Stars
Magnitudes: Absolute and Apparent
Magnitude is the brightness of a star, and the measures of magnitude are absolute (brightness as appears to observer) and apparent (measure of how much light is being put out by an object)
Color and Temperature
Star color is based on its temperature (hotter stars are blue, while cooler stars are red), and the color/temperature of a star can be classified into stellar classes
Parallax
Parallax is the apparent shift in position of an object because of a change in the point of view. Closer objects have a larger parallax than farther objects.
Proper Motion
Proper motion is the change in (x, y) tangential motion of a star, and described in two coordinates: Right Ascension and Declination
Angular Measurements of the Sky
When describing night-sky objects, spherical (not linear) measurements are used. These measurements are typically in degrees, arcminutes, and arcseconds.
Radial Velocity
A measure of movement towards or away from the observer, radial velocity is just one component of stellar motion that is derived through measurement of the doppler effect.
WCS Coordinates With Astrometry.Net
Astrometry.net is a highly effective tool that analyzes astronomical images and can determine the WCS coordinates of the image as well as details of the known celestial objects contained within it.
Stellar Populations I, II, III
The three population (pop) classifications categorize stars based on how much metal is contained within them, and this concept of "pop" stars is sometimes crucial to research.
Parsecs and Light Years
Parsecs and light years are common measurements of distance to celestial objects, and the former is especially significant for its importance to scientific writing and its relationship with parallax.
Constellations
The result of countless different cultures naming the same stars, inconsistent star names have necessitated the need for a dependable and systematic method of stellar nomenclature based on the brightness of stars within any given constellation.