Lecture 10
... Gravitational lensing conserves surface brightness, so the distortion of the image of the source across a larger area of ...
... Gravitational lensing conserves surface brightness, so the distortion of the image of the source across a larger area of ...
ASTRONOMY: WHAT DO YOU NEED TO KNOW
... What is the CNO cycle and what is formed through this cycle? How massive are stars that follow this cycle? This cycle is found in stars more massive than our Sun. The cores of such stars are hotter than the Sun and use the CNO cycle to produce helium instead of the hydrogen to helium formation of th ...
... What is the CNO cycle and what is formed through this cycle? How massive are stars that follow this cycle? This cycle is found in stars more massive than our Sun. The cores of such stars are hotter than the Sun and use the CNO cycle to produce helium instead of the hydrogen to helium formation of th ...
Ay123 Fall 2011 STELLAR STRUCTURE AND EVOLUTION Problem Set 2
... (3) Stein 2051, M = 0.50 M⊙ or 0.72 M⊙ , R = 0.0115 R⊙ , and try to infer their compositions. e. The results you have derived above should show that as M → 0, R → ∞. Clearly, at some point this result must break down (think about where Jupiter would fall on this plot !). This is because when the den ...
... (3) Stein 2051, M = 0.50 M⊙ or 0.72 M⊙ , R = 0.0115 R⊙ , and try to infer their compositions. e. The results you have derived above should show that as M → 0, R → ∞. Clearly, at some point this result must break down (think about where Jupiter would fall on this plot !). This is because when the den ...
Astronomical distances and Stellar magnitudes
... 1. What is meant by a light year? 2. What is meant by an astronomical unit (AU)? 3. What is meant by a parsec (pc)? 4. What is meant by a mega parsec (Mpc)? 5. What is meant by the apparent magnitude of an astronomical object? 6. Give the approximate distance of the following in AU: (a) Sun to the E ...
... 1. What is meant by a light year? 2. What is meant by an astronomical unit (AU)? 3. What is meant by a parsec (pc)? 4. What is meant by a mega parsec (Mpc)? 5. What is meant by the apparent magnitude of an astronomical object? 6. Give the approximate distance of the following in AU: (a) Sun to the E ...
Globular Cluster Formation in CDM Cosmologies
... First stars, formed in primordial gas, devoid of metals, dust, strong B field,… Going back in time – to 400 million years after the Big Bang – to the “dark era” In what kind of objects did such stars form, and how did they influence their ...
... First stars, formed in primordial gas, devoid of metals, dust, strong B field,… Going back in time – to 400 million years after the Big Bang – to the “dark era” In what kind of objects did such stars form, and how did they influence their ...
1. What is the black hole?
... 5.Could the Sun become a black hole? No, the Sun is much too small to ever become a black hole. A star has to be much more massive than the Sun before it can collapse into a black hole. ...
... 5.Could the Sun become a black hole? No, the Sun is much too small to ever become a black hole. A star has to be much more massive than the Sun before it can collapse into a black hole. ...
CBradleyLoutl
... . Looking at what wavelengths of light are present on emission/absorption spectra will tell exact constituents. Examples: - Age: . For a star around one solar mass, it takes a few million years to move to the main sequence. At twice this mass it takes less than a million years, and at half the mass ...
... . Looking at what wavelengths of light are present on emission/absorption spectra will tell exact constituents. Examples: - Age: . For a star around one solar mass, it takes a few million years to move to the main sequence. At twice this mass it takes less than a million years, and at half the mass ...
Universe Now - Course Pages of Physics Department
... neutron star and an ordinary star matter flow from the ordinary star to the poles of the neutron star causes narrow pulses of X-rays. When matter is accreted on the top of the neutron star, helium can ignite and cause an explosion seen as an X-ray burst in ...
... neutron star and an ordinary star matter flow from the ordinary star to the poles of the neutron star causes narrow pulses of X-rays. When matter is accreted on the top of the neutron star, helium can ignite and cause an explosion seen as an X-ray burst in ...
Brichler-powerpoint
... • Parallax – an apparent shift in the position of an object when viewed from different locations. • Using parallax and trigonometry, astronomers can find distances to stars. • Closer stars seem to move more than distant stars as the earth revolves around the sun. ...
... • Parallax – an apparent shift in the position of an object when viewed from different locations. • Using parallax and trigonometry, astronomers can find distances to stars. • Closer stars seem to move more than distant stars as the earth revolves around the sun. ...
aas_gdemessieres - Astronomy at Swarthmore College
... about 2-3 radii. The Si XIII data suggest that the hottest material is nearest the star, but there are uncertainties in the photospheric EUV flux that may affect this result. ...
... about 2-3 radii. The Si XIII data suggest that the hottest material is nearest the star, but there are uncertainties in the photospheric EUV flux that may affect this result. ...
Solutions to test #2 taken on Tuesday
... 2. (15) Millions, Billions or One. This is an “order of magnitude” question. Pick the number (the order of magnitude) that is closest for each. a) _millions_The temperature in the core of the Sun. b) ___one__ The size of a typical black hole’s event horizon (in kilometers) created in the death of a ...
... 2. (15) Millions, Billions or One. This is an “order of magnitude” question. Pick the number (the order of magnitude) that is closest for each. a) _millions_The temperature in the core of the Sun. b) ___one__ The size of a typical black hole’s event horizon (in kilometers) created in the death of a ...
Stars and Deep Time
... • The remnants of the massive star begin to cool and contract. • Nothing can stop this process, so eventually even protons and electrons contract to become neutrons. ...
... • The remnants of the massive star begin to cool and contract. • Nothing can stop this process, so eventually even protons and electrons contract to become neutrons. ...
Stellar Evolution and the Herzsprung-Russell Diagram
... • Electrons repel each other when highly compressed (not due to charge) • Requires no energy source – keeps working as the star cools • Star maintains constant radius (about same as Earth) • Example: Sirius B • Maximum mass 1.4 Msun or collapse! ...
... • Electrons repel each other when highly compressed (not due to charge) • Requires no energy source – keeps working as the star cools • Star maintains constant radius (about same as Earth) • Example: Sirius B • Maximum mass 1.4 Msun or collapse! ...
The Mass Assembly of Galaxies
... At least part of the young massive stars at the GC appear to have formed in-situ from a dense accretion disk. The disk has a hole in the center exactly where the S-stars are found. The size of this hole (1’’) agrees well with the size of the region where star formation is not expected. The origin of ...
... At least part of the young massive stars at the GC appear to have formed in-situ from a dense accretion disk. The disk has a hole in the center exactly where the S-stars are found. The size of this hole (1’’) agrees well with the size of the region where star formation is not expected. The origin of ...
Masers and high mass star formation Claire Chandler
... yet, but molecular gas available (a few of these cores are known) • Massive hot cores: Star has formed already, but accretion so strong that quenches ionization => no HII region (tens are known). Jets and disks expected in standard model • Ultracompact HII region: Accretion has ceased and detectable ...
... yet, but molecular gas available (a few of these cores are known) • Massive hot cores: Star has formed already, but accretion so strong that quenches ionization => no HII region (tens are known). Jets and disks expected in standard model • Ultracompact HII region: Accretion has ceased and detectable ...
HW10_Answers
... 1) Explain why a stellar core that has a greater mass than 4 solar masses, will not become a neutron star, but instead become a black hole. In a neutron star the neutron degeneracy pressure is holding up against gravity trying to collapse the core of the star. When neutrons are packed very close tog ...
... 1) Explain why a stellar core that has a greater mass than 4 solar masses, will not become a neutron star, but instead become a black hole. In a neutron star the neutron degeneracy pressure is holding up against gravity trying to collapse the core of the star. When neutrons are packed very close tog ...
Stellar evolution - Chandra X
... about them. X-ray data reveal extreme or violent conditions where gas has been heated to very high temperatures or particles have been accelerated to extremely high energies. These conditions can exist near collapsed objects such as white dwarfs, neutron stars, and black holes; in giant bubbles of h ...
... about them. X-ray data reveal extreme or violent conditions where gas has been heated to very high temperatures or particles have been accelerated to extremely high energies. These conditions can exist near collapsed objects such as white dwarfs, neutron stars, and black holes; in giant bubbles of h ...
White Dwarfs and Neutron Stars
... pulsations. Energy source is gravitational energy of infalling matter. ...
... pulsations. Energy source is gravitational energy of infalling matter. ...
White Dwarfs and Neutron Stars
... pulsations. Energy source is gravitational energy of infalling matter. ...
... pulsations. Energy source is gravitational energy of infalling matter. ...
White Dwarfs - Chandra X
... While still in his twenties Subrahmanyan Chandrasekhar, the Chandra X-ray Observatory's namesake, used relativity theory and quantum mechanics to show that degenerate electron pressure can do only so much. If the mass of the white dwarf becomes greater than about 1.4 times the mass of the sun—called ...
... While still in his twenties Subrahmanyan Chandrasekhar, the Chandra X-ray Observatory's namesake, used relativity theory and quantum mechanics to show that degenerate electron pressure can do only so much. If the mass of the white dwarf becomes greater than about 1.4 times the mass of the sun—called ...
Physics 11 Fall 2012 Practice Problems 7 - Solutions
... 5. The Principle of Equivalence states that the free-fall acceleration of any object in a gravitational field is independent of the mass of the object. This can be deduced from the law of universal gravitation, but how well does it hold up experimentally? The Roll-Krotkov-Dicke experiment performed ...
... 5. The Principle of Equivalence states that the free-fall acceleration of any object in a gravitational field is independent of the mass of the object. This can be deduced from the law of universal gravitation, but how well does it hold up experimentally? The Roll-Krotkov-Dicke experiment performed ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.