obafgkm - Piscataway High School
... Astronomers cannot physically measure properties of stars. They rely on interpreting data that can be gathered from the earth. Determine what information about stars can be revealed using the following methods: Parallax effect ...
... Astronomers cannot physically measure properties of stars. They rely on interpreting data that can be gathered from the earth. Determine what information about stars can be revealed using the following methods: Parallax effect ...
Mark scheme for Support Worksheet – Topic E, Worksheet 1
... A constellation is a collection of stars usually in a recognisable pattern that are not necessarily physically close to each other; whereas a stellar cluster consists of stars that are close to each other and attract each other gravitationally. ...
... A constellation is a collection of stars usually in a recognisable pattern that are not necessarily physically close to each other; whereas a stellar cluster consists of stars that are close to each other and attract each other gravitationally. ...
Stellar Evolution - FSU High Energy Physics
... • H He C Ne O Si Fe • Cannot burn beyond Fe because it is the most tightly bound state. Burning Fe would no longer release energy, but require energy absorption. • These stars have short violent lives. ...
... • H He C Ne O Si Fe • Cannot burn beyond Fe because it is the most tightly bound state. Burning Fe would no longer release energy, but require energy absorption. • These stars have short violent lives. ...
Evolution of Massive Stars
... Stars more massive than 8 times the Sun’s mass, evolve differently than stars of lower initial mass. Like lower-mass stars, high-mass stars fuse hydrogen in their cores during their main sequence lifetime. Massive stars also spend 90% of the total lifetimes as stars located on the main sequence. The ...
... Stars more massive than 8 times the Sun’s mass, evolve differently than stars of lower initial mass. Like lower-mass stars, high-mass stars fuse hydrogen in their cores during their main sequence lifetime. Massive stars also spend 90% of the total lifetimes as stars located on the main sequence. The ...
Study Notes for Chapter 30: Stars, Galaxies, and the Universe
... 10. After its temperature rises to 10,000,000°C, a protostar becomes a star when nuclear fusion begins. 11. Apparent magnitude is the brightness of a star as it appears from Earth. 12. Astronomers believe that cosmic background radiation formed shortly after the big bang. 13. By analyzing the light ...
... 10. After its temperature rises to 10,000,000°C, a protostar becomes a star when nuclear fusion begins. 11. Apparent magnitude is the brightness of a star as it appears from Earth. 12. Astronomers believe that cosmic background radiation formed shortly after the big bang. 13. By analyzing the light ...
Study Notes for Chapter 30:
... Hubble’s discovery that there was ____ shift in the spectra of galaxies lead to an understanding that the universe is ____. ...
... Hubble’s discovery that there was ____ shift in the spectra of galaxies lead to an understanding that the universe is ____. ...
Study Notes for Chapter 30:
... Hubble’s discovery that there was ____ shift in the spectra of galaxies lead to an understanding that the universe is ____. ...
... Hubble’s discovery that there was ____ shift in the spectra of galaxies lead to an understanding that the universe is ____. ...
PowerPoint File
... • The fuel of a main sequence star is its own mass • More massive stars have more fuel than less massive stars. • But they are using their fuel up at a fast rate, much faster than proportional to their mass. • So, massive stars run out of fuel sooner. The more massive, the shorter their Main Sequenc ...
... • The fuel of a main sequence star is its own mass • More massive stars have more fuel than less massive stars. • But they are using their fuel up at a fast rate, much faster than proportional to their mass. • So, massive stars run out of fuel sooner. The more massive, the shorter their Main Sequenc ...
Solution to Problem Set 1 1. The total number of nucleons in one
... naked eye, 6 = 4.7 + 5 log 10 pc , which gives d = 18.2 pc. The flux is then f = L/(4πd2 ) = 9.6 × 10−11 W m−2 . Assuming the area of the eyes is about A = 1 cm2 , then the total energy received in a time period of t = 1s is E = f At = 9.6 × 10−15 J. The photons are mostly in the visible range, so h ...
... naked eye, 6 = 4.7 + 5 log 10 pc , which gives d = 18.2 pc. The flux is then f = L/(4πd2 ) = 9.6 × 10−11 W m−2 . Assuming the area of the eyes is about A = 1 cm2 , then the total energy received in a time period of t = 1s is E = f At = 9.6 × 10−15 J. The photons are mostly in the visible range, so h ...
Stellar Evolution
... • If a protostar forms with a mass less than 0.08 solar masses, its internal temperature never reaches a value high enough for thermonuclear fusion to begin. • This failed star is called a brown dwarf, halfway between a planet (like Jupiter) and a star. ...
... • If a protostar forms with a mass less than 0.08 solar masses, its internal temperature never reaches a value high enough for thermonuclear fusion to begin. • This failed star is called a brown dwarf, halfway between a planet (like Jupiter) and a star. ...
Stellar Evolution
... It glows with infrared light generated from its gravitational contraction like Jupiter does. They don’t “evolve” but stay brown dwarfs and slowly fade over 100s of billions of years ...
... It glows with infrared light generated from its gravitational contraction like Jupiter does. They don’t “evolve” but stay brown dwarfs and slowly fade over 100s of billions of years ...
Stellar Evolution
... It glows with infrared light generated from its gravitational contraction like Jupiter does. They don’t “evolve” but stay brown dwarfs and slowly fade over 100s of billions of years ...
... It glows with infrared light generated from its gravitational contraction like Jupiter does. They don’t “evolve” but stay brown dwarfs and slowly fade over 100s of billions of years ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.