COMMISSION 27 OF THE I. A. U.
             INFORMATION BULLETIN ON VARIABLE STARS
                          Number 3601     

                                              Konkoly Observatory
                                              Budapest
                                              8 May 1991

                                              HU ISSN 0374 - 0676


       A RECENT BRIGHTENING FOR THE HERBIG Be STAR HD 53367


HD 53367 is one of the brightest of the Herbig Be stars:  objects thought to be
either zero-age or pre-main sequence stars.  Alternately known as MWC 166 and
RST 3489 (separation = 0.6 arc sec; Delta m = 1.3 with a B1 Ve star), the star
is associated with the nebulosity IC 2177 and is a member of the CMa OB1
association.  Spectral types for the star range from B0 IVe (Buscombe 1980) to
B1ne (Merrill & Burwell 1933).

Halbedel (1989) has previously published photometry of HD 53367 which shows it
to be variable.  This paper continues these observations and reports on a
recent brightening that the star has undergone.  Differential photometry has
been carried out by the author for the past six observing seasons with the
0.6-m.  telescope of the Corralitos Observatory and its ambient temperature EMI
9924A-based pulse-counting photometer.  Standard stars utilized were HD 53240
(V=6.441; B-V=-.083) and HD 53302 (V=8.164; B-V=+.227), These stars were stable
over the time period of observation to within 0.017 V and 0.020 B-V magnitudes.
HD 53367 is sufficiently bright that short integration times could be used.
Therefore, there is likely no interference from the surrounding nebulosity
which at no time could be seen by the eye.

The previously published four seasons' magnitudes as well as those from the two
most recent observing seasons appear in Figure 1, while the newest magnitudes
are listed in Table 1.  It may be seen that the relatively steady decline in V
mag has reversed itself dramatically.  Observing season 6 reveals a sudden
brightening of 0.239 magnitudes in


                                  [FIGURE 1]

 FIGURE 1: MAGNITUDES FOR HD 53367. THE TOP DIAGRAM SHOWS V MAGNITUDE,
           THE BOTTOM B-V.


TABLE 1: MAGNITUDES FOR HD 53367

JD                              JD
(2440000+)      V       B-V     (2440000+)      V       B-V
7806.95833    7.148    +.393    8205.88680   7.132     +.415
7828.00000    7.182     .379    8225.89097   7.125      .386
7878.92013    7.187     .386    8243.80625   7.142      .373
7881.78750    7.142     .368    8292.83194   7.158      .371
7896.80208    7.205     .358    8313.75606   6.989      ----
7933.62291    7.194     - --    8328.69792   7.170      .378
7952.66805    7.107     .381    8347.66111   6.931      .462
7965.70417    7.217     .367    8348.67500   6.965      .408
7985.63472    7.186     .343    8364.63611   6.976      .454
8176.96250    7.190     .379    8367.62917   6.980      .446

a time period of 19 days.  The B-V magnitudes show anticorrelation with the V
mag:  as the star brightens, its color reddens.  This is likely indicative of
an increase in optical depth of circumstellar material.

It should be recalled that HD 53367 is visually binary with another Be star
whose potential light variations may be influencing the situation since it is
only a magnitude and a half fainter than its primary.  Perhaps some of the
variation proceeds from this source.

HD 53367 will continue to be observed at the Corralitos Observatory in the
future in order that is long-term behavior may be understood.


E.M. HALBEDEL
Corralitos Observatory
P.O. Box 16314
Las Cruces, NM
U.S.A. 88004-6314

REFERENCES

Buscombe, W. 1980, MK SPECTRAL CLASSIFICATIONS, FOURTH GENERAL 
     CATALOGUE (Northwestern Univ., Evanston) [BIBCODE 1980mscf.book.....B ]
Halbedel, E.M. 1989, PASP, 101, 1004  [BIBCODE 1989PASP..101.1004H ]
Merrill, P.W. & Burwell, C.G. 1933, ApJ, 78, 87 [BIBCODE 1933ApJ....78...87M ]