 IN THE LARGE-MAGELLANIC-CLOUD

Using improved techniques, high-quality CCD uvbyVI photometry has been obtained for the eclipsing binary HV982 in the Large Magellanic Cloud (LMC). International Ultraviolet Explorer ultraviolet spectrophotomet ry was also obtained. These data have been analysed using the Wilson-D evinney synthetic light-curve code and Kurucz low-metallicity model at mospheres as well as the EBOP code. The system is detached and the orb it is eccentric. Apsidal motion is detected with apsidal period 205 +/ - 7 yr. The effective temperatures of the components are found via flu x fitting to be T-eff,T-1 = 28000 +/- 5000 K and T-eff,T-2 = 27 200 +/ - 5000 K, The large errors result from uncertainties over the appropri ate interstellar extinction correction. The system plausibly comprises two similar to 8 M. stars of radius 6-7 R. separated by similar to 30 R.. For pedagogical and historical interest, the near simultaneity of the eclipse minima at different wavelengths is used to constrain the constancy of the speed of light with wavelength and the mass of the ph oton, yielding m gamma < 10(-41) kg. Because of the great distance to HV 982, this limit is some 10(2) times smaller than previously achieve d with eclipse timings, but it is nevertheless 10 orders of magnitude less stringent than that which is provided by satellite measurements o f planetary magnetic fields.