SIMBAD references

Photoelectric UBVRI photometry and polarimetry and photographic UBVR photometry have been used to study the stellar cluster NGC 2175 associated with the HII region-molecular cloud complex Sharpless252. The colour excess E_B–V of stars in NGC 2175 ranges from the foreground colour excess of 0.4mag up to 1.7mag. The distance modulus of S252 obtained by fitting ZAMS to the colour-magnitude diagrams of NGC 2175 is 11.7±0.3mag (2.2±0.3kpc). The lower part of the colour-magnitude diagrams of the main cluster contains stars still contracting towards ZAMS indicating an age of the order of one million years for the cluster. The age of a small subcluster to the east of the HII region is a few million years. High stellar polarizations up to 12% have been observed. The average wavelength of the maximum polarization in S252 is 0.53±0.01µm and the polarization efficiency is near the empirical maximum value 3A_v. The polarization field in S252 is regular but cannot be explained by a single magnetic field direction.