Table 1: Observations used in L1 fit.

Observations	Period covered	Type	Frame
Old observations	1891-1936	photographic plate	astrographic B1950 tangential coordinates	1635
Long focus observations	1967-1978	photographic plate	astrographic B1950 tangential coordinates	1771
Long focus observations	1986-1990	photographic plate	apparent equatorial tangential coordinates	1390
Mutual events campaign of 1973 and 1979	1973 and 1979	photometry	astrometric J2000 differential coordinates	224
Mutual events campaign of 1985	1985	photometry	astrometric J2000 differential coordinates	392
Mutual events campaign of 1991	1990-1992	photometry	astrometric J2000 differential coordinates	410
FASTT observations	1998-2003	CCD	astrometric J2000 coordinates	1127