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Roach DN
Is our Earth's sun is a dwarf star?
If you're curious as to why main sequence stars are sometimes called dwarf stars, this video that compares the sizes of a number of stars might be instructive:Roach DN said:Is our Earth's sun is a dwarf star?
phyzguy said:In some references you will see anything that isn't a giant or supergiant star referred to as a dwarf star, but it would be more accurate to refer to our sun as a main sequence star.
rootone said:Sun is a main sequence star, a bit bigger than average, but nothing special.
The Sun is mostly interesting because it's a solo star, and most star systems are binary, or moreso.
This seems to be contentious. For exampleVanadium 50 said:the (large) majority of star systems are singles.
Another way to look at it is that main sequence stars behave like balls of ideal gas with fusion at their cores.CygnusX-1 said:The Sun is a main-sequence star, which means it is using nuclear reactions to convert hydrogen into helium at its core. This is the definition of a main-sequence star.
Ophiolite said:This seems to be contentious. For example
Chandra X-Ray Observatory
"More than 80% of all stars are members of multiple star systems containing two or more stars"
Not in size. Puny compared to O,B,A and F stars.CygnusX-1 said:The Sun is actually FAR above average.
Drakkith said:Indeed. I believe that all stars larger than "dwarf" stars have passed beyond the main sequence phase, correct?
That's part of the reason. But they're also less common just because it's less common that there is a collapsing gas cloud massive enough to form the more massive stars.ensign_nemo said:The largest stars burn out far more quickly than their smaller brethren.
https://en.wikipedia.org/wiki/Stellar_evolution
This means that there are relatively few type O, B, or A stars compared to the smaller and dimmer types.
The lifetime of the sun is estimated at 10 billion years (it's middle-aged right now at about 4.5 billion).
The current lifetime of the universe is about 13.7 billion years, so relatively few type G stars have died of old age compared to O, B, A, or F stars.
Any star much smaller than the Sun (K, M, etc.) hasn't had enough time to burn out and die, even if it was born in the first billion years after the Big Bang.
ensign_nemo said:...This means that there are relatively few type O, B, or A stars compared to the smaller and dimmer types...
Any star much smaller than the Sun (K, M, etc.) hasn't had enough time to burn out and die, even if it was born in the first billion years after the Big Bang.
kimbyd said:...they are so very much brighter than their less massive peers that they make up most of the light. This is why many very distant galaxies appear blue.
A dwarf star is a type of star that is smaller, cooler, and less luminous than the average stars in the universe. They are also known as "red dwarfs" due to their reddish color.
The Sun is actually considered a medium-sized star, so it is larger and more luminous than most dwarf stars. However, compared to other stars in the universe, the Sun is relatively small.
Dwarf stars have a lower mass and temperature compared to other stars, and they also have a longer lifespan. They are also much more common than larger stars, making up about 75% of the stars in the Milky Way galaxy.
The Sun is currently in the middle of its main sequence stage, where it fuses hydrogen into helium. It is estimated that the Sun will remain in this stage for another 5 billion years before it expands into a red giant and eventually becomes a white dwarf.
Yes, there are many dwarf stars that are visible in the night sky. The most well-known dwarf star is Proxima Centauri, which is the closest star to our Sun. It is part of a triple star system, along with the larger stars Alpha Centauri A and B.