Variable star - Wikipedia
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: [ 1 ]
What is a variable star? - EarthSky
2023年1月15日 · Bottom line: A variable star is one whose brightness changes regularly. Here we discuss the different kinds of variable stars and what causes their brightness variations.
Types of Variable Stars: Cepheid, Pulsating and Cataclysmic
2015年1月29日 · A variable star is, quite simply, a star that changes brightness. A star is considered variable if its apparent magnitude (brightness) is altered in any way from our perspective on Earth.
Types of Variable Stars: A Guide for Beginners - aavso
Amplitude—intensity of a star’s brightness measured in magnitudes. Giant—evolved star; Variable stars are divided into two main categories: Intrinsic: physical changes within or on the surface of the star cause the brightness of the star to vary.
Variable star | Pulsating, Light Curve, Magnitude | Britannica
variable star, any star whose observed light varies notably in intensity. The changes in brightness may be periodic, semiregular, or completely irregular. A brief treatment of variable stars follows. For full treatment, see star: Variable stars.
Variable star - Simple English Wikipedia, the free encyclopedia
A variable star is a star that is sometimes brighter or dimmer. Most stars have only very small differences in brightness, like the Sun ; but some stars can vary hugely. There are generally two types of variable stars:
It contains a variable star that is located in the middle of a set of crosshairs, and surrounding the variable star are several comparison stars of known magnitudes.
19.3 Variable Stars: One Key to Cosmic Distances - OpenStax
The breakthrough in measuring distances to remote parts of our Galaxy, and to other galaxies as well, came from the study of variable star s. Most stars are constant in their luminosity, at least to within a percent or two. Like the Sun, they generate a steady flow of energy from their interiors.
Variable Stars and Binaries | Center for Astrophysics | Harvard ...
For some stars, known as Cepheid variables, variations are very regular in period and in the amount of light they produce: the longer the period of pulsation, the brighter the star. This “period-luminosity relation” was first identified by Harvard College astronomer Henrietta Swan Leavitt in the early 1900s.
Variables: What Are They and Why Observe Them? - aavso
What Are Variable Stars? Variable stars are stars that change brightness. The brightness changes of these stars can range from a thousandth of a magnitude to as much as twenty magnitudes over periods of a fraction of a second to years, depending on the type of variable star. Over 1,000,000 variable stars are known and catalogued, and many ...