COMMISSIONS 27 AND 42 OF THE IAU
                INFORMATION BULLETIN ON VARIABLE STARS
                             Number 4090

                                                    Konkoly Observatory
                                                    Budapest
                                                    19 September 1994

                                                    HU ISSN 0374 - 0676


 	 MWC147: A SUSPECT OF A PRE-MAIN SEQUENCE BINARY STAR

 MWC147 (HD259431, SAO95823, alpha_1950.0 = 6h30m19.37s delta_1950.0 = 10d21'38.2") is 
embedded in the nebulosity of NGC2247 and is a probable member of the Monoceros RI
association (Halbedel 1989). It is classified as a B6pe star (Finkenzeller and Mundt, 1984),
and has a visual magnitude of V = 8.7 (Terra-Negra et al., 1994).
 Being classified as a Herbig Ae/Be star, MWC147 has been observed since 1992 in
a systematic survey that is being conducted at the Astrophysical National Laboratory
(LNA - Brazil), aiming at investigating the properties of these stars. The spectra were
obtained using the Coude focus in the 1.6 m (LNA, Brazil, 0.12 A/pixel), and in one
mission, the 1.4 m CAT (ESO, Chile) was used. MWC147 was observed in the visible
region of the spectrum (Halpha) and showed a double peak emission profile (Fig. 1).
  It is clearly seen that the emission Halpha profiles show a transit. This behavior might
suggest that this star is a member of a binary system.


                                [FIGURE 1]

  Figure 1. Spectra of MWC 147 showing the variation in the center of the Halpha emission lines. The vertical bar
(top and left) indicates five units in relative intensity, continuum intensity for each spectrum is one. The Julian
date of observations is indicated in each spectrum.

                                [FIGURE 2]

                 Figure 2. Radial velocity of MWC 147.

  A preliminary analysis of the variations of the radial velocity assuming a circular orbit
(Fig. 2), give the following orbital parameters:

                  Period = 365+/-3days
                  e = 0
                  omega = -
                  K = 67+/-2 km/s
                  V_CM = 23+/-2 km/s

  These results are first approximation because of the small amount of the observed
points (only 9), but the period found is in agreement with the transit showed by the
spectral lines.
  Further observations are needed in order to confirm the obtained orbital parameters.


                           S. L. A. VIEIRA
                           Depto de Fisica-ICEx-Universidade
                           Federal de Minas Gerais
                           Caixa Postal 702 - CEP 30.161
                           Belo Horizonte - MG - Brazil
                           E-mail:svieira@fisica.ufmg.br

                           N. C. S. CUNHA
                           Laboratorio de Astrofisica Espacial
                           y Fisica Fundamental
                           Villafranca del Castillo
                           Apartado de Correos 50727
                           Madrid, Spain
                           E-mail:nuno@laeff.esa.es

References:

Finkenzeller, U. & Mundt, R.: 1984, A&AS, 55, 109 [BIBCODE 1984A&AS...55..109F ]
Halbedel, E. M.: 1989, PASP, 101, 1004 [BIBCODE 1989PASP..101.1004H ]
Terra-Negra, L., Chavarria-K, C., Diaz, S. & Gonzales-Patino, D.: 1994, A&AS, 104, 557 [BIBCODE 1994A&AS..104..557T ]