Article 8
... happening inside the ball of gas and dust? It happens like this..... As the contraction of the gas and dust progresses and the temperature reaches 15 million degrees or so, the pressure at the center of the ball becomes enormous. The electrons are stripped off of their parent atoms, creating a plasm ...
... happening inside the ball of gas and dust? It happens like this..... As the contraction of the gas and dust progresses and the temperature reaches 15 million degrees or so, the pressure at the center of the ball becomes enormous. The electrons are stripped off of their parent atoms, creating a plasm ...
ASTR220 Collisions in Space
... Bright and variable X-ray emission. Found high-mass star at approximate location of X-ray source. Found that star has very large velocity shifts (40 m/s in each direction)… … must be something very massive swinging it around! ...
... Bright and variable X-ray emission. Found high-mass star at approximate location of X-ray source. Found that star has very large velocity shifts (40 m/s in each direction)… … must be something very massive swinging it around! ...
Today`s Powerpoint
... Mass of end products is less than mass of 4 protons by 0.7%. Mass converted to energy. 600 millions of tons per second fused. Takes billions of years to convert p's to 4He in Sun's core. Process sets lifetime of stars. Hydrostatic Equilibrium: pressure from fusion reactions balances gravity. Sun is ...
... Mass of end products is less than mass of 4 protons by 0.7%. Mass converted to energy. 600 millions of tons per second fused. Takes billions of years to convert p's to 4He in Sun's core. Process sets lifetime of stars. Hydrostatic Equilibrium: pressure from fusion reactions balances gravity. Sun is ...
Question C:
... The easy way is to look up B−V=−0.30 for a B0V star in table A4-3, so B=2.5−0.3=2.2. The hard way is to first get the temperature of a B0 star from Figure 13-6 (25,000K), and calculate B−V=−0.52 using Equation 11-11a (although it is not meant for such hot stars). c. (5 pt): In a certain star, hydrog ...
... The easy way is to look up B−V=−0.30 for a B0V star in table A4-3, so B=2.5−0.3=2.2. The hard way is to first get the temperature of a B0 star from Figure 13-6 (25,000K), and calculate B−V=−0.52 using Equation 11-11a (although it is not meant for such hot stars). c. (5 pt): In a certain star, hydrog ...
S E D
... To explain the stellar structure we need to assume thermodynamical equilibrium. It results in that we do not need to think of reactions in the gas. This assumption is okay, as long as there is full ionization, and therefore we can assume this almost in the whole star except the surface. Another assu ...
... To explain the stellar structure we need to assume thermodynamical equilibrium. It results in that we do not need to think of reactions in the gas. This assumption is okay, as long as there is full ionization, and therefore we can assume this almost in the whole star except the surface. Another assu ...
A star is born: understanding the physics of star formation
... acting to expand the cloud and those trying to collapse it (primarily gravity). However, if this equilibrium is perturbed, either by an external force, such as a supernova explosion, or by the cloud becoming sufficiently massive, the molecular cloud begins to undergo gravitational collapse. While th ...
... acting to expand the cloud and those trying to collapse it (primarily gravity). However, if this equilibrium is perturbed, either by an external force, such as a supernova explosion, or by the cloud becoming sufficiently massive, the molecular cloud begins to undergo gravitational collapse. While th ...
What is a Star?
... • It is difficult to distinguish between colors at low levels of light because of the way the eye is made. – Two types of cells, rods and cones, enable you to see color and differences in color. – Rods distinguish shades of color while cones distinguish color in general. – Cones do not work well wit ...
... • It is difficult to distinguish between colors at low levels of light because of the way the eye is made. – Two types of cells, rods and cones, enable you to see color and differences in color. – Rods distinguish shades of color while cones distinguish color in general. – Cones do not work well wit ...
Stars
... Milky Way galaxy. White dwarfs are stars that have burned up all of the hydrogen and helium they once used as nuclear fuel to elements such as carbon, nitrogen, and oxygen ...
... Milky Way galaxy. White dwarfs are stars that have burned up all of the hydrogen and helium they once used as nuclear fuel to elements such as carbon, nitrogen, and oxygen ...
The Distance Ladder I - Sierra College Astronomy Home Page
... Being highly repeatable, it is thought that Type Ia supernovae are very ...
... Being highly repeatable, it is thought that Type Ia supernovae are very ...
III. Contents of The Universe
... the apparent shift of an object against a background due to a change in observer’s position ...
... the apparent shift of an object against a background due to a change in observer’s position ...
Document
... • RR Lyrae variables have periods of about a day. Their brightness doubles from dimest to brightest. • Typical light curve for a Cepheid variable star. • Cepheid variables have longer periods, from one day up to about 50 days. Their brightness also doubles from dimmest to brightest. • From the shape ...
... • RR Lyrae variables have periods of about a day. Their brightness doubles from dimest to brightest. • Typical light curve for a Cepheid variable star. • Cepheid variables have longer periods, from one day up to about 50 days. Their brightness also doubles from dimmest to brightest. • From the shape ...
Great Astronomers of the 20th Century
... Jill Tarter • Joint appointment at UC Berkeley and SETI ...
... Jill Tarter • Joint appointment at UC Berkeley and SETI ...
ASTR 1101-001 Spring 2008 - Louisiana State University
... Masses obtained from Fig. 17-21 and Table 19-1 ...
... Masses obtained from Fig. 17-21 and Table 19-1 ...
After the ZAMS - Lincoln-Sudbury Regional High School
... This means that anything near a star will be blown away, or eroded. If it moves anywhere, it will be most likely away from the star, not towards it. But far greater than this is the loss of material from the star’s outer layers: it is just swept into space by the pressure of radiation from the core. ...
... This means that anything near a star will be blown away, or eroded. If it moves anywhere, it will be most likely away from the star, not towards it. But far greater than this is the loss of material from the star’s outer layers: it is just swept into space by the pressure of radiation from the core. ...
The Sun and other Stars
... the same time, but independently of each other. H-R Diagram – A graph on which stars are located according to their temperature and luminosity. ...
... the same time, but independently of each other. H-R Diagram – A graph on which stars are located according to their temperature and luminosity. ...
STAR SYTEMS AND GALAXIES
... • In a binary system usually one star is much brighter than the other. • We can detect binary systems easily if one star blocks another, called an eclipsing binary. • We have found planets moving around stars in other systems. We can only detect very large planets because the planets must have enoug ...
... • In a binary system usually one star is much brighter than the other. • We can detect binary systems easily if one star blocks another, called an eclipsing binary. • We have found planets moving around stars in other systems. We can only detect very large planets because the planets must have enoug ...
Lecture 11, PPT version
... the “zero velocity” line pattern. The curved magenta line above shows you how one particular black absorption line sweeps up and down the spectrum due to orbital motion. ...
... the “zero velocity” line pattern. The curved magenta line above shows you how one particular black absorption line sweeps up and down the spectrum due to orbital motion. ...
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.