Bibcode
Contreras, M. E.; Rodriguez, L. F.; Tapia, M.; Cardini, D.; Badiali, M.; Emanuele, A.; Persi, P.
Bibliographical reference
Proceedings of the ESA Symposium `Hipparcos - Venice '97', 13-16 May, Venice, Italy, ESA SP-402 (July 1997), p. 401-404
Advertised on:
8
1997
Citations
3
Refereed citations
3
Description
Cyg OB2 No. 5 (BD+40deg4220; V729 Cyg) is known to be a contact binary
system formed by two O-type stars. For this object a 6-cm radio emission
has been detected at the optical position as well as an additional weak
non-thermal radio source located at ~ 0.9 arcsec to the north east of
the contact binary. It has been suggested that this radio component was
possibly a third stellar object in the system. This was the first time
that a radio companion was observed to be associated with the contact
binary system. In this work we present new radio, CCD and Hipparcos
observations that provide the basis for a plausible explanation of the
origin of the non-thermal radiation emitted by the `third' component of
this system and its nature.