Astronomy Flashcards
Ecliptic
Plane of earth orbit around the sun: a line through the 12 zodiac constellations.
Precession
Earth’s spin axis is not fixed, but sweeps out a conical section of space over 25,800 years
Declination
Up and down in degrees
Ascension
Left and right in degrees
Parallax
Is the only direct measurement we have for nearby objects within a few hundred light-years distance
Light year
(For measuring distances) A light year is the distance a bean of light travels through the vacuum of space in one year
Parsec
Parallax arc second
Luminosity
Amount of radiation produced by the source
Brightness
Amount of radiation that we receive
The Hubble Constant
Velocity = Hubble constant X distance. The Hubble constant reflects the rate at which the Universe is expanding
Chromosphere
The sun “atmosphere”
Solar Prominences
High density blasts of plasma