Chapter 09 - The Independent School
... of stars, astronomers must use their telescopes and spectrographs in ingenious ways to learn the secrets hidden in starlight. The result is a family portrait of the stars. Here you will find answers to five essential questions about stars: • How far away are the stars? • How much energy do stars mak ...
... of stars, astronomers must use their telescopes and spectrographs in ingenious ways to learn the secrets hidden in starlight. The result is a family portrait of the stars. Here you will find answers to five essential questions about stars: • How far away are the stars? • How much energy do stars mak ...
Siriusposter
... white dwarfs. At these energies, white dwarfs are far brighter than most normal stars, and with ROSAT’s help we have been able to identify over 20 of these degenerate objects in binaries with bright, normal companions, just like the Sirius system. At optical wavelengths the white dwarfs are unresolv ...
... white dwarfs. At these energies, white dwarfs are far brighter than most normal stars, and with ROSAT’s help we have been able to identify over 20 of these degenerate objects in binaries with bright, normal companions, just like the Sirius system. At optical wavelengths the white dwarfs are unresolv ...
• This chapter concentrates on five goals:
... At the bend of the handle of the Big Dipper lies a pair of stars, Mizar and Alcor. Through a telescope you can discover that Mizar has a fainter companion and so is a member of a visual binary system. Adaptive optics observations have discovered a faint close companion of Alcor, not pictured in thi ...
... At the bend of the handle of the Big Dipper lies a pair of stars, Mizar and Alcor. Through a telescope you can discover that Mizar has a fainter companion and so is a member of a visual binary system. Adaptive optics observations have discovered a faint close companion of Alcor, not pictured in thi ...
The Death of High Mass Stars
... are moving with speeds according to the temperature of the cloud. If the cloud is cold enough, the particles will begin to come together due to the attractive force of gravity. The first several stages of star formation take about 2 million years as the densest pockets collapse first leading to frag ...
... are moving with speeds according to the temperature of the cloud. If the cloud is cold enough, the particles will begin to come together due to the attractive force of gravity. The first several stages of star formation take about 2 million years as the densest pockets collapse first leading to frag ...
NASAexplores 9-12 Lesson: Classified Stars - Science
... you while gazing into the night sky. The absolute magnitude and luminosity are used for that. They give you the relative brightness based on all of the stars being the same distance away from the earth. On this diagram, you do not see all of the individual stars. Since there are so many stars, only ...
... you while gazing into the night sky. The absolute magnitude and luminosity are used for that. They give you the relative brightness based on all of the stars being the same distance away from the earth. On this diagram, you do not see all of the individual stars. Since there are so many stars, only ...
The Classification of Stellar Spectra
... massive core is physically smaller. The gravity experienced by overlying layers is hence stronger, requiring higher luminosities to maintain the balance between pressure and gravity. Thus the star expends energy at a very high rate and may well become a red supergiant. Stars in this phase of stellar ...
... massive core is physically smaller. The gravity experienced by overlying layers is hence stronger, requiring higher luminosities to maintain the balance between pressure and gravity. Thus the star expends energy at a very high rate and may well become a red supergiant. Stars in this phase of stellar ...
Star Life Cycle Web Activity
... ____ the final stage of most small to medium sized stars (like our sun) ____ an intermediate phase of medium sized stars when carbon is the product of nuclear fusion ____ a stage reached only if the protostar never begins the fusion process ____ a brilliant explosion leading into the formati ...
... ____ the final stage of most small to medium sized stars (like our sun) ____ an intermediate phase of medium sized stars when carbon is the product of nuclear fusion ____ a stage reached only if the protostar never begins the fusion process ____ a brilliant explosion leading into the formati ...
Supernovae - Michigan State University
... If a stellar core grows beyond its Chandrasekhar mass limit, it will collapse. Typically this will result in a Supernova explosion at least the outer part of a star is blown off into space ...
... If a stellar core grows beyond its Chandrasekhar mass limit, it will collapse. Typically this will result in a Supernova explosion at least the outer part of a star is blown off into space ...
Fifth - Department of Physics and Astronomy
... wind material up and creates a shells. • When the photosphere of the heating star passes the ~25,000-K mark the swept up shell is ionized and can be seen in forbidden ...
... wind material up and creates a shells. • When the photosphere of the heating star passes the ~25,000-K mark the swept up shell is ionized and can be seen in forbidden ...
Distance, Size, and Temperature of a Star
... planetary nebula they explode in what is called a super nova. Super nova explosions can be brighter than an entire galaxy, and can be seen from very far away. Because blue giant stars only live a short time, scientists use them to find places in outer space where new stars are forming. Remember when ...
... planetary nebula they explode in what is called a super nova. Super nova explosions can be brighter than an entire galaxy, and can be seen from very far away. Because blue giant stars only live a short time, scientists use them to find places in outer space where new stars are forming. Remember when ...
Exercises - Leiden Observatory
... the star remains in hydrostatic equilibrium throughout. Why can we make this assumption? v. Rapid changes that are sometimes observed in stars may indicate that dynamical processes are taking place. From the timescales of such changes - usually oscillations with a characteristic period - we may roug ...
... the star remains in hydrostatic equilibrium throughout. Why can we make this assumption? v. Rapid changes that are sometimes observed in stars may indicate that dynamical processes are taking place. From the timescales of such changes - usually oscillations with a characteristic period - we may roug ...
Stellar Evolution
... Evolution of Stars More Massive than the Sun Star of more than 8 solar masses can fuse elements far beyond carbon in its core Leads to a very different fate Path across the H-R diagram is essentially a straight line Stays at just about the same luminosity as it cools off Eventually the star dies in ...
... Evolution of Stars More Massive than the Sun Star of more than 8 solar masses can fuse elements far beyond carbon in its core Leads to a very different fate Path across the H-R diagram is essentially a straight line Stays at just about the same luminosity as it cools off Eventually the star dies in ...
Day_29
... If the conditions are right, the star will ionize the gas in the expanding outer layers. Will last for about 50,000 years before the gas expands too far and disperses. ...
... If the conditions are right, the star will ionize the gas in the expanding outer layers. Will last for about 50,000 years before the gas expands too far and disperses. ...
Notes - Michigan State University
... If a stellar core grows beyond its Chandrasekhar mass limit, it will collapse. Typically this will result in a Supernova explosion at least the outer part of a star is blown off into space ...
... If a stellar core grows beyond its Chandrasekhar mass limit, it will collapse. Typically this will result in a Supernova explosion at least the outer part of a star is blown off into space ...
12-1 MAIN-SEQUENCE STARS
... Red dwarfs less massive than about 0.4 solar mass are completely mixed. They cannot ignite a hydrogen-fusion shell, so they cannot become giant stars. Because they have little weight to support and can fuse nearly all of their hydrogen fuel, they will remain on the main sequence for many times the p ...
... Red dwarfs less massive than about 0.4 solar mass are completely mixed. They cannot ignite a hydrogen-fusion shell, so they cannot become giant stars. Because they have little weight to support and can fuse nearly all of their hydrogen fuel, they will remain on the main sequence for many times the p ...
Star
A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun. Other stars are visible from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations.For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space. Once the hydrogen in the core of a star is nearly exhausted, almost all naturally occurring elements heavier than helium are created by stellar nucleosynthesis during the star's lifetime and, for some stars, by supernova nucleosynthesis when it explodes. Near the end of its life, a star can also contain degenerate matter. Astronomers can determine the mass, age, metallicity (chemical composition), and many other properties of a star by observing its motion through space, luminosity, and spectrum respectively. The total mass of a star is the principal determinant of its evolution and eventual fate. Other characteristics of a star, including diameter and temperature, change over its life, while the star's environment affects its rotation and movement. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung–Russell diagram (H–R diagram), allows the age and evolutionary state of a star to be determined.A star's life begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Once the stellar core is sufficiently dense, hydrogen becomes steadily converted into helium through nuclear fusion, releasing energy in the process. The remainder of the star's interior carries energy away from the core through a combination of radiative and convective processes. The star's internal pressure prevents it from collapsing further under its own gravity. Once the hydrogen fuel at the core is exhausted, a star with at least 0.4 times the mass of the Sun expands to become a red giant, in some cases fusing heavier elements at the core or in shells around the core. The star then evolves into a degenerate form, recycling a portion of its matter into the interstellar environment, where it will contribute to the formation of a new generation of stars with a higher proportion of heavy elements. Meanwhile, the core becomes a stellar remnant: a white dwarf, a neutron star, or (if it is sufficiently massive) a black hole.Binary and multi-star systems consist of two or more stars that are gravitationally bound, and generally move around each other in stable orbits. When two such stars have a relatively close orbit, their gravitational interaction can have a significant impact on their evolution. Stars can form part of a much larger gravitationally bound structure, such as a star cluster or a galaxy.