COMMISSIONS 27 AND 42 OF THE IAU
              INFORMATION BULLETIN ON VARIABLE STARS
                           Number 4011

                                            Konkoly Observatory
                                            Budapest
                                            7 April 1994

                                            HU ISSN 0374 - 0676



      Differential BV photometry of the EW variable NSV 7457 Her



   In a recent paper Vandenbroere (1993) reported photoelectric photometry
of the variable NSV 7457 = BV 103 = BD+50d2255. After a short overview of
the observational history of this star, she discusses her photometry which yields
the light curve of a typical EW eclipsing binary with the elements:
  JD_min,hel = 2447643.1786 + 0.4190306d  E (Vandenbroere, 1993).
  In the course of an observing run at the Rosemary Hill Observatory,
operated by the Department of Astronomy of the University of Florida,
Gainesville, U.S.A., in early 1993, we obtained independent BV photometry,
reported here.
   The details of our observing procedures are given in Diethelm (1993).

                             [FIGURE 1]

             Figure 1: V light curve of NSV 7457 Her

   As comparison star, we chose a star about 22^s preceding and some 4'
north of the variable. This star of similar colour and brightness as NSV 7457
proved to be constant to within the accuracy of the photometry. Using sigma 
Her as
check star, we find V = 10.67+/-0.03 mag and B = 11.10+/-0.03 mag for this
comparison star.
   In Figure 1 and 2, we show our 55 measurements in V and B respectively,
folded with the elements of Vandenbroere (1993). They were obtained during
five nights between JD 2449115 and 2449124. Although the light curve is not
completely covered by our observations, they can serve to fully confirm the
conclusions drawn by Vandenbroere (1993).
   The 29 observations between phases 0.31^p and 0.68^p, obtained on JD
2449116, 2449122 and 2449124, yield a time of secondary minimum at O =
2449124.65948 +/- 0.00012 (mean of determination in both colours with the
Kwee-van Woerden (1956) algorithm).

                             [FIGURE 2]

             Figure 2: B light curve of NSV 7457 Her

    Acknowledgements: We would like to thank the staff of the Dept. of
Astronomy of the University of Florida for their hospitality and for the allocation
of observing time at Rosemary Hill Observatory. The continuing technical
assistance by J. Baker is especially acknowledged. This research is supported
by a grant from the Emilia Guggenheim-Schnurr foundation.


                       R. Diethelm
                       BBSAG
                       Rennweg 1
                       CH-4118 Rodersdorf/Switzerland

References:

Diethelm, R: 1993, Inform. Bulletin on Variable Stars, No. 3903
Kwee, K. K, van Woerden, H: 1956, Bull. Astron. Soc. Netherlands 12, 327 [BIBCODE 1956BAN....12..327K ]
Vandenbroere, J: 1993, Inform. Bulletin on Variable Stars, No. 3946