COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       Number 989

                                     Konkoly Observatory
                                     Budapest
                                     1975 April 15


              A NOTE ON V Cr A AND W Men

   It is well known that V Cr A and W Men belong to the class of
the R Cr B stars. The values in Table 1 are quoted from the "General 
Catalogue of Variable Stars" (Kukarkin et al., 1969).

                               Table 1.

                        Max.(1)  Min.(1)  Ampl.

                V Cr A   9.4     <14.0    >4.6
                W Men   13.8      16.0     2.2

(1) Photographic magnitude, Max=maximum light, Min=minimum,
Ampl.=maximum amplitude of the light variation.

   The purpose of this note is to show that, according to our 
observations, these stars have larger light variations than it was
previously suspected.
   While a UBV-photoelectric photometry program on R Cr B was 
being developed in July and August 1974, the star V Cr A was not
seen visually with the 154 centimeter reflector of the Bosque
Alegre Field Station which means that it was fainter than visual
magnitude 16.5. As its spectral type is R 0 (Kukarkin et al., op.
cit.), its colour index ought t.0 be around 1.1 magnitudes (Mendoza
and Johnson, 1965), and so its visual magnitude at maximum light
approximately equal to 8.3 from which a light variation larger
than 8 magnitudes is derived.
   In the same way, the variable W Men is not seen on a blue plate
taken (on its field) on October 20, 1974^*. The magnitude limit on
this plate being around 18.3, the light variation of W Men must be
larger than 4.5 magnitudes.
   Two other well studied stars of the R Cr B-type, R Cr B itself
and RY Sgr, have light variations of 9 and 7.5 magnitudes, 
respectively. These values are quite similar to those found for V Cr A
and W Men. If we assume that in these four stars the physical and
geometrical conditions in which the absorbing clouds are condensed
are nearly the same, their similar light variations (the largest
ones) imply that the maximum amount of matter they eject is almost
the same.

                                              L.A. MILONE

References:
Kukarkin, B.V., Kholopov, P.N., et al. 1969, General Catalogue of
          Variable Stars (Moscow). [BIBCODE 1969gcvs.book.....K ]
Mendoza V.,E.E., and Johnson, H. 1965, Ap.J, 141, 161 [BIBCODE 1965ApJ...141..161M ]

 ^* Dr. C.U. Cesco was requested to obtain this plate with the Yale-
Columbia double astrograph of the astronomical observatory, in
"El Leoncito", San Juan, Argentina. We express our sincere thanks
for his kind cooperation.