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.
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.
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.
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.
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:
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 ...
What is a Variable Star - Universe Guide
A Variable Star is a star whose brightness or size changes over a period from microseconds (pulsars) to hours, months or even years. Our own star, the Sun, is classed as a variable star because its luminosity changes slightly over eleven years.