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A star is a massive, luminous ball of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of theenergy on Earth. Other stars are visible from Earth during the night when they are not outshone by the Sun or blocked by atmospheric phenomena. Historically, the most prominent stars on the celestial sphere were grouped together into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations.

For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen in its core releasing energy that traverses the star's interior and then radiates into outer space. Almost all naturally occurring elements heavier thanhelium were created by stars, either via stellar nucleosynthesis during their lifetimes or by supernova nucleosynthesiswhen stars explode. Astronomers can determine the mass, age, chemical composition and many other properties of a star by observing its spectrum, luminosity and motion through space. The total mass of a star is the principal determinant in its evolution and eventual fate. Other characteristics of a star are determined by its evolutionary history, including diameter, rotation, movement and temperature. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung-Russell diagram (H-R diagram), allows the age and evolutionary state of a star to be determined.

A star begins as a collapsing cloud of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Once the stellar core is sufficiently dense, some of the hydrogen is steadily converted into helium through the process of nuclear fusion.[1] The remainder of the star's interior carries energy away from the core through a combination of radiative and convective processes. The star's internal pressure prevents it from collapsing further under its own gravity. Once the hydrogen fuel at the core is exhausted, those stars having at least 0.4 times the mass of the Sun[2] expand to become a red giant, in some cases fusing heavier elements at the core or in shells around the core. The star then evolves into a degenerate form, recycling a portion of the matter into the interstellar environment, where it will form a new generation of stars with a higher proportion of heavy elements.[3]

Binary and multi-star systems consist of two or more stars that are gravitationally bound, and generally move around each other in stable orbits. When two such stars have a relatively close orbit, their gravitational interaction can have a significant impact on their evolution.[4] Stars can form part of a much larger gravitationally bound structure, such as a cluster or a galaxy.

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Spica and Rigel have similar surface temperatures but their absolute magnitudes are different why is this?

Spica has a surface temperature of 22,400K and an absolute magnitude of -3.55Rigel has a surface temperature of 11,000K and an absolute magnitude of -6.7So the question is incorrect.


The radius of Betelgeuse varies by about 60 percent within a period of 3 years If the stars surface temperature remains the same what is the ratio of the two absolute magnitudes?

If the radius of Betelgeuse varies by 60% within three years, its luminosity will also change proportionally. Since absolute magnitude is related to luminosity, the ratio of the two absolute magnitudes will be the square root of the ratio of the luminosities. So, the ratio of the two absolute magnitudes will be approximately 1.22.


Does a red giant or a white dwarf star have greater absolute?

Red giants have typical absolute magnitudes which are 10-15 magnitudes below white dwarfs, which means that the red giants are 10,000-1,000,000 times brighter, after due allowance for distance.


The distance from the earth to a star that has identical apparent and absolute magnitudes is?

The standard distance used for evaluating absolute magnitude is 10 parsec.The standard distance used for evaluating absolute magnitude is 10 parsec.The standard distance used for evaluating absolute magnitude is 10 parsec.The standard distance used for evaluating absolute magnitude is 10 parsec.


What is a H-R diagram and what two characteristics of stars are compared on it?

It is a diagram on which stars are plotted according to their absolute magnitudes (or luminosities) against their stellar classifications (or effective temperatures).

Related Questions

Spica and Rigel have similar surface temperatures but their absolute magnitudes are different why is this?

Spica has a surface temperature of 22,400K and an absolute magnitude of -3.55Rigel has a surface temperature of 11,000K and an absolute magnitude of -6.7So the question is incorrect.


What type of star has high absolute magnitudes and high temperatures?

supergiant


How much brighter are supergiants than giants?

According to Wikipedia giants have absolute magnitudes around 0 to -1 while supergiants have absolute magnitudes around -5 so they are 50-100 times brighter (5 magnitudes difference equals 100 times brighter).


Have absolute magnitudes of ones or less?

dwarf stars -Sydney-


The radius of Betelgeuse varies by about 60 percent within a period of 3 years If the stars surface temperature remains the same what is the ratio of the two absolute magnitudes?

If the radius of Betelgeuse varies by 60% within three years, its luminosity will also change proportionally. Since absolute magnitude is related to luminosity, the ratio of the two absolute magnitudes will be the square root of the ratio of the luminosities. So, the ratio of the two absolute magnitudes will be approximately 1.22.


How 2 stars could have the same apparent magnitude but different absolute magnitudes?

ble


Does a red giant or a white dwarf star have greater absolute?

Red giants have typical absolute magnitudes which are 10-15 magnitudes below white dwarfs, which means that the red giants are 10,000-1,000,000 times brighter, after due allowance for distance.


How do you solve absolute value involving fractions?

Fractions make no difference to absolute values.


What is the absolute magnitude of cassiopeia?

Cassiopeia is a constellation, not a single star, so it does not have a specific absolute magnitude. The stars within the constellation Cassiopeia have a range of absolute magnitudes depending on their distance and luminosity.


What is the absolute and apparent magnitude of a giant star?

Magnitudes require distance and luminosity. Therefore a specific star is required.


How can you interpret comparisons involving absolute values?

the absolute value of any number of spaces it is from 0


How can you interpet comparison involving absolute value?

the absolute value of any number of spaces it if from zero