- How to find and observe Almach (TOTS#6) (eyesonthesky.com)
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.
- Sphere (Wikipedia)
A sphere (from Greek σφαῖρα, sphaîra) is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. Formally, a sphere is the set of points that are all at the same distance r from a given point in three-dimensional space. That given point is the center of the sphere, and r is the sphere’s radius. The earliest known mentions of spheres appear in the work of the ancient Greek mathematicians.
