| A | B |
|---|
| Measure of the amount of light a star actually gives off. | Absolute Magnitude |
| Measure of the amount of light from a star that is recieved on earth. | Apparent Magnitude |
| States that about 13.7 billion years ago, the universe began with a huge,fiery explosion. | Big Bang Theory |
| Final stage in the evolution of a very massive star, where the core's mass collapses to a point that it's gravity is so strong that not even light can escape it. | Black Hole |
| Layer of the Sun's atmosphere above the photosphere. | Chromosphere |
| Group of stars that forms a pattern in the sky that looks like a familiar object, animal, or character. | Constellation |
| Outermost, largest layer of the Sun's atmosphere: extends millions of kilometers into space and has temperatures up to 2 million. | Corona |
| Large group of stars, dust, and gas held together by gravity: can be elliptical, spiral, or irregular. | Galaxy |
| Late stage in the life of comparatively low-mass main sequence star in which hydrogen in the core is deleted, the core contracts and temperatures inside the star increase, causing its outer layers to expand and cool. | Giant |
| Unit representing the distance light travels in one year- about 9.5 trillion km- used to record distances between stars and galaxies. | Light-year |
| Large cloud of gas and dust that contracts under gravitational force and breaks apart into smaller pieces, each of which might collapse to form a star. | Nebula |
| Collapsed core of a supernova that can shrink to about 20 km in diameter and contains only neutrons in the dense core. | Neutron Star |
| Lowest layer of the Sun's atmosphere; gives off light and has temperatures of about 6,000 K. | Photosphere |
| Areas on the Sun's surface that are cooler and less bright than surrounding areas, are caused by the Sun's magnetic field, and occur in cycles. | Sunspots |
| Late stage in the life cycle of a massive star in which the core heats up, heavy elements form by fusion, and the star expands; can eventually explode to form a supernova. | Supergiant |
| Late stage in the life cylce of a comparatively low-mass main sequence star; formed when its core depletes its helium and its outer layers escape into space, leaving behind a hot, dense core. | White Dwarf |
| An apparent shift in the position of an object when viewed from different locations | Parallax |
| When two atoms become one - energy source found in the sun | Fusion |
| The splitting of an atom to release energy | Fission |
