Some examples of star types that are not part of the Main Sequence are:
Red Giants, Blue Giants, Brown Dwarfs, and White Dwarfs.
When stars are plotted on a chart that compares their Temperature (color) to their Brightness (Luminosity), most of them fall into a diagonal line across the chart.
That chart is known as a Hertzsprung-Russell diagram and the diagonal line on it is called the Main Sequence of stars.
Stars on the Main Sequence fit this pattern because they are in balance between collapse and expansion. Their gravity that is trying to collapse them is in balance with their nuclear fusion that is trying to expand them.
A difference to notice between Main Sequence stars and other stars is:
Main Sequence stars are dimmer if they are cooler and brighter if they are hotter.
Giant stars are brighter whether they are hot or cool.
Dwarf stars are dimmer whether they are hot or cool.
On the HR diagram, any star that does not have Yerkes spectral classification of "V" is not on the main sequence.
Viewing the HR diagram you will see a band called "main sequence" ranging from -5 to +10 luminosity.
Basically, the main sequence represents a point of equilibrium for a star that gets its energy from nuclear fusion, specifically, by converting hydrogen-1 to helium-4. If a star is not in the main sequence, this can be either temporarily, when it is not in a state of equilibrium, or, once it has run out of most of its hydrogen, when it fuses helium into heavier elements.
Here's a list of stars:
red giants white dwarf
protostars black dwarf
The red super giant Betelgeuse (left shoulder of Orion) or Rigel (the right knee, also in Orion).
A main sequence star is NOT a TYPE of star but a period in a stars evolution. Therefore all stars from the hottest to the coolest are on the main sequence at some stage - with the exception of brown dwarfs which do not reach the main sequence.
A "main sequence star" is not really a type of star but a period in a stars life. When a star is in "main sequence" it is converting hydrogen into helium. It is then usually called a dwarf star. This is the longest period in a stars lifetime. Our Sun is a yellow dwarf in "main sequence".
In some binary systems, the less-massive star has become a giant, while the more-massive star is still on the main sequence. If higher-mass stars evolve faster than lower-mass stars, how do the lower-mass stars in such binaries manage to leave the main sequence first? This is called the Algol paradox, after the binary system Algol.
This is not necessarily true. most of the time stars with a larger diameter have more mass but some stars with a smaller diameter are more dense and have a greater mass. Find a main sequence star chart and you can compare the data.
The most massive star (The star with the most mass) is a star in a super star cluster called R136 or RMC 136 in the Large Magellanic Cloud (LMC). [See related link for more information] The star, for all its fame has a rather unremarkable name of R136a1. It has the mass of about 265 -> 300 solar masses (256 x the mass of the Sun - See related question). See related link [BBC] for a pictorial size comparison. It is a blue supergiant with a spectral type of O3. Because of its mass and intense luminosity (10 million times that of our own Sun) it, astronomically, will have a very short lifetime in the millions of years rather than billions. At the end of its life, R136a1 will explode as a supernova and because of its relatively close distance to Earth (165,000 light years/ALU [See related question] it might be visible during the day. This question is about the most massive star (mass), not the largest (Radius) [See related question]
Stars are classified by their type and temperature. Amongst some of the types of stars in our galaxy are white dwarfs, blue giants, and red supergiants. Our own Sun is a yellow dwarf, and like most stars is a main-sequence star.
A main sequence star is NOT a TYPE of star but a period in a stars evolution. Therefore all stars from the hottest to the coolest are on the main sequence at some stage - with the exception of brown dwarfs which do not reach the main sequence.
A "main sequence star" is not really a type of star but a period in a stars life. When a star is in "main sequence" it is converting hydrogen into helium. It is then usually called a dwarf star. This is the longest period in a stars lifetime. Our Sun is a yellow dwarf in "main sequence".
By definition and experiance sol as a main sequence star and as a class planet earth and the earths moon with some comets as life as we know it. But a star like a gas giant its gravity may be to strong. Sol as a main sequence stars has the right gravity for earth and counter clock wise rotation and gravity
the main sequence of LIFE which some people can not be sure of
the main sequence of LIFE which some people can not be sure of
All of them - but mostly hydrogen & helium.
some stars are hotter than others because they have more hydrogen to use and create heat with. BTW- answered by a 6th grader.
In some binary systems, the less-massive star has become a giant, while the more-massive star is still on the main sequence. If higher-mass stars evolve faster than lower-mass stars, how do the lower-mass stars in such binaries manage to leave the main sequence first? This is called the Algol paradox, after the binary system Algol.
Information on millions of stars shows that there is a relationship between temperature and brightness. Surface temperature is measured in degrees C and brightness is measured in absolute magnitude (the star's brightness at a standard distance). If all the stars are plotted on a graph of temperature against absolute magnitude, called a Hertzsprung-Russell diagram, very many of them lie close to a straight line that is called the Main Sequence. There are some stars that do not lie on the Main Sequence, notably the red giants that are very bright despite having a relatively low temperature. The Sun is right in the middle of the Main Sequence showing it is an average star in the middle of its life and very stable.
This is not necessarily true. most of the time stars with a larger diameter have more mass but some stars with a smaller diameter are more dense and have a greater mass. Find a main sequence star chart and you can compare the data.
Information on millions of stars shows that there is a relationship between temperature and brightness. Surface temperature is measured in degrees C and brightness is measured in absolute magnitude (the star's brightness at a standard distance). If all the stars are plotted on a graph of temperature against absolute magnitude, called a Hertzsprung-Russell diagram, very many of them lie close to a straight line that is called the Main Sequence. There are some stars that do not lie on the Main Sequence, notably the red giants that are very bright despite having a relatively low temperature. The Sun is right in the middle of the Main Sequence showing it is an average star in the middle of its life and very stable.