When
stars run out of hydrogen, they begin to fuse helium in their cores
. This is when they leave the main sequence. High-mass stars become red supergiants, and then evolve to become blue supergiants. … When that happens, the outer layers of the star collapse in on the core.
What causes a star to leave the main sequence quizlet?
What causes a star to leave the main sequence?
The fuel begins to be used up
. … Luminosity then increases as the core thermostat is broken – increasing fusion rate, causing too much energy and the star expands (into a red giant) to increase its area and radiate more.
When stars leave the main sequence they become?
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 will happen if a low massive main sequence star runs out?
When a main sequence star begins to run out of hydrogen fuel, the star becomes a red giant or a red super giant. THE DEATH OF A LOW OR MEDIUM MASS STAR After a low or medium mass or star
has become a red giant the outer parts grow bigger and drift into space
, forming a cloud of gas called a planetary nebula.
What are the 7 main types of stars?
There are seven main types of stars. In order of decreasing temperature,
O, B, A, F, G, K, and M
. This is known as the Morgan–Keenan (MK) system.
Which stars spend the least time in main sequence?
The result is that massive stars use up their core hydrogen fuel rapidly and spend less time on the main sequence before evolving into
a red giant star
. In the above image, T refers to the temperature of the star, and P refers to the pressure.
What type of stars live the longest?
Red dwarf stars make up the largest population of stars in the galaxy, but they hide in the shadows, too dim to be seen with the naked eye from Earth. Their limited radiance helps to extend their lifetimes, which are far greater than that of the sun.
What causes a star that is originally on the main sequence to leave the main sequence?
When stars run out of hydrogen, they begin to fuse helium in their cores
. This is when they leave the main sequence. High-mass stars become red supergiants, and then evolve to become blue supergiants. It’s fusing helium into carbon and oxygen.
What is the evolution of some massive stars in the correct order?
nebula
, protostar, supernova, neutron star.
What happens to a star after hydrogen stops fusing in the core?
When the core hydrogen is used up and no more nuclear fusion occurs,
the star’s outer stellar layers expand and the core shrinks
. At this point, the star becomes a Subgiant Star . The star’s outer layers continue to expand and the star brightens. The star then becomes a Red Giant Star .
Which star spends the longest time as a main sequence star?
While the sun will spend about 10 billion years on the main sequence, a star 10 times as massive will stick around for only 20 million years. A
red dwarf
, which is half as massive as the sun, can last 80 to 100 billion years, which is far longer than the universe’s age of 13.8 billion years.
When the core of a star shrinks after hydrogen fusion stops?
When the core of a star shrinks after hydrogen fusion stops-
the core cools and the star expands
. Which of the following nuclear fuels does a one star use over the course of its entire evolution- hydrogen. warm starlike object that has too little mass to suppor fusion it its core.
What is the rarest star in the universe?
An
O-type star
is a hot, blue-white star of spectral type O in the Yerkes classification system employed by astronomers.
How long does a star live for?
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. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for
about 10 billion years
.
What color is the hottest star?
White stars are hotter than red and yellow.
Blue stars
are the hottest stars of all.
Why are main sequence lifetimes shorter for more massive stars?
1. More massive stars start with more mass but have shorter main-sequence lifetimes. … Their
high mass causes their cores to have HIGH DENSITY and HIGH TEMPERATURE
, making the rate of hydrogen fusion very rapid.
