- Gamma Andromedae is a rather interesting double star within our own Milky Way galaxy. First, the primary is a very yellow star, and the secondary an intense blue. At over 350 light years distance, the light from these stars reaching us today left not long after Christian Huygens proposed that Saturn had rings… in the 1600’s! But the star gets even stranger. The dimmer blue secondary is itself a double star, averaging a Sun/Neptune distance. Stranger still, the primary of THAT system is ALSO double! So Gamma Andromedae is really a quadruple star system.
- Galaxy filament (Wikipedia)
In cosmology, galaxy filaments are the largest known structures in the universe, consisting of ‘walls’ of gravitationally bound galactic superclusters. These massive, thread-like formations can reach 80 megaparsecs h−1 (or of the order of 160 to 260 million light-years) and form the boundaries between voids. Galaxy filaments form the cosmic web and define the overall structure of the observable universe.