What kind of star is heavier than the sun

A few very old stars not in clusters have been discovered with even lower abundances of heavy elements. The differences in chemical composition are a direct consequence of the formation of a cluster of stars. The very first generation of stars initially contained only hydrogen and helium.

We have seen that these stars, in order to generate energy, created heavier elements in their interiors. In the last stages of their lives, they ejected matter, now enriched in heavy elements, into the reservoirs of raw material between the stars. Such matter was then incorporated into a new generation of stars.

This means that the relative abundance of the heavy elements must be less and less as we look further into the past. We saw that the globular clusters are much older than the open clusters. Since globular-cluster stars formed much earlier that is, they are an earlier generation of stars than those in open clusters, they have only a relatively small abundance of elements heavier than hydrogen and helium.

This means that the first generation of stars that formed in our Galaxy would not have been accompanied by a planet like Earth, full of silicon, iron, and many other heavy elements. Earth and the astronomy students who live on it was possible only after generations of stars had a chance to make and recycle their heavier elements.

Now the search is on for true first -generation stars, made only of hydrogen and helium. Theories predict that such stars should be very massive, live fast, and die quickly. They should have lived and died long ago. The place to look for them is in very distant galaxies that formed when the universe was only a few hundred million years old, but whose light is only arriving at Earth now.

Compared with the main-sequence lifetimes of stars, the events that characterize the last stages of stellar evolution pass very quickly especially for massive stars. But the energy yield of these reactions is much less than that of the fusion of hydrogen to helium. And to trigger these reactions, the central temperature must be higher than that required for the fusion of hydrogen to helium, leading to even more rapid consumption of fuel.

Clearly this is a losing game, and very quickly the star reaches its end. As it does so, however, some remarkable things can happen, as we will see in The Death of Stars. In stars with masses higher than about 8 solar masses, nuclear reactions involving carbon, oxygen, and still heavier elements can build up nuclei as heavy as iron. The creation of new chemical elements is called nucleosynthesis. The late stages of evolution occur very quickly.

Ultimately, all stars must use up all of their available energy supplies. In the process of dying, most stars eject some matter, enriched in heavy elements, into interstellar space where it can be used to form new stars. Each succeeding generation of stars therefore contains a larger proportion of elements heavier than hydrogen and helium. For instance, we often use the Henry Draper catalog designation such as HD for star number in that catalog. There are lots of catalogs with all kinds of names.

Some stars are listed in more than one catalog, so they have more than one name. In ancient times, people looked up at the stars and picked out patterns that they saw. They often associated these patterns with pictures from the stories that they told. Most of the constellations that we use today come from the ancient Romans, and they depict many of the people and animals from their myths. The word constellation means "with" con "stars" stella , and comes from the Latin word constellatio.

As you probably know, a "shooting star" is actually a meteor, a tiny bit of rock in space. Meteors are moving very fast, which is why they burn up when they hit our earth's atmosphere and make a nice, bright "shooting star.

But some go as fast as , miles an hour! The instrument I have used the most to study baby stars is an astronomy satellite called the International Ultraviolet Explorer spacecraft. I studied the ultraviolet light from my baby stars with it for many years to try to understand how they behave. Ultraviolet light is absorbed by the earth's atmosphere, so the only way to measure it is by using a satellite. Spectroscopes are a very important tool used by astronomers.

As you probably realize, astronomers must rely on the light that we can measure from the various astronomical objects. We can't put a star into a laboratory! The spectrum of a star can tell us the temperature, size, and composition of the star. It can also tell us how fast it is moving. If there are two stars in orbit around each other, a series of measurements can be used to get their masses weights. We can tell if the star has strong magnetic fields. Sometimes we can get the age of the star.

Most of what we know about stars has been learned from their spectra! Stars come in colors from red, orange, yellow, white, bluish-white, and blue. The color depends on how hot the star is. Yes, sometimes it happens. For instance, two stars may start out as a pair in orbit around each other. Then the heavier star which ages faster may become a red giant star, expanding big enough that the outer layers are close to the second star.

Then some of the gas in the outer parts of the red giant may get pulled by the second star's gravity and get pulled onto the second star. If the red giant expands large enough and the second star is close enough, it could even end up inside the red giant star!

A brown dwarf is a very small star, so small that it can't produce energy through nuclear reactions the way the normal stars do. It glows mostly in infrared light I guess that's where they came up with the "brown" part, actually it would look deep red to us and is not as bright as other stars.

During its long lifetime, it slowly contracts, gives off infrared light, and gets dimmer and dimmer. It takes a long time — several billion years — for a white dwarf star to completely cool and become a "black dwarf. If a person mapping the earth is a cartographer, is there a specific name for a person who draws constellations? A cartographer makes maps, and I think it doesn't matter what the map is of.

So they can make maps of the earth, the moon, Mars, and the constellations too. It is the closest bright star to the direction of the earth's North Pole, although it isn't exactly at the North Pole. You may know that the direction of the earth's North Pole changes with time, as the earth very slowly wobbles in a circle every 26, years.

Thousands of years ago, other stars were near the North Pole instead of Polaris! Polaris is a yellow supergiant star. It is a little hotter than our sun, and much bigger and brighter. It is also a star near the end of its life. In fact it has a little variable in its brightness, because it is a little unstable so it pulses, but it won't explode. It varies in brightness by about ten percent every four days. It is about light-years away. For many hundreds of years, Polaris has been well known as a guide pointing to the North Pole.

The North Star has often been used as a symbol for constancy and faithfulness. In ancient times, it was thought to lie at the point around which the earth spins — as if there were actually a spindle through the earth that stuck into the sky. The Chinese thought that the star was at the top of the heavenly Mountain of the World at the North Pole. In India, the great temples depict the Cosmic Mountain. But here's a funny thing. Create a List. List Name Save. Rename this List. Rename this list. List Name Delete from selected List.

Save to. Save to:. Save Create a List. White dwarfs no longer burn fusion at their center, but they still radiate heat. Eventually, white dwarfs should cool into black dwarfs , but black dwarfs are only theoretical; the universe is not old enough for the first white dwarfs to sufficiently cool and make the transition.

Larger stars find their outer layers collapsing inward until temperatures are hot enough to fuse helium into carbon. Then the pressure of fusion provides an outward thrust that expands the star several times larger than its original size, forming a red giant. The new star is far dimmer than it was as a main sequence star. Eventually, the sun will form a red giant, but don't worry — it won't happen for a while yet.

If the original star had up to 10 times the mass of the sun, it burns through its material within million years and collapses into a super-dense white dwarf. More massive stars explode in a violent supernova death , spewing the heavier elements formed in their core across the galaxy. The remaining core can form a neutron star , a compact object that can come in a variety of forms. The long lifetime of red dwarfs means that even those formed shortly after the Big Bang still exist today.

Eventually, however, these low-mass bodies will burn through their hydrogen. They will grow dimmer and cooler, and eventually the lights will go out. Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community space. Nola Taylor Tillman is a contributing writer for Space. She loves all things space and astronomy-related, and enjoys the opportunity to learn more.