Chapter 9 Post-main sequence evolution through helium burning
... cores during central hydrogen burning, and when they leave the main sequence their cores are relatively dense and already close to becoming degenerate (see Fig. 9.1). In stars with M < ∼ 1.1 M⊙ the transition from central to shell hydrogen burning is gradual and initially Mc /M < 0.1 so the star can ...
... cores during central hydrogen burning, and when they leave the main sequence their cores are relatively dense and already close to becoming degenerate (see Fig. 9.1). In stars with M < ∼ 1.1 M⊙ the transition from central to shell hydrogen burning is gradual and initially Mc /M < 0.1 so the star can ...
Observing Stellar Evolution
... sky can use one or more of the designations to identify a star, but not all. Astronomy is an old science and over time many names and catalogs have been developed. Those of us who are amateur astronomers will simply have to learn to live with this system. To help you along the way, here are some of ...
... sky can use one or more of the designations to identify a star, but not all. Astronomy is an old science and over time many names and catalogs have been developed. Those of us who are amateur astronomers will simply have to learn to live with this system. To help you along the way, here are some of ...
Stars Evolution of High Mass Stars Nucleosynthesis Supernovae
... • A star’s mass determines its entire life story because it determines its core temperature. • High-mass stars have short lives, eventually becoming hot enough to make iron, and end in ...
... • A star’s mass determines its entire life story because it determines its core temperature. • High-mass stars have short lives, eventually becoming hot enough to make iron, and end in ...
Stellar death - Department of Astronomy
... Teaspoon of white dwarf stuff weighs as much as SUV! A114: Lecture 20—28 Mar 2007 ...
... Teaspoon of white dwarf stuff weighs as much as SUV! A114: Lecture 20—28 Mar 2007 ...
metamorphosis of an aspheric Type Ib explosion
... (∼29.5 Mpc) galaxy NGC 2770. Analysis of the photometric observations revealed this explosion as an energetic event with peak absolute R-band magnitude −18.5 ± 0.16, which is about 1 mag brighter than the mean value (−17.6 ± 0.6) derived for well observed Type Ibc events. The SN is highly extinguish ...
... (∼29.5 Mpc) galaxy NGC 2770. Analysis of the photometric observations revealed this explosion as an energetic event with peak absolute R-band magnitude −18.5 ± 0.16, which is about 1 mag brighter than the mean value (−17.6 ± 0.6) derived for well observed Type Ibc events. The SN is highly extinguish ...
Chapter 5 Theory of Stellar Evolution
... layers can no longer remain in stable equilibrium, and the star will begin to shed its mass. Very few stars with masses above 100M⊙ are known to exist, and those that do show instabilities in their outer layers. At the other end of the mass scale, a mass of about 0.1M⊙ is required to produce core te ...
... layers can no longer remain in stable equilibrium, and the star will begin to shed its mass. Very few stars with masses above 100M⊙ are known to exist, and those that do show instabilities in their outer layers. At the other end of the mass scale, a mass of about 0.1M⊙ is required to produce core te ...
Interacting supernovae from photoionization
... the latter’s wind has much lower density. The only imaging detections of Betelgeuse’s gaseous circumstellar medium so far are the 21 cm H I data and unexplained far-ultraviolet emission from the bow shock5. The agreement of Betelgeuse’s neutral shell with our photoionizationconfined shell calculatio ...
... the latter’s wind has much lower density. The only imaging detections of Betelgeuse’s gaseous circumstellar medium so far are the 21 cm H I data and unexplained far-ultraviolet emission from the bow shock5. The agreement of Betelgeuse’s neutral shell with our photoionizationconfined shell calculatio ...
arXiv:astro-ph/0508448v1 22 Aug 2005
... However, the above assumes that all supernovae are equal – that is, that the distribution of parameters which produce WR evolution in the secondary1 and the distribution of parameters which produce an asymmetric SN explosion which unbinds the system are completely unrelated. In reality this is unlik ...
... However, the above assumes that all supernovae are equal – that is, that the distribution of parameters which produce WR evolution in the secondary1 and the distribution of parameters which produce an asymmetric SN explosion which unbinds the system are completely unrelated. In reality this is unlik ...
Complete Lecture Notes (pdf file)
... No direct information about physical conditions in stellar interiors (except from helioseismology and solar neutrinos) No direct evidence for stellar evolution......typical timescale 106 − 109 years.......(except for a few very unusual stars and supernovae) ...
... No direct information about physical conditions in stellar interiors (except from helioseismology and solar neutrinos) No direct evidence for stellar evolution......typical timescale 106 − 109 years.......(except for a few very unusual stars and supernovae) ...
Part IV: Stars
... cause the fusion rate to slow back down until the Sun was back to the original size and temperature and fusion occurred at the same rate. Photons take hundreds of thousands of years to get out of the Sun because their paths zigzag repeatedly. Because the plasma is so dense in the Sun’s interior, pho ...
... cause the fusion rate to slow back down until the Sun was back to the original size and temperature and fusion occurred at the same rate. Photons take hundreds of thousands of years to get out of the Sun because their paths zigzag repeatedly. Because the plasma is so dense in the Sun’s interior, pho ...
Effects of triple-α and C(α, γ )16 O reaction rates on the supernova
... The triple-α and 12 C(α, γ )16 O rates are the key nuclear reaction rates concerning He-burning in massive star evolution. As a consequence, explosive nucleosynthesis and the resulting supernova yields of a massive star would be influenced seriously by the two rates. We select four combinations from ...
... The triple-α and 12 C(α, γ )16 O rates are the key nuclear reaction rates concerning He-burning in massive star evolution. As a consequence, explosive nucleosynthesis and the resulting supernova yields of a massive star would be influenced seriously by the two rates. We select four combinations from ...
Chemical Signatures in Dwarf Galaxies
... can come from H ii region emission lines, planetary nebulae, or supernova remnants, but mostly they come from stars. Since stars can live a very long time, for example, a 0.8 MA star born at the time of the Big Bang would only now be ascending the red giant branch, and, if, for the most part, its qu ...
... can come from H ii region emission lines, planetary nebulae, or supernova remnants, but mostly they come from stars. Since stars can live a very long time, for example, a 0.8 MA star born at the time of the Big Bang would only now be ascending the red giant branch, and, if, for the most part, its qu ...
Chapter 17--Star Stuff
... The length of time from the formation of a protostar to the birth of a main-sequence star depends on the star’s mass. Massive stars do everything faster. The contraction of a high-mass protostar into a main-sequence star may take only a million years or less. A star like our Sun takes about 50 milli ...
... The length of time from the formation of a protostar to the birth of a main-sequence star depends on the star’s mass. Massive stars do everything faster. The contraction of a high-mass protostar into a main-sequence star may take only a million years or less. A star like our Sun takes about 50 milli ...
Chapter: The Evolution of Binary Systems
... One particularly important concept in studying the evolution of binary systems is the Roche lobe. Considering the so-called restricted three-body problem, where one follows the motion of a mass-less test particle in the gravitational field of two orbiting masses M1 and M2 , one can define an effecti ...
... One particularly important concept in studying the evolution of binary systems is the Roche lobe. Considering the so-called restricted three-body problem, where one follows the motion of a mass-less test particle in the gravitational field of two orbiting masses M1 and M2 , one can define an effecti ...
PDF hosted at the Radboud Repository of the Radboud University
... Despite the importance of type Ia supernovae for stellar astrophysics, galactic evolution and cosmology, the nature of the progenitor systems giving rise to these events remains mysterious, and no direct, unambiguous detection of a type Ia supernova progenitor has been made at the time of the writin ...
... Despite the importance of type Ia supernovae for stellar astrophysics, galactic evolution and cosmology, the nature of the progenitor systems giving rise to these events remains mysterious, and no direct, unambiguous detection of a type Ia supernova progenitor has been made at the time of the writin ...
The Swift satellite lives up to its name, revealing cosmic
... prompt phase the canonical afterglow decays very steeply before flattening out to what is known as a plateau phase. The light curve then breaks to the steeper decay rate known from pre-Swift data and may steepen again at a day or so after the GRB began indicating the sideways spreading of the jet as ...
... prompt phase the canonical afterglow decays very steeply before flattening out to what is known as a plateau phase. The light curve then breaks to the steeper decay rate known from pre-Swift data and may steepen again at a day or so after the GRB began indicating the sideways spreading of the jet as ...
ppt - chris.engelbrecht.nithep.ac.za
... 2. Expansion measurements from X-ray observations at different epochs yield a blast wave velocity of v_s = 6200 (+1500 -1600) km/s. What temperature does this correspond to? If this velocity is correct, what is the age under Sedov ...
... 2. Expansion measurements from X-ray observations at different epochs yield a blast wave velocity of v_s = 6200 (+1500 -1600) km/s. What temperature does this correspond to? If this velocity is correct, what is the age under Sedov ...
Lu_Ye
... Main features of GRB060614 A long GRB with duration of 102 s A low red shift of z=0.125, and not associated with any supernova Interesting substructures: the light curve of BAT reveals a first short episode of emission (lasting 4s) followed by an extended and some softer episode (lasting 100s) ...
... Main features of GRB060614 A long GRB with duration of 102 s A low red shift of z=0.125, and not associated with any supernova Interesting substructures: the light curve of BAT reveals a first short episode of emission (lasting 4s) followed by an extended and some softer episode (lasting 100s) ...
SPECTROSCOPY OF HIGH-REDSHIFT TYPE Ia SUPERNOVAE
... not be important. Paradoxically, this inference relies on the assumption that the high-z SNe Ia can indeed be “normalised” in the same way as their local counterparts, which is exactly the effect one is trying to measure! The issue of the SN Ia environment is easier to get a handle on, since SNe Ia ...
... not be important. Paradoxically, this inference relies on the assumption that the high-z SNe Ia can indeed be “normalised” in the same way as their local counterparts, which is exactly the effect one is trying to measure! The issue of the SN Ia environment is easier to get a handle on, since SNe Ia ...
Astro 102 Practice Test 3
... d. the material will increase in temperature and eventually undergo thermonuclear fusion. e. c and d ____ 27. As material leaves an expanding star and begins to fall into a white dwarf a. an accretion disk will form around the white dwarf. b. the material will cool off because it begins to move at h ...
... d. the material will increase in temperature and eventually undergo thermonuclear fusion. e. c and d ____ 27. As material leaves an expanding star and begins to fall into a white dwarf a. an accretion disk will form around the white dwarf. b. the material will cool off because it begins to move at h ...
Process of Science: PreMainSequence Stellar Life Tracks on the HR
... Hint 2. How do you determine luminosity during the protostar stage, from the diagram in Hint 1? The following figure is the same as the figure in Hint 1; it shows the progression of a onesolarmass star from the beginning of its formation until it reaches the main sequence. The star has its greates ...
... Hint 2. How do you determine luminosity during the protostar stage, from the diagram in Hint 1? The following figure is the same as the figure in Hint 1; it shows the progression of a onesolarmass star from the beginning of its formation until it reaches the main sequence. The star has its greates ...
Starburst Galaxies Under the Microscope: High
... which a large area becomes globally unstable, after which individual star-forming complexes form stochastically. There is thus no evidence for propagating star formation in this region. However, a global trigger is still needed. Presumably this may be found in the accumulation of gas in the barred p ...
... which a large area becomes globally unstable, after which individual star-forming complexes form stochastically. There is thus no evidence for propagating star formation in this region. However, a global trigger is still needed. Presumably this may be found in the accumulation of gas in the barred p ...
Supernova - Wikipedia, the free encyclopedia
... Because supernovae are relatively rare events within a galaxy, occurring about once every 50 years in the Milky Way,[9] obtaining a good sample of supernovae to study requires regular monitoring of many galaxies. Supernovae in other galaxies cannot be predicted with any meaningful accuracy. Normally ...
... Because supernovae are relatively rare events within a galaxy, occurring about once every 50 years in the Milky Way,[9] obtaining a good sample of supernovae to study requires regular monitoring of many galaxies. Supernovae in other galaxies cannot be predicted with any meaningful accuracy. Normally ...
Yellow supergiants as supernova progenitors: an indication of
... theoretical tracks with the observed yellow supergiant progenitors. Methods. We have performed calculations of 12 to 15 M rotating stellar models using the Geneva stellar evolution code. To account for the uncertainties in the mass-loss rates during the RSG phase, we increased the mass-loss rate of ...
... theoretical tracks with the observed yellow supergiant progenitors. Methods. We have performed calculations of 12 to 15 M rotating stellar models using the Geneva stellar evolution code. To account for the uncertainties in the mass-loss rates during the RSG phase, we increased the mass-loss rate of ...
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.