COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                             Number 3267

                                                         Konkoly Observatory
                                                         Budapest
                                                         23 November 1988

                                                         HU ISSN 0374 - 0676


               PHOTOELECTRIC UBV LIGHT CURVES OF RT And

The star RT And has been classified by Hall (1976) as an object belonging
to a "Short-Period Group" with properties similar to the RS CVn group.
   Mancuso et al. (1979a) have published a series of V light observations
for the years 1972, 1973, 1974 where a complete historical review of the
star's observations are also presented.
   The star was observed photoelectrically with the 1.2 m Kryonerion telescope 
from 26 Sep. 1988 to 19 Oct. 1988 through a single channel photon counting
photometer described by Dapergolas and Korakitis (1987). The photometer
employs a high gain 9789 QB phototube and UBV conventional filters. Its
output is fed directly to a microcomputer enabling rapid data access.
   The data reduction method is the standard one, comparison and check
stars are BD +52d3384 and BD +52d3377 and the accuracy of the observations
presented here is +-0.015 mag for V, B and +-0.025 for U.
   The observations have been reduced using the ephemeris:

            Min. I = 2443732.4498 + 0.62892965d*E

given by Mancuso et al. (1979b). Table I lists the dates of observations
and phases covered whereas Figures 1, 2 and 3 summarise the results for
U, B, V (Var. - Comp. star).


                            Table I

                       Date        Phase

                       26 Sep.   .42-.62
                       28 Sep.   .38-.81
                       29 Sep.   .87-.34
                       18 Oct.   .19-.47
                       19 Oct.   .75-.98

   Our light curves show asymmetry in the secondary minimum getting larger
towards shorter wavelengths. A distortion wave with a minimum at about
0.7-0.8 phase is also present in our light curves. Zeilik et al. (1982)
found this minimum at 0.8 phase.
   The variability in the levels of maxima noticed by Mancuso et al. (1979a)
have been noticed here as well comparing their observations and those
presented here.


                            [FIGURE 1]
                            [FIGURE 2]
                            [FIGURE 3]



A. DAPERGOLAS, E. KONTIZAS            M. KONTIZAS

National Observatory of Athens        University of Athens
Astronomical Institute                Laboratory of Astrophysics
P.O. Box 20048                        Panepistimioupolis
GR Athens 11810                       GR Athens 15171
Greece                                Greece



References:

Dapergolas, A., and Korakitis, R., 1987, Publ. Nat. Obs. of Athens, Ser. II,
   N28.
Hall, D.S., 1976, in "Multiple Periodic Variable Stars", IAU Coll., No. 29
   vol. I, p. 287, Reidel. [BIBCODE 1976ASSL...60..287H ]
Mancuso, S., Milano, L., and Russo, G., 1979a, Astron. Astrophys. Suppl.
   Ser., 36, 415. [BIBCODE 1979A&AS...36..415M ]
Mancuso, S., Milano, L., Russo, G., and Sollazzo, C., 1979b, Astron. Astrophys.
   Suppl. Ser., 38, 187. [BIBCODE 1979A&AS...38..187M ]
Zeilik, M., Elston, R., Henson, G., and Smith, P., 1982, in "Proc. of the
   southwest regional conference for Astronomy and Astrophysics"
   ed. Preston, F.G. and Riherd, S.P., Vol. VII, p. 15. [BIBCODE 1982srca.conf...15Z ]


                               AMENDMENT

In the No. 3246 issue of the IBVS both Figure 1 and Table I contain
erroneous data. The correct version of the Figure and Table on
HD 37020 is given below


                   Table I

a_1 sin i = 0.171 AU
e         = 0.709
omega     = 182 deg
V_0       = -5.8 km/sec + V_n (*)
T_0       = J.D. 2444194.651

(*) V is the radial velocity of the Orion Nebula


                          [FIGURE 4]


              M. BOSSI, M. SCARDIA, M. TADINI

             Osservatorio Astronomico di Brera
                   via E. Bianchi 46
                     22055 Merate
                        Italy