Concept
Colour Index
A star's colour expressed numerically.
The difference between a star's magnitude in two filters (such as B and V), giving a quick measure of temperature.
Overview
The difference between a star's magnitude in two filters (such as B and V), giving a quick measure of temperature.
See also
Proper Motion
A star's drift across the sky over years.
The Big Bang
How everything began, 13.8 billion years ago.
Black Holes
Regions where gravity stops light itself.
Dark Matter
The invisible mass holding galaxies together.
Dark Energy
The mysterious force accelerating the universe.
Light-Year & Astronomical Distances
Measuring the unimaginable.