SDSS J170745+302056: a low surface brightness galaxy in a group
  On the basis of the SDSS survey and spectral observations with the 6-m
telescope of SAO RAS, we have peformed a detailed study of SDSS J170745+302056.
By combination of its characteristics -- exponential surface brightness
distribution, central surface brightness of stellar disk $\mu_0(B) =
23.25\,^m/\square"$, blue colors, low metallicity and low star formation rate
-- the galaxy is a typical low surface brightness spiral galaxy. Exponential
scalelength of the galaxy is $\approx$3 kpc, its optical diameter exceeds 20
kpc. SDSS J170745+302056 is a member of a group of five galaxies and probably
it is in interaction with UGC 10716. The existence of a large low surface
brightness galaxy in such a dense environment is very unusual.
