COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2619

                                   Konkoly Observatory
                                   Budapest
                                   5 November 1984

                                   HU ISSN 0374 - 0676




         HR 1321 = ADS 3085 B : A NEW VARIABLE STAR


    The bright star HR 1321 = HD 26913 is the fainter component of the
visual binary ADS 3085. About 12 years ago the brighter component (HR 1322
= HD 26923) was found by Blanco et al. (1972) to be variable; later it was
designated V774 Tauri by Kholopov et al. (1981). The photometry reported
by Blanco et al. also showed some indication that HR 1321 was variable,
with a range of approximately 0.03m in V, but their data were neither 
tabulated nor plotted, so we cannot judge whether or not the suspected 
variability was periodic. On the strength of that reference HR 1321 was assigned
the suspected variable star number NSV 1534.

    In January and February of 1984 we observed HR 1321 differentially with
respect to the comparison star HR 1360 on 18 nights. Care was taken to 
exclude light from HR 1322, which is only 65 arcseconds away. The telescope
was the 11-inch Schmidt-Cassegrain at Gila Observatory, which has been 
described by Ziegler (1983). Table I lists the nightly means, where is in
the sense variable minus comparison and every value has been corrected for
differential atmospheric extinction and transformed differentially to V of
the UBV system. Figure 1 is a plot of those values using a period of 6.8d,
which seems to represent the periodicity evident in the data, with an 
uncertainty of approximately +- 0.2d. The total range in brightness is 
approximately 0.06m in V. A time of minimum brightness would be JD 2445719.7 .

   We have found three references presenting measures of the Ca II H and K
flux. Observations by Wilson (1978) between 1966 and 1972 showed no 
evidence of short-term variability but did indicate some "secular decrease".
Similar observations by Middlekoop et al. (1981) over a 10-day interval did
show short-term variability with a period, (we estimate from their figure 2)
of approximately 7 days. Nightly observations by Vaughan et al. (1981) over
a 14-week interval also showed short-term variability, with a range of 11 %
and a period of 7.2d.



                Table   I
Differential Photoelectric Photometry of HR 1321
JD(hel.)            JD(hel.)
------------------------------------------------
2445000+   DeltaV     2445000+   DeltaV
719.71     +1.215m    729.780    +1.172m
720.79     +1.208     730.715    +1.185
722.687    +1.153     731.644    +1.194
723.707    +1.176     734.653    +1.200
724.707    +1.194     735.742    +1.164
725.756    +1.204     737.738    +1.181
726.692    +1.209     739.608    +1.197
727.825    +1.168     750.669    +1.185
728.699    +1.182     751.650    +1.190


                           [FIGURE 1]

Figure 1  Light curve of the newly discovered variable star HR 1321. The
ordinate is differential magnitude. The abscissa is phase, in days, based
on a period of 6.8 days. Each point is a nightly mean although, in one case,
two points overlap.

  Vaughan et al. concluded that their 7.2d period was the rotational 
period, traced by chromospherically active regions on the star's surface. 
Similarly, we believe that our 6.8d +- 0.2d period is the same rotational 
period,
traced by areas of the photosphere which are darkened by large-scale 
starspot activity.
  With additional photometry during the next observing season we should
be able to refine the accuracy of the photometric (= rotational) period of
this interesting star, which is bright enough (V = 6.93m) to be observed
conveniently and important now that we see it belongs to a visual binary
system both components of which are variable stars.


                           KENNETH ZIEGLER
                           MICHAEL SHIRLEY
                           BRIAN FRANCOM
                           WILLIAM FLORENCE

                           Gila Observatory
                           Claypool, Arizona


                           DOUGLAS S. HALL

                           Dyer Observatory
                           Vanderbilt University
                           Nashville, Tennessee




References:

Blanco, C., Catalano, C., and Godoli, G. 1972, Memorie della Societa
   Astronomica di Italiana 43, 663. [BIBCODE 1972MmSAI..43..663B ]
Kholopov, P. N. et al. 1981, I.B.V.S. No. 1921.
Middlekoop, F., Vaughan, A. H., and Preston, G. W. 1981, Astronomy and
   Astrophysics 96, 401. [BIBCODE 1981A&A....96..401M ]
Vaughan, A. H. et al. 1981, Ap.J. 250, 276. [BIBCODE 1981ApJ...250..276V ]
Wilson, O. C. 1978, Ap.J. 226, 379. [BIBCODE 1978ApJ...226..379W ]
Ziegler, K. W. 1983, I.A.P.P.P. communication No. 14, 88. [BIBCODE 1983IAPPP..14...88Z ]