COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                     Number 3130


                                      Konkoly Observatory
                                      Budapest
                                      19 January 1988

                                      HU ISSN 0374-0676


            UPDATE ON THE RR LYRAE STAR NSV 134


    In a previous bulletin (Rossiger 1987) the announcement was made that the
star BD+40 0060 = NSV 134 was probably an RR Lyrae variable of type "ab". 
Mention was made of a companion star to NSV 134 that is as almost equally bright as
the variable and located about 6 arc-seconds away. Since it is not known whether or
not the variable and its bright companion are indeed a physical pair, we decided to
obtain spectra of them in order to help resolve this issue. On August 3,1987 (UT)
we obtained echelle spectra of both the variable and its companion using the coudeé
Hamilton Spectrograph at the Shane 3-meter telescope at Lick Observatory. Since it
was unknown how stable the period of the variable's light curve was, CCD images of
the variable's field were taken at approximately 5 minute intervals on August 25, 1987
(UT) using the Nickel 1-meter telescope at Lick Observatory. The CCD images were
reduced to derive the relative magnitudes of the variable and surrounding stars and to
construct the variable's light curve.

    The CCD was a Texas Instruments 500 x 500 pixel device used at an imaging 
scale of 0.18 arc-seconds per pixel. A red filter was employed which generally 
restricted the light transmission to the range 6100 A to 7300 A. From the CCD images it
was discovered that in fact there are two other fainter stars located near the variable
and the bright companion. Figure 1 shows the field of the variable (north at top, east
at left) with the designations A: NSV 134, the variable, B: the previously recognized
bright companion, C: a fainter companion located almost midway between A and B,
D: a very faint star just to the west of B, and E: a field star. All of these stars appear
blended together on the red and blue copies of the Palomar Observatory Sky Survey.
The apparent separation between the variable and its brightest companion is about
7.5 arc-seconds. The fainter companion is located about 4.5 arc-seconds from the 
variable and 3.5 arc-seconds from B.


                            [FIGURE 1]
                            [FIGURE 2]


     The variable's light curve from the images is given in Figure 2, plotted in
terms of the magnitude difference from the brighter companion (B) in the sense 
`variable magnitude minus companion magnitude'. The observations indicate that the
variable did go through an amplitude of 0.980 mag (sigma = 0.004 mag) in its light variation
on August 25 (UT). This amplitude is essentially twice that stated by Rossiger and
could mean that the comparison star he used, BD+40 0056, may have some variation
in brightness as well. No variability was detected in the companion B or any of the
other stars, except the star E whose relative magnitude was not calculated due to its
faint signal on the short exposure CCD images. The observed time of maximum for
NSV 134 coincides nicely with that calculated from the elements given by Rossiger
to within the time interval between exposures. The elements given by Rossiger were
therefore used to compute the variable's phase at the time its spectrum was taken on
August 3 (UT).

     The midpoint of the 20 minute exposure for the variable occured at
11.71444h Aug. 3,1987 universal time (JDgeo = 2447009.988). From Rossiger's 
elements this corresponds to the variable having a phase of approximately .24. The
high dispersion spectra indicate that the variable had a radial velocity at that time
of -194 km/sec while the companion's (B) radial velocity was -62 km/sec. This 
radial velocity for the variable can be regarded as near its mean radial velocity due to
its phase at the time of observation. The large difference in radial velocities indicates
that NSV 134 and its brightest companion B, do not form a physical pair. The 
spectra show that the variable did indeed have an early-type spectrum while that of B
was late-type - very probably late-G which would agree with the classification given
in the New Catalogue of Suspected Variable Stars (1982). Further study of the fainter
companion, C, is needed in order to determine what its relation is to either of the two
brighter stars.

     I am grateful to S. Rossiger for kindly supplying finding charts for NSV 134,
to R. Kraft of Lick Observatory who assisted in obtaining the echelle spectra, and to
R. Pogge for the image processing of Figure 1. This work was supported in part by
the University of California Davidson Fund.



                       CHARLES F. PROSSER

                       Board of Studies in Astronomy
                             and Astrophysics
                       Natural Sciences II
                       Univ. of California Santa Cruz
                       Santa Cruz, California 95064 USA





References :

New Catalogue of Suspected Variable Stars, Kholopov, P.N. editor, Kukarkin, B.V. et
  al., "Nauka", 1982.
Rossiger, S. 1987, Information Bulletin on Variable Stars, Konkoly Observatory,
   Number 2977. [IBVS 2977]