COMMISSIONS 27 AND 42 OF THE IAU
             INFORMATION BULLETIN ON VARIABLE STARS
                          Number 4034


                                               Konkoly Observatory
                                               Budapest
                                               30 May 1994

                                               HU ISSN 0374 - 0676


           NEAR-INFRARED PHOTOMETRY FOR THE Be STAR MX Per



MX Per (48 Per, HD 25940, B3Vpe, Vsini=215 km/s, M_v=4.02) is one of the most 
remarkable Be stars. Both photometric and spectroscopic variations (Jackisch, 1963 and
Baliunas et al., 1975) have been reported. We started our near-infrared photometry in
1989 (Guo et al., 1991). Later, in order to investigate the activity and variability of its
shell, differential near-infrared photometric observations were carried out in December
1991, January 1992, and December 1993 using the 1.26m infrared telescope at the Beijing
Astronomical Observatory. To get the extinction coefficients and the zero-point of the
instrument, two infrared photometric standard stars BS 1140 and BS 1641, were used.


                               [FIGURE 1]

  Figure 1. The near infrared photometric results of the peculiar Be star 48 Per
  in 1991 and 1992

                               [FIGURE 2]

  Figure 2. The near infrared photometric results of the peculiar Be star 48 Per
  in 1993 


 Along with MX Per, BS 1140 and BS 1641 were observed many times during the same
night. Extinction corrections and transformation into the standard photometric system
were performed by using a special software for infrared photometry. The error bars in the
Figures represent realistic estimates of observational error.
 Our observational results are shown in Figures 1 and 2. It is seen that there were
significant rapid variations from 1991 to 1993. As an interpretation, we think that the
ionized gas of the circumstellar shell of MX Per was active during our observing run. In
order to better understand the character of these variations we should continue to observe
the star both in the optical and the infrared.


                         Xiao-zhen GUO
                         Jun-jie WANG
                         Beijing Astronomical Observatory
                         Chinese Academy of Sciences
                         Beijing 100080



References:

Baliunas, S. L., Ciccone, M. A., Guinan, E. F., and Miskinis, P., 1975, Bull. Am. Astron.
   Soc., 7, 252 [BIBCODE 1975BAAS....7Q.252B ]
Jackisch, G., 1963, Inf. Bull. Var. Stars, No. 40
Guo, X., Guo, Z., and Hao, J., 1991, Acta Astronomica Sinica, 32, No. 4  [BIBCODE 1991AcASn..32..415G ]