A THIRD MASSIVE STAR COMPONENT IN THE sigma ORIONIS AB SYSTEM

作者：Simon Diaz S^*; Caballero J A; Lorenzo J

来源：Astrophysical Journal, 2011, 742(1): 55.

DOI：10.1088/0004-637X/742/1/55

• binaries: spectroscopic
• galaxies: star clusters: individual (sigma Orionis)
• stars: early-type
• stars: individual (sigma Ori AB)

We report on the detection of a third massive star component in the sigma Orionis AB system, traditionally considered as a binary system. The system has been monitored by the IACOB Spectroscopic Survey of Northern Massive Stars program, obtaining 23 high-resolution FIES@NOT spectra with a time span of similar to 2.5 years. The analysis of the radial velocity curves of the two spectroscopic components observed in the spectra has allowed us to obtain the orbital parameters of the system, resulting in a high eccentric orbit (e similar to 0.78) with an orbital period of 143.5 +/- 0.5 days. This result implies the actual presence of three stars in the sigma Orionis AB system when combined with previous results obtained from the study of the astrometric orbit (with an estimated period of similar to 157 years).

• 出版日期2011-11-20