Is this a lens?
"target object ID'd as galaxy in SDSS. the rest are 'star'.":(30x30@189,197)"'star' per NED/SDSS; appears to have arcs":(48x48@190,160)"'star' - appears to have arcs and brilliance of quasar":(75x62@146,216). This could be a complex lensing situation."'star' - appears to be lensing":(56x52@152,338) -- or the blue arcs could all be artifacts of the photography.
Khalila I think in this case your seeing a bit of a overlay issue in respect to the bands being blended together and colored. Sense the relative motion of each respective star moves as well as minor issues in the way the print was captured. . . Well it looks to me like the processing part embellished a bit along the edges of a layer or two.
Hum, maybe I lost ya a bit here. Ok when they bring the bands together they are done in layers and usually a certain amount of opaqueness is added so each layer 'bleeds though' thus your looking (at what I suspect in this case,) 5 images combined.
Now I don't think SDSS takes all 5 images at exactly the same time. (Even if it did there are still issues with the atmosphere distorting portions of the light entering the telescope that can be somewhat unique with respect to each band.) But multiple time lapsed photos the relative motion between layers can be much more obvious with more localized stars.
I think the arc you see is perhaps a artifact of the (multiple,) processing algorithms used to bring all of the blends together, color them, processed exposure adjustments, and noise reduction.
Still those things said, perhaps someone with a bit more familiarity with the inner workings of SDSS can explain it better than I. I'm not claiming what I said here is completely correct either, it's just I can't find more info on these particular stars.
Ya know in a nutshell maybe I should just say I'm leaning towards_ artifacts_ before I start babbling a bit too much . . . :p