NED object is MESSIER 033; Reference is 1987A&AS...68..171B

   FIGURE 6.-Distribution of the linearly polarized emission at 11.1 cm in the
 field of M33 shown as contours in equal steps of 2.5 mJy per b.a. (1.5
 {sigma}). Five positions of possibly polarized point sources are marked. Bars
 indicate the orientations of the measured E-field; their lengths give the
 degree P of polarization between 5% to 30% as described in the caption of
 figure 2. The coordinate grid is the same in all maps and refers to right
 ascension and declination of 1950.0. The optical centre at {alpha}_50_ =
 1h31m01.67s and {delta}_50_ = 30deg24'15.0" (de Vaucouleurs and Leach, 1981)
 is marked by << + >> in all figures.