COMMISSION 27 OF THE I. A. U.
     INFORMATION BULLETIN ON VARIABLE STARS
                 Number 1544

                            Konkoly Observatory
                            Budapest
                            1979 February 2




     HR 733: A NEW USPC IN THE HYADES GROUP


   The known ultrashortperiod cepheids (USPC) in the
Hyades group have been discussed elsewhere (Eggen 1979).
The distribution of luminosities shown in Figure 1 by
open circles is taken from that discussion. The filled

                   [FIGURE 1]

circle represents HR 733, a Hyades group member with
(U, V, W) = (+ 38, -17, -11) km/sec, based on a proper
motion from all available meridian positions and on the
FK4 system with precessional corrections of
(mu_alpha, mu_delta)=(+0.087, +0.033) arcsec, a radial velocity
from two accordant Mount Wilson plates of + 25 km/sec,
and a modulus of 4.45 mag., The star was monitored for

                    [FIGURE 2]

light variation on 13 and 29 December 1978 with the
0.6 m reflector on Cerro Tololo using HR 730 as a comparison
star. The resulting light curves are shown in Figure 2.
The light variation ranges from 0.003 to 0.02 mag. with
a period near 0.05 days. The two open circles nearest
the new variable in Figure 1 represent delta Sct, with a
period of 0.19 days and light amplitude of 0.1 to 0.2 mag.
and BQ Cnc, with a period near 0.07 days and light
amplitude near 0.01 mag.




                          O.J. EGGEN
               Cerro Tololo Inter-American Observatory


  Reference:

Eggen, O.J. 1979 Ap. J. (in press).



* Cerro Tololo Inter-American Observatory is supported by
  the National Science Foundation under contract No. AST 78-27879.