COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1772

                                     Konkoly Observatory
                                     Budapest
                                     1980 April 14


          SHORT PERIOD VARIABILITY OF HD 33474


Isolated observations of HD 33474, listed in the table, spread over several
years indicate a small range, short period variation. The star was monitored
for about three and a half hours on 20 Feb 1980 with the result shown in the
Figure. The spectral classification of F8 III (Przybylski and Kennedy 1965)
indicates a possible ultrashort period cepheid (USPC) but the mean indices in
Table I give [M_1]=0.235, [C_1]=0.430 and M_V=+3.6 mag, which are consistent
with the classification of F5 V by Houk and Cowley (1975). The star is redder
and fainter than any known USPC (Eggen 1979). The value of [M_1] indicates a
metal abundance near the solar value. The star is more probably a contact
binary, with a period near 0.4 days and very similar to AW UMa (See IBVS 1176),
but of even smaller amplitude. These binaries usually contain the light of two
equal components (Eggen 1976), giving a modulus for HD 33474 of 6.55 mag and a
space motion of (U,V,W)=(+79,-39,+48) km/sec from the proper motion of 
(mu_alpha, mu_delta)
=(+0."076, +0."072) on the FK4 system and a radial velocity of +6.8 km/sec.
The space motion and metal abundance indicate a member of the epsilon Ind
group; the motion of epsilon Ind is (U,V,W)=(+79,-39,+3) km/sec.

                           [FIGURE 1]

Table I

Observations of HD 33474

V           b-y        [M_1]       [C_1]   Beta        Date
9.42m      0.296m     0.153m      0.492m           11 Dec 1975
9.43       0.272      0.164       0.463            12 Dec 1975
9.52       0.304      0.137       0.493             6 Dec 1979
9.29       0.270      0.157       0.494    2.656    4 Jan 1980
9.51       0.296      0.140       0.491    2.650   14 Jan 1980
9.37       0.289      0.143       0.491    2.662    2 Feb 1980
mean       0.288      0.149       0.487    2.656


OLIN J. EGGEN
Cerro Tololo Inter-American Observatory *
La Serena, Chile

References:

Eggen, O.J. 1967, Mem. R.A.S., 70, 111.  [BIBCODE 1967MmRAS..70..111E ]
-----       1979, Ap. J. Suppl. 41, 413. [BIBCODE 1979ApJS...41..413E ]
Houk, N. and Cowley, A.P. 1975, University of Michigan Catalogue of
   Two-Dimensional Spectral Types for the HD Stars, Vol.  1. [BIBCODE 1975mcts.book.....H ]
Przybylski, A. and Kennedy, P.M. 1965, Mon. Not. R.A.S. 129, 63. [BIBCODE 1965MNRAS.129...63P ]

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