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We investigate an infrared-excess source called G2 or Dusty S-cluster Object(DSO) moving on a highly eccentric orbit around the Galaxy's central blackhole, Sgr A*. We use, for the first time, near-infrared polarimetric imagingdata to determine the nature and the properties of the DSO, and obtain animproved K_s-band identification of this source in median polarimetry images ofdifferent observing years. The source starts to deviate from the stellarconfusion in 2008, and it does not show any flux density variability over theyears we analyzed it. We measure the polarization degree and angle of the DSObetween 2008 and 2012 and conclude, based on the significance analysis onpolarization parameters, that it is an intrinsically polarized source (>20%)with a varying polarization angle as it approaches Sgr A* position. DSO shows anear-infrared excess of K_s-L' > 3 that remains compact close to the pericenterof its orbit. Its observed parameters and the significant polarization obtainedin this work show that the DSO might be a dust-enshrouded young star, forming abow shock as it approaches the super massive black hole. The significantly highmeasured polarization degree indicates that it has a non-spherical geometry andit can be modelled as a combination of a bow shock with a bipolar wind of thestar. We use a 3D radiative transfer model that can reproduce the observedproperties of the source such as the total flux density and the polarizationdegree. We obtain that the change of the polarization angle can be due to anintrinsic change in the source structure. Accretion disc precession of theyoung star in the gravitational field of the black hole can lead to the changeof the bipolar outflow and therefore the polarization angle variation. It mightalso be the result of the source interaction with the ambient medium.

Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center