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Document

... • The sun is not powered by cooling! • Nuclear fusion – We understand the physics of this very well indeed • We can create fusion reactions on Earth! • We can measure the sun’s energy output • We know the processes causing this • We know how much fuel the sun has ...
The fourth catalogue of Population I Wolf
The fourth catalogue of Population I Wolf

... classified C (carbon-type), N (nitrogen-type) or W+O (binaries); the more accurate spectral types previously assigned to 15 of them by Feast et al. (1960) being however given. The article included a study of the LMC W − R star surface distribution as well as a discussion of some fundamental physical ...
Pop III binary population synthesis
Pop III binary population synthesis

The Milky Way and Andromeda galaxies in a constrained
The Milky Way and Andromeda galaxies in a constrained

... whether our simulation predicts the formation of two large spiral galaxies similar to the MW and M 31 and what are the mechanisms determining/affecting their formation. We will show that only the simulated MW has a stable stellar disc that survives to z = 0; while in M 31 various mergers continuously ...
Distance
Distance

... account by – (a) Adding the corrections to absolute magnitudes ΔM and to colors ΔCI to ZAMS and isochrone of solar composition. These corrections can follow both from observations and theory. – (b) Direct fitting of observed CMD by ZAMS and isochrone of the appropriate Z – now most common used techn ...
High precision effective temperatures for 181 F-
High precision effective temperatures for 181 F-

Слайд 1 - Tuorla Observatory
Слайд 1 - Tuorla Observatory

... account by – (a) Adding the corrections to absolute magnitudes ΔM and to colors ΔCI to ZAMS and isochrone of solar composition. These corrections can follow both from observations and theory. – (b) Direct fitting of observed CMD by ZAMS and isochrone of the appropriate Z – now most common used techn ...
Lesson Plan - ScienceA2Z.com
Lesson Plan - ScienceA2Z.com

... that extend from the bulge into the disk. 3. The spiral arms are sites of ongoing star formation and are brighter than the surrounding disk because of the young, hot OB stars that inhabit them. (OB stars:Hot, massive, short lived stars) 4. Roughly half of all spirals are observed to have an addition ...
Calculate the Mass of the Milky Way Galaxy
Calculate the Mass of the Milky Way Galaxy

... University of Chicago. After World War I, Hubble started work at the Wilson Observatory, taking photographs of galaxies through the lens of a massive telescope. At about the same time, another American astronomer discovered that the Andromeda Nebula was moving away from the Earth. ...
Can Planets survive Stellar Evolution?
Can Planets survive Stellar Evolution?

Living Things - Fairfield-Suisun Unified School District
Living Things - Fairfield-Suisun Unified School District

... Four Views of the Crab Nebula Different type of telescopes collect electromagnetic radiation at different wavelengths. Astronomers are able to learn a great deal about the Crab Nebula by examining these different images. The images are shown at different scales. ...
copyright 2002 scientific american, inc.
copyright 2002 scientific american, inc.

... the explosive energy into the observed radiation, what generates the energy to begin with? That is a separate problem, and astronomers have yet to reach a consensus. One family of models, referred to as hypernovae or collapsars, involves stars born with masses greater than about 20 to 30 times that ...
FIRST DETECTION OF KRYPTON AND XENON IN A WHITE DWARF
FIRST DETECTION OF KRYPTON AND XENON IN A WHITE DWARF

DUSTY CIRCUMSTELLAR DISKS B. Zuckerman
DUSTY CIRCUMSTELLAR DISKS B. Zuckerman

... and planets, whereas the principal relevance of the gas is to the formation of giant gassy planets, such as Jupiter and Saturn. The first portion of this article is structured along the lines of stellar evolution, beginning about 5–10 million years after the formation of a star, putting it in the la ...
Dynamical Interactions Make Hot Jupiters in Open Star Clusters
Dynamical Interactions Make Hot Jupiters in Open Star Clusters

... of cluster stars near the planetary host stars, and that these events can only occur inside a star cluster. Solar systems born in the field with planets far from the dynamical instability, or ejected from clusters along with their host stars before stellar gravitational perturbations become signific ...
ppt file - Universitat de Barcelona
ppt file - Universitat de Barcelona

... IRAS 20343+4129 is a cluster environment with a variety of sources. IRS 1, an intermediate-mass Class I source, driving an east-west bipolar CO(2-1) outflow. IRS 3, seems to drive an expanding shell pushing out the dust condensations detected at both sides of this source. Our observations suggest th ...
Steps
Steps

Binarity in carbon-enhanced metal-poor stars
Binarity in carbon-enhanced metal-poor stars

More about the game plan:
More about the game plan:

... • Actual derived dark matter profiles often slightly different than this • What is CDM? Coming later in course. ...
Bonjour Eduardo,
Bonjour Eduardo,

... etc. One way to attempt to answer these questions is through asteroseismology.” Are there stars with rapid rotation and which pulsate? Yes, for instance delta Scuti stars and gamma Doradus stars can rotate with a v.sin.i > 200 km.s-1. An interesting example of a rapidly rotating star is Altair, rece ...
The Milky Way thin disk structure as revealed by stars and young
The Milky Way thin disk structure as revealed by stars and young

... small (Moitinho 2001), and star clusters can be detected to very distant regions (Carraro et al. 2010), because the young disk is significantly warped (Moitinho et al 2006). A major break-through is reported in Vázquez et al. (2008), where for the very first time, distances to a large sample of young ...
The Milky Way: Cartoon
The Milky Way: Cartoon

... Milky Way: Mass We don’t see the edge of the mass when we look at stars... ...or when we look at gas and dust, or anything else. A large fraction of the mass of the Galaxy must be “dark” ...
ppt - Serbian Virtual Observatory
ppt - Serbian Virtual Observatory

Full PDF
Full PDF

silicon and oxygen abundances in planet-host stars
silicon and oxygen abundances in planet-host stars

... on their results, stars with planets appear to be indistinguishable from other field stars and seem to simply lie on the highmetallicity end of otherwise “normal” stellar distributions. Given the metal-rich nature of planet-hosting stars, a pressing need when further exploring the planet formation i ...
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Stellar evolution



Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.
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