United States Flag
... flags and in foreign flags, including Puerto Rico, Uruguay, and the once sovereign nations of the Republic of Texas and the Kingdom of Hawaii. Based on the American usage, the star has come to be associated in flag design with unity, independence, or to represent the constituent parts of a nation. U ...
... flags and in foreign flags, including Puerto Rico, Uruguay, and the once sovereign nations of the Republic of Texas and the Kingdom of Hawaii. Based on the American usage, the star has come to be associated in flag design with unity, independence, or to represent the constituent parts of a nation. U ...
Lecture7 - Indiana University Astronomy
... Vesta, the second largest object in the asteroid belt, was recently imaged for the first time by the robotic Dawn satellite that arrived last month. ...
... Vesta, the second largest object in the asteroid belt, was recently imaged for the first time by the robotic Dawn satellite that arrived last month. ...
script
... that good. In a solar type star the presence of Lithium most likely means it is young. But the processes that affect the strength of lithium are poorly known. For instance, strong Li is also found in some evolved giant stars! ...
... that good. In a solar type star the presence of Lithium most likely means it is young. But the processes that affect the strength of lithium are poorly known. For instance, strong Li is also found in some evolved giant stars! ...
– 1 – 1. A Gas
... If star contracts, Ω becomes more negative, so U must become more positive, ∆U = −∆Ω/2. Then ∆W = ∆U + ∆Ω = − | ∆Ω | /2. So half of the contraction energy goes into heating up the interior of the star (increasing U), and half is lost through radiation. The other half cannot go into increasing U, oth ...
... If star contracts, Ω becomes more negative, so U must become more positive, ∆U = −∆Ω/2. Then ∆W = ∆U + ∆Ω = − | ∆Ω | /2. So half of the contraction energy goes into heating up the interior of the star (increasing U), and half is lost through radiation. The other half cannot go into increasing U, oth ...
Document
... o Theories predict mass loss to be much less than 10-6 solar masses per year, whereas models using those same theories pace mass loss at the order of 10-7 solar masses per year There was degeneracy in the models between different masses and levels of convective core overshooting Where is Polaris ...
... o Theories predict mass loss to be much less than 10-6 solar masses per year, whereas models using those same theories pace mass loss at the order of 10-7 solar masses per year There was degeneracy in the models between different masses and levels of convective core overshooting Where is Polaris ...
The Most Massive LMC Star Sk
... We got interested in Sk-66°41 during our analysis of an H 11 region in the LMC as apart of the search and investigation of the high excitation compact HIlblobs in the Magellanic Clouds. The knowledge of the physical characteristics of the associated H I1 region N 11 C (Henize, 1956) is important for ...
... We got interested in Sk-66°41 during our analysis of an H 11 region in the LMC as apart of the search and investigation of the high excitation compact HIlblobs in the Magellanic Clouds. The knowledge of the physical characteristics of the associated H I1 region N 11 C (Henize, 1956) is important for ...
PDF file - Memorie della SAIt
... a fossil record of the nucleosynthesis that occurred several Gyr ago in halo AGB stars. They are dwarfs or giants, whose surface composition was polluted by the wind of an AGB companion. Then, the C and s-element enhancements are ashes of the nucleosynthesis occurred in the He-rich inter-shell of a ...
... a fossil record of the nucleosynthesis that occurred several Gyr ago in halo AGB stars. They are dwarfs or giants, whose surface composition was polluted by the wind of an AGB companion. Then, the C and s-element enhancements are ashes of the nucleosynthesis occurred in the He-rich inter-shell of a ...
More detailed notes
... Stars generate energy by fusing light elements to produce heavier ones. As long as the mass of the product is less than the mass of the input, this will generate energy by E = mc2. For example: Hydrogen fusion Masses (in amu) ...
... Stars generate energy by fusing light elements to produce heavier ones. As long as the mass of the product is less than the mass of the input, this will generate energy by E = mc2. For example: Hydrogen fusion Masses (in amu) ...
New York City Disciple Code - EarthSpaceScience-Keller
... A correct range within 10² of luminosity And the correct spectral class are included for each star ...
... A correct range within 10² of luminosity And the correct spectral class are included for each star ...
Week 6
... The bright star in the top left corner of Orion, Betelgeuse, has a radius 936 times that of the Sun and a surface temperature of 3500 K. What is the luminosity of this star? If Betelgeuse is 640 ly from Earth, what is the brightness of the light from Betelgeuse that reaches Earth? ...
... The bright star in the top left corner of Orion, Betelgeuse, has a radius 936 times that of the Sun and a surface temperature of 3500 K. What is the luminosity of this star? If Betelgeuse is 640 ly from Earth, what is the brightness of the light from Betelgeuse that reaches Earth? ...
Lecture102102 - FSU High Energy Physics
... if gravity was stronger than pressure, the Sun would shrink if pressure was stronger than gravity, the Sun would grow ...
... if gravity was stronger than pressure, the Sun would shrink if pressure was stronger than gravity, the Sun would grow ...
Exercise 4
... 12. d = 1/p = 1/0.0889 = 11.25 pc = 11.25 x 206265 = 2.32 x 106 AU 13. L = 4R2 T4 =A T4, thus L is directly proportional to surface area A. The graph is a straight line through origin. 14. Surface temperature is known from H-R diagram. Radius can be found from L = 4R2 T4. L Apparent brightness ...
... 12. d = 1/p = 1/0.0889 = 11.25 pc = 11.25 x 206265 = 2.32 x 106 AU 13. L = 4R2 T4 =A T4, thus L is directly proportional to surface area A. The graph is a straight line through origin. 14. Surface temperature is known from H-R diagram. Radius can be found from L = 4R2 T4. L Apparent brightness ...
Orbits and Dark Matter, the Center of the Milky Way
... Sun enters and leaves a spiral arm D) By viewing the Milky Way from a point well above its plane ...
... Sun enters and leaves a spiral arm D) By viewing the Milky Way from a point well above its plane ...
Lecture 2 - SUNY Oswego
... If the Sun were to contract a bit, the core gets hotter, nuclear reactions go at a faster rate creating more energy and hence more pressure halting the contraction. If the Sun were to expand a bit, the core gets cooler, nuclear reactions go at a slower rate creating less energy and hence less pressu ...
... If the Sun were to contract a bit, the core gets hotter, nuclear reactions go at a faster rate creating more energy and hence more pressure halting the contraction. If the Sun were to expand a bit, the core gets cooler, nuclear reactions go at a slower rate creating less energy and hence less pressu ...
Chapter 13
... A) the period of pulsation must speed up as the neutron star continues collapsing. B) all pulsars must have their poles pointed directly toward us. C) the period of pulsation slows down due to the drag of the remnant on its field. D) the star literally turns on and off like a lighthouse beacon. E) i ...
... A) the period of pulsation must speed up as the neutron star continues collapsing. B) all pulsars must have their poles pointed directly toward us. C) the period of pulsation slows down due to the drag of the remnant on its field. D) the star literally turns on and off like a lighthouse beacon. E) i ...
Astron. J., 111
... free to use DR-12 if you want – just let us know this) to see what a variety of celestial objects (stars, galaxies) look like; what solar system objects look like (asteroids); and what other things look like (meteors, airplanes, “ghosts” – these are caused by internal reflections from bright objects ...
... free to use DR-12 if you want – just let us know this) to see what a variety of celestial objects (stars, galaxies) look like; what solar system objects look like (asteroids); and what other things look like (meteors, airplanes, “ghosts” – these are caused by internal reflections from bright objects ...
Astronomy Teaching that Focuses on Learning Subtitled
... If a student says it is hotter in the summer time because we are closer, what do you say? • No, are you stupid? • No, it’s the tilt of the Earth. • Hum, I heard that it is warmest in Australia in January. How can that be? • Why do you say that? • What is it you are listening for if you ask them to ...
... If a student says it is hotter in the summer time because we are closer, what do you say? • No, are you stupid? • No, it’s the tilt of the Earth. • Hum, I heard that it is warmest in Australia in January. How can that be? • Why do you say that? • What is it you are listening for if you ask them to ...
Chapter 12
... 1. Binary stars are important because they allow us to measure stellar masses using Kepler’s third law as modified by Newton. 2. Knowledge of the size of one of the star’s ellipses, along with knowledge of the period of its motion, permits calculation of the total mass of the two stars. 3. To determ ...
... 1. Binary stars are important because they allow us to measure stellar masses using Kepler’s third law as modified by Newton. 2. Knowledge of the size of one of the star’s ellipses, along with knowledge of the period of its motion, permits calculation of the total mass of the two stars. 3. To determ ...
Slide 1
... black holes GRBs probably will not occur at solar metallicity, if we need a direct collapse to black hole. At lower metallicities, weaker winds allow more massive cores. Below ~0.4 ZSun, the stars cannot loose the He envelope (Heger 2003). Star is either born rotating rapidly, or is spun up by inter ...
... black holes GRBs probably will not occur at solar metallicity, if we need a direct collapse to black hole. At lower metallicities, weaker winds allow more massive cores. Below ~0.4 ZSun, the stars cannot loose the He envelope (Heger 2003). Star is either born rotating rapidly, or is spun up by inter ...
Document
... • need about the same Luminosity – similar temperature gradient dT/dr • now much higher Tc – need larger star for same dT/dr Lower mass stars become red giants during shell H-burning ...
... • need about the same Luminosity – similar temperature gradient dT/dr • now much higher Tc – need larger star for same dT/dr Lower mass stars become red giants during shell H-burning ...
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.