What is the star's variable?
A variable star is a star with a brightness that differs from the viewer's point of view on the ground. Some variable stars have so gentle variations that they can only be identified by advanced spectroscopy, while others differ sufficiently, that they can be seen with the naked eye or a basic telescope. Variable stars are extremely interesting for astronomers, professional and amateur and others are constantly identified.
Historically, people considered stars firm and unchanged. This theory was refuted when people began to observe Novae, realizing that the content of heaven had actually changed over time. Several theories were developed to explain this, and astronomers began to identify variable stars. Initially, very little was developed and was considered relatively rare. With the advent of a better observation device, astronomers realized that variable stars were actually quite numerous. Examples of well -known variable stars include Betelgeuse, Beta Lyrae, Eta Aquila and Polaris.
eA number of types of variable stars xist. They are roughly divided into two main categories: inner and outer variable stars. Inner variable stars have a brightness that differs due to internal processes that occur in the star. At the beginning and at the end of their lives, the stars are actually a bit different due to the cascading series of processes that occur inside and around the star. The outer variable stars differ due to factors outside the star.
In the case of an outer variable star, the brightness of the star may vary due to periodic occultization by another star, which means that another star crosses its path and temporarily eclipse. Stars may also differ in brightness when they rotate if they have a dark area on their surface. Both types of variable stars have a very regular period, which makes it easier to monitor the waxing of brightness.
Inner variable stars are divided into cataclysmatic, pulsating, eruption and rEntgen variable stars. These stars go through processes, such as chemical changes that cause brightness changes, as the star swells and contracts, emits the flares of energy, etc. Novae are a particularly remarkable example of cataclysmatic variable star, with light brightness so intense that the star of the novae can light up the sky.
amateur astronomers who are interested in variable stars can actually contribute to the body of scientific research of these stars. Amateur observation organizations collect data from garden astronomers around the world and provide this data to astronomers. The amateur astronomer sometimes even identifies a variable star or notes in a variable star before noticing professional astronomers; Thanks to the huge number of celestial bodies, it is impossible for professional astronomers to do everything.