Orbital solution of the supergiant HD 327083

KRAUS, M.; CIDALE, L.; MARCHIANO, P.; BORGES FERNANDES, M.

San Juan

Congreso; 59º Reunión Anual de la Asociación Argentina de Astronomía; 2016

Icate - Conicet - UNSJ

HD 327083 is an early B-type star with E(B 􀀀 V ) 1:9 exhibiting a spectrum of emission lines, mainly of HI, HeI and FeII ions. The optical spectrum shows P-Cygni proles with mid-term variations.Based on observed variability in optical spectroscopic data, the star is supposed to be a binary. However, the period could not be setteled so far. A minimum period determined for this binary system was estimated to about56:5 days considering a circular orbit (Miroshnichenko, A. S. et al. 2003, A&A, 406, 673). On the other hand, these authors also t a radial velocity curve by a period of around 173:5 days in combination with an eccentric orbit.Observations of CO band emission displayed variability as well. The modelling of the CO emission suggests the presence of a detached inhomogeneous ring revolving the binary on a Keplerian orbit with a projected rotational velocity of 55 kms􀀀1. The variability observed in the CO region could be related to gravitational interactions.During the past years we collected additional spectroscopic observations in the optical range with the RE-OSC/CASLEO and FEROS/ESO spectrographs. These high-quality spectroscopic observations will allow us to better constrain the orbital period of this interesting binary.