The young O9.5 V spectroscopic binary \theta ^ { 2 } Ori A shows moderately hard X-ray emission and relatively narrow X-ray lines , suggesting that it may be a Magnetically Confined Wind Shock ( MCWS ) source , similar to its more massive analogue \theta ^ { 1 } Ori C. X-ray flares occurring near periastron led to the suggestion that the flares are produced via magnetic reconnection as magnetospheres on both components of the \theta ^ { 2 } Ori A binary interact at closest approach .

We use a series of high-resolution spectropolarimetric observations of \theta ^ { 2 } Ori A to place an upper limit on the magnetic field strength of 135 G ( 95 % credible region ) .
Such a weak dipole field would not produce magnetic confinement , or a large magnetosphere .
A sub-pixel analysis of the Chandra ACIS images of \theta ^ { 2 } Ori A obtained during quiescence and flaring show that the hard , flaring X-rays are offset from the soft , quiescent emission by 0.4 arcsec .
If the soft emission is associated with the A1/A2 spectroscopic binary , the offset and position angle of the hard , flaring source place it at the location of the intermediate-mass A3 companion , discovered via speckle interferometry .
The spectropolarimetric and X-ray results taken together point to the A3 companion , not the massive A1/A2 binary , as the source of hard , flaring X-ray emission .

We also discuss a similar analysis performed for the magnetic Bp star \sigma Ori E. We find a similar origin for its X-ray flaring .