AU - Astronomical unit, measure of distance equal to that of the average distance of the Earth from the sun (150 Km).
black holes - As mass increases, so does gravity. when the escape velocity becomes greater than the speed of light, a black hole is formed. Since nothing can travel faster than light, nothing can escape.
dobsonian - Telescope mount where a Newtonian telescope is placed in a box-like stand.
bolide - Meteor fireball that breaks apart with an explosion.
escape velocity - Speed needed to overcome a objects gravity ex. Earth 11.2 Km/s Jupiter 60.22 Km/s
eyepiece - Collects light from the primary/secondary mirror and magnifies it
galactic nuclei - Center of a galaxy
galaxy - A large number of stars orbiting around a center. There are hundreds of millions of stars in a galaxy. They range from 1,500 light years to 300,000 light years in diameter.
light year - Distance light travels in a year in a vacuum. 9.46 trillion kilometers
luminosity - A measure of this is called "apparent visual magnitude." The scale is based upon numbers. The smaller the number, the brighter the object. ex. Betelgeuse/.6/bright - M61/9.69/extremely dim
Milky Way - Our home galaxy - a spiral galaxy approximately 100 light years in diameter - contains approximately 400 billion + stars
motor drive - Motor that allows a telescope to track a star
nebula - "Birthplace" of stars - contrary to science-fiction, you would not notice being inside a nebula (the nebula is spaced over many light years so there would be too little matter near you to detect)
objective/primary mirror - Reflects the light to a eyepiece or secondary mirror in a telescope
parsec - Unit of distance - 3.258 light years
Photo-adapter - Attaches telescope to T-adapter
red shift - As objects recede, the wavelengths of light lengthen due to the Doppler effect thus causing spectral lines to shift to the red
secondary mirror - Reflects the light from the primary mirror into the eyepiece on some telescopes
single lens reflex - Camera best suited for astrophotography. allows more control over exposure time.
spectra - When an atom is excited, the electrons "jump up." On the way down, they release light, which can be observed to identify the element. The spectrum can only be seen through a spectrometer or diffraction grating. A continuous spectrum is emitted by a liquid, solid, or dense gas composed of many elements (dark lines called absorption lines are produced by gaseous materials inside an object such as the sun - below, left). A gas when free of impurities emits bright lines (below, right). The lines are unique to each element.
Spectrum of Jupiter Hydrogen spectra
T-ring- There are many types of cameras with many types of connectors. a T-ring is needed to connect the camera to a photo-adapter
viewfinder - Allows targeting
