Editing Bellatrix (section)

==Companions==
Bellatrix was thought to belong to the [[Orion OB1 association]] of stars that share a common motion through space, along with the stars of [[Orion's Belt]]: [[Alnitak]] (Zeta Orionis), [[Alnilam]] (Epsilon Orionis), and [[Mintaka]] (Delta Orionis). However, this is no longer believed to be the case, as Bellatrix is now known to be much closer than the rest of the group.<ref name=kaler/> It is not known to have a stellar companion,<ref name=mnras389_2_869/> although researchers Maria-Fernanda Nieva and Norbert Przybilla raised the possibility it might be a spectroscopic binary.<ref name=nieva/> A 2011 search for nearby companions failed to conclusively find any objects that share a [[proper motion]] with Bellatrix. Three nearby candidates were all found to be background stars.<ref name=apj736_2_89/>

Some researchers suspected that Bellatrix was a member of the [[32 Orionis|32 Orionis group]]. They proposed that the 32 Ori group should instead be termed the Bellatrix Cluster on the basis that the sky position and distance of Bellatrix are similar to those of the 32 Ori group.<ref name=Buoy_Alves_2015/> The [[proper motion]] of Bellatrix deviates significantly from the mean motion of the group, leaving its membership in question. However, it may be possible to reconcile membership if the divergent velocity is the result of an unseen companion. For example, a face-on orbit with a [[black hole]] companion orbiting {{val|100|ul=AU|p=~}} from the star with a period measured in centuries could account for the discrepancy.<ref name=Bell_et_al_2017/>