COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1710

                                   Konkoly Observatory
                                   Budapest
                                   1979 December 3


       PHOTOMETRIC OBSERVATIONS OF TT Ari


During the nights of 22nd, 23rd, 24th, 25th November 1978, photoelectric
observations in B light have been carried out of the nova-like variable TT Ari
(=BD+14d341). Observations were made with the 60 cm Cassegrain telescope of
the Observatory of Bulgarian Academy of Sciences at Belogradchik (Bulgaria).

A single channel photoelectric photometer with an FEU 64 photomultiplier and a
pulse photon counter were used. The sky was measured after each 10 minute
interval. Observed light variations are shown in Figures 1-4, where the
starting points are marked for each night and delta mag. is with respect to
the comparison star (=BD+14d336).

The analysis of the observational data was carried out by making a least square
fitting of the sine-waves

A * sin ((2*pi)/P * t+phi)+B

with a range of values for the period. For the 3-hour variations the resulting
value of the period is P=0.1326+-0.0002 and the amplitude is about 0.2 mag. A
similar value of P=0.1329 was given by Smak and Stepien (1968) also (1975). In
a similar way the fast variations were also analysed and it was found that
quasi-periodic component with an amplitude of about 0.2 mag. was present with
periods of 13.6, 13.1, 14.4, and 13.5 minutes for the four nights,
respectively. This is in agreement with the results given by Williams (1966).
Finally, using the same method (with a pre-whitening technique), a strong
quasi-periodicity with an amplitude of about 0.1 mag. and P around 40 seconds
was found. This is in good agreement with Mardirossian et al. (1979).

                           [FIGURE 1]
                           [FIGURE 2]
                           [FIGURE 3]
                           [FIGURE 4]

On the first three nights the observations reported here were simultaneous with
those of Mardirossian et al. (1979). A comparison of the two sets of data
shows that the star was more active in B than in white light.

The photometric period of P=0.1326 is significantly different from the
spectroscopic period of P=0.1375 found by Cowley et al. (1975). It is
possible that in this star we have two different periods connected with its
photometric and spectroscopic activity.

Acknowledgements:

The author wishes to express his gratitude to Prof. J. Smak for critical
evaluation the elaborated results and deeply indebted to Dr. M. Popova for
enabling the photoelectrical observations at the Observatory of Bulgarian
Academy of Sciences.


MIROSLAW SZTAJNO
N. Copernicus Astronomical Center
Polish Academy of Sciences
18 Bartycka Str., 00-716 Warsaw,
Visiting astronomer from Astronomical Observatory of Jagiellonian University,
Cracow, Poland.

References:

Cowley, A.P., Crampton, D., Hutchings, J.B., Marlborough, J.M., 1975, Ap.J.,
   195, 413 [BIBCODE 1975ApJ...195..413C ]
Mardirossian, F., Mezzetti, M., Pucillo, M., Santin, P., Sedmak, G., Cester,
   B., Giuricin, G., 1979, I.B.V.S., No. 1622
Smak, J., Sepien, K., 1969, Non-Periodic Phenomena in Variable Stars, ed. L.
   Detre (Budapest: Academic Press) p. 335 [BIBCODE 1969CoKon..65..355S ]
						[CoKon No. 65]
Smak, J., Stepien, K., 1975, Acta Astr., 25, 379 [BIBCODE 1975AcA....25..379S ]
Williams, J.O., 1966, Publ. Astr. Soc. Pacific 78, 279 [BIBCODE 1966PASP...78..279W ]