Urban Sunset #1 was shot in Buenos Aires from a panoramic vantage point, where distant trees, buildings and a telecom antenna are silhouetted against the setting sun.
On the upper limb of the Sun we can appreciate the effect of atmospheric refraction in what is called green and blue fringing. Blue and green wavelengths are refracted upwards by the atmosphere creating this effect of colored borders in the upper limb, whereas the lower limb would appear red as the blue and green are displaced upwards (not visible in this image as the lower limb was already below the horizon).
This image was minted as a Bidders Reward for the SuperRare piece "Helios".