Chapter 26
... 100,000 light-years from one side to the other. The Sun lies about 26,000 lightyears from the galactic center on the edge of one of the spiral arms. The Milky Way’s disk is about 1,000 lightyears thick. ...
... 100,000 light-years from one side to the other. The Sun lies about 26,000 lightyears from the galactic center on the edge of one of the spiral arms. The Milky Way’s disk is about 1,000 lightyears thick. ...
1_Introduction
... In the jargon of astronomers, a “standard candle” is a light source of known luminosity. Luminosity is the rate at which light source radiates away energy (in other words, it’s the wattage). ...
... In the jargon of astronomers, a “standard candle” is a light source of known luminosity. Luminosity is the rate at which light source radiates away energy (in other words, it’s the wattage). ...
Bluffer`s Guide to Sirius
... have to assume that there has been some kind of mistake made. Today Sirius is what proper astronomers call a ‘main sequence star’, meaning it is happily shining away generating energy from hydrogen. We expect Sirius will stay like this for another billion years or so. Since the 1840s we have known t ...
... have to assume that there has been some kind of mistake made. Today Sirius is what proper astronomers call a ‘main sequence star’, meaning it is happily shining away generating energy from hydrogen. We expect Sirius will stay like this for another billion years or so. Since the 1840s we have known t ...
Energy Generation in Stars
... Thus for a star like the sun, it will take about 10 billion years for the core hydrogen to be fully converted to Helium. We are about 1/2 way through that process now. Overall the evolutionary timescale of main sequence stars is entirely driven by stellar mass in the sense that massive stars evolve ...
... Thus for a star like the sun, it will take about 10 billion years for the core hydrogen to be fully converted to Helium. We are about 1/2 way through that process now. Overall the evolutionary timescale of main sequence stars is entirely driven by stellar mass in the sense that massive stars evolve ...
White Dwarf
... •Helium is burning to Carbon in a shell around the Carbon core while H-to-He burning occurs in an outer ...
... •Helium is burning to Carbon in a shell around the Carbon core while H-to-He burning occurs in an outer ...
Stellar Masses
... slightly higher in energy (5.9 x 10-6 eV ). Compare this with the binding energy of the 1s state = -13.6 eV Hydrogen in its ground state will absorb 21 cm. radiation. If it is already in the upper state it will radiate 21 cm. radiation, which penetrates the dust clouds in interstellar space. 21.1 cm ...
... slightly higher in energy (5.9 x 10-6 eV ). Compare this with the binding energy of the 1s state = -13.6 eV Hydrogen in its ground state will absorb 21 cm. radiation. If it is already in the upper state it will radiate 21 cm. radiation, which penetrates the dust clouds in interstellar space. 21.1 cm ...
PRS Questions (queestions after Midterm 2)
... The graph below shows the blackbody spectra of three different stars. All three stars have the same size. Which of the stars is at the highest temperature? ...
... The graph below shows the blackbody spectra of three different stars. All three stars have the same size. Which of the stars is at the highest temperature? ...
the curious incident of the dog in the night-time
... are visible. A distinction must also be made between constellations and their similar cousins, asterisms. An asterism is constructed by using the brighter portions of one or several already established constellations. The most well-known asterism, the Big Dipper, is formed from the brightest stars o ...
... are visible. A distinction must also be made between constellations and their similar cousins, asterisms. An asterism is constructed by using the brighter portions of one or several already established constellations. The most well-known asterism, the Big Dipper, is formed from the brightest stars o ...
Black Holes, Part 3, Dark Energy
... One of the measured evidence is, that the Sun's mass density is a thousand times too low for the Sun to be a hydrogen gas sphere. Just look at the comparison. In comparing Saturn with Jupiter, Jupiter that has nearly twice the volume, has also nearly twice the mass density. In comparison with Jupit ...
... One of the measured evidence is, that the Sun's mass density is a thousand times too low for the Sun to be a hydrogen gas sphere. Just look at the comparison. In comparing Saturn with Jupiter, Jupiter that has nearly twice the volume, has also nearly twice the mass density. In comparison with Jupit ...
1, Scientific notation (2 points) A) Undergraduate Enrolment. In a
... C) Distance to a Star. The nearest star, Alpha Centauri C, is about 4.22 light-years from Earth. One light-year is the distance that light travels in one year and is about 5.88x1012 miles. How many miles is it from Earth to Alpha Centauri C? Express your answer in scientific notation. D) Distance to ...
... C) Distance to a Star. The nearest star, Alpha Centauri C, is about 4.22 light-years from Earth. One light-year is the distance that light travels in one year and is about 5.88x1012 miles. How many miles is it from Earth to Alpha Centauri C? Express your answer in scientific notation. D) Distance to ...
The Sun and the Stars
... subtypes WC, WN or WO (for Carbon, Nitrogen and Oxygen) (Possible GRB/Hypernovae progenitors) Carbon stars, C (originally R and N classification), red-giants/supergiants near end of lives with excess, Carbon in atmosphere WDs, D – stars are no longer undergoing thermonuclear reactions, simply coolin ...
... subtypes WC, WN or WO (for Carbon, Nitrogen and Oxygen) (Possible GRB/Hypernovae progenitors) Carbon stars, C (originally R and N classification), red-giants/supergiants near end of lives with excess, Carbon in atmosphere WDs, D – stars are no longer undergoing thermonuclear reactions, simply coolin ...
Characteristics of the Sun
... However, compared with other stars, the Sun is rather ordinary. It is about in the middle of the ranges for star size and brightness. Many of the stars that you can see in the night sky are actually bigger and brighter than the Sun—they only appear smaller because they are much farther away. Howeve ...
... However, compared with other stars, the Sun is rather ordinary. It is about in the middle of the ranges for star size and brightness. Many of the stars that you can see in the night sky are actually bigger and brighter than the Sun—they only appear smaller because they are much farther away. Howeve ...
theh – rdiagramsofyoungclust ersandtheformati on ofp
... attitudes with which the empirical evidence was looked upon. Haro has pointed out that, for a number of years, there has been some evidence that the H-R diagrams of young clusters are more complex than what it is expected from the simple contraction theory. Good examples of this are the color magnit ...
... attitudes with which the empirical evidence was looked upon. Haro has pointed out that, for a number of years, there has been some evidence that the H-R diagrams of young clusters are more complex than what it is expected from the simple contraction theory. Good examples of this are the color magnit ...
Accretion
... • There is a limit to the luminosity that can be produced by a given object, known as the Eddington luminosity. • Effectively this is when the inward gravitational force on matter is balanced by the outward transfer of momentum by ...
... • There is a limit to the luminosity that can be produced by a given object, known as the Eddington luminosity. • Effectively this is when the inward gravitational force on matter is balanced by the outward transfer of momentum by ...
absolute brightness: The apparent brightness a star would have if it
... collapse of certain very massive stars at the ends of their evolution. blazars: a class of active galaxies that exhibit rapidly variable emission from the radio through gamma-ray band. The radiation is predominantly from jets moving near the speed of light. Blazars are thought to be radio galaxies w ...
... collapse of certain very massive stars at the ends of their evolution. blazars: a class of active galaxies that exhibit rapidly variable emission from the radio through gamma-ray band. The radiation is predominantly from jets moving near the speed of light. Blazars are thought to be radio galaxies w ...
CHP 13
... b. produced by a supernova explosion. c. produced by a nova explosion. d. a nebula within which planets are forming. e. a cloud of hot gas surround a planet 3. The Chandrasekhar limit tells us that a. accretion disks can grow hot through friction. b. neutron stars of more than 3 solar masses are not ...
... b. produced by a supernova explosion. c. produced by a nova explosion. d. a nebula within which planets are forming. e. a cloud of hot gas surround a planet 3. The Chandrasekhar limit tells us that a. accretion disks can grow hot through friction. b. neutron stars of more than 3 solar masses are not ...
The Death of Stars
... b. produced by a supernova explosion. c. produced by a nova explosion. d. a nebula within which planets are forming. e. a cloud of hot gas surround a planet 3. The Chandrasekhar limit tells us that a. accretion disks can grow hot through friction. b. neutron stars of more than 3 solar masses are not ...
... b. produced by a supernova explosion. c. produced by a nova explosion. d. a nebula within which planets are forming. e. a cloud of hot gas surround a planet 3. The Chandrasekhar limit tells us that a. accretion disks can grow hot through friction. b. neutron stars of more than 3 solar masses are not ...
absolute brightness: The apparent brightness a star would have if it
... collapse of certain very massive stars at the ends of their evolution. blazars: a class of active galaxies that exhibit rapidly variable emission from the radio through gamma-ray band. The radiation is predominantly from jets moving near the speed of light. Blazars are thought to be radio galaxies w ...
... collapse of certain very massive stars at the ends of their evolution. blazars: a class of active galaxies that exhibit rapidly variable emission from the radio through gamma-ray band. The radiation is predominantly from jets moving near the speed of light. Blazars are thought to be radio galaxies w ...
Ursa Minor
Ursa Minor (Latin: ""Smaller She-Bear"", contrasting with Ursa Major), also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the name Little Dipper. It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor has traditionally been important for navigation, particularly by mariners, due to Polaris being the North Star.Polaris, the brightest star in the constellation, is a yellow-white supergiant and the brightest Cepheid variable star in the night sky, ranging from apparent magnitude 1.97 to 2.00. Beta Ursae Minoris, also known as Kochab, is an aging star that has swollen and cooled to become an orange giant with an apparent magnitude of 2.08, only slightly fainter than Polaris. Kochab and magnitude 3 Gamma Ursae Minoris have been called the ""guardians of the pole star"". Planets have been detected orbiting four of the stars, including Kochab. The constellation also contains an isolated neutron star—Calvera—and H1504+65, the hottest white dwarf yet discovered with a surface temperature of 200,000 K.