Brighter than the average star?
... So why do most astronomy books denigrate our star? It is probably a result of over zealously applying the mediocrity principle. This is the philosophical idea that there is nothing special about our place in the Universe (“we live on an ordinary planet, orbiting an ordinary star in an ordinary galax ...
... So why do most astronomy books denigrate our star? It is probably a result of over zealously applying the mediocrity principle. This is the philosophical idea that there is nothing special about our place in the Universe (“we live on an ordinary planet, orbiting an ordinary star in an ordinary galax ...
Star formation - Grosse Pointe Public School System
... • Some protostars are not massive enough to ever begin nuclear fusion, since they will never achieve high enough temperatures and pressures in their cores. • These “wanna-be” stars still glow red from light generated due to gravitational contraction. They are known as brown dwarfs, but aren’t really ...
... • Some protostars are not massive enough to ever begin nuclear fusion, since they will never achieve high enough temperatures and pressures in their cores. • These “wanna-be” stars still glow red from light generated due to gravitational contraction. They are known as brown dwarfs, but aren’t really ...
Xtra_credit_MC_chapt_10−12_2014.txt Xtra_credit_MC_chapt_10
... 1) In the video at the instant of the first appearance of the Sun on the eastern horizon (called dawn) then the video says to look in the sky: a) just above the sun b) straight up (at 90−degrees from the direction to the sun) c) directly opposite the sun (at 180−degrees from the sun) d) a) or c) dep ...
... 1) In the video at the instant of the first appearance of the Sun on the eastern horizon (called dawn) then the video says to look in the sky: a) just above the sun b) straight up (at 90−degrees from the direction to the sun) c) directly opposite the sun (at 180−degrees from the sun) d) a) or c) dep ...
charts_set_8
... equivalent. So in freefall, light and ball also travel in straight lines. 3. Now imagine two people in freefall on Earth, passing a ball back and forth. From their perspective, they pass it in a straight line. From a stationary perspective, it follows a curved path. So will a flashlight beam, but cu ...
... equivalent. So in freefall, light and ball also travel in straight lines. 3. Now imagine two people in freefall on Earth, passing a ball back and forth. From their perspective, they pass it in a straight line. From a stationary perspective, it follows a curved path. So will a flashlight beam, but cu ...
Galaxies - Where Science Meets Life
... Very little gas or dust. No recent star formation within galaxy. ...
... Very little gas or dust. No recent star formation within galaxy. ...
Powerpoint for today
... As a clump collapses, it heats up. Becomes very luminous. Now a protostar. May form proto-planetary disk. ...
... As a clump collapses, it heats up. Becomes very luminous. Now a protostar. May form proto-planetary disk. ...
Test 1 - Brock physics
... (a) yellow, because they emit a significant amount of yellow electromagnetic radiation. (b) blue, because they emit a significant amount of blue and ultraviolet electromagnetic radiation. (c) red, because electrons recombine with protons and then make transitions to lower energy levels, emitting red ...
... (a) yellow, because they emit a significant amount of yellow electromagnetic radiation. (b) blue, because they emit a significant amount of blue and ultraviolet electromagnetic radiation. (c) red, because electrons recombine with protons and then make transitions to lower energy levels, emitting red ...
Apparent versus Event Horizon
... it collapses, into what kind of object, and at what rate, is determined by the star's final mass and the remaining outward pressure that the burnt-up nuclear residue (largely iron) can muster. If the star is sufficiently massive or compressible, it may collapse to a black hole. If it is less massive ...
... it collapses, into what kind of object, and at what rate, is determined by the star's final mass and the remaining outward pressure that the burnt-up nuclear residue (largely iron) can muster. If the star is sufficiently massive or compressible, it may collapse to a black hole. If it is less massive ...
4550-15Lecture33
... between the core and outer layers, which are still H-rich. The interior part of the core collapses under gravity until temperature and pressure are great enough for He burning to begin. At the same time the exterior expands and cools, resulting in a red giant, a star that is overluminous relative to ...
... between the core and outer layers, which are still H-rich. The interior part of the core collapses under gravity until temperature and pressure are great enough for He burning to begin. At the same time the exterior expands and cools, resulting in a red giant, a star that is overluminous relative to ...
Luminosity
... The stars are not randomly distributed on the diagram. There are 3 features that emerge from the H-R diagram: Most stars fall on a strip extending diagonally across the diagram from top left to bottom right. This is called the MAIN SEQUENCE. Some large stars, reddish in colour occupy the top ...
... The stars are not randomly distributed on the diagram. There are 3 features that emerge from the H-R diagram: Most stars fall on a strip extending diagonally across the diagram from top left to bottom right. This is called the MAIN SEQUENCE. Some large stars, reddish in colour occupy the top ...
- hoganshomepage
... chemical composition of the stars. (also temperature and direction the star is moving in relation to the Earth.) How? Set up a spectroscope with different tubes; each gas has different spectras – light patterns. ...
... chemical composition of the stars. (also temperature and direction the star is moving in relation to the Earth.) How? Set up a spectroscope with different tubes; each gas has different spectras – light patterns. ...
Standard Set 2 - Atascadero High School
... accomplish because all nuclei are positively charged and repel their neighbors, creating a barrier that inhibits close approach. However, the barrier can be bypassed if the nuclei have high velocities because of high temperature. Once the process begins, fusion of lightweight nuclei leads to a net r ...
... accomplish because all nuclei are positively charged and repel their neighbors, creating a barrier that inhibits close approach. However, the barrier can be bypassed if the nuclei have high velocities because of high temperature. Once the process begins, fusion of lightweight nuclei leads to a net r ...
THE HERTZSPRUNG-RUSSELL DIAGRAM (H
... marked “solar radii” (radii is plural for radius) on the righthand side. These lines are used to represent the physical size of stars on the diagram. Using the diagonal solar radii lines, give the solar radius (size) of the sun. ___________ ...
... marked “solar radii” (radii is plural for radius) on the righthand side. These lines are used to represent the physical size of stars on the diagram. Using the diagonal solar radii lines, give the solar radius (size) of the sun. ___________ ...
JimH This is Your Life - The Atlanta Astronomy Club
... • You can actually see the knots, called Herbig-Haro objects, in the jet move with time •They can have wind velocities of 200-300 km/s. This phase lasts about 10 million years. ...
... • You can actually see the knots, called Herbig-Haro objects, in the jet move with time •They can have wind velocities of 200-300 km/s. This phase lasts about 10 million years. ...
Where do elements come from?
... • Lighter elements fuse to create heavier elements like carbon and oxygen • During the life span of a star, fusion can take place up to the formation of Iron (Fe) ...
... • Lighter elements fuse to create heavier elements like carbon and oxygen • During the life span of a star, fusion can take place up to the formation of Iron (Fe) ...
Supernovae and cosmology
... Metal core too heavy for electron degeneracy Weight more than Chandrasekar limit Core collapses Pressure increases on gas surrounding core Potential energy is released as heat ...
... Metal core too heavy for electron degeneracy Weight more than Chandrasekar limit Core collapses Pressure increases on gas surrounding core Potential energy is released as heat ...
printer-friendly sample test questions
... 2nd Item Specification: Recognize the life-cycles of mid-size and massive stars and their stellar remnants. Depth of Knowledge Level 1 8. When fusion of hydrogen ceases in our Sun’s core, the Sun will A. explode as a supernova. B. collapse into white dwarf star. C. contract into a black hole. D. exp ...
... 2nd Item Specification: Recognize the life-cycles of mid-size and massive stars and their stellar remnants. Depth of Knowledge Level 1 8. When fusion of hydrogen ceases in our Sun’s core, the Sun will A. explode as a supernova. B. collapse into white dwarf star. C. contract into a black hole. D. exp ...
Study Guide – Midterm 3
... What are the three possible end states of a star’s life? What determines which end state befalls a particular star? ...
... What are the three possible end states of a star’s life? What determines which end state befalls a particular star? ...
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.