Ghost Light Galaxy Clusters Compass Image

Image of galaxy clusters MOO J1014+0038 (left panel) and SPT-CL J2106-5844 (right panel) captured by Hubble's Wide Field Camera 3, with color key, compass arrows, and scale bar for reference.

This image shows near-infrared wavelengths of light. The color key shows which filters were used when collecting the light. The color of each filter name is the color used to represent the wavelength that passes through that filter.

• The compass graphic points to the object's orientation on the celestial sphere. North points to the north celestial pole which is not a fixed point in the sky, but it currently lies near the star Polaris, in the circumpolar constellation Ursa Minor. Celestial coordinates are analogous to a terrestrial map, though east and west are transposed because we are looking up rather than down.

The scale bar is labeled in light-years (ly) and parsecs (pc).

• A light-year is the distance that light travels in one Earth-year. (It takes 100,000 years for light to travel a distance equal to the length of the bar.) One light-year is equal to about 5.88 trillion miles or 9.46 trillion kilometers.
• A parsec is also a measure of length or distance. One parsec is approximately 3.26 light-years across.

Note that the distance in light-years and parsecs shown on this scale bar applies to the galaxy cluster, not to foreground or background objects.

Click here for a full description of the image.