Why Study Cosmic Near Infrared Background? (1-4um)
... The metal density now is 1.2 * 108 M8 Mpc-3 -> The upper limit from the near infrared background for a larson IMF is excluded, but most of the parameter space survives the metallicity constraint. ...
... The metal density now is 1.2 * 108 M8 Mpc-3 -> The upper limit from the near infrared background for a larson IMF is excluded, but most of the parameter space survives the metallicity constraint. ...
Report for European Helioseismology and Asteroseismology Network
... large frequency spacings of the acoustic mode spectra of these stars, from analysis of the timeseries data. The results of this first “Exercise #1” were reported at the HELAS NA3-2 Workshop, “low-degree and low-frequency modes” (La Palma, 2007 September); at the First KASC Workshop (Orsay, Paris, 20 ...
... large frequency spacings of the acoustic mode spectra of these stars, from analysis of the timeseries data. The results of this first “Exercise #1” were reported at the HELAS NA3-2 Workshop, “low-degree and low-frequency modes” (La Palma, 2007 September); at the First KASC Workshop (Orsay, Paris, 20 ...
Powerpoint for today
... Solar System Rotation Curve: when almost all mass at center, velocity decreases with radius ("Keplerian") ...
... Solar System Rotation Curve: when almost all mass at center, velocity decreases with radius ("Keplerian") ...
Gravitational Wave Generation in Rotating Compact Stars
... density are ρ(0) = 0.14 fm−3 and nν (0) = 1.40 × 10−2 fm−3 , respectively. For L0 = 2.6 × 1049 g · cm2 · s−1 the initial values of the semi-axes are a1 (0) = 2.96 × 106 cm, a2 (0) = 1.48 × 106 cm and a3 (0) = 8.6 × 105 cm. In this case the values of the initial baryon density and neutrino density ar ...
... density are ρ(0) = 0.14 fm−3 and nν (0) = 1.40 × 10−2 fm−3 , respectively. For L0 = 2.6 × 1049 g · cm2 · s−1 the initial values of the semi-axes are a1 (0) = 2.96 × 106 cm, a2 (0) = 1.48 × 106 cm and a3 (0) = 8.6 × 105 cm. In this case the values of the initial baryon density and neutrino density ar ...
IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861.
... This method of analysis has shown to be a simple method of verifying the new intensity formula by using atomic, ionic and stellar data. By using this method together with the new intensity formula it has been possible to determine the mean electron temperature in different laboratory plasmas and in ...
... This method of analysis has shown to be a simple method of verifying the new intensity formula by using atomic, ionic and stellar data. By using this method together with the new intensity formula it has been possible to determine the mean electron temperature in different laboratory plasmas and in ...
What is a standard candle?
... galaxy A has a bright-dim-bright period of 10 days, while the one in galaxy B has a bright-dim-bright period of 30 days. Which of the two galaxies is at a greater distance from us? a) ...
... galaxy A has a bright-dim-bright period of 10 days, while the one in galaxy B has a bright-dim-bright period of 30 days. Which of the two galaxies is at a greater distance from us? a) ...
Neutron Stars and Black Holes
... galaxy A has a bright-dim-bright period of 10 days, while the one in galaxy B has a bright-dim-bright period of 30 days. Which of the two galaxies is at a greater distance from us? a) ...
... galaxy A has a bright-dim-bright period of 10 days, while the one in galaxy B has a bright-dim-bright period of 30 days. Which of the two galaxies is at a greater distance from us? a) ...
Spatial distribution of stars in the Milky Way
... Spatial distribution of stars in the Milky Way • We use a statistical approach to determine and describe the spatial distribution of stars in the Galaxy • This approach allows us to derive the structure of the disk and spheroidal components (density distribution and extent). • This information can ...
... Spatial distribution of stars in the Milky Way • We use a statistical approach to determine and describe the spatial distribution of stars in the Galaxy • This approach allows us to derive the structure of the disk and spheroidal components (density distribution and extent). • This information can ...
WASP-7: The brightest transiting-exoplanet system in the Southern
... (Teff ) comes from an analysis of the Hα line while the surface gravity (log g) comes from the Na i D and Mg i b lines. An estimate of the microturbulence (ξt ) comes from several clean and unblended Fe i and Fe ii lines, while the ionization balance between Fe i and Fe ii was used as an additional ...
... (Teff ) comes from an analysis of the Hα line while the surface gravity (log g) comes from the Na i D and Mg i b lines. An estimate of the microturbulence (ξt ) comes from several clean and unblended Fe i and Fe ii lines, while the ionization balance between Fe i and Fe ii was used as an additional ...
Systematics of Galaxy Properties and Scaling Relations Ay 127
... If gas settles into a (dynamically cold) disk before stars form, then stars formed in that disk will inherit the motions of the gas (mainly an ordered rotation). ...
... If gas settles into a (dynamically cold) disk before stars form, then stars formed in that disk will inherit the motions of the gas (mainly an ordered rotation). ...
Measuring Distances
... Measuring Distances Hold your finger out in front of your face at arm’s length. Look at your finger through each eye separately. What do you notice? This change in perspective is known as parallax. Ancient Greek astronomers expected to see a similar change in the positions of nearby stars if Earth ...
... Measuring Distances Hold your finger out in front of your face at arm’s length. Look at your finger through each eye separately. What do you notice? This change in perspective is known as parallax. Ancient Greek astronomers expected to see a similar change in the positions of nearby stars if Earth ...
Satellities - stoweschools.com
... Bipolar Star System Two stars 8x1010m apart rotate about a point 4x1010 m from each other in a circular path in 12.6 years. The two stars have the same mass. What is the mass of the stars? Fg causes the centripetal acceleration therefore Fg = Fc ...
... Bipolar Star System Two stars 8x1010m apart rotate about a point 4x1010 m from each other in a circular path in 12.6 years. The two stars have the same mass. What is the mass of the stars? Fg causes the centripetal acceleration therefore Fg = Fc ...
Neutron stars: compact objects with relativistic gravity
... As m(0) = 0, it might be tempting to think that the gravity would also be weak and so the general relativistic effects could be negligible near the center. This is not correct as it carries a Newtonian imprint in thinking about gravity. Although the Newtonian gravitational acceleration, Gm(r)/r2 , i ...
... As m(0) = 0, it might be tempting to think that the gravity would also be weak and so the general relativistic effects could be negligible near the center. This is not correct as it carries a Newtonian imprint in thinking about gravity. Although the Newtonian gravitational acceleration, Gm(r)/r2 , i ...
The mass function of star clusters formed in turbulent molecular clouds
... in galactic environment ...
... in galactic environment ...
How to predict the meridian passage time of a star. This is not an
... First, to get a quick estimate that might be used for example, just to guess when the star will be visible (without other aids such as the star finder), we can just look at what is called the “Planet Diagram” in the Nautical Almanac (NA). First we have to look up the SHA of Deneb, which we get from ...
... First, to get a quick estimate that might be used for example, just to guess when the star will be visible (without other aids such as the star finder), we can just look at what is called the “Planet Diagram” in the Nautical Almanac (NA). First we have to look up the SHA of Deneb, which we get from ...
ref evlution of stars
... Where the heck does all this dust come from in the first place? It contains lots of different elements that can’t have been magically created from interstellar hydrogen. The only way we know of to turn hydrogen into these heavier atoms is by nuclear fusion, which as we know takes place in the cores ...
... Where the heck does all this dust come from in the first place? It contains lots of different elements that can’t have been magically created from interstellar hydrogen. The only way we know of to turn hydrogen into these heavier atoms is by nuclear fusion, which as we know takes place in the cores ...
The Stars education kit - Student activities 1-4
... km. This distance is too large for most people to imagine or understand. There are ways to make such large numbers more manageable. For instance, it is easier to understand and work with 15 years than it is with 5 475 days, even though they both represent the same amount of time. A ‘Year’ is a much ...
... km. This distance is too large for most people to imagine or understand. There are ways to make such large numbers more manageable. For instance, it is easier to understand and work with 15 years than it is with 5 475 days, even though they both represent the same amount of time. A ‘Year’ is a much ...
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.