In the list of young stellar objects compiled by Megeath et al . ( 45 ) for the Orion A molecular cloud , only 44 out of 1208 sources found projected onto low extinction ( A _ { K } < 0.8 mag ) gas are identified as protostars .
These objects are puzzling because protostars are not typically expected to be associated with extended low extinction material .
Here , we use high resolution extinction maps generated from Herschel data , optical/infrared and Spitzer Space Telescope photometry and spectroscopy of the low extinction protostellar candidate sources to determine if they are likely true protostellar sources or contaminants .
Out of 44 candidate objects , we determine that 10 sources are likely protostars , with the rest being more evolved young stellar objects ( 18 ) , galaxies ( 4 ) , false detections of nebulosity and cloud edges ( 9 ) , or real sources for which more data are required to ascertain their nature ( 3 ) .
We find none of the confirmed protostars to be associated with recognizable dense cores and we briefly discuss possible origins for these orphaned objects .