What Determines The Size Of A Star

What Determines The Size Of A Star?

In brief a star’s size is predominantly set by its own mass. … The mass and density of interstellar clouds appear to be important physical properties for determining the number of these cores and thus the number of stars that the cloud will form.In brief a star’s size is predominantly set by its own mass. … The mass and density of interstellar clouds

interstellar clouds
An interstellar cloud is generally an accumulation of gas plasma and dust in our and other galaxies. Put differently an interstellar cloud is a denser-than-average region of the interstellar medium (ISM) the matter and radiation that exists in the space between the star systems in a galaxy.

How can we determine the size of a star?

Direct imaging. It seems obvious: if you want to measure the size of a star just point your telescope at it and take a picture. Measure the angular size of the star in the image then multiply by the distance to find the true linear diameter.

What two things determine the size of a star?

What we know right away is a star’s temperature (through its spectral type). If we know the distance (through parallax) and of course we know its apparent magnitude we get its luminosity (same as absolute magnitude). These two then give us the size of the star.

What determines if a star will become a large or small star?

A star’s life cycle is determined by its mass. The larger the mass the shorter the life cycle. A star’s mass is determined by the amount of matter that is available in its nebula the giant cloud of gas and dust in which it is born.

What dictates the life of a star?

A star’s life cycle is determined by its mass. The larger its mass the shorter its life cycle. A star’s mass is determined by the amount of matter that is available in its nebula the giant cloud of gas and dust from which it was born.

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What makes a star a star?

But just what is a star exactly? A star is a luminous ball of gas mostly hydrogen and helium held together by its own gravity. Nuclear fusion reactions in its core support the star against gravity and produce photons and heat as well as small amounts of heavier elements. The Sun is the closest star to Earth.

What determines if a star becomes a giant or a supergiant?

The fusion of hydrogen to form helium changes the interior composition of a star which in turn results in changes in its temperature luminosity and radius. Eventually as stars age they evolve away from the main sequence to become red giants or supergiants.

What factors control the lifespan of stars?

A star’s life expectancy depends on its mass. Generally the more massive the star the faster it burns up its fuel supply and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion.

What two factors determine how long a star stays on the main sequence?

The rate at which they do this and the amount of fuel available depends upon the mass of the star. Mass is the key factor in determining the lifespan of a main sequence star its size and its luminosity. Stars on the main sequence also appear to be unchanging for long periods of time.

How do astronomers use spectra to determine the composition of a star?

Each element absorbs light at specific wavelengths unique to that atom. When astronomers look at an object’s spectrum they can determine its composition based on these wavelengths. The most common method astronomers use to determine the composition of stars planets and other objects is spectroscopy.

What are the 5 characteristics of a star?

Characteristics used to classify stars include color temperature size composition and brightness.

Are the stars bigger than the Sun?

It turns out that our Sun is an average sized star. There are bigger stars and there are smaller stars. We have found stars that are 100 times bigger in diameter than our sun. … We have also seen stars that are just one tenth the size of our sun.

How are stars made?

A star is born when atoms of light elements are squeezed under enough pressure for their nuclei to undergo fusion. … And once the fusion reactions begin they exert an outward pressure. As long as the inward force of gravity and the outward force generated by the fusion reactions are equal the star remains stable.

How does a star become a giant?

A star becomes a giant after all the hydrogen available for fusion at its core has been depleted and as a result leaves the main sequence. The behaviour of a post-main-sequence star depends largely on its mass.

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Why does a star become a red giant?

When hydrogen fuel at the centre of a star is exhausted nuclear reactions will start move outwards into its atmosphere and burn the hydrogen that’s in a shell surrounding the core. As a result the outside of the star starts to expand and cool turning much redder.

Why does a star become a supergiant?

Supergiants develop when massive main-sequence stars run out of hydrogen in their cores at which point they start to expand just like lower-mass stars. … They cannot lose enough mass to form a white dwarf so they will leave behind a neutron star or black hole remnant usually after a core collapse supernova explosion.

Why is there a lower limit to the mass of a star?

Why is there a lower limit to the mass of a main-sequence star? Objects with masses lower than 0.08 of the suns mass cannot raise their central temperature high enough to sustain hydrogen fusion.

How long does it take for a star to explode?

The explosion of a supernova occurs in a star in a very short timespan of about 100 seconds.

Will our Sun become a black hole?

Will the Sun become a black hole? No it’s too small for that! The Sun would need to be about 20 times more massive to end its life as a black hole. … In some 6 billion years it will end up as a white dwarf — a small dense remnant of a star that glows from leftover heat.

How do you know if a star is main sequence?

Main sequence is when a star is burning hydrogen in its core. The luminosity and temperature of a main-sequence star are set by its mass. More massive means brighter and hotter. A ten solar mass star has about ten times the sun’s supply of nuclear energy.

What do we need to measure in order to determine a star’s luminosity?

What do we need to measure in order to determine a star’s luminosity? Apparent brightness and distance.

What effect sets the largest size a star can have?


The main determining factor in all of this is the mass of the star. The mass of the star eventually determines the potential size of a star.

How the spectra can be used to determine the speed of stars?

When we measure the spectrum of a star we determine the wavelength of each of its lines. … The greater the shift the faster the star is moving. Such motion along the line of sight between the star and the observer is called radial velocity and is usually measured in kilometers per second.

What are the 3 features of a star you can determine from a complete analysis of an absorption spectra of a star?

My list of three was: Chemical composition. Temperature. Relative motion.

How do scientists use spectra to identify the elements in the sun’s outer layer?

How do scientists use spectra to identify the elements in the Sun’s outer layer? Different chemical elements emit (or absorb) certain specific frequencies of light. 12. What information can plotting a star on the graph of an H-R Diagram tell us about a star?

How does size influence the appearance of a star?

As the size of a star increases luminosity increases. If you think about it a largerstar has more surface area. That increased surface area allows more light and energy to be given off. Temperature also affects a star’s luminosity.

What are the main components of stars?

Stars are made of very hot gas. This gas is mostly hydrogen and helium which are the two lightest elements. Stars shine by burning hydrogen into helium in their cores and later in their lives create heavier elements.

What are the 3 main types of stars?

So let’s take a look at all the different types of stars that have been discovered so far.
  • Protostar. …
  • T Tauri Stars. …
  • Main Sequence Stars. …
  • Red Giant Stars. …
  • White Dwarf Stars. …
  • Red Dwarf Stars. …
  • Neutron Stars. …
  • Supergiant Stars.

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What is the biggest thing in the universe?

Hercules-Corona Borealis Great Wall
The largest known structure in the Universe is called the ‘Hercules-Corona Borealis Great Wall’ discovered in November 2013. This object is a galactic filament a vast group of galaxies bound together by gravity about 10 billion light-years away.

What is the closest star to Earth?

The closest star to Earth is a triple-star system called Alpha Centauri. The two main stars are Alpha Centauri A and Alpha Centauri B which form a binary pair. They are about 4.35 light-years from Earth according to NASA.

How many galaxies are there?

The Hubble Deep Field an extremely long exposure of a relatively empty part of the sky provided evidence that there are about 125 billion (1.25×1011) galaxies in the observable universe.

Can a star turn into a planet?

Yes a star can turn into a planet but this transformation only happens for a very particular type of star known as a brown dwarf. Some scientists do not consider brown dwarfs to be true stars because they do not have enough mass to ignite the nuclear fusion of ordinary hydrogen.

What is a shooting star?

noun. rocky debris from space that enters Earth’s atmosphere. Also called a meteor.

What is star death?

When a star like the Sun has burned all of its hydrogen fuel it expands to become a red giant. … This may be millions of kilometres across – big enough to swallow the planets Mercury and Venus. After puffing off its outer layers the star collapses to form a very dense white dwarf.

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