DOC
... The existence of planetary systems beyond our own has been repeatedly confirmed over the past decade. In fact, over 200 planets have already been discovered orbiting stars other than the Sun. The great majority of these planets are giant gas planets, similar to Jupiter in our solar system, many of t ...
... The existence of planetary systems beyond our own has been repeatedly confirmed over the past decade. In fact, over 200 planets have already been discovered orbiting stars other than the Sun. The great majority of these planets are giant gas planets, similar to Jupiter in our solar system, many of t ...
12 Stellar Evolution
... Evolution of Stars More Massive than the Sun A star of more than 8 solar masses can fuse elements far beyond carbon in its core, leading to a very different fate. Its path across the H–R diagram is essentially a straight line – it stays at just about the same luminosity as it cools off. Eventually ...
... Evolution of Stars More Massive than the Sun A star of more than 8 solar masses can fuse elements far beyond carbon in its core, leading to a very different fate. Its path across the H–R diagram is essentially a straight line – it stays at just about the same luminosity as it cools off. Eventually ...
The Universe - IES Alyanub
... The theory that is more or less the one we use today was proposed by someone who doesn't get a lot of attention in the popular press. He was a Catholic Priest from Belgium called Georges Lemaître and put forward the theory in 1931. The theory says that the universe began as a very small particle con ...
... The theory that is more or less the one we use today was proposed by someone who doesn't get a lot of attention in the popular press. He was a Catholic Priest from Belgium called Georges Lemaître and put forward the theory in 1931. The theory says that the universe began as a very small particle con ...
Stars M. R. W. Masheder Room 4.15
... over all the estimated distances for different sorts of stars. However, we also need to assume that none of the light from the stars is absorbed before it gets to us (see below). [Fig. 7] A related method is to use variable stars. For instance, certain variable stars called Cepheids (after the first ...
... over all the estimated distances for different sorts of stars. However, we also need to assume that none of the light from the stars is absorbed before it gets to us (see below). [Fig. 7] A related method is to use variable stars. For instance, certain variable stars called Cepheids (after the first ...
Summary of Double Star Discoveries and JDSO Submissions
... This was an outstanding example of how a visual observer can detect a double star with careful observation and recording of their observation notes. Here is the actual report excerpt: At 04:28:01.0 the magnitude 10.1 target star TYC 4677-00696-1 crisply faded but did NOT disappear. It remained at le ...
... This was an outstanding example of how a visual observer can detect a double star with careful observation and recording of their observation notes. Here is the actual report excerpt: At 04:28:01.0 the magnitude 10.1 target star TYC 4677-00696-1 crisply faded but did NOT disappear. It remained at le ...
The Origin, Structure, and Evolution of the Stars
... source is now shifted to an envelope around the core as illustrated in figure 5 the increase in the luminosity of the star resulting from increased size more than compensates for the decrease in luminosa luminos luminosity ity caused by the drop in temperature so the star moves up and to the right i ...
... source is now shifted to an envelope around the core as illustrated in figure 5 the increase in the luminosity of the star resulting from increased size more than compensates for the decrease in luminosa luminos luminosity ity caused by the drop in temperature so the star moves up and to the right i ...
M13 – The Great Hercules Cluster
... like a pinwheel. On a clear, dark summer night in the country, you can see a pale glow arching overhead from South to North. This is just the glow of that disk of a hundred billion stars seen edge-on. When we look at this band of light we are looking out along the plane of the galaxy. Surrounding th ...
... like a pinwheel. On a clear, dark summer night in the country, you can see a pale glow arching overhead from South to North. This is just the glow of that disk of a hundred billion stars seen edge-on. When we look at this band of light we are looking out along the plane of the galaxy. Surrounding th ...
Make Your Own Star Bracelet
... cool stars. Much cooler than their bright blue-white cousins. Stars that are cooler than this type cannot be seen with eyes or optical telescopes. We must look for them by their heat, looking at their infrared radiation." "The next two beads tell us of two possible endings for stars." (pick up the ...
... cool stars. Much cooler than their bright blue-white cousins. Stars that are cooler than this type cannot be seen with eyes or optical telescopes. We must look for them by their heat, looking at their infrared radiation." "The next two beads tell us of two possible endings for stars." (pick up the ...
THE LIFE CYCLES OF STARS (3)
... The ancient Babylonians 1800 BC put together the first star catalogues. The Greek Hipparchus (180-125 BC) and later Claudius Ptolemy in Alexandria about 150 AD classified stars according to their apparent brightness to the eye, dividing them six into classes of brightness. The brightest stars were c ...
... The ancient Babylonians 1800 BC put together the first star catalogues. The Greek Hipparchus (180-125 BC) and later Claudius Ptolemy in Alexandria about 150 AD classified stars according to their apparent brightness to the eye, dividing them six into classes of brightness. The brightest stars were c ...
Variability of Be stars
... ~200 Be stars are currently known among 1660 B-type stars brighter than V=6.5 mag ...
... ~200 Be stars are currently known among 1660 B-type stars brighter than V=6.5 mag ...
Chapter 22
... The Sun produces energy from hydrogen. Energy flows through the Sun’s layers. Features appear on the Sun’s surface. ...
... The Sun produces energy from hydrogen. Energy flows through the Sun’s layers. Features appear on the Sun’s surface. ...
Stellar Evolution Project
... a. How long does this stage last? b. Why would the nebula begin to contract/shrink? c. As the matter collapses, what does the nebula look like and what does it do? 2. Protostar a. How long does this stage last? b. Describe the protostar c. Why does the protostar heat up? 3. Main Sequence Star a. How ...
... a. How long does this stage last? b. Why would the nebula begin to contract/shrink? c. As the matter collapses, what does the nebula look like and what does it do? 2. Protostar a. How long does this stage last? b. Describe the protostar c. Why does the protostar heat up? 3. Main Sequence Star a. How ...
Lecture 10 Spectra of Stars and Binaries
... Summary: • Types of Binary Stars – Visual – Spectroscopic – Eclipsing • Only way to measure stellar masses: – Only ~150 stars ...
... Summary: • Types of Binary Stars – Visual – Spectroscopic – Eclipsing • Only way to measure stellar masses: – Only ~150 stars ...
The Abundances of the Fe Group Elements in Three Early B Stars in
... relative to H by -0.70 dex and N by ∼ -0.90 dex. The C/N ratio in the sun is 0.61 dex (Asplund et al. 2005) but in NGC 8181-D1 we find C/N∼0.20 dex. The elevated abundance of nitrogen relative to carbon suggests that CNO-processed material from the star’s core (first dredge-up) may have mixed with t ...
... relative to H by -0.70 dex and N by ∼ -0.90 dex. The C/N ratio in the sun is 0.61 dex (Asplund et al. 2005) but in NGC 8181-D1 we find C/N∼0.20 dex. The elevated abundance of nitrogen relative to carbon suggests that CNO-processed material from the star’s core (first dredge-up) may have mixed with t ...
QSOs . Continuum Radiation Energy Source
... The Black Hole at the the Galactic Center Velocities of stars in very center 4 million M black hole at position of Sagittarius A* ...
... The Black Hole at the the Galactic Center Velocities of stars in very center 4 million M black hole at position of Sagittarius A* ...
Solar-like oscillations in intermediate red giants
... Helioseismology is currently the best method for verifying stellar evolution modelling theories and for understanding the structure and interior processes within the sun. It was able to rule out the possibility that the solar neutrino problem was due to incorrect models. ...
... Helioseismology is currently the best method for verifying stellar evolution modelling theories and for understanding the structure and interior processes within the sun. It was able to rule out the possibility that the solar neutrino problem was due to incorrect models. ...
File - The Physics Doctor
... balloon rose there would be changes in the pressure of the hydrogen due to the temperature changes of the atmosphere. (i) Calculate the new pressure exerted by the hydrogen if the temperature changed from 20.0 °C to −5.0 °C, as the balloon rose from ground level. pressure exerted by the hydrogen in ...
... balloon rose there would be changes in the pressure of the hydrogen due to the temperature changes of the atmosphere. (i) Calculate the new pressure exerted by the hydrogen if the temperature changed from 20.0 °C to −5.0 °C, as the balloon rose from ground level. pressure exerted by the hydrogen in ...
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.