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Study Guide Astronomy
Study Guide Astronomy

... 9. What is the relationship between surface temperature and brightness for main sequence stars on the Hertzsprung-Russell Diagram? ...
TYPES OF PLANETS AND STARS
TYPES OF PLANETS AND STARS

... dwarf planets that we know are Pluto, Eris, and Ceres. However, only two of the planets, Ceres and Pluto, have been observed in enough in detail to demonstrate that they actually fit the IAU's definition. The IAU accepted Eris as a dwarf planet because it is bigger than Pluto. 4) Exoplanet – are pla ...
Astronomy
Astronomy

... 21. The sun is made mostly of which two elements? ...
Star and Sun Properties
Star and Sun Properties

... rest heavier element. This is similar to the composition of the universe. • The Sun is about 4.6 billion years old. ...
Death of Low Mass Stars 8 Solar Masses or less
Death of Low Mass Stars 8 Solar Masses or less

... • The shell of the star (red giant outer surface) is subject to a series of explosions that eject gas and dust into space (nebula). • A star can lose up to 1/2 the original mass. • Diameter can be very large (typically 1 ly) • Gas expands 30 km/s ...
Option: Astrophysics Objects in the Universe: Asteroid: a small rocky
Option: Astrophysics Objects in the Universe: Asteroid: a small rocky

... 2. The layer becomes compressed and less transparent to radiation. 3. The temperature in the core increases, causing the pressure to increase 4. Surface is pushed outwards 5. Surface expands, cools, becomes less dense 6. The layer becomes more transparent ...
Ch.11 Massive star death
Ch.11 Massive star death

... • The Crab Nebula is the remnant of the supernova seen in A.D. 1054 ...
Chapter 25 - Notes Super Size
Chapter 25 - Notes Super Size

... Large Mass Stars » Blue stars will expand into Red Giants when they run out of _________________ and helium fuses into carbon. » Carbon will then fuse into heavier & heavier elements causing the star to expand further into a Red _________________. When iron is formed from fusion, iron can’t be fused ...
Ch 28 Vocab cnp
Ch 28 Vocab cnp

... The measure of how bright a star would be if it were located 10 parsecs from Earth A group of millions, or even billions of stars held together by gravity A unit of measurement used to describe distances between celestial objects, equal to 3.258 light-years A large cloud of gas and dust in space Ene ...
The Life of a Star
The Life of a Star

... begins in the core (secondary fusion). Once all fusion reactions stop, the star throws its outer layers into space, forming a planetary nebula – This leaves behind the hot dense core of the red giant. – The remaining core is called a white dwarf. Over time, the white dwarf cools off and becomes a bl ...
Chapter 30.1
Chapter 30.1

... Characteristics of Stars ...
Death of Stars with the Mass of 0.3
Death of Stars with the Mass of 0.3

... outer layers are able to begin fusing. If the star has enough mass, this alternating growing and collapsing continues until it is hot enough for heavier elements to fuse. If the red giant has only a mass of less than about 1.4 sun masses, the fusion stops after the helium in the core has been burned ...
31 — Main-Sequence Stars [Revision : 1.1]
31 — Main-Sequence Stars [Revision : 1.1]

... To drive radiative flux, temperature gradient can be moderate; no need for convection So, radiative envelope In the more-massive stars (M & 10 M ), iron and nickel cause opacity peak at ∼ 200, 000 K; this ‘iron bump’ can cause thin, weak convection zone ...
Quiz 1 Review
Quiz 1 Review

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Powerpoint of lecture 16

... • Pressure drops, core cannot support itself, collapses catastrophically (timescale: 10s of milliseconds!) to nuclear densities, and bounces, leading to outward-travelling shock wave • Shock also accelerated by pressure of neutrinos, produced in explosive nucleosynthesis generated by energy of colla ...
Chapter 13 - USD Home Pages
Chapter 13 - USD Home Pages

... require a temperature of 600 million K (pg 387). This is a lot hotter than the 10 million K for hydrogen fusion because the carbon nuclei are heavier and have a charge of +6, which gets squared. Oxygen, with a charge of +8, is even more difficult to fuse. The interior of a white dwarf never gets thi ...
N.2 Formation of Mass
N.2 Formation of Mass

... 2. Strong Force: the force between the protons and neutrons of the nucleus of atoms. It holds the nucleus together. 3. Weak Force: An attraction between hydrogen atoms. Causes nuclear fusion between hydrogen atoms, it is the reason the sun burns. ...
Exploration of the Universe
Exploration of the Universe

... Exploration of the Universe 1. What astronomical observations allow us to know the time of day, the date, direction and the timing of ocean tides? 2. What is the difference between an asterism and a constellation? 3. How would observations of stars differ from the observations of planets? 4. What is ...
Astronomy HOMEWORK Chapter 12 - 9th Edition 1. Consider a star
Astronomy HOMEWORK Chapter 12 - 9th Edition 1. Consider a star

There's more than one way to make a  Blue Straggler 1
There's more than one way to make a Blue Straggler 1

... There's more than one way to make a Blue Straggler The Collision Model ...
Barred Spiral Galaxy
Barred Spiral Galaxy

... •A white dwarf is a very small and cool, formed when middle size stars die ...
Life of a star - bahringcarthnoians
Life of a star - bahringcarthnoians

Place the stars in the proper sequence, following the
Place the stars in the proper sequence, following the

... Along the main sequence, stars of greater magnitude are hotter (have more energy) c. How is a star’s luminosity related to its energy? For main-sequence stars, the luminosity increases with temperature. For the giants and super-giants, large (high magnitude) and luminous stars are actually quite coo ...
life cycle of stars notes
life cycle of stars notes

... How a star lives and dies depends on how much mass it has. ...
Star Life Cycle Poster
Star Life Cycle Poster

... How big and how hot is our sun? How does our sun compare in size and temp. to other stars? What phase in the life cycle of a star is our sun in right now? What is the composition of our sun? What is the next phase of our sun’s life cycle and how long until it gets there? How long is the typical life ...
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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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