Lab 21.1 Classifying Stars
... Using the diagram on page 382 of the text, label the five groups (four of them are circled). The third group from the top of the page is not in the text and is called Subgiants. 6. Answer the questions that follow below, directly onto this sheet. 7. Hand in on due date. Questions: 1. Compare the sta ...
... Using the diagram on page 382 of the text, label the five groups (four of them are circled). The third group from the top of the page is not in the text and is called Subgiants. 6. Answer the questions that follow below, directly onto this sheet. 7. Hand in on due date. Questions: 1. Compare the sta ...
Stars: from Adolescence to Old Age
... The shell layer outside the core becomes hot enough for hydrogen fusion to start This fusion in the layer just outside the core is called shell burning The helium core continues to contract, creating more heat in the shell around it, leading to more fusion This causes the star’s luminosity to increa ...
... The shell layer outside the core becomes hot enough for hydrogen fusion to start This fusion in the layer just outside the core is called shell burning The helium core continues to contract, creating more heat in the shell around it, leading to more fusion This causes the star’s luminosity to increa ...
Initial Evolution-The Main Sequence
... Two scenarios: stars with as mass less than 8 times the mass of the sun and stars with a mass greater than 8 times the mass of the sun. ...
... Two scenarios: stars with as mass less than 8 times the mass of the sun and stars with a mass greater than 8 times the mass of the sun. ...
Characteristics of Stars
... Classification • H-R diagram • Absolute magnitude vs. temperature • For most stars the brightness increases as surface temp increases • Main sequence stars are band in center ...
... Classification • H-R diagram • Absolute magnitude vs. temperature • For most stars the brightness increases as surface temp increases • Main sequence stars are band in center ...
lifedeath - University of Glasgow
... can do this for many billions of years, using the P-P chain of nuclear reactions ...
... can do this for many billions of years, using the P-P chain of nuclear reactions ...
Astronomy – Studying the Stars & Space
... star’s life • Can shine for billions of years before they cool completely ...
... star’s life • Can shine for billions of years before they cool completely ...
Astronomy Assignment #1
... temperature and density that controls the fusion rates and fusion rates determine luminosity, and lifetime. 2. Why do massive stars last for a short time as main sequence stars but low-mass stars last a long time in the main sequence stage? Massive stars last for a short time as main sequence stars ...
... temperature and density that controls the fusion rates and fusion rates determine luminosity, and lifetime. 2. Why do massive stars last for a short time as main sequence stars but low-mass stars last a long time in the main sequence stage? Massive stars last for a short time as main sequence stars ...
The Whole Darn Thing!
... Absorption and emission spectra are due to photon-atom interactions. The Doppler Effect tells us how fast an object is moving towards or away from you. Chapter 7 – The Sun The Sun, like all “healthy” stars, is in hydrostatic equilibrium. Hydrogen fusion produces helium in the Sun’s core;,the lost ma ...
... Absorption and emission spectra are due to photon-atom interactions. The Doppler Effect tells us how fast an object is moving towards or away from you. Chapter 7 – The Sun The Sun, like all “healthy” stars, is in hydrostatic equilibrium. Hydrogen fusion produces helium in the Sun’s core;,the lost ma ...
Stellar evolution, I
... Msun (giving hotter core temperatures), the CNO cycle is the primary energy generation mechanism. ...
... Msun (giving hotter core temperatures), the CNO cycle is the primary energy generation mechanism. ...
starevolution - Global Change Program
... masses of "Main Sequence" stars range from one-tenth of the Sun's mass at the lowest part, to some 50 or 100 solar masses at the upper end. Heavier stars burn up their fuel more quickly than the smaller stars. Happily for us, the Sun has been on the main sequence for around 4.5 billion years and wil ...
... masses of "Main Sequence" stars range from one-tenth of the Sun's mass at the lowest part, to some 50 or 100 solar masses at the upper end. Heavier stars burn up their fuel more quickly than the smaller stars. Happily for us, the Sun has been on the main sequence for around 4.5 billion years and wil ...
The Stars
... Plotting the Properties of Stars Two astronomers created a special kind of graph that compares star brightness with their ________________ ________________. When this was plotted it showed that these properties are related. For example, as the temperature of a star __________________, its colour bec ...
... Plotting the Properties of Stars Two astronomers created a special kind of graph that compares star brightness with their ________________ ________________. When this was plotted it showed that these properties are related. For example, as the temperature of a star __________________, its colour bec ...
Nuclear Nomenclature
... Neutron Stars and Black Holes • If matter is forced to even higher densities than in a white dwarf, 106 times that of water, it collapses but could stabilize to form a neutron star with aid of additional pressure from nucleon degeneracy and the strong nuclear force. ...
... Neutron Stars and Black Holes • If matter is forced to even higher densities than in a white dwarf, 106 times that of water, it collapses but could stabilize to form a neutron star with aid of additional pressure from nucleon degeneracy and the strong nuclear force. ...
Stars and Deep Time
... • What creates energy in a star? • What are the stages in a star’s lifecycle? • How is the fate of a small or medium star different from that of a massive star? • How does this story connect with the atoms that make up your body? ...
... • What creates energy in a star? • What are the stages in a star’s lifecycle? • How is the fate of a small or medium star different from that of a massive star? • How does this story connect with the atoms that make up your body? ...
Stellar Evolution
... We do not know that all stars, regardless of their size, eventually run out of fuel and collapse due to gravity Low Mass Stars – consume fuel at a slow rate, may remain on main-sequence for up to 100 billion years, end up collapsing into white dwarfs Medium Mass Stars – go into red-giant stage, foll ...
... We do not know that all stars, regardless of their size, eventually run out of fuel and collapse due to gravity Low Mass Stars – consume fuel at a slow rate, may remain on main-sequence for up to 100 billion years, end up collapsing into white dwarfs Medium Mass Stars – go into red-giant stage, foll ...
Lecture 33: The Lives of Stars Astronomy 141
... Main Sequence stars are powered by the fusion of Hydrogen into Helium in their cores The more massive a star is, the shorter its lifetime. Low-Mass stars are long-lived, spend some time as Red Giants, then leave behind a White Dwarf. Very high-mass stars have very short lives, spend a short time as ...
... Main Sequence stars are powered by the fusion of Hydrogen into Helium in their cores The more massive a star is, the shorter its lifetime. Low-Mass stars are long-lived, spend some time as Red Giants, then leave behind a White Dwarf. Very high-mass stars have very short lives, spend a short time as ...
slides
... The gas also starts out hot, and initially is kept hot by the white dwarf, but it will also cool off over time. So the lifetime of a PN is relatively short, just a few 10s of thousands of years. ...
... The gas also starts out hot, and initially is kept hot by the white dwarf, but it will also cool off over time. So the lifetime of a PN is relatively short, just a few 10s of thousands of years. ...
Why is there a main sequence?
... Mmax ~ 100 solar masses a) More massive clouds fragment into smaller pieces during star formation ...
... Mmax ~ 100 solar masses a) More massive clouds fragment into smaller pieces during star formation ...
PRESENTATION: Evolution of the elements through the lifecycles of
... -Picture striking a rubber ball on the ground with a hammer. It will compress, but eventually expand and throw off the hammer, if the blow (the solar mass) is not strong enough to compress it into a black hole. -The Iron atoms are compressed to the point that the electrons are collapsing into the pr ...
... -Picture striking a rubber ball on the ground with a hammer. It will compress, but eventually expand and throw off the hammer, if the blow (the solar mass) is not strong enough to compress it into a black hole. -The Iron atoms are compressed to the point that the electrons are collapsing into the pr ...
11.1 Stars - St John Brebeuf
... a nebula, when enough gravity causes all the molecules to collapse in on themselves. If enough matter gathers, the gravity becomes so massive that hydrogen atoms join to form helium atoms, producing huge amounts of energy through the process of fusion. It is the energy given off by fusion that cause ...
... a nebula, when enough gravity causes all the molecules to collapse in on themselves. If enough matter gathers, the gravity becomes so massive that hydrogen atoms join to form helium atoms, producing huge amounts of energy through the process of fusion. It is the energy given off by fusion that cause ...
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.