COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                    NUMBER 257

                                Konkoly Observatory
                                Budapest
                                1968 February 26


         THE TRIPLE SYSTEM LAMBDA TAURI


During 1966-1967 we have observed, at the Observatory of Merate, the eclipsing
triple system Lambda Tauri, securing 16 grating spectra, dispersion 34 A/mm,
well distributed along the period, for redetermining the orbital elements of
the system. The usefulness of this study has been pointed out by Koch,
Sobieski and Wood^1) in 1963. We have obtained the following results:

gamma=15.23+-0.53
e=0.12+-0.11
omega=141.d95+-0.25
K=55.44+-0.81
P=3.9540+-0.0066
T_o=2439137.623+-0.190
a sin i =2.990.732 km.

The residuals computed to study the third body are all very small i.e.
slightly more than the probable error of each plate (about 2.5 km/s). We are
interested in going on further with the analysis of the behaviour of the third
body, for wich Ebbighausen, Struve have found a 33 days period in 1956^2).


                                        C. CASIM
                                        P. GALEOTTI
                                        G. GUERRERO
Merate, February 19, 1968

1) Koch, Sobieski, Wood; A Finding list for Observers of Eclipsing Binaries,
   University of Pennsylvania, Vol. IX, 1963
2) Ebbighausen, Struve; ApJ 124, 507, 1956 [BIBCODE 1956ApJ...124..507E ]