大爆炸---宇宙的起源
... body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000. As the universe expanded, adiabatic cooling caused the plasma to lose energy until it became favorable for electrons to combine with protons, forming hydrogen atoms. This recombination ev ...
... body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000. As the universe expanded, adiabatic cooling caused the plasma to lose energy until it became favorable for electrons to combine with protons, forming hydrogen atoms. This recombination ev ...
Sample Final
... 37. When the signals from pulsars were first discovered, they were thought to be a) Mass exchange between a normal star and a white dwarf. b) Mass exchange between a normal star and a black hole. c) Signals from an extraterrestrial intelligence. d) Stars in the process of collapsing down to a black ...
... 37. When the signals from pulsars were first discovered, they were thought to be a) Mass exchange between a normal star and a white dwarf. b) Mass exchange between a normal star and a black hole. c) Signals from an extraterrestrial intelligence. d) Stars in the process of collapsing down to a black ...
Life Cycles of Stars
... • Different size stars go through similar life cycles, however they are different: 1) Low Mass Stars 2) Medium Mass Stars 3) High Mass Stars ...
... • Different size stars go through similar life cycles, however they are different: 1) Low Mass Stars 2) Medium Mass Stars 3) High Mass Stars ...
PHYS3380_111115_bw - The University of Texas at Dallas
... objects to novae (meaning new stars). • So-called by Fritz Zwicky, after Edwin Hubble estimated distance to Andromeda galaxy (through Cepheids) • Hence the luminosity of the “nova” discovered in 1885 in Andromeda was determined • Supernovae outbursts last for short periods: typically months to a few ...
... objects to novae (meaning new stars). • So-called by Fritz Zwicky, after Edwin Hubble estimated distance to Andromeda galaxy (through Cepheids) • Hence the luminosity of the “nova” discovered in 1885 in Andromeda was determined • Supernovae outbursts last for short periods: typically months to a few ...
Geochemistry & Lab
... suggests that at least initially it was a neutron star). In any case, the basic idea is that when the central part of the star fuses its way to iron, it can't go any farther because at low pressures iron 56 has the highest binding energy per nucleon of any element, so fusion or fission of iron 56 re ...
... suggests that at least initially it was a neutron star). In any case, the basic idea is that when the central part of the star fuses its way to iron, it can't go any farther because at low pressures iron 56 has the highest binding energy per nucleon of any element, so fusion or fission of iron 56 re ...
The Birth of a Supernova Seen in Real Time
... with the X-ray outburst, but just two hours later it spotted a new optical source rising quickly in brightness. Through optical spectroscopy we quickly established that the nature of the transient was a very young supernova. In particular, the lack of hydrogen and silicon lines in the spectrum marke ...
... with the X-ray outburst, but just two hours later it spotted a new optical source rising quickly in brightness. Through optical spectroscopy we quickly established that the nature of the transient was a very young supernova. In particular, the lack of hydrogen and silicon lines in the spectrum marke ...
Stellar Evolution Lab
... Stage 1- Stars are born in clouds of gas and dust called Nebulas. Stage 2- The gas and dust spiral together and contract under their own gravity. The gas and dust will begin to heat up and start to glow forming Protostars. Stage 3- If a protostar contains enough matter, the central temperature will ...
... Stage 1- Stars are born in clouds of gas and dust called Nebulas. Stage 2- The gas and dust spiral together and contract under their own gravity. The gas and dust will begin to heat up and start to glow forming Protostars. Stage 3- If a protostar contains enough matter, the central temperature will ...
Star Types - University of Massachusetts Amherst
... While the exterior layers expand, the helium core continues to contract and eventually becomes hot enough (100 million Kelvin) for helium to begin to fuse into carbon (if M > 0.5 Mo) Carbon ash is deposited in core and eventually a heliumburning shell develops. This shell is itself surrounded by a ...
... While the exterior layers expand, the helium core continues to contract and eventually becomes hot enough (100 million Kelvin) for helium to begin to fuse into carbon (if M > 0.5 Mo) Carbon ash is deposited in core and eventually a heliumburning shell develops. This shell is itself surrounded by a ...
A Star is Born!
... • The Zero Age Main Sequence (ZAMS) represents the onset or start of nuclear burning (fusion) • The properties of a star on the ZAMS are primarily determined by its mass, somewhat dependent on composition (He and heavier elements) ...
... • The Zero Age Main Sequence (ZAMS) represents the onset or start of nuclear burning (fusion) • The properties of a star on the ZAMS are primarily determined by its mass, somewhat dependent on composition (He and heavier elements) ...
大爆炸---宇宙的起源 - 中正大學化學系
... body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000. As the universe expanded, adiabatic cooling caused the plasma to lose energy until it became favorable for electrons to combine with protons, forming hydrogen atoms. This recombination ev ...
... body thermal energy coming from all parts of the sky. The radiation is isotropic to roughly one part in 100,000. As the universe expanded, adiabatic cooling caused the plasma to lose energy until it became favorable for electrons to combine with protons, forming hydrogen atoms. This recombination ev ...
Astronomy 100 Tuesday, Thursday 2:30
... How do we know there are neutron stars? • The identification of Pulsars • Pulsars give out pulses of radio waves at precise ...
... How do we know there are neutron stars? • The identification of Pulsars • Pulsars give out pulses of radio waves at precise ...
Document
... If a star’s iron core reaches 1.4 times the mass of the Sun, gravity becomes strong enough to combine electrons and protons into neutrons. During this brief period, heavier elements such as gold and uranium are created, as atomic nuclei are smashed together. The core of the star collapses and ...
... If a star’s iron core reaches 1.4 times the mass of the Sun, gravity becomes strong enough to combine electrons and protons into neutrons. During this brief period, heavier elements such as gold and uranium are created, as atomic nuclei are smashed together. The core of the star collapses and ...
NEUTRON STAR?
... dwarfs are smaller in size than less massive ones. More specifically, why does gravity compress white dwarfs to different sizes? • I absolutely loved the part on neutron stars and on how powerful their density was. That power is almost unimaginable to me. Other than that, I found the reading to be p ...
... dwarfs are smaller in size than less massive ones. More specifically, why does gravity compress white dwarfs to different sizes? • I absolutely loved the part on neutron stars and on how powerful their density was. That power is almost unimaginable to me. Other than that, I found the reading to be p ...
A massive hypergiant star as the progenitor of the supernova SN
... point source detected in 1997 was a compact cluster of many stars, with a combined luminosity of the order of 106 solar luminosities (106L[). Second, the spatial coincidence of the putative single star with SN 2005gl alone did not provide conclusive evidence that the supernova explosion was actually ...
... point source detected in 1997 was a compact cluster of many stars, with a combined luminosity of the order of 106 solar luminosities (106L[). Second, the spatial coincidence of the putative single star with SN 2005gl alone did not provide conclusive evidence that the supernova explosion was actually ...
Star Life Cycles
... A white dwarf is a star that has exhausted most or all of its nuclear fuel and has collapsed to a very small size; such a star is near its final stage of life. White dwarfs eventually become black dwarfs, which is a white dwarf that has cooled down enough that it no longer emits light. Interes ...
... A white dwarf is a star that has exhausted most or all of its nuclear fuel and has collapsed to a very small size; such a star is near its final stage of life. White dwarfs eventually become black dwarfs, which is a white dwarf that has cooled down enough that it no longer emits light. Interes ...
Stars
... • Then, star collapses under the weight and because it is electron degenerate, energy created will not expand the star and shut off the fusion. • So, entire star (carbon, mostly) undergoes fusion at once. What a star normally takes billions of years to burn, this star burns all at once. BIG explosio ...
... • Then, star collapses under the weight and because it is electron degenerate, energy created will not expand the star and shut off the fusion. • So, entire star (carbon, mostly) undergoes fusion at once. What a star normally takes billions of years to burn, this star burns all at once. BIG explosio ...
Foundation 1 - Discovering Astronomy
... High Mass Giant Stars (> 8 M ) Have a Different Story • Fusion in the core continues through many more stages than for low mass stars • Heavier elements are produced: ...
... High Mass Giant Stars (> 8 M ) Have a Different Story • Fusion in the core continues through many more stages than for low mass stars • Heavier elements are produced: ...
Lecture 16, PPT version
... At their maximum brightness, supernovae are as bright as an entire galaxy. ...
... At their maximum brightness, supernovae are as bright as an entire galaxy. ...
Chapter 15. The Chandrasekhar Limit, Iron-56 and Core
... be composed of Carbon and Oxygen. Its dimensions will be roughly that of the Earth, but its mass will be typically about 0.5 solar masses or more. Its maximum mass is 1.4 solar masses, namely the Chandrasekhar limit. White dwarfs are supported by electron degeneracy pressure and therefore do not hav ...
... be composed of Carbon and Oxygen. Its dimensions will be roughly that of the Earth, but its mass will be typically about 0.5 solar masses or more. Its maximum mass is 1.4 solar masses, namely the Chandrasekhar limit. White dwarfs are supported by electron degeneracy pressure and therefore do not hav ...
Red Giants
... I'll give you a short answer and a longer one. The short answer is that towards the end of a star's life, the temperature near the core rises and this causes the size of the star to expand. This is the fate of the Sun in about 5 billion years. You might want to mark your calendar!The long answer is ...
... I'll give you a short answer and a longer one. The short answer is that towards the end of a star's life, the temperature near the core rises and this causes the size of the star to expand. This is the fate of the Sun in about 5 billion years. You might want to mark your calendar!The long answer is ...
Self Assessment: Life Cycle of a Star
... a) the collapse of the iron core of an intermediate mass star b) the collapse of the iron core of a star with a mass greater than about six solar masses c) the collapse of a planetary nebula d) the collapse of the a star's core during the formation of a planetary nebula 4. The length of a star's l ...
... a) the collapse of the iron core of an intermediate mass star b) the collapse of the iron core of a star with a mass greater than about six solar masses c) the collapse of a planetary nebula d) the collapse of the a star's core during the formation of a planetary nebula 4. The length of a star's l ...
Lecture Summary (11/22)
... main sequence lifetime of the Sun and other one solar mass stars is approximately 10 billion years. More massive stars have shorter main sequence lifetimes; lower mass stars have longer main sequence lifetimes. Stars more massive than the Sun are born as protostars in nebulae. Due to their great ma ...
... main sequence lifetime of the Sun and other one solar mass stars is approximately 10 billion years. More massive stars have shorter main sequence lifetimes; lower mass stars have longer main sequence lifetimes. Stars more massive than the Sun are born as protostars in nebulae. Due to their great ma ...
wk09noQ
... • The Zero Age Main Sequence (ZAMS) represents the onset or start of nuclear burning (fusion) • The properties of a star on the ZAMS are primarily determined by its mass, somewhat dependent on chemical composition (fraction of He and heavier elements) • The classification of stars in an HR diagram b ...
... • The Zero Age Main Sequence (ZAMS) represents the onset or start of nuclear burning (fusion) • The properties of a star on the ZAMS are primarily determined by its mass, somewhat dependent on chemical composition (fraction of He and heavier elements) • The classification of stars in an HR diagram b ...
Stellar Structure - McMurry University
... the flashes (“pulses”) of light happen many times a second. When observed with telescopes, these rapidly flashing (“pulsing”) objects were originally called pulsars. Pulsars are just neutron stars that are easy to observe because the pulsing makes them stand out. ...
... the flashes (“pulses”) of light happen many times a second. When observed with telescopes, these rapidly flashing (“pulsing”) objects were originally called pulsars. Pulsars are just neutron stars that are easy to observe because the pulsing makes them stand out. ...
Supernova
A supernova is a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the Sun or any ordinary star is expected to emit over its entire life span, before fading from view over several weeks or months. The extremely luminous burst of radiation expels much or all of a star's material at a velocity of up to 7007300000000000000♠30,000 km/s (10% of the speed of light), driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. Supernovae are potentially strong galactic sources of gravitational waves. A great proportion of primary cosmic rays comes from supernovae.Supernovae are more energetic than novae. Nova means ""new"" in Latin, referring to what appears to be a very bright new star shining in the celestial sphere; the prefix ""super-"" distinguishes supernovae from ordinary novae, which are far less luminous. The word supernova was coined by Walter Baade and Fritz Zwicky in 1931. It is pronounced /ˌsuːpərnoʊvə/ with the plural supernovae /ˌsuːpərnoʊviː/ or supernovas (abbreviated SN, plural SNe after ""supernovae"").Supernovae can be triggered in one of two ways: by the sudden re-ignition of nuclear fusion in a degenerate star; or by the gravitational collapse of the core of a massive star. In the first case, a degenerate white dwarf may accumulate sufficient material from a companion, either through accretion or via a merger, to raise its core temperature, ignite carbon fusion, and trigger runaway nuclear fusion, completely disrupting the star. In the second case, the core of a massive star may undergo sudden gravitational collapse, releasing gravitational potential energy that can create a supernova explosion.The most recent directly observed supernova in the Milky Way was Kepler's Star of 1604 (SN 1604); remnants of two more recent supernovae have been found retrospectively. Observations in other galaxies indicate that supernovae should occur on average about three times every century in the Milky Way, and that any galactic supernova would almost certainly be observable in modern astronomical equipment. Supernovae play a significant role in enriching the interstellar medium with higher mass elements. Furthermore, the expanding shock waves from supernova explosions can trigger the formation of new stars.