COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       Number 3095


                                        Konkoly Observatory
                                        Budapest
                                        9 October 1987

                                        HU ISSN 0374-0676



                 V471 TAURI ECLIPSE TIMINGS


   Further timings of the eclipse of the white-dwarf member of the V471
Tauri system are reported. The observations were obtained with the two-
channel photometer at the f/16 Cassegrain focus of the 61 cm. Fick
Observatory reflector. Simultaneous measurements in V and R bands provide 
compensation for varying sky conditions and guiding errors. An
integration time of four seconds was employed for both bands.


                              Table I.
          V471 Tau Occultation Timing
UT DATE   EPOCH(a) tmid(b)  Delta ts(c) O-C(d)   O-C(e)
                   MJD        (sec)      (sec)   (sec)
1-03-87   11874 46798.09374   358        -308    -11
1-27-87   11920 46822.08823   187        -303    -5
1-28-87   11922 46823.11062   179        -301    -3
       
       (a) As given by ephemeris of Young and Lanning (1975).
       (b) Heliocentric mid-eclipse time given in modified Julian date. Estimated
       errors are +/-5 sec =  0.00005 days.
       (c) Observer's solar correction for time of observation,
       (d) C based on ephemeris of Young and Lanning.
       (e) O-C of three body model of Beavers et al.(1986).

   Table I lists the results of these timings. The next to last column
contains the O-C values calculated from the Young and Lanning (1975)
ephemeris. The final column contains O-C values of the three-body
model of Beavers et al.(1986). With assumed timing errors of +/-5 seconds,
the results suggest that the Young and Lanning ephemeris O-C curve may
be passing through or near its minimum as predicted by the three-body
model. Additional eclipse timings over the next several years are needed
to confirm this. Such data would be very useful in attempting a refinement
of the present three-body orbit.


                         J.J. EITTER
                         Erwin W. Fick Observatory
                         Department of Physics
                         Iowa State University
                         Ames, Iowa 50011
                         U.S.A.


References:

Young, A. and Lanning., H., 1975, Pub. A.S.P., 87, 461. [BIBCODE 1975PASP...87..461Y ]
Beavers, W. I., Herczeg, T. J., and Lui, A., 1986, Ap. J., 300, 785. [BIBCODE 1986ApJ...300..785B ]