High-Mass Star Formation
... CAVEAT: may be contribution from compact components (UCHIIs or disks) within central beam W3(OH) UCHII may contribute as much as 25% of the central flux assuming optically thick free-free scaled from 3mm flux (Wilner, Welch, & Forster 1995) ...
... CAVEAT: may be contribution from compact components (UCHIIs or disks) within central beam W3(OH) UCHII may contribute as much as 25% of the central flux assuming optically thick free-free scaled from 3mm flux (Wilner, Welch, & Forster 1995) ...
Observations of V838 Mon light echo
... In classical novae, hydrogen explosion happens in a layer on a white dwarf surface. A small amount of matter located above being ejected into space has a mass of 1/1000 or 1/10000 solar masses. When the ejected gas expands, its density decreases rapidly, it passes into the optically thin state and g ...
... In classical novae, hydrogen explosion happens in a layer on a white dwarf surface. A small amount of matter located above being ejected into space has a mass of 1/1000 or 1/10000 solar masses. When the ejected gas expands, its density decreases rapidly, it passes into the optically thin state and g ...
Molecular Gas in Nearby Dwarf Galaxies:
... Correlations with B-K could arise from enhanced photodissociation/less dust in bluer systems… …but systems with no CO tend to be underluminous (for their mass) in K-band, not overluminous in B-band ...
... Correlations with B-K could arise from enhanced photodissociation/less dust in bluer systems… …but systems with no CO tend to be underluminous (for their mass) in K-band, not overluminous in B-band ...
Edexcel GCE - physicsinfo.co.uk
... (d) (i) Near the end of its life the Sun will decrease in size and become a white dwarf. State two other ways in which this type of star differs from the Sun as it is ...
... (d) (i) Near the end of its life the Sun will decrease in size and become a white dwarf. State two other ways in which this type of star differs from the Sun as it is ...
Stars and Planets - The University of Texas at Dallas
... In the 1920’s Edwin Hubble not only showed that many “nebula” were in fact other galaxies, but that galaxies appear to be speeding away from one another. The further away a galaxy was (measured with standard candles), the faster it seemed to move away from us! velocity = Ho x distance, where Ho is a ...
... In the 1920’s Edwin Hubble not only showed that many “nebula” were in fact other galaxies, but that galaxies appear to be speeding away from one another. The further away a galaxy was (measured with standard candles), the faster it seemed to move away from us! velocity = Ho x distance, where Ho is a ...
PP and CNO-Cycle Nucleosynthesis
... temperatures and pressures of a stellar core are suitable for proton-proton fusion—anything less dense or less hot and fusion simply cannot occur due to Coulombic repulsion (this has important implications as to the explanation of pre-stellar mass objects observed in recent years known as brown dwar ...
... temperatures and pressures of a stellar core are suitable for proton-proton fusion—anything less dense or less hot and fusion simply cannot occur due to Coulombic repulsion (this has important implications as to the explanation of pre-stellar mass objects observed in recent years known as brown dwar ...
Colour - Magnitude Diagram for M 45
... In blue, circle the most massive star/s on your Colour-Magnitude plot. In red, circle the least massive group of stars on the diagram. What is the source of fuel for all the stars shown on the diagram? Comment on the relative age of the stars. Are they young or old? How can you ...
... In blue, circle the most massive star/s on your Colour-Magnitude plot. In red, circle the least massive group of stars on the diagram. What is the source of fuel for all the stars shown on the diagram? Comment on the relative age of the stars. Are they young or old? How can you ...
G W ORIONIS, A 20000 YEARS OLD T TAURI STAR? 1\/"", _ 0.14
... Our knowledge 01' the actual ages 01' very young stars is very meager; the first indication Lhat we may be observing stars with ages 01' the onler 01' 10 000 years came indirectly from the analysis 01' the density distribution in the Orion nebula (Kahn am! Menon ]9(1) which showed that the latter co ...
... Our knowledge 01' the actual ages 01' very young stars is very meager; the first indication Lhat we may be observing stars with ages 01' the onler 01' 10 000 years came indirectly from the analysis 01' the density distribution in the Orion nebula (Kahn am! Menon ]9(1) which showed that the latter co ...
![David`s Mapping the Heavens[1]](http://s1.studyres.com/store/data/008084229_1-877ead4b57cbb51d927fdcd6d06ce5c8-300x300.png)
David`s Mapping the Heavens[1]
... seconds of arc is a distance of 0.25 parsec. As the angle decreases the distance ...
... seconds of arc is a distance of 0.25 parsec. As the angle decreases the distance ...
Question paper
... Monday 27 June 2011 – Morning Time: 1 hour 35 minutes You do not need any other materials. ...
... Monday 27 June 2011 – Morning Time: 1 hour 35 minutes You do not need any other materials. ...
Glossary Topics - Home - DMNS Galaxy Guide Portal
... layers. Such stars also become blue and red supergiants. As they build up an iron core, they too explode as supernovae. The remaining core then begins to collapse. If the core is larger than five solar masses, collapse continues until it becomes a black hole. If the core is less than five solar mass ...
... layers. Such stars also become blue and red supergiants. As they build up an iron core, they too explode as supernovae. The remaining core then begins to collapse. If the core is larger than five solar masses, collapse continues until it becomes a black hole. If the core is less than five solar mass ...
The Interstellar Medium Chapter 10
... absorbed by interstellar clouds. Red light can more easily penetrate the cloud, but is still absorbed to some extent. ...
... absorbed by interstellar clouds. Red light can more easily penetrate the cloud, but is still absorbed to some extent. ...
Exercise 5
... 2. Using an appropriate diagram in your textbook, label the various areas of your diagram that classify the various stars. Introduction to spectroscopy You’ve now seen that stars seem to group into various parts of the Hertzsprung-Russell diagram. The next step is to ask “Why do they do that?”, whic ...
... 2. Using an appropriate diagram in your textbook, label the various areas of your diagram that classify the various stars. Introduction to spectroscopy You’ve now seen that stars seem to group into various parts of the Hertzsprung-Russell diagram. The next step is to ask “Why do they do that?”, whic ...
Expanding the Catalog: Considering the Importance
... makes a bigger difference to the evolution relative to its abundance in stars. Oxygen is not only much more abundant than carbon, but also has a high contribution to the opacity. Table 2 shows ∆(L/LZAM S ) at each mass and end-member composition for all elements. Stars with longer MS lifetimes than ...
... makes a bigger difference to the evolution relative to its abundance in stars. Oxygen is not only much more abundant than carbon, but also has a high contribution to the opacity. Table 2 shows ∆(L/LZAM S ) at each mass and end-member composition for all elements. Stars with longer MS lifetimes than ...
The Milky Way Galaxy
... To determine the rotation curve of the Galaxy, we will introduce a more convenient coordinate system, called the Galactic coordinate system. Note that the plane of the solar system is not the same as the plane of the Milky Way disk, and the Earth itself is tipped with respect to the plane of the sol ...
... To determine the rotation curve of the Galaxy, we will introduce a more convenient coordinate system, called the Galactic coordinate system. Note that the plane of the solar system is not the same as the plane of the Milky Way disk, and the Earth itself is tipped with respect to the plane of the sol ...
The abundance of 26Al-rich planetary systems in the Galaxy
... excluding low-mass supernovae is that stars with masses lower than 20 M have lifetimes that are longer than (or comparable to) those of molecular clouds, so they explode when the starforming region where they were born has disappeared. Very massive supernovae are very rare and extremely disruptive ...
... excluding low-mass supernovae is that stars with masses lower than 20 M have lifetimes that are longer than (or comparable to) those of molecular clouds, so they explode when the starforming region where they were born has disappeared. Very massive supernovae are very rare and extremely disruptive ...
7.1 What The Heavens Are Declaring About God`s
... Clouds of hydrogen gas and dust called nebulae contract and heat up due to gravity compression. If they are large enough, they eventually reach the temperature, 15,000,000 oC, which causes atomic fusion to start, the process that generates the light energy we see coming from stars. A new star is bor ...
... Clouds of hydrogen gas and dust called nebulae contract and heat up due to gravity compression. If they are large enough, they eventually reach the temperature, 15,000,000 oC, which causes atomic fusion to start, the process that generates the light energy we see coming from stars. A new star is bor ...
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.