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Why there are so many Main Sequence stars compared to the much smaller percentage of stars that are Red Giants and White Dwarfs?
Wiki User
∙ 13y ago
For three reasons.
1) Hydrogen is the most abundant element in the universe.
2) ALL stars spend a part of their life on the main sequence because wile on the main sequence the fuel they are fusing is Hydrogen.
3) For a given mass of hydrogen, the energy output created by fusing hydrogen is the greatest of all fusible elements (i.e the elements up to Iron). Thus as stars start fusing other elements (and thereby moving off the main sequence) they burn through their fuel very quickly and either explode a supernovae or decay into white dwarfs (depending on their initial mass).
One may also note that the most common type of stars are red dwarf stars on the main sequence and this is because the rate of hydrogen fusion depends on the stars mass a really big star will only last a few million years while a small red dwarf will shine for trillions of years. Thus the big stars die quickly while the small ones last a long time so one ends up with more of them (more smaller stars may also be produced in the first place too).
Wiki User
∙ 14y ago
Wiki User
∙ 14y agoAs gravity pulls a star together in the main sequence the increased density and heat causes faster nuclear fusion of hydrogen into helium. This force tries to expand the star. But the more the star expands the slower and less powerful the fusion.
These two forces come into equilibrium until the hydrogen runs low. This takes a relatively long time. In other stages of stars life cycles they are not in equilibrium. Either the force of gravity or the expanding forces are stronger. In these cases the star contracts or expands.
There are other stable states for stars besides the main sequence. These sometimes do not last as long as the main sequence because the force keeping the star from collapsing further does not last as long. Some star states are actually more stable than the main sequance stage though. White dwarf stars will stay white dwarfs for longer than main sequence stars will stay in the main sequence.
Wiki User
∙ 11y agoOnly stars that have enough mass, have a core temperature > 10 million degrees kelvin, which is when nuclear fusion occurs, the star is then said to be on the main sequence.
It will stay on the main sequence until all of the hydrogen in the core has been used up.
See related question
Wiki User
∙ 13y agoThere aren't, really; it's just that the big main sequence stars are BIG and BRIGHT, and can be seen from thousands of light-years away, while a red dwarf like Proxima Centauri isn't visible from Earth, even though it is the closest star to our Sun.
The facts are that there are far more small dim red dwarf and even dimmer brown dwarf stars than there are big stars - but we can't see them without powerful telescopes.
The few big, bright stars get the attention, partly BECAUSE they are unusual.
For red giant and white dwarf stars, these are old stars near the end of their lives; they don't spend much time as "red giants" or "white dwarves".
Wiki User
∙ 14y agoBecause luminosity is related to temperature
Wiki User
∙ 11y agoThe lesser anthropic principle.
Expanding on that a bit: if the Sun were NOT a main sequence star, we wouldn't be around to be asking the question.
Wiki User
∙ 10y agoThe main sequence is the longest period of a star's life.
Wiki User
∙ 14y agoBecause they are hotter.
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Why are there no white dwarfs among the 100 brightest stars?
White dwarfs have very small surface areas compared to main sequence stars and therefore cannot emit as much light.
Which types of stars is considered part of the main sequence?
Red Dwarfs.
Which main sequence stars on the hertz sprung Russell diagram are the least massive?
Red Dwarfs
Where on the Main Sequence are stars cool and dim?
None of them are cool and dim; the one in the white/black dwarfs are cool and dim.
Can a netherland dwarf rabbit get along with a regular sized rabbit?
If you look at the difference in the look of their ears, the netherland dwarfs have really short ears, kind of a squirrel face. Normal dwarfs can have long ears and are just a small size compared to a normal rabbit.
Why are there no white dwarfs among the 100 brightest stars?
White dwarfs have very small surface areas compared to main sequence stars and therefore cannot emit as much light.
What kinds of stars are smaller than the sun?
There are other "main sequence" stars smaller than the Sun, but the classes of much smaller stars are:white dwarf stars (once Sun-like but no longer support fusion)red dwarfs and orange dwarfs (small dim stars that have very long lives)"brown dwarfs" (oversized Jovian gas giants with little or no fusion)neutron stars (smaller than the Earth but immensely dense, remnants of massive stars that went supernova)
Do dwarfs have smaller genitals?
No who told you this ?
Are main sequence stars older than white dwarfs?
no
What is the percentage of stars in the universe are red dwarfs?
70-75% of stars are red dwarfs.
Why do you like a dwarfs?
cause they stay smaller.
How many babies can a dWARFS rabbit have?
dwarfs tend to have a smaller litter (say 4 on avg.)
What percent of the stars are considered part of the main sequence?
Red Dwarfs
Which types of stars is considered part of the main sequence?
Red Dwarfs.
Describe two types of stars that are not on the main sequence-?
Red Giants - although they can be branch main sequence for a while.Brown DwarfsBlack dwarfsWhite dwarfsT-Tauri starsProtostarsNeutron starsPre-main sequence stars (PMS stars)
Giants supergiants white dwarfs have left the main sequence?
Yes, all those types of stars have left the main sequence.
What is the name for older stars?
"Main sequence" stars are no longer new, and are just cookin' along for millions of years. "Main sequence" stars, depending on their weight and whether they orbit another nearby star can get old and become red dwarfs, white dwarfs, black dwarfs, neutron stars, novas, or super-novas.
