Chapter 16 Star Birth
... Trapping of Thermal Energy • As contraction packs the molecules and dust particles of a cloud fragment closer together, it becomes harder for infrared and radio photons to escape • Thermal energy then begins to build up inside, increasing the internal pressure • Contraction slows down, and the cent ...
... Trapping of Thermal Energy • As contraction packs the molecules and dust particles of a cloud fragment closer together, it becomes harder for infrared and radio photons to escape • Thermal energy then begins to build up inside, increasing the internal pressure • Contraction slows down, and the cent ...
32Brightness
... source, where discrete colors are absorbed by atoms – From emission and absorption lines, get composition of objects and also their temperature ...
... source, where discrete colors are absorbed by atoms – From emission and absorption lines, get composition of objects and also their temperature ...
Rotation
... and the Eddington Sweet time scale is about 1012 years, i.e., it is unimportant. It can become more important near the surface though as the density decreases (Kippenhahn 42.36) For a 20 M e star , the Kelvin Helmholtz time scale relative to the nuclear lifetime is about three times greater . More i ...
... and the Eddington Sweet time scale is about 1012 years, i.e., it is unimportant. It can become more important near the surface though as the density decreases (Kippenhahn 42.36) For a 20 M e star , the Kelvin Helmholtz time scale relative to the nuclear lifetime is about three times greater . More i ...
HR Diagram Explorer Worksheet
... In addition to the isoradius lines, check show luminosity classes. This green region (dwarfs V) is known as the main sequence and contains all stars that are fusing hydrogen into helium as their primary energy source. Over 90% of all stars fall in this region on the HR diagram. Move the active curso ...
... In addition to the isoradius lines, check show luminosity classes. This green region (dwarfs V) is known as the main sequence and contains all stars that are fusing hydrogen into helium as their primary energy source. Over 90% of all stars fall in this region on the HR diagram. Move the active curso ...
Ay 112 Midterm review
... that hydrogen in the stellar photosphere is almost entirely neutral, but Ca is almost entirely singly ionized. The population of the n = 2 level in H is very small and hence the Balmer hydrogen ...
... that hydrogen in the stellar photosphere is almost entirely neutral, but Ca is almost entirely singly ionized. The population of the n = 2 level in H is very small and hence the Balmer hydrogen ...
CHAPTER 12—STELLAR EVOLUTION
... ____ 27. Stars support their weight by generating energy in their centers. ____ 28. Stars swell into giants when hydrogen is exhausted in their centers. ____ 29. The helium flash is the cause of some supernovae. ____ 30. Helium fusion does not begin until the star has entered the giant region of the ...
... ____ 27. Stars support their weight by generating energy in their centers. ____ 28. Stars swell into giants when hydrogen is exhausted in their centers. ____ 29. The helium flash is the cause of some supernovae. ____ 30. Helium fusion does not begin until the star has entered the giant region of the ...
I Cloudy with a Chance of Making a star is no easy thing
... it needs to become dense enough to initiate nuclear fusion but has not done so yet. Astronomers can see how this process begins and how it ends, but what comes in the middle is inherently hard to observe, because much of the radiation comes out at far-infrared and submillimeter wavelengths where the ...
... it needs to become dense enough to initiate nuclear fusion but has not done so yet. Astronomers can see how this process begins and how it ends, but what comes in the middle is inherently hard to observe, because much of the radiation comes out at far-infrared and submillimeter wavelengths where the ...
Astronomy Activity: The Life-Line of the Stars
... The brightness that a star has as seen from the Earth is called the apparent brightness . Stars which are very bright are called magnitude 1 stars . The next brightest are magnitude 2 stars. Then comes magnitude 3, 4, 5, and down to the very faintest stars visible with the naked eye, magnitude 6 sta ...
... The brightness that a star has as seen from the Earth is called the apparent brightness . Stars which are very bright are called magnitude 1 stars . The next brightest are magnitude 2 stars. Then comes magnitude 3, 4, 5, and down to the very faintest stars visible with the naked eye, magnitude 6 sta ...
THE LIFE CYCLES OF STARS (3)
... classified stars according to their apparent brightness to the eye, dividing them six into classes of brightness. The brightest stars were called first magnitude, the somewhat dimmer stars were second magnitude, even dimmer were third magnitude, down to sixth magnitude which were the faintest stars ...
... classified stars according to their apparent brightness to the eye, dividing them six into classes of brightness. The brightest stars were called first magnitude, the somewhat dimmer stars were second magnitude, even dimmer were third magnitude, down to sixth magnitude which were the faintest stars ...
PHYSICS – Astrophysics Section I
... of the Moon. Galileo saw that the Moon was not perfect and unchanging as was the prevailing Aristotelian view, but in fact had a very rough surface. He observed the “seas” and mountains on the surface of the Moon as well as craters. These observations blatantly contradicted the Church’s Aristotelian ...
... of the Moon. Galileo saw that the Moon was not perfect and unchanging as was the prevailing Aristotelian view, but in fact had a very rough surface. He observed the “seas” and mountains on the surface of the Moon as well as craters. These observations blatantly contradicted the Church’s Aristotelian ...
CS3_Ch 3 - Leon County Schools
... The universe is made up of stars, gas, and dust, as well as invisible dark matter. Material in the universe is pulled by gravity into galaxies, including our own Milky Way galaxy. ...
... The universe is made up of stars, gas, and dust, as well as invisible dark matter. Material in the universe is pulled by gravity into galaxies, including our own Milky Way galaxy. ...
across
... energy came from gravity- the Sun was converting gravitational energy to heat. Egrav=GMm/R. So as R get smaller, energy can be released. Lord Kelvin estimated the Sun could last 30 million years based on this. ...
... energy came from gravity- the Sun was converting gravitational energy to heat. Egrav=GMm/R. So as R get smaller, energy can be released. Lord Kelvin estimated the Sun could last 30 million years based on this. ...
Life Stages of High
... carbon in a shell around the carbon core, and H fuses to He in a shell around the helium layer. • This double-shell-burning stage never reaches equilibrium—the fusion rate periodically spikes upward in a series of thermal pulses. • With each spike, convection dredges carbon up from the core and tran ...
... carbon in a shell around the carbon core, and H fuses to He in a shell around the helium layer. • This double-shell-burning stage never reaches equilibrium—the fusion rate periodically spikes upward in a series of thermal pulses. • With each spike, convection dredges carbon up from the core and tran ...
Contents ISP 205 Section 2 Study Guide for Test 3 28 March 2007
... Why do the oxygen molecules in air move? Why do the electrons in a white dwarf move? A white dwarf has about the same mass as the sun and the same size as the earth. True or false? A neutron star has about the same mass as the sun and the same size as the earth. True or false? If the temperature of ...
... Why do the oxygen molecules in air move? Why do the electrons in a white dwarf move? A white dwarf has about the same mass as the sun and the same size as the earth. True or false? A neutron star has about the same mass as the sun and the same size as the earth. True or false? If the temperature of ...
2017 Div. C (High School) Astronomy Help Session
... They are red giants – very late stages of stellar evolution for low mass stars, on the asymptotic giant branch, – will expel their outer envelopes as planetary nebulae and become white dwarfs within a few million years. Massive enough that they have undergone helium fusion in their cores but are les ...
... They are red giants – very late stages of stellar evolution for low mass stars, on the asymptotic giant branch, – will expel their outer envelopes as planetary nebulae and become white dwarfs within a few million years. Massive enough that they have undergone helium fusion in their cores but are les ...
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.