General astronomy

General astronomy

Contributors in General astronomy

General astronomy

two stars orbiting each other in a plane that is along your line of sight so you see one star periodically pass in front of the other star. They are especially useful for determining the diameters ...

ecliptic

Astronomy; General astronomy

great circle that is a projection of the Earth's orbit onto the sky, or the path the Sun takes through the stars in its annual motion. It is tilted by 23.5° with respect to the celestial equator.

electromagnetic radiation

Astronomy; General astronomy

a form of energy made of oscillating electric and magnetic fields. It is a fancy word for ``light'' and it includes (in order of increasing energy) radio, infrared, visible light (optical), ...

electron

Astronomy; General astronomy

negatively-charged subatomic particle that moves around the atomic nucleus in specific energy levels. It has about 1800 times less mass than the proton and neutron.

electron degeneracy pressure

Astronomy; General astronomy

pressure exerted by a degenerate gas made of electrons. It is what prevents further collapse of a white dwarf.

element

Astronomy; General astronomy

a substance that cannot be decomposed by chemical means into simpler substances. All atoms of an element have the same number of protons in the nucleus.

ellipse

Astronomy; General astronomy

squashed circle that tapers at both ends. The total of the distance between any point on the ellipse and one focus + the distance from the point to the other focus = a constant. It is the shape of ...