COMMISSION 27 OF THE I. A. U.
        	INFORMATION BULLETIN ON VARIABLE STARS
                            NUMBER 894

					Konkoly Observatory
					Budapest
					1974 June 6


		THE LIGHT VARIATION OF HD 34626

  HD 34626 (B. 1.5 IV np, mv 8.2m) is one of several stars described
by Petrie and Pearce (1962) as having spectral lines which vary
in width, but not in a way which is explicable in terms of two spectra. These
stars were examined photometrically by Percy (1970) in the hope that
some of them might be Beta Canis Majoris stars: however, most of them
did not vary in light. HD 34626 was an exception: it varied by nearly
0.1m on a time scale >= 8 hours.
  Further observations of this star were obtained at Kitt Peak National
Observatory in October 1970, using a 41 cm reflector  with refrigerated
1P21 photomultiplier tube. Observations were made through a standard B
filter, relative to BD +36d1086, and were corrected for differential 
extinction and reduced to the sun.
  The star varies in brightness by about 0.1m on a time scale of 12
hours (the time required for the star to complete half a cycle). However,
the variation is not strictly periodic - the range varies from 0.02m
to 0.10m.
  The spectral type of HD 34626 is B 1.5 IV np according to Walborn
(1971). According to Walker and Hodge (1966), the absolute magnitude
is -3.7 (consistent with the spectral type) and the projected rotational
velocity is 570 km-sec^-1. If the latter figure is correct, the inclination
must be almost 90d: otherwise the star would be rotationally disrupted.
  There is no simple explanation for the light variations. The observed
time scale is much greater than the longest radial pulsation period for
a star of absolute magnitude -3.7. The star might possibly be an 
ellipsoidal variable with an orbital period of 24 hours, although the 
observed range in radial velocity is only 23 km-sec^-1. Finally, the
star might be rotating with a period of 12 hours. If the radius is 7 R_sun,
and the rotational velocity is 570 km-sec^-1, then the rotation period 
would be 14 hours. In this case, the variation in brightness might be
due to the rotation of a nun-uniform star. Further spectroscopic 
observations would be valuable.
  This research was supported by the National Research Council
of Canada.



Photometric Observations of HD 34626 Relative to BD +36d1086

JD hel.   DeltaB         J.D.hel.  DeltaB      J.D.hel.  DeltaB
2440000+                 2440000+              2440000+
881.809   0.677          884.994   0.683       886.882   0.712
883.803   0.670          885.027   0.709          .935   0.718
   .850   0.659             .767   0.711          .983   0.716
   .896   0.659             .839   0.759       887.770   0.677
   .962   0.658             .917   0.758          .825   0.671
884.793   0.689             .962   0.740          .877   0.692
   .857   0.668          886.007   0.703          .965   0.666
   .912   0.660             .778   0.679
   .950   0.661             .827   0.694



                           JOHN R. PERCY
                           David Dunlap Observatory
                           University of Toronto,
                           Toronto, Canada.




 References:
 Percy, J.R. 1970, Astron. J. 75. 818. [BIBCODE 1970AJ.....75..818P ]
 Petrie, R.M. and Pearce, J.A. 1962, Publ. Dom. Astrophys. Obs. 12, 1. [BIBCODE 1961PDAO...12....1P ]
 Walborn, N.R. 1971, Astrophys. J. Suppl. 23, 257. [BIBCODE 1971ApJS...23..257W ]
 Walker, G.A.H., and Hodge, S.M. 1966, Publ. Dom. Astrophys. 12, 401. [BIBCODE 1965PDAO...12..401W ]

                        [FIGURE 1]