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What else can I help you with?
What are the large cool stars that are not in the main sequence?
Red giants. They are medium and large stars that have used up all of their hydrogen and gave begun burning the helium. They begin to expand while they are in their "dying" phase. They will ultimately become a white dwarf if they were a medium sized star during their main sequence, or they will become a black hole or a neutron star if they were a large star during their main sequence.
Do dwarf stars emit light?
Brown Dwarfs (maybe not true stars)Red Dwarfs (on the main sequence)Orange Dwarf (on the main sequence)Yellow Dwarfs (stars smaller than our sun but on the main sequence)White Dwarfs (old stars that have run out of hydrogen and are now off the main sequence)Neutron Stars (old large stars who's cores have collapsed during a supernova)---------------------------------------------------------------------------------Red dwarf - Like Proxima Centauri.White dwarf - A degenerate star. The remains of a Sun like star.Yellow dwarf - A G type main sequence star, like our own SunBlue dwarf - A hypothetical star formed from a red dwarf.Brown dwarf - A star that did not have enough mass to initiate nuclear fusion.Black dwarf - A hypothetical star formed when a white dwarf has cooled to absolute zero.Orange dwarf. A K type main sequence star, like Alpha Centauri B
Why there are so many Main Sequence stars compared to the much smaller percentage of stars that are Red Giants and White Dwarfs?
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).
Why is an old main -sequence star have a higher percentage helium then a young main - sequence star?
Most stars - and specifically main-sequence stars - get their energy from converting hydrogen-1 to helium-4, so you would expect that the percentage of hydrogen will decrease over time, while the percentage of helium would increase over time. Please note that the rate of fusion depends a LOT on the mass of the star; so you might have a very massive star that's only a few million years old and has already burned up most of its fuel (hydrogen), and another star, a red dwarf, that's 10 billion years old and has only used a small percentage of its fuel.
What are the letters that follow the spectral sequence OBAFGKM?
The next sequence of letters following OBAFGKM in the spectral classification system are L, T, Y. These letters are used to classify cooler and less luminous stars outside the main sequence, such as brown dwarfs.
Most of the stars in the main sequence are to the lower right of the sun what can you conclude about the brightness of these stars and their temperatures?
Main Sequence stars can be any spectral class of star. Something that might help you in the future is when you look up a star and see its spectral class, its always followed by a roman numeral to define where the star is in its life and size and they go as follows. I-a= A hyper Giant Star I-b= A very bright Super Giant star I= A normal Super Giant star II= Bright Giant star III= Giant star IV= Sub Giant star V= Dwarf Star(which this is where most main sequence stars fall into, While a main sequence star could also be one of the classifications listed above. it just depends on its spectral class. for example the star Deneb is in its main sequence still and its classified as a hyper giant) VI= Sub Dwarfs (this is a very rare classification and are mostly used for brown dwarfs. I hope this helps mate.
What are some characteristics used to classify stars?
In Astronomy stars can be classified by theircolor (temperature)composition (as found by their spectrum)agelocation in a galaxymassproximity to other stars
How could the sun be burning if there is no air in space?
The sun and other stars don't burn oxygen, they burn other gases. that's what a star is, a big ball of gas. It burns these gases, which is also what is used to classified the stars into Main Sequence stars, Giants, Dwarfs, etc. The sun and other stars don't burn oxygen, they burn other gases. that's what a star is, a big ball of gas. It burns these gases, which is also what is used to classified the stars into Main Sequence stars, Giants, Dwarfs, etc. from the answer on the top.. the sun does not burn oxygen... is eats up the oxygen and make carbon dioxide.
What is the name of the chart of the diagram we use to classify stars?
The chart used to classify stars is called the Hertzsprung-Russell diagram (H-R diagram). This diagram plots stars based on their luminosity and temperature, helping to illustrate their evolutionary stages. It reveals relationships between different types of stars, including main-sequence stars, giants, and white dwarfs.
Where do main-sequence stars end up as they evolve?
A star just massive enough to burn helium will eject its outer layers as a planetary nebula and its core will form a white dwarf. --- If it is using helium as fuel then it stopped being a main sequence star long long ago and if it has used up its helium and is now fusing carbon it has gone well outside the main sequence and is in the process of dying. All stars go through the process of being main sequence, so its a popular misnomer that a star has to be like the sun to be main sequence. The term refers to the time a star is converting hydrogen to helium, and any cycle after that changes what the star is called. If you want to take the Sun as an example when it ends fusing hydrogen into helium, it will expand to a be a red giant about 250 times the size it is now and it will also lose about 30% of its mass. Stars also continuously expel matter and winds into space, at the end of a stars life they either explode like a supernova (typical in stars much larger than the Sun), or each time a fuel source is used up, the star will expand until core temperatures and pressures rise enough to start a new fusion reaction. At this point, some of the outer layer is expelled and the star contracts to start its next life cycle. No star fuses elements heavier than iron.
What element is used as the primary fuel source for stars?
hydrogen
Point in stellar evolution when a star has used up all its fuel?
When a star has used up all the hydrogen in its core, it has reached the end of the main sequence. Subsequent developments depend on the mass and composition of the star. Sun-type stars may expand and continue to fuse ever heavier elements in and about their core, until fusion no longer yields sufficient energy to prevent collapse.
