A6 - Vicphysics
... useful as it specifically shows how these appear to viewers in the southern hemisphere whereas as much of the other material available online and in publications shows it from a northern hemisphere perspective. The level is aimed below that of VCE students but it is probably worth using as a startin ...
... useful as it specifically shows how these appear to viewers in the southern hemisphere whereas as much of the other material available online and in publications shows it from a northern hemisphere perspective. The level is aimed below that of VCE students but it is probably worth using as a startin ...
Seal of the United States
... President Harry Truman had the seal redesigned on October 26, 1945, adding the circle of stars and re-orienting the eagle towards the right (the side with the olive branch). The seal of the President of the United States of America is based upon the Great Seal of the USA. The Presidential seal pictu ...
... President Harry Truman had the seal redesigned on October 26, 1945, adding the circle of stars and re-orienting the eagle towards the right (the side with the olive branch). The seal of the President of the United States of America is based upon the Great Seal of the USA. The Presidential seal pictu ...
Edexcel GCE - The Student Room
... All quasars show large red shifts in the light received from them. This shows that they A ...
... All quasars show large red shifts in the light received from them. This shows that they A ...
Evolution and fate of very massive stars
... very massive stars, we calculated a new grid of models for such objects, for solar, LMC and SMC metallicities, which covers the initial mass range from 120 to 500 M . Both rotating and non-rotating models were calculated using the Geneva stellar evolution code and evolved until at least the end of ...
... very massive stars, we calculated a new grid of models for such objects, for solar, LMC and SMC metallicities, which covers the initial mass range from 120 to 500 M . Both rotating and non-rotating models were calculated using the Geneva stellar evolution code and evolved until at least the end of ...
Binding Energy Powerpoint
... (energy) required to completely separate the nucleons of a nucleus The work required to remove one nucleon from the nucleus is very roughly the binding energy divided by the number of nucleons More importantly, the binding energy of a nucleus is a measure of how stable it is – higher the binding ...
... (energy) required to completely separate the nucleons of a nucleus The work required to remove one nucleon from the nucleus is very roughly the binding energy divided by the number of nucleons More importantly, the binding energy of a nucleus is a measure of how stable it is – higher the binding ...
here - Diana`s Fixed Stars
... at the North lunar node at the Titanic disaster, and shows up in many shipwreck charts. At the peak of his career, when Al Gore ran for U.S. President in 2000, even though he won the popular vote by more than half a million, he lost the election on technicalities and so was “shipwrecked” – left high ...
... at the North lunar node at the Titanic disaster, and shows up in many shipwreck charts. At the peak of his career, when Al Gore ran for U.S. President in 2000, even though he won the popular vote by more than half a million, he lost the election on technicalities and so was “shipwrecked” – left high ...
PDF file
... Shu et al., 1987) protostellar clouds contract slowly until ambipolar diffusion removes enough magnetic flux for dynamical (inside-out) collapse to set in. It was expected that the diffusion timescale of ∼ 10 Myr should produce a similar age spread in the resulting populations of stars, consistent w ...
... Shu et al., 1987) protostellar clouds contract slowly until ambipolar diffusion removes enough magnetic flux for dynamical (inside-out) collapse to set in. It was expected that the diffusion timescale of ∼ 10 Myr should produce a similar age spread in the resulting populations of stars, consistent w ...
The Milky Way Galaxy 1 Introduction 2 Globular Clusters and
... What are some of the properties inferred about dark matter? What are some candidates for dark matter? ...
... What are some of the properties inferred about dark matter? What are some candidates for dark matter? ...
Neutron stars: the densest state of condensed matter
... conference in Paris in 1939, Chandrasekhar also pointed out “If the degenerate core attain sufficiently high densities, the protons and electrons will combine to form neutrons. This would cause a sudden diminution of pressure resulting in the collapse of the star to a neutron core.” A neutron star s ...
... conference in Paris in 1939, Chandrasekhar also pointed out “If the degenerate core attain sufficiently high densities, the protons and electrons will combine to form neutrons. This would cause a sudden diminution of pressure resulting in the collapse of the star to a neutron core.” A neutron star s ...
Ch. 16 - Astro1010
... Once many stars are plotted on an H–R diagram, a pattern begins to form. These are the 80 closest stars to us; note the dashed lines of constant radius. The darkened band is called the main sequence, as this is where most stars are. ...
... Once many stars are plotted on an H–R diagram, a pattern begins to form. These are the 80 closest stars to us; note the dashed lines of constant radius. The darkened band is called the main sequence, as this is where most stars are. ...
Neutrinos and Nucleosynthesis
... Scientists all over the world try to solve the question why the universe looks the way it does today. The formation of heavy elements like the ones found on earth is one big aspect of this search because it is expected to give great insight into the evolution process of our universe. Especially, the ...
... Scientists all over the world try to solve the question why the universe looks the way it does today. The formation of heavy elements like the ones found on earth is one big aspect of this search because it is expected to give great insight into the evolution process of our universe. Especially, the ...
Doppler imaging of stellar surfaces
... main-sequence stars and to compare the activity on those, in turn, with that of the Sun. The images produced show some startling differences between stellar and solar activity. The strengths and weakness of the Doppler imaging technique must be reviewed regularly to remind us of what observed featur ...
... main-sequence stars and to compare the activity on those, in turn, with that of the Sun. The images produced show some startling differences between stellar and solar activity. The strengths and weakness of the Doppler imaging technique must be reviewed regularly to remind us of what observed featur ...
A Digital Spectral Classification Atlas
... The MK Spectral classification system was founded by W.W. Morgan and P.C. Keenan in the year 1943, with the publication of the first photographic spectral classification atlas, An Atlas of Stellar Spectra (Morgan, Keenan & Kelleman, 1943). Since that time, the MK system has been extensively revised ...
... The MK Spectral classification system was founded by W.W. Morgan and P.C. Keenan in the year 1943, with the publication of the first photographic spectral classification atlas, An Atlas of Stellar Spectra (Morgan, Keenan & Kelleman, 1943). Since that time, the MK system has been extensively revised ...
New Double Stars from Asteroidal Occultations, 1971 - 2008
... observations were made visually. For the last several years the great majority of observations are made using video cameras with a time signal obtained from the GPS satellite system inserted into the video stream. Compared to visual observing, video provides enhanced time resolution, and a record th ...
... observations were made visually. For the last several years the great majority of observations are made using video cameras with a time signal obtained from the GPS satellite system inserted into the video stream. Compared to visual observing, video provides enhanced time resolution, and a record th ...
Infrared Astronomy More than Our Eyes Can See
... than visible radiation). To see the newborn stars embedded in these clouds of dust and gas, astronomers depend on observations made at shon infrared wavelengths which penetrate through the obscuring dusl. Building New Planets. Using data from the Infrared Astronomical Satellite (lRAS), astronomers d ...
... than visible radiation). To see the newborn stars embedded in these clouds of dust and gas, astronomers depend on observations made at shon infrared wavelengths which penetrate through the obscuring dusl. Building New Planets. Using data from the Infrared Astronomical Satellite (lRAS), astronomers d ...
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.