  Massive B-type stars with strong magnetic fields and fast rotation are very
rare and provide a mystery for theories of both star formation and magnetic
field evolution. Only two such stars, called sigma Ori E analogs, were
previously known. Recently, a team involved in APOGEE, one of the Sloan Digital
Sky Survey III programs, announced the discovery of two additional rigidly
rotating magnetosphere stars, HD23478 and HD345439. The presence of magnetic
fields in these newly discovered sigma Ori E analogs was not investigated in
the past.
  In the framework of our ESO Large Programme, and one normal ESO programme, we
carried out low-resolution FORS2 spectropolarimetric observations of HD23478
and HD345439.
  From the measurements using hydrogen lines, we discover a rather strong
longitudinal magnetic field of the order of up to 1.5kG in HD23478, and up to
1.3kG using the entire spectrum. The analysis of HD345439 using four subsequent
spectropolarimetric subexposures does not reveal the presence of a magnetic
field at a significance level of 3sigma. On the other hand, the inspection of
individual subexposures indicates that HD345439 may host a strong magnetic
field, rapidly varying over 88 minutes. A hint at the fast rotation of HD345439
is also given by the behaviour of several metallic and He I lines in the
low-resolution FORS2 spectra, showing profile variations already on such a
short time scale.
