8. Provisional note on the HIPPARCOS measurements
After submission of this paper, the measurements of the HIPPARCOS satellite became public. The photometry made by the TYCHO project confirms the stability of the light-curve. The HIPPARCOS ephemeris (ESA, 1997 ),
agrees very well with the period and phasing of our observations, within the uncertainties quoted; the shape and the amplitude of the light-curve are indistinguishable from those measured from a smooth spline representation of our observations. The HIPPARCOS astrometry places TV Pic at a distance of pc, i.e. significantly further away than suggested by Shaw's distance scale adopted in this paper. The HIPPARCOS distance measurements suggest that TU Hor and TV Pic are intrinsically brighter in the visual ( = 0.7 for TU Hor and 0.9 for TV Pic) than any of the eclipsing near-contact binaries of the list of Shaw (1994 ) and which HIPPARCOS considers to be nearer than 250 pc. The majority of the latter are within , and some are still fainter. This could be seen as a suggestion that a statistical relation between intrinsic brightness and orientation with respect to the observer might exist, but that should be confirmed by studying larger samples of eclipsing and non-eclipsing near-contact binaries. Such relation might find its origin, for example, in the presence and distribution of obscuring material in the system.
© European Southern Observatory (ESO) 1998
Online publication: February 16, 1998