Satellites
Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin.The name "satellite DNA" refers to the phenomenon that repetitions of a short DNA sequence tend to produce a different frequency of the bases adenine, cytosine, guanine, and thymine, and thus have a different density from bulk DNA such that they form a second or "satellite" band(s) when genomic DNA is separated along a cesium chloride density gradient using buoyant density centrifugation.
Satellites observed for the first time the smaller black hole of a black hole pair at the centre of the galaxy OJ 287. The smaller black hole was revealed by a sudden burst of brightness when it "swallowed" a large slice of the accretion disk surrounding the larger one, turning it into a jet of gas.