The number of well-studied early-type pre-main-sequence objects is very limited , hampering the study of massive star formation from an observational point of view .
Here , we present the results of VLT/FORS2 spectropolarimetric and VLT/X-shooter spectroscopic observations of two recently recognised candidate Herbig Be stars , PDS 27 and PDS 37 .
Through analysis of spectral lines and photometry , we find that these two objects are hot , 17500 \pm 3500 K , have large radii , 17.0 \pm 4.0 and 25.8 \pm 5.0 { R } _ { \odot } , and are very massive , 15.3 ( +5.4 , -4.4 ) and 21.1 ( +11.0 , -5.3 ) M _ { \odot } for PDS 27 and PDS 37 , respectively .
This suggests that these two objects are very young in their evolution and may become O-type stars .
Their youth is supported by their high accretion rates of the order of 10 ^ { -3 } – 10 ^ { -4.5 } ~ { } { M } _ { \odot } /yr .
A change in linear polarisation across the absorption component of H \alpha is detected in both objects .
This change indicates that the circumstellar environment close to the star , at scales of several stellar radii , has a flattened structure , which we identify as an inner accretion disc .
Strong variability is seen in both objects in many lines as further indication of an active circumstellar environment .