What is the most important determining factor for a star’s evolutionary track?
Mass is the single most important property of a star. It determines the evolution of a star as well as its lifetime (e.g. lower mass stars live longer). In all the above discussed cases this means the initial mass, which decreases by less than 1% from birth to onset of a planetary nebula or a supernova.
What is a possible evolutionary path for a star?
The order of evolutionary stages of a star like the Sun wound be main sequence, red giant, planetary nebula, and finally. white dwarf. At which stage in a Sun-like star's life it its core least dense. main sequence. A star is on the horizontal branch of the HR diagram.
What inevitably forces a star like the Sun to evolve away from being a main sequence?
What inevitably forces a star like the Sun to evolve away from being a main sequence star? Helium builds up in the core, while the hydrogen burning shell expands. Just as a low-mass main sequence star runs out of fuel in its core, it actually becomes brighter.
What spectral type of star that is still around formed longest ago quizlet?
still evolving toward their ZAMS positions. What spectral type of star that is still around formed longest ago? massive blue stars at the top left on the H-R diagram.
Which of the following is most important in determining a star’s life?
Mass: the most important factor in determining the life of a star.
What is the massive star?
A massive star is a star that is larger than eight solar masses during its regular main sequence lifetime. Massive stars are born, just like average stars, out of clouds of dust called nebulae.
What are the evolutionary stages of a star more than eight times the mass of the sun?
Stars having initial mass between 8 to 25 times the mass of Sun become neutron stars through a supernova. Stars having initial mass larger than 25 times the mass of the Sun undergo a supernova, but turn into black holes.
Which correctly describes a different evolutionary stage of a star like the Sun?
Step 1. Protostar, main-sequence star, red giant and white dwarf correctly describe evolution of sun-like star from young to old.
Which is a possible sequence in the life cycle of a massive star?
The beginning steps in the life cycle of a massive star include the stellar nebula, protostars, and then the main sequence stage. Then the massive stars become supergiant and later undergo supernova explosions.
What spectral type of star has existed for the longest?
The stars with the longest lifetimes are red dwarfs some may be nearly as old as the universe itself.
What is the correct order of evolutionary stages for a solar mass star?
The correct order of evolutionary stages for a solar mass star is: Main sequence, horizontal branch, asymptotic branch, white dwarf. The energy that fuels the Sun is generated: Only in its core.
What is the largest factor that determines the lifespan of a star?
A star's life cycle is determined by its mass. The larger its mass, the shorter its life cycle.
How do the most massive stars form?
During the expansion, a dense layer of gas and dust is collected around the HII region, after which gravitational instabilities in the layer cause it to fragment into dense clumps, which then go on to collapse into new stars. The fragments are massive and thus form massive objects (stars or clusters).
Which of these stars is the most massive?
The star R136a1 currently holds the record as the most massive star known to exist in the universe. It's more than 265 times the mass of our Sun, more than double most stars on this list.
What are the stages in the life cycle of a massive star?
The beginning steps in the life cycle of a massive star include the stellar nebula, protostars, and then the main sequence stage. Then the massive stars become supergiant and later undergo supernova explosions.
What happens during the massive star stage?
The stars shine steadily until the hydrogen has fused to form helium ( it takes billions of years in a small star, but only millions in a massive star). Stage 2 – The massive star then becomes a Red Supergiant and starts of with a helium core surrounded by a shell of cooling, expanding gas.
What is the life cycle of massive stars?
Any star which is larger than eight solar masses during its regular main sequence lifetime is considered a massive star. They typically have a quick main sequence phase, a short red supergiant phase, and a spectacular death via a supernova explosion.
How are massive stars formed?
Stars form within dense clouds of dust and gas located in the interstellar medium of a galaxy. Gravity causes these clouds to collapse in on themselves, with small disturbances within a cloud causing denser clumps of matter to form.
Which main sequence stars are the least massive?
stars on the main sequence are powered by hydrogen fusion, which takes place in their cores, and the main sequence is just a sequence of mass (faint red stars are the least massive – starting at around one-tenth that of the Sun – and bright blue ones the most – about 20 times).
What is the life cycle of a high mass star?
Like low-mass stars, high-mass stars are born in nebulae and evolve and live in the Main Sequence. However, their life cycles start to differ after the red giant phase. A massive star will undergo a supernova explosion.
What is true about massive stars?
Massive Star Definition Massive stars are classified by having a solar mass that is eight times the size of the sun during its main sequence life cycle stage. Not only do stars go through a life cycle, but they are also compared to the sun at the center of our solar system.
What are the massive stars?
On the other hand, the most massive stars, known as hypergiants, may be 100 or more times more massive than the Sun, and have surface temperatures of more than 30,000 K. Hypergiants emit hundreds of thousands of times more energy than the Sun, but have lifetimes of only a few million years.
How do we know how massive stars are quizlet?
How do we know how massive stars are? We measure the orbital periods and velocities of stars in binary systems.
What is a massive star’s life cycle?
The beginning steps in the life cycle of a massive star include the stellar nebula, protostars, and then the main sequence stage. Then the massive stars become supergiant and later undergo supernova explosions.
What is a massive star made of?
Since they're all just made of hydrogen and helium, when it comes to stars, mass is everything. The amount of mass that a star has defines its luminosity, size and even how long it will live.
WHAT IS A massive stars life cycle?
Massive stars transform into supernovae, neutron stars and black holes while average stars like the sun, end life as a white dwarf surrounded by a disappearing planetary nebula. All stars, irrespective of their size, follow the same 7 stage cycle, they start as a gas cloud and end as a star remnant.
Which main sequence stars are the most massive?
Although R136a1 is the most massive known star, it is not the largest, since it only stretches about 30 times the radius of our sun. The largest known star is UY Scuti, a hypergiant with a radius somewhere around 1,700 times larger than the sun. Its mass, however, is only 30 times that of our nearest star.
Which main sequence stars are the least massive quizlet?
The least massive main-sequence stars are blue in color. The measure of a star's brightness is called its magnitude.
How is a massive star formed?
Stars form within dense clouds of dust and gas located in the interstellar medium of a galaxy. Gravity causes these clouds to collapse in on themselves, with small disturbances within a cloud causing denser clumps of matter to form.
What are the life stages of a high mass star quizlet?
Terms in this set (7)
- Protostar. A star system forms when a cloud of interstellar gas collapses under gravity.
- Blue Main-Sequence Star. …
- Red Supergiant. …
- Helium-burning Supergiant. …
- Multiple Shell-burning Supergiant. …
- Supernova. …
- Neutron Star or Black Hole.