COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                        Number 2596

                                             Konkoly Observatory
                                             Budapest
                                             1 October 1984

                                             HU ISSN 0374 - 0676

                     UBVR PHOTOMETRY OF NQ Her

  NQ Her was observed on 23 nights during the period from June to December
1979 using the 50-cm reflector of the Mountain Station "Terskol" of Main
Astronomical Observatory of the Ukrainian Academy of Sciences.
  The data were obtained with a single-channel photon-counting automatic
photometer with a PEM-79 uncooled photomultiplier tube. The photometer
employed a combination of glass filters designed to match the standard UBVR
system. Differential measurements were made using BD + 18d 3580 (7.6m, Sp A3)
as comparison star and BD +18d 3582 (7.2m, Sp A2) as check.
  The average standard deviations of a single measure of the comparison
star in U, B, V and R filters are:

     sigma(U)=0.016m; sigma(B)=0.012m; sigma(V)=0.010m; sigma(R)=0.010m

respectively. The measurements showed that the magnitude differences between
the comparison and check stars were constant:
   Delta U = 0.618m +- 0.010m;    Delta B = 0.728m +- 0.009m;
   Delta V = 0.636m +- 0.005m;    Delta R = 0.508m +- 0.004m
The mean V magnitude and the colour indices U-B, B-V, and V-R of the
comparison star have been determined from observations of UBVR standard
stars:
      V = 8.034m;   U-B = 0.033m;   B-V = 0.351m;   V-R = 0.381m .
The instrumental magnitudes have been converted into standard magnitudes
with the help of several standard stars chosen from the list of Johnson et
al. (1966). Due to the angular proximity of the variable and comparison star
no corrections for differential extinction were necessary. The mean V magnitude
and the mean colour indices U-B, B-V, and V-R of all the observations
of the variable star are given as follows:
      V = 8.463m;   U-B = -0.044m;   B-V = -0.028m;   V-R = 0.089m .
No brightness variations have been detected within the errors. It was not
possible to extract any periodicity from our observational data. For the
phase computations the elements of Kukarkin et al. (1970) are used:

      J.D.(Vmin.) = 2426894.433 + 0.870218d E


                            [FIGURE 1]


In Figure 1 the observations in V light and the colours U-B, B-V, and V-R
are plotted versus phase. The inspection of Fig. 1 leads to the conclusion
that NQ Her did not show any variability with the period of P = 0.870218d.
Our results agree with those obtained by Rossati (1964), Schneller (1965),
Popovici (1971), Blanco (1971), Bozkurt et al. (1975) and Padalia (1975).
  However, the absence of any notable brightness variation in NQ Her at
present is not an evidence of the constancy of NQ Her in general. It is
possible that a weakening of the variable star photometric activity followed
the active phase when the photographic observations had been made.


                     G.A. VOITENKO and G.U. KOVALCHUCK

                     Main Astronomical observatory
                     of the Ukrainian Academy of Sciences
                            Kiev, U.S.S.R.

References:

Blanco, C., 1971, I.B.V.S., No. 571.
Bozkurt, S., et al., 1975, I.B.V.S., No. 1021.
Johnson, H.L., et al., 1966, Arizona Comm., 4, 99.
Kukarkin, B.V. et al., 1970, Ceneral Catalogue of Variable Stars, Moscow. 
Padalia, T.D., 1975, I.B.V.S., No. 1059.
Popovici, C., 1971, I.B.V.S., No. 509.
Rossati, F., 1964, Mem. Soc. Astr. Ital., 35, 81. [BIBCODE 1964MmSAI..35...81R ]
Schneller, H., 1965, Mitt. Verand. Sterne, 3, 4.